bims-stacyt Biomed News
on Paracrine crosstalk between cancer and the organism
Issue of 2021‒07‒25
146 papers selected by
Cristina Muñoz Pinedo
L’Institut d’Investigació Biomèdica de Bellvitge

  1. Cancers (Basel). 2021 Jul 02. pii: 3328. [Epub ahead of print]13(13):
      Extracellular vesicles (EVs) are crucial elements that sustain the communication between tumor cells and their microenvironment, and have emerged as a widespread mechanism of tumor formation and metastasis. In obesity, the adipose tissue becomes hypertrophic and hyperplastic, triggering increased production of pro-inflammatory adipokines, such as tumor necrosis factor α, interleukin 6, interleukin 1, and leptin. Furthermore, obese adipose tissue undergoes dysregulation in the cargo content of the released EVs, resulting in an increased content of pro-inflammatory proteins, fatty acids, and oncogenic microRNAs. These alterations drive obesity-associated inflammatory responses both locally and systemically. After being ignored for a long time, adipose tissues have recently received considerable attention as a major player in tumor microenvironment-linked obesity and cancer. The role of adipose tissue in the establishment and progression of cancer is reinforced by its high plasticity and inflammatory content. Such a relationship may be established by direct contact between adipocytes and cancer cells within the microenvironment or systemically, via EV-mediated cell-to-cell communication. Here, we highlight cues evidencing the influence of adipose tissue-derived EVs on the hallmarks of cancer, which are critical for tumor malignancy.
    Keywords:  adipose tissue; cancer; extracellular vesicles; hallmarks of cancer; tumor microenvironment
  2. Adv Exp Med Biol. 2021 ;1302 25-39
      The tumor microenvironment represents a dynamic and complex cellular network involving intricate communications between the tumor and highly heterogeneous groups of cells, including tumor-supporting immune and inflammatory cells, cancer-associated fibroblasts, endothelial cells, tumor-associated macrophages, adipose cells, and pericytes. Associated with a variety of growth factors, chemokines, cytokines, and other signaling molecules, the interaction between the tumor microenvironment and the tumor cells empowers aggressiveness of tumor by enhancing its survivability. CXCL8 (also known as Interleukin 8), a multifunctional proinflammatory chemokine that was initially classified as a neutrophil chemoattractant, recently has been found to be a key contributor in tumorigenesis. The upregulation of CXCL8 at the tumor invasion front in several human cancers suggests its interplay between the tumor and its microenvironment rendering tumor progression by enhancing angiogenesis, tumor genetic diversity, survival, proliferation, immune escape, metastasis, and multidrug resistance. The autocrine and paracrine modulation of CXCL8 via the chemokine receptors CXCR1/2 promotes several intracellular signaling cascades that fosters tumor-associated inflammation, reprogramming, epithelial-mesenchymal transition, and neovascularization. Hence, decrypting the regulatory/signaling cascades of CXCL8 and its downstream effects may harbor prognostic clinical prospects of a tumor microenvironment-oriented cancer therapeutics.
    Keywords:  Angiogenesis; Angiogenic switch; Autocrine signaling; CXCL8; CXCR1/2; Cancer; Chemokines; Epithelial-mesenchymal transition; Interleukin-8; Intracellular signaling cascade; Invasion front; Metastasis; Survival; Tumor microenvironment; Tumor-related inflammation
  3. J Mol Cell Cardiol. 2021 Jul 19. pii: S0022-2828(21)00144-9. [Epub ahead of print]
      While largely appreciated for their antimicrobial and repair functions, macrophages have emerged as indispensable for the development, homeostasis, and regeneration of tissue, including regeneration of the neonatal heart. Upon activation, mammalian neonatal macrophages express and secrete factors that coordinate angiogenesis, resolution of inflammation, and ultimately cardiomyocyte proliferation. This is contrary to adult macrophages in the adult heart, which are incapable of inducing significant levels of cardiac regeneration. The underlying mechanisms by which pro-regenerative macrophages are activated and regulated remain vague. A timely hypothesis is that macrophage metabolism contributes to this proliferative and regenerative potential. This is because we now appreciate the significant contributions of metabolites to immune cell programming and function, beyond solely bioenergetics. After birth, the metabolic milieu of the neonate is subject to significant alterations in oxygenation and nutrient supply, which will affect how metabolic substrates are catabolized. In this context, we discuss potential roles for select macrophage metabolic pathways during cardiac regeneration.
    Keywords:  Cardiac; Immunometabolism; Macrophage; Regeneration
  4. Mol Med. 2021 Jul 16. 27(1): 78
      BACKGROUND: Extracellular vesicles (EVs) derived from tumor cells are implicated in the progression of malignancies through the transfer of molecular cargo microRNAs (miRNAs or miRs). We aimed to explore the role of EVs derived from breast cancer cells carrying miR-182-5p in the occurrence and development of breast cancer.METHODS: Differentially expressed miRNAs and their downstream target genes related to breast cancer were screened through GEO and TCGA databases. miR-182-5p expression was examined in cancer tissues and adjacent normal tissues from patients with breast cancer. EVs were isolated from breast cancer cell line MDA-MB-231 cells and identified. The gain- and loss-of function approaches of miR-182-5p and CKLF-like MARVEL transmembrane domain-containing 7 (CMTM7) were performed in MDA-MB-231 cells and the isolated EVs. Human umbilical vein endothelial cells (HUVECs) were subjected to co-culture with MDA-MB-231 cell-derived EVs and biological behaviors were detected by CCK-8 assay, flow cytometry, immunohistochemical staining, Transwell assay and vessel-like tube formation in vitro. A xenograft mouse model in nude mice was established to observe the tumorigenesis and metastasis of breast cancer cells in vivo.
    RESULTS: miR-182-5p was highly expressed in breast cancer tissues and cells, and this high expression was associated with poor prognosis of breast cancer patients. miR-182-5p overexpression was shown to promote tumor angiogenesis in breast cancer. Moreover, our data indicated that miR-182-5p was highly enriched in EVs from MDA-MD-231 cells and then ultimately enhanced the proliferation, migration, and angiogenesis of HUVECs in vitro and in vivo. Moreover, we found that CMTM7 is a target of miR-182-5p. EVs-miR-182-5p promotes tumorigenesis and metastasis of breast cancer cells by regulating the CMTM7/EGFR/AKT signaling axis.
    CONCLUSIONS: Taken altogether, our findings demonstrates that EVs secreted by breast cancer cells could carry miR-182-5p to aggravate breast cancer through downregulating CMTM7 expression and activating the EGFR/AKT signaling pathway.
    Keywords:  Angiogenesis; Breast cancer; CMTM7; EGFR/AKT signaling pathway; Extracellular vesicles; Human umbilical vein endothelial cells; miR-182-5p
  5. Adv Exp Med Biol. 2021 ;1302 51-70
      Tumor microenvironment (TME) is the local environment of tumor, composed of tumor cells and blood vessels, extracellular matrix (ECM), immune cells, and metabolic and signaling molecules. Chemokines and their receptors play a fundamental role in the crosstalk between tumor cells and TME, regulating tumor-related angiogenesis, specific leukocyte infiltration, and activation of the immune response and directly influencing tumor cell growth, invasion, and cancer progression. The chemokine CXCL12 is a homeostatic chemokine that regulates physiological and pathological process such as inflammation, cell proliferation, and specific migration. CXCL12 activates CXCR4 and CXCR7 chemokine receptors, and the entire axis has been shown to be dysregulated in more than 20 different tumors. CXCL12 binding to CXCR4 triggers multiple signal transduction pathways that regulate intracellular calcium flux, chemotaxis, transcription, and cell survival. CXCR7 binds with high-affinity CXCL12 and with lower-affinity CXCL11, which binds also CXCR3. Although CXCR7 acts as a CXCL12 scavenger through ligand internalization and degradation, it transduces the signal mainly through β-arrestin with a pivotal role in endothelial and neural cells. Recent studies demonstrate that TME rich in CXCL12 leads to resistance to immune checkpoint inhibitors (ICI) therapy and that CXCL12 axis inhibitors sensitize resistant tumors to ICI effect. Thus targeting the CXCL12-mediated axis may control tumor and tumor microenvironment exerting an antitumor dual action. Herein CXCL12 physiology, role in cancer biology and in composite TME, prognostic role, and the relative inhibitors are addressed.
    Keywords:  Angiogenesis; Antitumor immune response; CXCL12; CXCL12 antagonist; CXCR4; CXCR4-CXCL12-CXCR7 axis; CXCR7; Cancer; Checkpoint inhibitors; Chemokine receptors; Chemokines; Immunotherapy; Metastasis; Tumor microenvironment; Tumor progression
  6. Cancers (Basel). 2021 Jul 10. pii: 3459. [Epub ahead of print]13(14):
      PURPOSE: To understand how tumor cells alter macrophage biology once they are recruited to triple-negative breast cancer (TNBC) tumors by CCL5.METHOD: Mouse bone marrow derived macrophage (BMDMs) were isolated and treated with recombinant CCL5 protein alone, with tumor cell conditioned media, or with tumor extracellular vesicles (EVs). Media from these tumor EV-educated macrophages (TEMs) was then used to determine how these macrophages affect TNBC invasion. To understand the mechanism, we assayed the cytokine secretion from these macrophages to determine how they impact tumor cell invasion. Tumor CCL5 expression was varied in tumors to determine its role in regulating macrophage biology through EVs.
    RESULTS: Tumor EVs are a necessary component for programming naïve macrophages toward a pro-metastatic phenotype. CCL5 expression in the tumor cells regulates both EV biogenesis/secretion/cargo and macrophage EV-education toward a pro-metastatic phenotype. Analysis of the tumor EV-educated macrophages (TEMs) showed secretion of a variety of factors including CXCL1, CTLA-4, IFNG, OPN, HGF, TGFB, and CCL19 capable of remodeling the surrounding tumor stroma and immune infiltrate. Injection of tumor cells with macrophages educated by metastatic tumor cell EVs into mice increased tumor metastasis to the lung.
    CONCLUSION: These results demonstrate that tumor-derived EVs are key mediators of macrophage education and likely play a more complex role in modulating tumor therapeutic response by regulating the tumor immune infiltrate.
    Keywords:  CCL5; exosomes; extracellular vesicles (EVs); metastasis; triple-negative breast cancer (TNBC); tumor microenvironment (TME); tumor-associated macrophages (TAMs)
  7. Adv Exp Med Biol. 2021 ;1302 15-24
      Cancer progression is driven, to a large extent, by the action of immune cells that have been recruited to tumor sites through interactions between chemokines and their receptors. Chemokines of the CXC subfamily are secreted by both tumor and non-tumor cells within the microenvironment of the tumor, where they induce either antitumor or protumor activity that fosters either clearance or progression of the tumor, respectively. Understanding the nature of these interactions is important to envisage novel approaches targeting the essential components of the tumor microenvironment, increasing the odds for favorable patient outcomes. In this chapter we describe the involvement of the chemokine (C-X-C motif) ligand 3 (CXCL3) in the human tumor microenvironment and its effects on immune and non-immune cells. Because of the limited data on the CXCL3 signaling in the tumor microenvironment, we extend the review to other members of the CXC subfamily of chemokines. This review also addresses the future trends or directions for therapeutic interventions that target signaling pathways used by these molecules in the tumor microenvironment.
    Keywords:  CXC chemokine; CXCL3; Carcinogenesis; Chemokine; Chemokine receptor; ELR motif; Extracellular matrix; Fibroblasts; Inflammation; Macrophages; Neovascularization; Neutrophils; Stromal cells; Tumor; Tumor microenvironment
  8. Front Cell Dev Biol. 2021 ;9 684505
      As a significant component in ovarian cancer microenvironment, cancer-associated fibroblasts (CAFs) contribute to cancer progression through interaction with cancer cells. Recent studies demonstrate that interleukin-8 (IL-8) is overexpressed in multiple cancer types and is essential for tumor development. Nonetheless, the underlying mechanism that the CAF-derived IL-8 promotes ovarian tumorigenesis is unknown. Here, we show that IL-8 secreted from CAFs could activate normal ovarian fibroblasts (NFs) through multiple signaling and that IL-8 stimulated malignant growth of ovarian cancer cells in animals and increased the IC50 of cisplatin (CDDP) in ovarian cancer cells. Further study showed that IL-8 induced cancer cell stemness via the activation of Notch3 and that the high level of IL-8 in ascites was positively correlated with the expression of Notch3 in ovarian cancer tissues. Collectively, IL-8 secreted from CAFs and cancer cells promotes stemness in human ovarian cancer via the activation of the Notch3-mediated signaling, which may provide a novel strategy for ovarian cancer treatment.
    Keywords:  IL-8; Notch3 signal pathway; cancer-associated ovarian fibroblasts; epithelial ovarian cancer; tumor stemness
  9. Front Physiol. 2021 ;12 670653
      Endothelial cells (ECs) form a physical barrier between the lumens and vascular walls of arteries, veins, capillaries, and lymph vessels; thus, they regulate the extravasation of nutrients and oxygen from the circulation into the perivascular space and participate in mechanisms that maintain cardiovascular homeostasis and promote tissue growth and repair. Notably, their role in tissue repair is facilitated, at least in part, by their dependence on glycolysis for energy production, which enables them to resist hypoxic damage and promote angiogenesis in ischemic regions. ECs are also equipped with a network of oxygen-sensitive molecules that collectively activate the response to hypoxic injury, and the master regulators of the hypoxia response pathway are hypoxia-inducible factors (HIFs). HIFs reinforce the glycolytic dependence of ECs under hypoxic conditions, but whether HIF activity attenuates or exacerbates the progression and severity of cardiovascular dysfunction varies depending on the disease setting. This review summarizes how HIF regulates the metabolic and angiogenic activity of ECs under both normal and hypoxic conditions and in a variety of diseases that are associated with cardiovascular complications.
    Keywords:  atherosclerosis; cardiovascular disease; diabetic endothelial dysfunction; endothelial metabolism; hypoxia-inducible factor; myocardial ischemia; pulmonary hypertension
  10. Cancers (Basel). 2021 Jul 06. pii: 3388. [Epub ahead of print]13(14):
      Hypoxia is a key regulator of cancer progression and chemoresistance. Ambiguity remains about how cancer cells adapt to hypoxic microenvironments and transfer oncogenic factors to surrounding cells. In this study, we determined the effects of hypoxia on the bioactivity of sEVs in a panel of ovarian cancer (OvCar) cell lines. The data obtained demonstrate a varying degree of platinum resistance induced in OvCar cells when exposed to low oxygen tension (1% oxygen). Using quantitative mass spectrometry (Sequential Window Acquisition of All Theoretical Fragment Ion Mass Spectra, SWATH) and targeted multiple reaction monitoring (MRM), we identified a suite of proteins associated with glycolysis that change under hypoxic conditions in cells and sEVs. Interestingly, we identified a differential response to hypoxia in the OvCar cell lines and their secreted sEVs, highlighting the cells' heterogeneity. Proteins are involved in metabolic reprogramming such as glycolysis, including putative hexokinase (HK), UDP-glucuronosyltransferase 1-6 (UD16), and 6-phosphogluconolactonase (6 PGL), and their presence correlates with the induction of platinum resistance. Furthermore, when normoxic cells were exposed to sEVs from hypoxic cells, platinum-resistance increased significantly (p < 0.05). Altered chemoresistance was associated with changes in glycolysis and fatty acid synthesis. Finally, sEVs isolated from a clinical cohort (n = 31) were also found to be enriched in glycolysis-pathway proteins, especially in patients with recurrent disease. These data support the hypothesis that hypoxia induces changes in sEVs composition and bioactivity that confers carboplatin resistance on target cells. Furthermore, we propose that the expression of sEV-associated glycolysis-pathway proteins is predictive of ovarian cancer recurrence and is of clinical utility in disease management.
    Keywords:  exosomes; extracellular vesicles; hypoxia; ovarian cancer
  11. Cancers (Basel). 2021 Jul 02. pii: 3327. [Epub ahead of print]13(13):
      Disruption of metabolic homeostasis at the organismal level can cause metabolic syndrome associated with obesity. The role of adipose tissue in cancer has been investigated over the last several decades with many studies implicating obesity as a risk factor for the development of cancer. Adipose tissue contains a diverse array of immune cell populations that promote metabolic homeostasis through a tightly controlled balance of pro- and anti-inflammatory signals. During obesity, pro-inflammatory cell types infiltrate and expand within the adipose tissue, exacerbating metabolic dysfunction. Some studies have now shown that the intracellular metabolism of immune cells is also deregulated by the lipid-rich environment in obesity. What is not fully understood, is how this may influence cancer progression, metastasis, and anti-tumor immunity. This review seeks to highlight our current understanding of the effect of adipose tissue on immune cell function and discuss how recent results offer new insight into the role that adipose tissue plays in cancer progression and anti-tumor immunity.
    Keywords:  adipocyte; adipose tissue; cancer; immune cell; immunometabolism; metastasis
  12. Int J Oncol. 2021 Aug;pii: 62. [Epub ahead of print]59(2):
      Leukemia is a group of malignant diseases of clonal hematopoietic stem‑progenitor cells and its pathological mechanisms remain to be elucidated. Genetic and epigenetic abnormalities, as well as microenvironmental factors, including cytokines, serve critical roles in leukaemogenesis. Macrophage migration inhibitory factor (MIF) has been presented as one of the key regulators in tumorigenesis, angiogenesis and tumor metastasis. This article focuses on the functional role of MIF and its pathway in cancer, particularly in leukemia. MIF/CD74 interaction serves prominent roles in tumor cell survival, such as upregulating BCL‑2 and CD84 expression, and activating receptor‑type tyrosine phosphatase ζ. Furthermore, MIF upregulation forms a pro‑tumor microenvironment in response to hypoxia‑induced factors and promotes pro‑inflammatory cytokine production. Additionally, polymorphisms of the MIF promoter sequence are associated with leukemia development. MIF signal‑targeted early clinical trials show positive results. Overall, these efforts provide a promising means for intervention in leukemia.
    Keywords:  AKT; ICBP90; IL‑8; MAPK; MIF; leukemia
  13. Oncogene. 2021 Jul 21.
      The exploitation of T cell-based immunotherapies and immune checkpoint blockade for cancer treatment has dramatically shifted oncological treatment paradigms and broadened the horizons of cancer immunology. Dendritic cells have emerged as the critical tailors of T cell immune responses, which initiate and coordinate anti-tumor immunity. Importantly, genetic alterations in cancer cells, cytokines and chemokines produced by cancer and stromal cells, and the process of tumor microenvironmental regulation can compromise dendritic cell-T cell cross-talk, thereby disrupting anti-tumor T cell responses. This review summarizes how T cell activation is controlled by dendritic cells and how the tumor microenvironment alters dendritic cell properties in the context of the anti-tumor immune cycle. Furthermore, we will highlight therapeutic options for tailoring dendritic cell-mediated decision-making in T cells for cancer treatment.
  14. Int J Mol Sci. 2021 Jul 05. pii: 7220. [Epub ahead of print]22(13):
      Muscular dystrophies (MDs) are a group of inherited degenerative muscle disorders characterized by a progressive skeletal muscle wasting. Respiratory impairments and subsequent hypoxemia are encountered in a significant subgroup of patients in almost all MD forms. In response to hypoxic stress, compensatory mechanisms are activated especially through Hypoxia-Inducible Factor 1 α (HIF-1α). In healthy muscle, hypoxia and HIF-1α activation are known to affect oxidative stress balance and metabolism. Recent evidence has also highlighted HIF-1α as a regulator of myogenesis and satellite cell function. However, the impact of HIF-1α pathway modifications in MDs remains to be investigated. Multifactorial pathological mechanisms could lead to HIF-1α activation in patient skeletal muscles. In addition to the genetic defect per se, respiratory failure or blood vessel alterations could modify hypoxia response pathways. Here, we will discuss the current knowledge about the hypoxia response pathway alterations in MDs and address whether such changes could influence MD pathophysiology.
    Keywords:  HIF-1α; hypoxia; myopathies
  15. Biochim Biophys Acta Mol Cell Res. 2021 Jul 16. pii: S0167-4889(21)00155-5. [Epub ahead of print] 119101
      A critical unknown in the field of skeletal metastases is how cancer cells find a way to thrive under harsh conditions, as exemplified by metastatic colonization of adipocyte-rich bone marrow by prostate carcinoma cells. To begin understanding molecular processes that enable tumor cells to survive and progress in difficult microenvironments such as bone, we performed unbiased examination of the transcriptome of two different prostate cancer cell lines in the absence or presence of bone marrow adipocytes. Our RNAseq analyses and subsequent quantitative PCR and protein-based assays reveal that upregulation of Endoplasmic Reticulum (ER) stress and Unfolded Protein Response (UPR) genes is a shared signature between two metastatic prostate carcinoma cell lines of different origin. Pathway analyses and pharmacological examinations highlight the ER chaperone BIP as an upstream coordinator of this transcriptomic signature. Additional patient-based data support our overall conclusion that ER stress and UPR induction are shared, important factors in the response and adaptation of metastatic tumor cells to their micro-environment. Our studies pave the way for additional mechanistic investigations and offer new clues towards effective therapeutic interventions in metastatic disease.
    Keywords:  BIP; ER stress; HSPA5; bone marrow adipocyte; bone metastasis; prostate cancer; unfolded protein response
  16. Sci Rep. 2021 Jul 19. 11(1): 14693
      It has been previously shown that chronic ethanol administration-induced increase in adipose tissue lipolysis and reduction in the secretion of protective adipokines collectively contribute to alcohol-associated liver disease (ALD) pathogenesis. Further studies have revealed that increased adipose S-adenosylhomocysteine (SAH) levels generate methylation defects that promote lipolysis. Here, we hypothesized that increased intracellular SAH alone causes additional related pathological changes in adipose tissue as seen with alcohol administration. To test this, we used 3-deazaadenosine (DZA), which selectively elevates intracellular SAH levels by blocking its hydrolysis. Fully differentiated 3T3-L1 adipocytes were treated in vitro for 48 h with DZA and analysed for lipolysis, adipokine release and differentiation status. DZA treatment enhanced adipocyte lipolysis, as judged by lower levels of intracellular triglycerides, reduced lipid droplet sizes and higher levels of glycerol and free fatty acids released into the culture medium. These findings coincided with activation of both adipose triglyceride lipase and hormone sensitive lipase. DZA treatment also significantly reduced adipocyte differentiation factors, impaired adiponectin and leptin secretion but increased release of pro-inflammatory cytokines, IL-6, TNF and MCP-1. Together, our results demonstrate that elevation of intracellular SAH alone by DZA treatment of 3T3-L1 adipocytes induces lipolysis and dysregulates adipokine secretion. Selective elevation of intracellular SAH by DZA treatment mimics ethanol's effects and induces adipose dysfunction. We conclude that alcohol-induced elevations in adipose SAH levels contribute to the pathogenesis and progression of ALD.
  17. Redox Biol. 2021 Jul 11. pii: S2213-2317(21)00224-X. [Epub ahead of print]46 102065
      Although glucose, through pentose phosphate pathway (PPP), is the main source to generate NADPH, solid tumors are often deprived of glucose, hence alternative metabolic pathways to maintain NADPH homeostasis in cancer cells are required. Here, we report that lactate and glutamine support NADPH production via isocitrate dehydrogenase 1 (IDH1) and malic enzyme 1 (ME1), respectively, under glucose-deprived conditions. Isotopic tracing demonstrates that lactate participates in the formation of isocitrate. Malate derived from glutamine in mitochondria shuttles to cytosol to produce NADPH. In cells cultured in the absence of glucose, knockout of IDH1 and ME1 decreases NADPH/NADP+ and GSH/GSSG, increases ROS level and facilitates cell necrosis. In 4T1 murine breast tumors, knockout of ME1 retards tumor growth in vivo, with combined ME1/IDH1 knockout more strongly suppressing tumor growth. Our findings reveal two alternative NADPH-producing pathways that cancer cells use to resist glucose starvation, reflecting the metabolic plasticity and flexibility of cancer cells adapting to nutrition stress.
    Keywords:  Glucose deprivation; Glutamine; IDH1; Lactate; ME1; NADPH
  18. Adv Exp Med Biol. 2021 ;1302 99-111
      Multiple checkpoint mechanisms are overridden by cancer cells in order to develop into a tumor. Neoplastic cells, while constantly changing during the course of cancer progression, also craft their surroundings to meet their growing needs. This crafting involves changing cell surface receptors, affecting response to extracellular signals and secretion of signals that affect the nearby cells and extracellular matrix architecture. This chapter briefly comprehends the non-cancer cells facilitating the cancer growth and elaborates on the notable role of the CCR9-CCL25 chemokine axis in shaping the tumor microenvironment (TME), directly and via immune cells. Association of increased CCR9 and CCL25 levels in various tumors has demonstrated the significance of this axis as a tool commonly used by cancer to flourish. It is involved in attracting immune cells in the tumor and determining their fate via various direct and indirect mechanisms and, leaning the TME toward immunosuppressive state. Besides, elevated CCR9-CCL25 signaling allows survival and rapid proliferation of cancer cells in an otherwise repressive environment. It modulates the intra- and extracellular protein matrix to instigate tumor dissemination and creates a supportive metastatic niche at the secondary sites. Lastly, this chapter abridges the latest research efforts and challenges in using the CCR9-CCL25 axis as a cancer-specific target.
    Keywords:  Angiogenesis; CCL25; CCR9; Chemoresistance; Dendritic cells; Extracellular matrix; MMP; Macrophages; Metastasis; T cells; TGF-β; Tumor microenvironment; VEGF
  19. Cancer Res. 2021 Jul 21. pii: canres.1723.2020. [Epub ahead of print]
      Elevated infiltration of immunosuppressive alternatively polarized (M2) macrophages is associated with poor prognosis in cancer patients. The tumor microenvironment remarkably orchestrates molecular mechanisms that program these macrophages. Here we identify a novel role for oncogenic Hedgehog (Hh) signaling in programming signature metabolic circuitries that regulate alternative polarization of tumor-associated macrophages. Two immunocompetent orthotopic mouse models of mammary tumors were used to test the effect of inhibiting Hh signaling on tumor-associated macrophages. Treatment with the pharmacological Hh inhibitor Vismodegib induced a significant shift in the profile of tumor-infiltrating macrophages. Mass spectrometry-based metabolomic analysis showed Hh inhibition induced significant alterations in metabolic processes, including metabolic sensing, mitochondrial adaptations, and lipid metabolism. In particular, inhibition of Hh in M2 macrophages reduced flux through the UDP-GlcNAc biosynthesis pathway. Consequently, O-GlcNAc-modification of STAT6 decreased, mitigating the immune suppressive program of M2 macrophages, and the metabolically demanding M2 macrophages shifted their metabolism and bioenergetics from fatty acid oxidation to glycolysis. M2 macrophages enriched from Vismodegib-treated mammary tumors showed characteristically decreased O-GlcNAcylation and altered mitochondrial dynamics. These Hh-inhibited macrophages are reminiscent of inflammatory (M1) macrophages, phenotypically characterized by fragmented mitochondria. This is the first report highlighting the relevance of Hh signaling in controlling a complex metabolic network in immune cells. These data describe a novel immunometabolic function of Hh signaling that can be clinically exploited.
  20. Front Cell Dev Biol. 2021 ;9 683276
      Glioblastoma is a primary malignant brain tumor with a median survival under 2 years. The poor prognosis glioblastoma caries is largely due to cellular invasion, which enables escape from resection, and drives inevitable recurrence. While most studies to date have focused on pathways that enhance the invasiveness of tumor cells in the brain microenvironment as the primary driving forces behind GBM's ability to invade adjacent tissues, more recent studies have identified a role for adaptations in cellular metabolism in GBM invasion. Metabolic reprogramming allows invasive cells to generate the energy necessary for colonizing surrounding brain tissue and adapt to new microenvironments with unique nutrient and oxygen availability. Historically, enhanced glycolysis, even in the presence of oxygen (the Warburg effect) has dominated glioblastoma research with respect to tumor metabolism. More recent global profiling experiments, however, have identified roles for lipid, amino acid, and nucleotide metabolism in tumor growth and invasion. A thorough understanding of the metabolic traits that define invasive GBM cells may provide novel therapeutic targets for this devastating disease. In this review, we focus on metabolic alterations that have been characterized in glioblastoma, the dynamic nature of tumor metabolism and how it is shaped by interaction with the brain microenvironment, and how metabolic reprogramming generates vulnerabilities that may be ripe for exploitation.
    Keywords:  brain tumor; glioblastoma; invasion; metabolism; microenvironment
  21. Hepatology. 2021 Jul 23.
      BACKGROUND & AIMS: ZEB1 is a transcription factor that promotes metastatic and stem cell features, which has been associated with poor prognosis in cholangiocarcinoma (CCA), a desmoplastic cancer enriched in cancer-associated fibroblasts (CAF). Here, we aimed to define ZEB1 regulatory functions in malignant and stroma compartments of CCA.APPROACH AND RESULTS: Bioinformatic and immunohistochemical analyses were performed to determine correlations between ZEB1 and markers of progressiveness in human intrahepatic CCA (iCCA). Gain/loss of function models were generated in CCA cells, and liver myofibroblasts, as a model of CAF. Conditioned media (CM) was used to unravel tumor-stroma interplay. In vivo experiments were performed using xenograft CCA model. ZEB1 expression in tumor cells of human iCCA was associated with undifferentiated tumor and vascular invasion. In vitro, ZEB1 promoted epithelial-mesenchymal transition and stemness in tumor cells leading to cell migration and spheroid formation. In vivo, ZEB1-overexpressing CCA cells formed larger tumors with more abundant stroma. CCN2/CTGF expression was increased in tumor cells from ZEB1-overexpressing xenografts and correlated with ZEB1 expression in human tumors. In vitro, CM from ZEB1-overexpressing tumor cells or recombinant CTGF induced myofibroblast proliferation. ZEB1 was also expressed by CAF in human CCA and its expression correlated with CCN2 in myofibroblast and CCA stroma. In mice, co-transplantation of CCA cells with ZEB1-depleted myofibroblasts reduced CCA progressiveness compared to CCA cells/ZEB1-expressing myofibroblasts. Furthermore, ZEB1 controls the expression of paracrine signals (i.e. HGF and IL6) in tumor cells and myofibroblasts.
    CONCLUSIONS: ZEB1 plays a key role in CCA progression by regulating tumor cell-CAF cross-talk, leading to tumor dedifferentiation and CAF activation.
    Keywords:  CTGF/CCN2; Cholangiocarcinoma; ZEB1; cancer-associated fibroblasts; stroma
  22. NPJ Breast Cancer. 2021 Jul 21. 7(1): 95
      Breast cancer bone metastasis is currently incurable, ~75% of patients with late-stage breast cancer develop disease recurrence in bone and available treatments are only palliative. We have previously shown that production of the pro-inflammatory cytokine interleukin-1B (IL-1B) by breast cancer cells drives bone metastasis in patients and in preclinical in vivo models. In the current study, we have investigated how IL-1B from tumour cells and the microenvironment interact to affect primary tumour growth and bone metastasis through regulation of the immune system, and whether targeting IL-1 driven changes to the immune response improves standard of care therapy for breast cancer bone metastasis. Using syngeneic IL-1B/IL1R1 knock out mouse models in combination with genetic manipulation of tumour cells to overexpress IL-1B/IL1R1, we found that IL-1B signalling elicited an opposite response in primary tumours compared with bone metastases. In primary tumours, IL-1B inhibited growth, by impairing the infiltration of innate immune cell subsets with potential anti-cancer functions but promoted enhanced tumour cell migration. In bone, IL-1B stimulated the development of osteolytic metastases. In syngeneic models of breast cancer, combining standard of care treatments (Doxorubicin and Zoledronic acid) with the IL-1 receptor antagonist Anakinra inhibited both primary tumour growth and metastasis. Anakinra had opposite effects on the immune response compared to standard of care treatment, and its anti-inflammatory signature was maintained in the combination therapy. These data suggest that targeting IL-1B signalling may provide a useful therapeutic approach to inhibit bone metastasis and improve efficacy of current treatments for breast cancer patients.
  23. Cancers (Basel). 2021 Jul 08. pii: 3433. [Epub ahead of print]13(14):
      Resistance to anti-vascular endothelial growth factor (VEGF) molecules causes lack of response and disease recurrence. Acquired resistance develops as a result of genetic/epigenetic changes conferring to the cancer cells a drug resistant phenotype. In addition to tumor cells, tumor endothelial cells also undergo epigenetic modifications involved in resistance to anti-angiogenic therapies. The association of multiple anti-angiogenic molecules or a combination of anti-angiogenic drugs with other treatment regimens have been indicated as alternative therapeutic strategies to overcome resistance to anti-angiogenic therapies. Alternative mechanisms of tumor vasculature, including intussusceptive microvascular growth (IMG), vasculogenic mimicry, and vascular co-option, are involved in resistance to anti-angiogenic therapies. The crosstalk between angiogenesis and immune cells explains the efficacy of combining anti-angiogenic drugs with immune check-point inhibitors. Collectively, in order to increase clinical benefits and overcome resistance to anti-angiogenesis therapies, pan-omics profiling is key.
    Keywords:  VEGF; angiogenesis; anti-angiogenesis; bevacizumab; drug resistance
  24. iScience. 2021 Jul 23. 24(7): 102778
      Emerging evidence has shown that amino acids act as metabolic regulatory signals. Here, we showed that glucose-6-phosphatase (G6Pase) mRNA levels in cultured hepatocyte models were downregulated in an amino-acid-depleted medium. Inversely, stimulation with amino acids increased G6Pase mRNA levels, demonstrating that G6Pase mRNA level is directly controlled by amino acids in a reversible manner. Promoter assay revealed that these amino-acid-mediated changes in G6Pase mRNA levels were attributable to transcriptional regulation, independent of canonical hormone signaling pathways. Metabolomic analysis revealed that amino acid starvation induces a defect in the urea cycle, decreasing ornithine, a major intermediate, and supplementation of ornithine in an amino-acid-depleted medium fully rescued G6Pase mRNA transcription, similar to the effects of amino acid stimulation. This pathway was also independent of established mammalian target of rapamycin complex 1 pathway. Collectively, we present a hypothetical concept of "metabolic regulatory amino acid signal," possibly mediated by ornithine.
    Keywords:  Biochemistry; Biological Sciences; Cell Biology; Metabolomics; Molecular Biology; Molecular Mechanism of Gene Regulation; Natural Sciences
  25. Bull Exp Biol Med. 2021 Jul 23.
      We studied changes in the subpopulation composition and phagocytic activity of monocytes in patients with kidney cancer under the influence of metabolites of the tumor microenvironment in vitro (lactate, ADP, and glutamate). Incubation with metabolites caused similar shifts in the monocyte subsets in kidney cancer patients (an increase in the relative content of classical CD14++CD16- monocytes and a decrease in the content of the fraction of intermediate CD14++CD16+ monocytes), but different changes in their phagocytic activity. The regulatory effect of metabolites on cells is realized by various mechanisms: receptor, metabolic, and epigenomic. The reactions of monocytes to metabolites in vitro confirm the existence of a distant metabolic effect of the tumor on blood cells that should be taken into account when developing new immunotherapeutic methods.
    Keywords:  kidney cancer; metabolites; monocytes; phagocytosis; phenotype
  26. Int J Mol Sci. 2021 Jul 09. pii: 7379. [Epub ahead of print]22(14):
      The development of drug resistance in tumors is a major obstacle to effective cancer chemotherapy and represents one of the most significant complications to improving long-term patient outcomes. Despite early positive responsiveness to platinum-based chemotherapy, the majority of lung cancer patients develop resistance. The development of a new combination therapy targeting cisplatin-resistant (CR) tumors may mark a major improvement as salvage therapy in these patients. The recent resurgence in research into cellular metabolism has again confirmed that cancer cells utilize aerobic glycolysis ("the Warburg effect") to produce energy. Hence, this observation still remains a characteristic hallmark of altered metabolism in certain cancer cells. However, recent evidence promotes another concept wherein some tumors that acquire resistance to cisplatin undergo further metabolic alterations that increase tumor reliance on oxidative metabolism (OXMET) instead of glycolysis. Our review focuses on molecular changes that occur in tumors due to the relationship between metabolic demands and the importance of NAD+ in redox (ROS) metabolism and the crosstalk between PARP-1 (Poly (ADP ribose) polymerase-1) and SIRTs (sirtuins) in CR tumors. Finally, we discuss a role for the tumor metabolites of the kynurenine pathway (tryptophan catabolism) as effectors of immune cells in the tumor microenvironment during acquisition of resistance in CR cells. Understanding these concepts will form the basis for future targeting of CR cells by exploiting redox-metabolic changes and their consequences on immune cells in the tumor microenvironment as a new approach to improve overall therapeutic outcomes and survival in patients who fail cisplatin.
    Keywords:  cisplatin resistance; metabolism; oxidative metabolism; reactive oxygen species
  27. Int J Mol Sci. 2021 Jul 19. pii: 7712. [Epub ahead of print]22(14):
      BACKGROUND: Due to its prominence in the regulation of metabolism and inflammation, adipose tissue is a major target to investigate alterations in insulin action. This hormone activates PI3K/AKT pathway which is essential for glucose homeostasis, cell differentiation, and proliferation in insulin-sensitive tissues, like adipose tissue. The aim of this work was to evaluate the impact of chronic and intermittent high glucose on the expression of biomolecules of insulin signaling pathway during the differentiation and maturation of human visceral preadipocytes.METHODS: Human visceral preadipocytes (HPA-V) cells were treated with high glucose (30 mM)during the proliferation and/or differentiation and/or maturation stage. The level of mRNA (by Real-Time PCR) and protein (by Elisa tests) expression of IRS1, PI3K, PTEN, AKT2, and GLUT4 was examined after each culture stage. Furthermore, we investigated whether miR-29a-3p, miR-143-3p, miR-152-3p, miR-186-5p, miR-370-3p, and miR-374b-5p may affect the expression of biomolecules of the insulin signaling pathway.
    RESULTS: Both chronic and intermittent hyperglycemia affects insulin signaling in visceral pre/adipocytes by upregulation of analyzed PI3K/AKT pathway molecules. Both mRNA and protein expression level is more dependent on stage-specific events than the length of the period of high glucose exposure. What is more, miRs expression changes seem to be involved in PI3K/AKT expression regulation in response to hyperglycemic stimulation.
    Keywords:  AKT2; GLUT4; IRS1; PI3K; PTEN; adipocytes; adipogenesis; diabetes; hyperglycemia; miR
  28. Life Sci. 2021 Jul 19. pii: S0024-3205(21)00826-2. [Epub ahead of print] 119839
      AIMS: Respiratory disorders are a prominent component of Gulf War Illness. Although much of the underlying mechanisms of Gulf War Illness remain undefined, chronic immune dysfunction is a consistent feature of this multi-symptomatic, multi-organ disorder. Alveolar macrophages represent the predominant mononuclear phagocytes of the pulmonary mucosa, orchestrating the host response to pathogens and environmental stimuli. Herein, we sought to characterize the innate immune response of the pulmonary mucosa, with a focus on macrophages, to experimental respiratory exposure to two putative Gulf War Toxins (GWTs).MATERIALS AND METHODS: Utilizing commercially available instrumentation, we evaluated the effect of aerosolized exposure to the pesticide malathion and diesel exhaust particulate (DEP) on the immune composition and inflammatory response of the lung in FVB/N mice using multiparametric spectral cytometry, cytokine analysis, and histology.
    KEY FINDINGS: Aerosolized GWTs induced gross pulmonary pathology with transient recruitment of neutrophils and sustained accumulation of alveolar macrophages to the lung for up to two weeks after exposure cessation. High-dimensional cytometry and unbiased computational analysis identified novel myeloid subsets recruited to the lung post-exposure driven by an influx of peripheral monocyte-derived progenitors. DEP and malathion, either alone or in combination, induced soluble mediators in bronchoalveolar lavage indicative of oxidative stress (PGF2α), inflammation (LTB4, TNFα, IL-12), and immunosuppression (IL-10), that were sustained or increased two weeks after exposures concluded.
    SIGNIFICANCE: These findings indicate that macrophage accumulation and pulmonary inflammation induced by GWTs continue in the absence of toxin exposure and may contribute to the immunopathology of respiratory Gulf War Illness.
    Keywords:  Diesel exhaust particulate; Gulf War Illness; Immunopathology; Inflammation; Macrophage; Malathion; Pulmonary immunity; Respiratory disease
  29. Dis Model Mech. 2021 Jul 19. pii: dmm.048942. [Epub ahead of print]
      There is an urgent need for accurate, scalable, and cost-efficient experimental systems to model the complexity of the tumor microenvironment. Here, we detail how to fabricate and use the Metabolic Microenvironment Chamber (MEMIC) - a 3D-printed ex vivo model of intratumoral heterogeneity. A major driver of the cellular and molecular diversity in tumors is the accessibility to the blood stream that provides key resources such as oxygen and nutrients. While some tumor cells have direct access to these resources, many others must survive under progressively more ischemic environments as they reside further from the vasculature. The MEMIC is designed to simulate the differential access to nutrients and allows co-culturing different cell types, such as tumor and immune cells. This system is optimized for live imaging and other microscopy-based approaches, and it is a powerful tool to study tumor features such as the effect of nutrient scarcity on tumor-stroma interactions. Due to its adaptable design and full experimental control, the MEMIC provide insights into the tumor microenvironment that would be difficult to obtain via other methods. As a proof of principle, we show that cells sense gradual changes in metabolite concentration resulting in multicellular spatial patterns of signal activation and cell proliferation. To illustrate the ease of studying cell-cell interactions in the MEMIC, we show that ischemic macrophages reduce epithelial features in neighboring tumor cells. We propose the MEMIC as a complement to standard in vitro and in vivo experiments, diversifying the tools available to accurately model, perturb, and monitor the tumor microenvironment, as well as to understand how extracellular metabolites affect other processes such as wound healing and stem cell differentiation.
    Keywords:  Tissue mimetics; Tumor metabolism; Tumor microenvironment
  30. Adv Exp Med Biol. 2021 ;1302 41-50
      CXCL11 which can bind to two different chemokine receptors, CXCR3 and CXCR7, has found a prominent place in current tumor research. In this chapter, we mainly discuss the current evidence on the role of the immune response of CXCL11 in tumor microenvironment (TME). The diverse functions of CXCL11 include inhibiting angiogenesis, affecting the proliferation of different cell types, playing a role in fibroblast directed carcinoma invasion, increasing adhesion properties, suppressing M2 macrophage polarization, and facilitating the migration of certain immune cells. In addition, we discussed the application of CXCL11 as an adjuvant to various mainstream anti-cancer therapies and the future challenges in the application of CXCL11 targeted therapies.
    Keywords:  Angiogenesis; CXCL11; CXCR3; CXCR7; Cell adhesion; Cytotoxic T lymphocytes; Fibroblast migration; Immune cells; Immune cells migration; Polarization of immune cells; Proliferation; Self-renewal; Tumor microenvironment; Tumorigenicity; vvDD-CXCL11
  31. Int J Mol Sci. 2021 Jul 02. pii: 7171. [Epub ahead of print]22(13):
      The transcription factor nuclear factor-kappa B (NF-κB) is critically involved in inflammation and cancer development. Activation of NF-κB induces the expression and release of several pro-inflammatory proteins, which include the cytokine interleukin-6 (IL-6). Perturbation of the actin cytoskeleton has been previously shown to activate NF-κB signaling. In this study, we analyze the influence of different compounds that modulate the actin cytoskeleton on NF-κB activation, IL-6 signaling and the proteolytic generation of the soluble IL-6 receptor (sIL-6R) in human hepatoma cells. We show that perturbation of the actin cytoskeleton is not sufficient to induce NF-κB activation and IL-6 secretion. However, perturbation of the actin cytoskeleton reduces IL-6-induced activation of the transcription factor STAT3 in Hep3B cells. In contrast, IL-6R proteolysis by the metalloprotease ADAM10 did not depend upon the integrity of the actin cytoskeleton. In summary, we uncover a previously unknown function of the actin cytoskeleton in IL-6-mediated signal transduction in Hep3B cells.
    Keywords:  NF-κB; STAT3; actin; interleukin-6; interleukin-6 receptor
  32. Cancer Res. 2021 Jul 23. pii: canres.0345.2021. [Epub ahead of print]
      Clear-cell renal cell carcinoma (ccRCC) is the most prevalent subtype of RCC, and its progression has been linked to chronic inflammation. About 70% of the ccRCC cases are associated with inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene. However, it is still not clear how mutations in VHL, encoding the substrate-recognition subunit of an E3 ubiquitin ligase that targets the alpha subunit of hypoxia-inducible factor (HIF-α), can coordinate tissue inflammation and tumorigenesis. We previously generated mice with conditional Vhlh knockout in kidney tubules, which resulted in severe inflammation and fibrosis in addition to hyperplasia and the appearance of transformed clear cells. Interestingly, the endothelial cells (ECs), although not subject to genetic manipulation, nonetheless showed profound changes in gene expression that suggest a role in promoting inflammation and tumorigenesis. Oncostatin M (OSM) mediated the interaction between VHL-deficient renal tubule cells and the ECs, where the activated ECs in turn induce macrophage recruitment and polarization. The OSM-dependent microenvironment also promoted metastasis of exogenous tumors. Thus, OSM signaling initiates reconstitution of an inflammatory and tumorigenic microenvironment by VHL-deficient renal tubule cells, which plays a critical role in ccRCC initiation and progression.
  33. Physiol Genomics. 2021 Jul 23.
      Intermittent hypoxia (IH) is a hallmark manifestation of Obstructive Sleep Apnea (OSA). Rodents treated with IH exhibit hypertension. Hypoxia-inducible factor (HIF)-1-dependent transcriptional activation of NADPH oxidases (Nox) and the resulting increase in reactive oxygen species (ROS) levels is a major molecular mechanism underlying IH/OSA-induced hypertension. Jumanji C (JmjC)-containing histone lysine demethylases (JmjC-KDMs) are coactivators of HIF-1-dependent transcriptional activation. In the present study, we tested the hypothesis that JmjC-KDMs are required for IH-evoked HIF-1 transcriptional activation of Nox4 and the ensuing hypertension. Studies were performed on pheochromocytoma (PC)12 cells and rats. IH increased KDM6B protein and enzyme activity in PC12 cells in a HIF-1-independent manner as evidenced by unaltered KDM6B activation by IH in HIF-1α shRNA treated cells. Cells treated with IH showed increased HIF-1-dependent Nox4 transcription as indicated by increased HIF-1α binding to hypoxia responsive element (HRE) sequence of the Nox4 gene promoter demonstrated by chromatin immunoprecipitation (ChiP) assay. Pharmacological blockade of KDM6B with GSKJ4, a specific KDM6 inhibitor, or genetic silencing of KDM6B with shRNA abolished IH-induced Nox4 transcriptional activation by blocking HIF-1α binding to the promoter of the NOX4 gene. Treating IH exposed rats with GSKJ4 showed: a) absence of KDM6B activation and HIF-1-dependent Nox4 transcription in the adrenal medullae, as well as b) absence of elevated plasma catecholamines and hypertension. Collectively, these findings indicate that KDM6B functions as a coactivator of HIF-1-mediated Nox4 transactivation and demonstrate a hitherto uncharacterized role for KDM's in IH-induced hypertension by HIF-1.
    Keywords:  Hypoxia inducible factor; NADPH oxidase; intermittent hypoxia; lyisne demethylases; sleep apnea
  34. Adv Exp Med Biol. 2021 ;1302 1-14
      The C-C motif chemokine ligand 2 (CCL2) is a crucial mediator of immune cell recruitment during microbial infections and tissue damage. CCL2 is also frequently overexpressed in cancer cells and other cells in the tumor microenvironment, and a large body of evidence indicates that high CCL2 levels are associated with more aggressive malignancies, a higher probability of metastasis, and poorer outcomes in a wide range of cancers. CCL2 plays a role in recruiting tumor-associated macrophages (TAMs), which adopt a pro-tumorigenic phenotype and support cancer cell survival, facilitate tumor cell invasion, and promote angiogenesis. CCL2 also has direct, TAM-independent effects on tumor cells and the tumor microenvironment, including recruitment of other myeloid subsets and non-myeloid cells, maintaining an immunosuppressive environment, stimulating tumor cell growth and motility, and promoting angiogenesis. CCL2 also plays important roles in the metastatic cascade, such as creating a pre-metastatic niche in distant organs and promoting tumor cell extravasation across endothelia. Due to its many roles in tumorigenesis and metastatic processes, the CCL2-CCR2 signaling axis is currently being pursued as a potential therapeutic target for cancer.
    Keywords:  Angiogenesis; CCL2; CCR2; Cancer; Extravasation; Immunity; Immunosuppression; Invasion; MCP-1; Macrophage; Metastasis; Microenvironment; NFκB; TAM; Tumor
  35. J Immunol. 2021 Jul 23. pii: ji2000318. [Epub ahead of print]
      Migration of mature dendritic cells (DCs) to lymph nodes is critical for the initiation of adaptive immunity. CCR7, a G-protein-coupled receptor for CCL19/21 chemokines, is known to be essential for chemotaxis of mature DCs, but the molecular mechanism linking inflammation to chemotaxis remains unclear. We previously demonstrated that fascin1, an actin-bundling protein, increases chemotaxis of mature mouse DCs. In this article, we demonstrated that fascin1 enhanced IL-6 secretion and signaling of mature mouse DCs. Furthermore, we demonstrated that IL-6 signaling is required for chemotaxis. Blockage of IL-6 signaling in wild-type DCs with an anti-IL-6 receptor α (IL-6Rα) Ab inhibited chemotaxis toward CCL19. Likewise, knockout of IL-6Rα inhibited chemotaxis of bone marrow-derived DCs. The addition of soluble IL-6Rα and IL-6 rescued chemotaxis of IL-6Rα knockout bone marrow-derived DCs, underscoring the role of IL-6 signaling in chemotaxis. We found that IL-6 signaling is required for internalization of CCR7, the initial step of CCR7 recycling. CCR7 recycling is essential for CCR7-mediated chemotaxis, explaining why IL-6 signaling is required for chemotaxis of mature DCs. Our results have identified IL-6 signaling as a new regulatory pathway for CCR7/CCL19-mediated chemotaxis and suggest that rapid migration of mature DCs to lymph nodes depends on inflammation-associated IL-6 signaling.
  36. Cancer Cell. 2021 Jul 14. pii: S1535-6108(21)00339-1. [Epub ahead of print]
      Fibroblasts display extensive transcriptional heterogeneity, yet functional annotation and characterization of their heterocellular relationships remains incomplete. Using mass cytometry, we chart the stromal composition of 18 murine tissues and 5 spontaneous tumor models, with an emphasis on mesenchymal phenotypes. This analysis reveals extensive stromal heterogeneity across tissues and tumors, and identifies coordinated relationships between mesenchymal and immune cell subsets in pancreatic ductal adenocarcinoma. Expression of CD105 demarks two stable and functionally distinct pancreatic fibroblast lineages, which are also identified in murine and human healthy tissues and tumors. Whereas CD105-positive pancreatic fibroblasts are permissive for tumor growth in vivo, CD105-negative fibroblasts are highly tumor suppressive. This restrictive effect is entirely dependent on functional adaptive immunity. Collectively, these results reveal two functionally distinct pancreatic fibroblast lineages and highlight the importance of mesenchymal and immune cell interactions in restricting tumor growth.
    Keywords:  CAF; CD105; CyTOF; Eng; cancer-associated fibroblast lineages; mass cytometry; pancreatic cancer; tumor microenvironment; tumor-restrictive fibroblasts
  37. Obes Facts. 2021 Jul 20. 1-12
      INTRODUCTION: The biggest risk factor for obesity and its associated comorbidities is a Western diet. This Western diet induces adipose tissue (AT) inflammation, which causes an AT dysfunction. Since AT is a vital endocrine organ, its dysfunction damages other organs, thus inducing a state of chronic inflammation and causing various comorbidities. Even though it is evident a Western diet, high in fat and carbohydrates, induces obesity and its complications, it is not known yet which macronutrient plays the most important role. Therefore, the aim of this study was to investigate the effect of macronutrient composition on obesity and to reverse the Western diet-induced metabolic risk via caloric restriction (CR) or a change of diet composition.MATERIALS AND METHODS: Male, C57BL/6JRj mice were fed with a diet high in fat, sucrose, fructose, sucrose and fructose, starch, a Western diet, or a control diet for 15 weeks. To assess reversibility of the metabolic risk, mice were first made obese via 15 weeks of WD and then put on either a CR or switched to a sucrose-rich diet.
    RESULTS: A sucrose-rich and high-starch diet induced less obesity and a better metabolic profile than a Western diet, evidenced by less hepatic steatosis, lower plasma cholesterol, and less insulin resistance. Furthermore, these diets induced less intra-abdominal AT inflammation than a Western diet, since mRNA levels of pro-inflammatory markers were lower and there was less macrophage infiltration. Expression of tight junction markers in colon tissue was higher in the sucrose-rich and high-starch group than the Western group, indicating a better intestinal integrity upon sucrose-rich and high-starch feeding. Additionally, CR induced weight loss and decreased both metabolic abnormalities and AT inflammation, regardless of macronutrient composition. However, effects were more pronounced upon CR with sucrose-rich or high-starch diet. Even without CR, switching obese mice to a sucrose-rich diet induced weight loss and decreased AT inflammation and metabolic aberrations.
    DISCUSSION: A diet high in sucrose or starch induces less obesity and obesity-associated complications. Moreover, switching obese mice to a sucrose-rich diet elicits weight loss and decreases obesity-induced metabolic complications, highlighting the potential of carbohydrates to treat obesity.
    Keywords:  Adipose tissue; Animal models; Carbohydrates; Inflammation; Obesity
  38. Anticancer Res. 2021 Aug;41(8): 4071-4076
      BACKGROUND/AIM: Increased expression of inflammatory cytokine genes through cell interactions in tissues may cause chronic inflammation, leading to the development of lifestyle-related diseases. Since the activation of inflammatory cytokine genes in monocytes/macrophages by co-culturing with cancer cells or adipocytes was suppressed by pre-treatment with low-dose lipopolysaccharide (LPS), we hypothesized that low-dose LPS-activated macrophages may regulate the expression of immune response-related genes in other cells.MATERIALS AND METHODS: Phorbol myristate acetate-treated human monocytes (THP-1) were activated by LPS. The conditioned medium of LPS-activated THP-1 cells was added to human adipocytes. After 5 days, the expression of genes encoding interleukin (IL)-6 (IL6), IL-8 (IL8), monocyte chemotactic protein (MCP)-1 (CCL2), adiponectin (ADIPOQ), and plasminogen activator inhibitor (PAI)-1 (SERPINE1) was analyzed using quantitative real-time PCR.
    RESULTS: The increased expression of inflammation-related genes and SERPINE1 in adipocytes was suppressed by the conditioned medium of THP-1 cells activated by low-dose LPS, whereas the expression of ADIPOQ was significantly increased.
    CONCLUSION: Low-dose LPS-activated macrophages convert adipocytes to anti-inflammatory phenotypes.
    Keywords:  Macrophage; adipocyte; inflammatory cytokine genes; lipopolysaccharide; plasminogen activator inhibitor-1
  39. Cancers (Basel). 2021 Jul 14. pii: 3519. [Epub ahead of print]13(14):
      Pancreatic ductal adenocarcinoma is an aggressive tumor characterized by the presence of an abundant stromal compartment contributing significantly to the malignant phenotype. Pancreatic stellate cells are peculiar fibroblasts present in the stroma and represent the predominant source of extracellular matrix proteins, pro-inflammatory cytokines, and growth factors, including hepatocyte growth factor (HGF). Exploiting a co-culture system of human pancreatic stellate cells and cancer cells, we demonstrated that fibroblast activation was reduced upon HGF/MET axis inhibition. To unveil the signaling pathways sustaining stroma modulation orchestrated by MET activation in the tumor, we analyzed the gene expression profile in pancreatic cancer cells stimulated with HGF and treated with HGF/MET inhibitors. Transcriptome analysis showed that, among all the genes modulated by HGF, a subset of 125 genes was restored to the basal level following treatment with the inhibitors. By examining these genes via ingenuity pathway analysis, tenascin C emerged as a promising candidate linking MET signaling and tumor microenvironment. MET-dependent tenascin C modulation in pancreatic cancer cells was validated at RNA and protein levels both in vitro and in vivo. In conclusion, this work identifies tenascin C as a gene modulated by MET activation, suggesting a role in MET-mediated tumor-stroma interplay occurring during pancreatic tumor progression.
    Keywords:  MET oncogene; hepatocyte growth factor; metastasis; pancreatic ductal adenocarcinoma; tenascin C; tumor microenvironment
  40. Front Immunol. 2021 ;12 696784
      Atopic dermatitis (AD) is a multifaceted, chronic relapsing inflammatory skin disease that affects people of all ages. It is characterized by chronic eczema, constant pruritus, and severe discomfort. AD often progresses from mild annoyance to intractable pruritic inflammatory lesions associated with exacerbated skin sensitivity. The T helper-2 (Th2) response is mainly linked to the acute and subacute phase, whereas Th1 response has been associated in addition with the chronic phase. IL-17, IL-22, TSLP, and IL-31 also play a role in AD. Transient receptor potential (TRP) cation channels play a significant role in neuroinflammation, itch and pain, indicating neuroimmune circuits in AD. However, the Th2-driven cutaneous sensitization of TRP channels is underappreciated. Emerging findings suggest that critical Th2-related cytokines cause potentiation of TRP channels, thereby exaggerating inflammation and itch sensation. Evidence involves the following: (i) IL-13 enhances TRPV1 and TRPA1 transcription levels; (ii) IL-31 sensitizes TRPV1 via transcriptional and channel modulation, and indirectly modulates TRPV3 in keratinocytes; (iii) The Th2-cytokine TSLP increases TRPA1 synthesis in sensory neurons. These changes could be further enhanced by other Th2 cytokines, including IL-4, IL-25, and IL-33, which are inducers for IL-13, IL-31, or TSLP in skin. Taken together, this review highlights that Th2 cytokines potentiate TRP channels through diverse mechanisms under different inflammatory and pruritic conditions, and link this effect to distinct signaling cascades in AD. This review strengthens the notion that interrupting Th2-driven modulation of TRP channels will inhibit transition from acute to chronic AD, thereby aiding the development of effective therapeutics and treatment optimization.
    Keywords:  T helper-2; interleukin-13; interleukin-31; itch; protease activated receptor 2; pruritus; thymic stromal lymphopoietin; transient receptor potential channel
  41. Immunother Adv. 2021 Jan;1(1): ltab011
      OBJECTIVES: Cachexia is a systemic metabolic disorder characterized by loss of fat and muscle mass, which disproportionately impacts patients with gastrointestinal malignancies such as pancreatic cancer. While the immunologic shifts contributing to the development of other adipose tissue (AT) pathologies such as obesity have been well described, the immune microenvironment has not been studied in the context of cachexia.METHODS: We performed bulk RNA-sequencing, cytokine arrays, and flow cytometry to characterize the immune landscape of visceral AT (VAT) in the setting of pancreatic and colorectal cancers.
    RESULTS: The cachexia inducing factor IL-6 is strongly elevated in the wasting VAT of cancer bearing mice, but the regulatory type 2 immune landscape which characterizes healthy VAT is maintained. Pathologic skewing toward Th1 and Th17 inflammation is absent. Similarly, the VAT of patients with colorectal cancer is characterized by a Th2 signature with abundant IL-33 and eotaxin-2, albeit also with high levels of IL-6.
    CONCLUSIONS: Wasting AT during the development of cachexia may not undergo drastic changes in immune composition like those seen in obese AT. Our approach provides a framework for future immunologic analyses of cancer associated cachexia.
    Keywords:  adipose tissue; cachexia; pancreatic cancer
  42. Cancers (Basel). 2021 Jul 09. pii: 3442. [Epub ahead of print]13(14):
      Despite recent advances, treatment for head and neck squamous cell carcinoma (HNSCC) has limited efficacy in preventing tumor progression. We confirmed previously that carcinoma-associated fibroblasts (CAF)-induced interleukin-33 (IL-33) contributed to cancer progression. However, the molecular mechanisms underlying the complex communication network of the tumor microenvironment merited further evaluation. To simulate the IL-33-induced autocrine signaling, stable clones of IL-33-overexpressing HNSCC cells were established. Besides well-established IL-33/ST2 and SDF1/CXCR4 (stromal-derived factor 1/C-X-C motif chemokine receptor 4) signaling, the CAF-induced IL-33 upregulated CXCR4 via cancer cell induction of IL-33 self-production. The IL-33-enhanced-CXCR4 regulatory circuit involves SDF1/CXCR4 signaling activation and modulates tumor behavior. An in vivo study confirmed the functional role of IL-33/CXCR4 in tumor initiation and metastasis. The CXCR4 and/or IL-33 blockade reduced HNSCC cell aggressiveness, with attenuated invasions and metastases. Immunohistochemistry confirmed that IL-33 and CXCR4 expression correlated significantly with disease-free survival and IL-33-CXCR4 co-expression predicted a poor outcome. Besides paracrine signaling, the CAF-induced IL-33 reciprocally enhanced the autocrine cancer-cell self-production of IL-33 and the corresponding CXCR4 upregulation, leading to the activation of SDF1/CXCR4 signaling subsequent to cancer progression. Thus, targeting the IL-33-enhanced-CXCR4 regulatory circuit attenuates tumor aggressiveness and provides a potential therapeutic option for improving the prognosis in HNSCC patients.
    Keywords:  carcinoma-associated fibroblast; head and neck squamous cell carcinoma; interleukin-33/CXCR4 regulatory circuit; tumor microenvironment; tumor progression
  43. Int J Mol Sci. 2021 Jul 15. pii: 7575. [Epub ahead of print]22(14):
      Transforming growth factor-β (TGF-β) signaling triggers diverse biological actions in inflammatory diseases. In tissue fibrosis, it acts as a key pathogenic regulator for promoting immunoregulation via controlling the activation, proliferation, and apoptosis of immunocytes. In cancer, it plays a critical role in tumor microenvironment (TME) for accelerating invasion, metastasis, angiogenesis, and immunosuppression. Increasing evidence suggest a pleiotropic nature of TGF-β signaling as a critical pathway for generating fibrotic TME, which contains numerous cancer-associated fibroblasts (CAFs), extracellular matrix proteins, and remodeling enzymes. Its pathogenic roles and working mechanisms in tumorigenesis are still largely unclear. Importantly, recent studies successfully demonstrated the clinical implications of fibrotic TME in cancer. This review systematically summarized the latest updates and discoveries of TGF-β signaling in the fibrotic TME.
    Keywords:  TGF-β; fibrosis; tumor microenvironment
  44. Cell. 2021 Jul 14. pii: S0092-8674(21)00796-0. [Epub ahead of print]
      The process of pyroptosis is mediated by inflammasomes and a downstream effector known as gasdermin D (GSDMD). Upon cleavage by inflammasome-associated caspases, the N-terminal domain of GSDMD forms membrane pores that promote cytolysis. Numerous proteins promote GSDMD cleavage, but none are known to be required for pore formation after GSDMD cleavage. Herein, we report a forward genetic screen that identified the Ragulator-Rag complex as being necessary for GSDMD pore formation and pyroptosis in macrophages. Mechanistic analysis revealed that Ragulator-Rag is not required for GSDMD cleavage upon inflammasome activation but rather promotes GSDMD oligomerization in the plasma membrane. Defects in GSDMD oligomerization and pore formation can be rescued by mitochondrial poisons that stimulate reactive oxygen species (ROS) production, and ROS modulation impacts the ability of inflammasome pathways to promote pore formation downstream of GSDMD cleavage. These findings reveal an unexpected link between key regulators of immunity (inflammasome-GSDMD) and metabolism (Ragulator-Rag).
    Keywords:  gasdermin D; inflammasomes; inflammation; innate immunity; macrophages; mtorc1; pyroptosis; ragulator; reactive oxygen species
  45. Amino Acids. 2021 Jul 22.
      Proline is a non-essential amino acid with key roles in protein structure/function and maintenance of cellular redox homeostasis. It is available from dietary sources, generated de novo within cells, and released from protein structures; a noteworthy source being collagen. Its catabolism within cells can generate ATP and reactive oxygen species (ROS). Recent findings suggest that proline biosynthesis and catabolism are essential processes in disease; not only due to the role in new protein synthesis as part of pathogenic processes but also due to the impact of proline metabolism on the wider metabolic network through its significant role in redox homeostasis. This is particularly clear in cancer proliferation and metastatic outgrowth. Nevertheless, the precise identity of the drivers of cellular proline catabolism and biosynthesis, and the overall cost of maintaining appropriate balance is not currently known. In this review, we explore the major drivers of proline availability and consumption at a local and systemic level with a focus on cancer. Unraveling the main factors influencing proline metabolism in normal physiology and disease will shed light on new effective treatment strategies.
    Keywords:  Cancer; Disease; Proline; Redox
  46. Mediators Inflamm. 2021 ;2021 6660640
      Myopia is a highly prevalent refractive disorder. We investigated the effect of diacerein on monocular form deprivation (MFD) in hamsters as a possible therapeutic intervention. Diacerein is an anthraquinone derivative drug whose active metabolite is rhein. Diacerein or atropine was applied to the MFD hamsters, and their refractive error and axial length were measured after 21 days. The refractive error (control: -0.91 ± 0.023, atropine: -0.3 ± 0.08, and diacerein: -0.27 ± 0.07 D) and axial length (control: 0.401 ± 0.017, atropine: 0.326 ± 0.017, and diacerein: 0.334 ± 0.016 mm) showed statistically significant differences between control, atropine-treated, and diacerein-treated MFD eyes. Furthermore, we determined the level of transforming growth factor-beta- (TGF-) β1, matrix metalloproteinase- (MMP-) 2, type I collagen, interleukin- (IL-) 6, IL-8, and monocyte chemoattractant protein- (MCP-) 1 in the retina. Atropine and diacerein suppressed levels of the myopia-related TGF-β1 and MMP-2 while increasing type I collagen expression. They also inhibited the interleukin IL-6, IL-8, and MCP-1 levels. Diacerein reduced the IL-6, IL-8, and MCP-1 expression in ARPE-19 cells. Furthermore, diacerein inhibited inflammation by attenuating the phosphorylation of protein kinase B (AKT) and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) pathway. This suggests that diacerein has a therapeutic effect on myopia and is a potential treatment option.
  47. Cancers (Basel). 2021 Jul 12. pii: 3481. [Epub ahead of print]13(14):
      Many cancer studies now recognize that disease initiation, progression, and response to treatment are strongly influenced by the microenvironmental niche. Widespread desmoplasia, or fibrosis, is fundamental to pancreatic cancer development, growth, metastasis, and treatment resistance. This fibrotic landscape is largely regulated by cancer-associated fibroblasts (CAFs), which deposit and remodel extracellular matrix (ECM) in the tumor microenvironment (TME). This review will explore the prognostic and functional value of the stromal compartment in predicting outcomes and clinical prognosis in pancreatic ductal adenocarcinoma (PDAC). We will also discuss the major dynamic stromal alterations that occur in the pancreatic TME during tumor development and progression, and how the stromal ECM can influence cancer cell phenotype, metabolism, and immune response from a biochemical and biomechanical viewpoint. Lastly, we will provide an outlook on the latest clinical advances in the field of anti-fibrotic co-targeting in combination with chemotherapy or immunotherapy in PDAC, providing insight into the current challenges in treating this highly aggressive, fibrotic malignancy.
    Keywords:  biomechanics; cancer-associated fibroblasts; extracellular matrix; pancreatic cancer; stroma; stromal targeting; tumor microenvironment
  48. Function (Oxf). 2020 ;1(2): zqaa013
      Obesity is associated with adipose tissue hypertrophy, systemic inflammation, mitochondrial dysfunction, and intestinal dysbiosis. Rodent models of high-fat diet (HFD)-feeding or genetic deletion of multifunctional proteins involved in immunity and metabolism are often used to probe the etiology of obesity; however, these models make it difficult to divorce the effects of obesity, diet composition, or immunity on endocrine regulation of blood glucose. We, therefore, investigated the importance of adipose inflammation, mitochondrial dysfunction, and gut dysbiosis for obesity-induced insulin resistance using a spontaneously obese mouse model. We examined metabolic changes in skeletal muscle, adipose tissue, liver, the intestinal microbiome, and whole-body glucose control in spontaneously hyperphagic C57Bl/6J mice compared to lean littermates. A separate subset of lean and obese mice was subject to 8 weeks of obesogenic HFD feeding, or to pair feeding of a standard rodent diet. Hyperphagia, obesity, adipose inflammation, and insulin resistance were present in obese mice despite consuming a standard rodent diet, and these effects were blunted with caloric restriction. However, hyperphagic obese mice had normal mitochondrial respiratory function in all tissues tested and no discernable intestinal dysbiosis relative to lean littermates. In contrast, feeding mice an obesogenic HFD altered the composition of the gut microbiome, impaired skeletal muscle mitochondrial bioenergetics, and promoted poor glucose control. These data show that adipose inflammation and redox stress occurred in all models of obesity, but gut dysbiosis and mitochondrial respiratory dysfunction are not always required for obesity-induced insulin resistance. Rather, changes in the intestinal microbiome and mitochondrial bioenergetics may reflect physiological consequences of HFD feeding.
    Keywords:  inflammation; insulin resistance; microbiome; mitochondrial function; obesity; redox balance
  49. Cancer Cell Int. 2021 Jul 20. 21(1): 387
      We have read with great interest the article entitled "Identification of an immune-related signature indicating the dedifferentiation of thyroid cells" by Wang et al. Their data reinforce our own previous results, here compiled. Anaplastic thyroid carcinoma had higher stromal scores, immune scores and enrichment of most immune cells than the control groups, suggesting that the immune microenvironment may correlate with differentiation status in thyroid cancer. We previously demonstrated that the differentiation status expressed by the pattern of protein expression may be related to the profile of immune cell infiltration of differentiated thyroid carcinoma. Wang et al. also explored the differences between the high-risk and low-risk score groups of samples. Among the distinct signaling pathways enriched in the high-risk score group, the epithelial to mesenchymal transition, TNFα signaling, and some common immune-related signaling pathways, including the IL-6/JAK/STAT3 pathway, interferon alpha response, interferon gamma response and inflammatory response were observed with high normalized enrichment score. We also investigated the IL-6 protein immune-histochemical expression in a retrospective study of 114 patients with papillary thyroid carcinoma and 39 patients with follicular thyroid carcinoma. We also obtained samples of 14 normal thyroid tissues from autopsies, 50 goiters and 43 follicular adenoma. We found IL-6 more frequently positive among malignant tumors than non-malignant samples. We demonstrated that IL-6 positivity was associated with infiltration of CD3 + cells, CD16 + cells and CD68 + macrophages. In addition, IL-6 expression was associated with infiltration of activated lymphocytes such as Granzyme B + cells and CD69 + cells. IL-6 positivity was not associated with infiltration of CD4+, CD8+, CD20+, FOXP3+, CD25 + cells but IL-6 was associated with tumor expression of PD-L1, FOXP3, IL-17, COX2, IL-1β, IL-10, CD134, IL-23. In summary, Wang et al. beautiful data reinforce the seminal idea that the immune landscape is closely related to the differentiation status of the tumor. This concept may help select individuals who deserve more careful attention, an essential point in the management of patients with mostly indolent tumors such as those of the thyroid. In fact, our results, here compiled, were obtained with immune-histochemistry, a routine laboratory technique that offers the possibility of simpler and practical execution.
    Keywords:  Immune microenvironment; Thyroid cancer; Tumor dedifferentiation
  50. Sci Signal. 2021 Jul 20. pii: eabf6685. [Epub ahead of print]14(692):
      Cellular adaptation to low-oxygen environments is mediated in part by the hypoxia-inducible factors (HIFs). Like other transcription factors, the stability and transcriptional activity of HIFs-and consequently, the hypoxic response-are regulated by post-translational modifications (PTMs) and changes in protein-protein interactions. Our current understanding of PTM-mediated regulation of HIFs is primarily based on in vitro protein fragment-based studies typically validated in fragment-expressing cells treated with hypoxia-mimicking compounds. Here, we used immunoprecipitation-based mass spectrometry to characterize the PTMs and binding partners for full-length HIF-1α and HIF-2α under normoxic (21% oxygen) and hypoxic (1% oxygen) conditions. Hypoxia substantially altered the complexity and composition of the HIFα protein interaction networks, particularly for HIF-2α, with the hypoxic networks of both isoforms being enriched for mitochondrial proteins. Moreover, both HIFα isoforms were heavily covalently modified. We identified ~40 PTM sites composed of 13 different types of modification on both HIFα isoforms, including multiple cysteine modifications and an unusual phosphocysteine. More than 80% of the PTMs identified were not previously known and about half exhibited oxygen dependency. We further characterized an evolutionarily conserved phosphorylation of Ser31 in HIF-1α as a regulator of its transcriptional function, and we propose functional roles for Thr406, Thr528, and Ser581 in HIF-2α. These data will help to delineate the different physiological roles of these closely related isoforms in fine-tuning the hypoxic response.
  51. Front Cell Neurosci. 2021 ;15 698126
      The immune system is crucial for defending against various invaders, such as pathogens, cancer cells or misfolded proteins. With increasing age, the diminishing immune response, known as immunosenescence, becomes evident. Concomitantly, some diseases like infections, autoimmune diseases, chronic inflammatory diseases and cancer, accumulate with age. Different cell types are part of the innate immunity response and produce soluble factors, cytokines, chemokines, and type I interferons. Improper maturation of innate immune cells or their dysfunction have been linked to numerous age-related diseases. In parallel to the occurrence of the many functional facets of the immune response, a symbiotic microbiota had been acquired. For the relevant and situation-dependent function of the immune system the microbiome plays an essential role because it fine-tunes the immune system and its responses during life. Nevertheless, how the age-related alterations in the microbiota are reflected in the innate immune system, is still poorly understood. With this review, we provide an up-to-date overview on our present understanding of the gut microbiota effects on innate immunity, with a particular emphasis on aging-associated changes in the gut microbiota and the implications for the brain innate immune response.
    Keywords:  bacteria; brain; gut micobiota; inflammaging; innate immunity; metabolites; microglia; senescence
  52. Mol Cells. 2021 Jul 23.
      Cyclase-associated protein 2 (CAP2) has been addressed as a candidate biomarker in various cancer types. Previously, we have shown that CAP2 is expressed during multi-step hepatocarcinogenesis; however, its underlying mechanisms in liver cancer cells are not fully elucidated yet. Here, we demonstrated that endoplasmic reticulum (ER) stress induced CAP2 expression, and which promoted migration and invasion of liver cancer cells. We also found that the ER stress-induced CAP2 expression is mediated through activation of protein kinase C epsilon (PKCε) and the promotor binding of activating transcription factor 2 (ATF2). In addition, we further demonstrated that CAP2 expression promoted epithelial-mesenchymal transition (EMT) through activation of Rac1 and ERK. In conclusion, we suggest that ER stress induces CAP2 expression promoting EMT in liver cancers cells. Our results shed light on the novel functions of CAP2 in the metastatic process of liver cancer cells.
    Keywords:  activating transcription factor 2; cyclase-associated protein 2; endoplasmic reticulum-stress; epithelial-mesenchymal transition; extracellular signal-regulated kinase; hepatocellular catcinoma; protein kinase C epsilon
  53. Curr Opin Clin Nutr Metab Care. 2021 Jul 19.
      PURPOSE OF REVIEW: To highlight emerging evidence challenging traditional recommendations to increase carbohydrate intake to optimize performance at high altitude.RECENT FINDINGS: Several studies have now clearly demonstrated that, compared with sea level, exogenous carbohydrate oxidation during aerobic exercise is blunted in lowlanders during initial exposure to high altitude. There is also no apparent ergogenic effect of ingesting carbohydrate during aerobic exercise on subsequent performance at high altitude, either initially after arriving or even after up to 22 days of acclimatization. The inability to oxidize and functionally benefit from exogenous carbohydrate intake during exercise after arriving at high altitude coincides with hyperinsulinemia, accelerated glycogenolysis, and reduced peripheral glucose uptake. Collectively, these responses are consistent with a hypoxia-mediated metabolic dysregulation reflective of insulin resistance. Parallel lines of evidence have also recently demonstrated roles for the gut microbiome in host metabolism, bioenergetics, and physiologic responses to high altitude, implicating the gut microbiome as one potential mediator of hypoxia-mediated metabolic dysregulation.
    SUMMARY: Identification of novel and well tolerated nutrition and/or pharmacological approaches for alleviating hypoxia-mediated metabolic dysregulation and enhancing exogenous carbohydrate oxidation may be more effective for optimizing performance of lowlanders newly arrived at high altitude than traditional carbohydrate recommendations.
  54. ACS Chem Biol. 2021 Jul 23.
      Cancer cells reprogram their metabolism to survive and grow. Small-molecule inhibitors targeting cancer are useful for studying its metabolic pathways and functions and for developing anticancer drugs. Here, we discovered that glutipyran and its derivatives inhibit glycolytic activity and cell growth in human pancreatic cancer cells. According to proteomic profiling of glutipyran-treated cells using our ChemProteoBase, glutipyran was clustered within the group of endoplasmic reticulum (ER) stress inducers that included glycolysis inhibitors. Glutipyran inhibited glucose uptake and suppressed the growth of various cancer cells, including A431 cells that express glucose transporter class I (GLUT1) and DLD-1 GLUT1 knockout cells. When cotreated with the mitochondrial respiration inhibitor metformin, glutipyran exhibited a synergistic antiproliferative effect. Metabolome analysis revealed that glutipyran markedly decreased most metabolites of the glycolytic pathway and the pentose phosphate pathway. Glutipyran significantly suppressed tumor growth in a xenograft mouse model of pancreatic cancer. These results suggest that glutipyran acts as a broad-spectrum GLUT inhibitor and reduces cancer cell growth.
  55. Adv Exp Med Biol. 2021 ;1302 71-90
      Chemokines have emerged as important players in tumorigenic process. An extensive body of literature generated over the last two or three decades strongly implicate abnormally activated or functionally disrupted chemokine signaling in liaising most-if not all-hallmark processes of cancer. It is well-known that chemokine signaling networks within the tumor microenvironment are highly versatile and context-dependent: exert both pro-tumoral and antitumoral activities. The C-X-C motif chemokine ligand 13 (CXCL13), and its cognate receptor CXCR5, represents an emerging example of chemokine signaling axes, which express the ability to modulate tumor growth and progression in either way. Collateral evidence indicate that CXCL13-CXCR5 axis may directly modulate tumor growth by inducing proliferation of cancer cells, as well as promoting invasive phenotypes and preventing their apoptosis. In addition, CXCL13-CXCR5 axis may also indirectly modulate tumor growth by regulating noncancerous cells, particularly the immune cells, within the tumor microenvironment. Here, we review the role of CXCL13, together with CXCR5, in the human tumor microenvironment. We first elaborate their patterns of expression, regulation, and biological functions in normal physiology. We then consider how their aberrant activity, as a result of differential overexpression or co-expression, may directly or indirectly modulate the growth of tumors through effects on both cancerous and noncancerous cells.
    Keywords:  Antitumoral; B-cell differentiation; BCA-1; BLR1; CXCL13; CXCR5; Cancer progression; Chemokines; GPCR; Immune responses; Lymphoid neogenesis; Pro-umoral; Survival niche; TLSs; Tumor microenvironment
  56. J Nutr. 2021 Jul 22. pii: nxab235. [Epub ahead of print]
      BACKGROUND: Omega-3 fatty acids, including DHA and α-linolenic acid (ALA), are proposed to improve metabolic health by reducing obesity-associated inflammation. Their effects are mediated in part by conversion to oxylipins. ALA is relatively understudied, and direct comparisons to other omega-3 fatty acids are limited.OBJECTIVES: We compared the effects of equal doses of ALA and DHA on plasma oxylipins and markers of metabolic health in women with obesity.
    METHODS: We carried out a randomized, double-blind, crossover clinical trial where women aged 20-51 with a BMI of 30-51 kg/m2 were supplemented with 4 g/day of ALA or DHA for 4 weeks in the form of ALA-rich flaxseed oil or DHA-rich fish oil. The primary outcome, the plasma oxylipin profile, was assessed at Days 0 and 28 of each phase by HPLC-MS/MS. Plasma fatty acids, inflammatory markers, and the monocyte glucose metabolism were key secondary outcomes. Data were analyzed using a mixed model.
    RESULTS: Compared to the baseline visit, there were higher plasma levels of nearly all oxylipins derived from DHA (3.8-fold overall; P < 0.001) and EPA (2.7-fold overall; P < 0.05) after 28 days of fish-oil supplementation, while there were no changes to oxylipins after flaxseed-oil supplementation. Neither supplement altered plasma cytokines; however, adiponectin was increased (1.1-fold; P < 0.05) at the end of the fish-oil phase. Compared to the baseline visit, 28 days of flaxseed-oil supplementation reduced ATP-linked oxygen consumption (0.75-fold; P < 0.05) and increased spare respiratory capacity (1.4-fold; P < 0.05) in monocytes, and countered the shift in oxygen consumption induced by LPS.
    CONCLUSIONS: Flaxseed oil and fish oil each had unique effects on metabolic parameters in women with obesity. The supplementation regimens were insufficient to reduce inflammatory markers but adequate to elicit increases in omega-3 oxylipins and adiponectin in response to fish oil and to alter monocyte bioenergetics in response to flaxseed oil. This trial was registered at as NCT03583281.
    Keywords:  adiponectin; bioenergetics; docosahexaenoic acid; inflammation; metabolism; obesity; omega-3 fatty acids; oxylipins; α-linolenic acid
  57. Front Mol Biosci. 2021 ;8 683519
      Over the past five years, oxygen-based nanocarriers (NCs) to boost anti-tumor therapy attracted tremendous attention from basic research and clinical practice. Indeed, tumor hypoxia, caused by elevated proliferative activity and dysfunctional vasculature, is directly responsible for the less effectiveness or ineffective of many conventional therapeutic modalities. Undeniably, oxygen-generating NCs and oxygen-carrying NCs can increase oxygen concentration in the hypoxic area of tumors and have also been shown to have the ability to decrease the expression of drug efflux pumps (e.g., P-gp); to increase uptake by tumor cells; to facilitate the generation of cytotoxic reactive oxide species (ROS); and to evoke systematic anti-tumor immune responses. However, there are still many challenges and limitations that need to be further improved. In this review, we first discussed the mechanisms of tumor hypoxia and how it severely restricts the therapeutic efficacy of clinical treatments. Then an up-to-date account of recent progress in the fabrications of oxygen-generating NCs and oxygen-carrying NCs are systematically introduced. The improved physicochemical and surface properties of hypoxia alleviating NCs for increasing the targeting ability to hypoxic cells are also elaborated with special attention to the latest nano-technologies. Finally, the future directions of these NCs, especially towards clinical translation, are proposed. Therefore, we expect to provide some valued enlightenments and proposals in engineering more effective oxygen-based NCs in this promising field in this comprehensive overview.
    Keywords:  nanocarriers; nanoenzyme; oxygen; tumor hypoxia; tumor therapy
  58. Nature. 2021 Jul 21.
    Keywords:  Cancer; Cell biology; Metabolism
  59. Sci Signal. 2021 Jul 20. pii: eabc5884. [Epub ahead of print]14(692):
      Murine γδ17 cells, which are T cells that bear the γδ T cell receptor (TCRγδ) and secrete interleukin-17A (IL-17A), are generated in the thymus and are critical for various immune responses. Although strong TCRγδ signals are required for the development of interferon-γ (IFN-γ)-secreting γδ cells (γδIFN cells), the generation of γδ17 cells requires weaker TCRγδ signaling. Here, we demonstrated that constrained activation of the kinase Syk downstream of TCRγδ was required for the thymic development of γδ17 cells. Increasing or decreasing Syk activity by stimulating TCRγδ or inhibiting Syk, respectively, substantially reduced γδ17 cell numbers. This delimited Syk activity optimally engaged the phosphoinositide 3-kinase (PI3K)-Akt signaling pathway, which maintained the expression of master regulators of the IL-17 program, RORγt and c-Maf. Inhibition of PI3K not only abrogated γδ17 cell development but also augmented the development of a distinct, previously undescribed subset of γδ T cells. These CD8+Ly6a+ γδ T cells had a type-I IFN gene expression signature and expanded in response to stimulation with IFN-β. Collectively, these studies elucidate how weaker TCRγδ signaling engages distinct signaling pathways to specify the γδ17 cell fate and identifies a role for type-I IFNs in γδ T cell development.
  60. Front Immunol. 2021 ;12 701739
      Interleukin 7 (IL-7) is a cell growth factor with a central role in normal T cell development, survival and differentiation. The lack of IL-7-IL-7 receptor(R)-mediated signaling compromises lymphoid development, whereas increased signaling activity contributes to the development of chronic inflammation, cancer and autoimmunity. Gain-of-function alterations of the IL-7R and the signaling through Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) are enriched in T cell acute lymphoblastic leukemia (T-ALL) and autocrine production of IL-7 by T-ALL cells is involved in the phenotypes of leukemic initiation and oncogenic spreading. Several IL-7-associated pathologies are also characterized by increased presence of matrix metalloproteinase-9 (MMP-9), due to neutrophil degranulation and its regulated production by other cell types. Since proteases secreted by neutrophils are known to modulate the activity of many cytokines, we investigated the interactions between IL-7, MMP-9 and several other neutrophil-derived proteases. We demonstrated that MMP-9 efficiently cleaved human IL-7 in the exposed loop between the α-helices C and D and that this process is delayed by IL-7 N-linked glycosylation. Functionally, the proteolytic cleavage of IL-7 did not influence IL-7Rα binding and internalization nor the direct pro-proliferative effects of IL-7 on a T-ALL cell line (HPB-ALL) or in primary CD8+ human peripheral blood mononuclear cells. A comparable effect was observed for the neutrophil serine proteases neutrophil elastase, proteinase 3 and combinations of neutrophil proteases. Hence, glycosylation and disulfide bonding as two posttranslational modifications influence IL-7 bioavailability in the human species: glycosylation protects against proteolysis, whereas internal cysteine bridging under physiological redox state keeps the IL-7 conformations as active proteoforms. Finally, we showed that mouse IL-7 does not contain the protease-sensitive loop and, consequently, was not cleaved by MMP-9. With the latter finding we discovered differences in IL-7 biology between the human and mouse species.
    Keywords:  IL-7; matrix metalloproteinase-9; neutrophils; proliferation; proteolysis; signal transduction
  61. Int J Mol Sci. 2021 Jul 06. pii: 7265. [Epub ahead of print]22(14):
      As the cornerstone of high-grade glioma (HGG) treatment, radiotherapy temporarily controls tumor cells via inducing oxidative stress and subsequent DNA breaks. However, almost all HGGs recur within months. Therefore, it is important to understand the underlying mechanisms of radioresistance, so that novel strategies can be developed to improve the effectiveness of radiotherapy. While currently poorly understood, radioresistance appears to be predominantly driven by altered metabolism and hypoxia. Glucose is a central macronutrient, and its metabolism is rewired in HGG cells, increasing glycolytic flux to produce energy and essential metabolic intermediates, known as the Warburg effect. This altered metabolism in HGG cells not only supports cell proliferation and invasiveness, but it also contributes significantly to radioresistance. Several metabolic drugs have been used as a novel approach to improve the radiosensitivity of HGGs, including dichloroacetate (DCA), a small molecule used to treat children with congenital mitochondrial disorders. DCA reverses the Warburg effect by inhibiting pyruvate dehydrogenase kinases, which subsequently activates mitochondrial oxidative phosphorylation at the expense of glycolysis. This effect is thought to block the growth advantage of HGGs and improve the radiosensitivity of HGG cells. This review highlights the main features of altered glucose metabolism in HGG cells as a contributor to radioresistance and describes the mechanism of action of DCA. Furthermore, we will summarize recent advances in DCA's pre-clinical and clinical studies as a radiosensitizer and address how these scientific findings can be translated into clinical practice to improve the management of HGG patients.
    Keywords:  cancer metabolism; dichloroacetate; glycolysis; high-grade gliomas; hypoxia; radioresistance; radiotherapy
  62. Cancer Res. 2021 Jul 23. pii: canres.0691.2021. [Epub ahead of print]
      Immune cells regulate tumor growth by mirroring their function as tissue repair organizers in normal tissues. To understand the different facets of immune-tumor collaboration through genetics, spatial transcriptomics, and immunological manipulation with non-invasive, longitudinal imaging, we generated a penetrant double oncogene-driven autochthonous model of neuroblastoma. Spatial transcriptomic analysis showed that CD4+ and myeloid populations co-localized within the tumor parenchyma, while CD8+ T cells and B cells were peripherally dispersed. Depletion of CD4+ T cells or CCR2+ macrophages, but not B cells, CD8+, or NK cells, prevented tumor formation. Tumor CD4+ T cells displayed unconventional phenotypes and were clonotypically diverse and antigen-independent. Within the myeloid fraction, tumor growth required myeloid cells expressing arginase-1. Overall, these results demonstrate how arginine-metabolizing myeloid cells conspire with pathogenic CD4+ T cells to create permissive conditions for tumor formation, suggesting that these pro-tumorigenic pathways could be disabled by targeting myeloid arginine metabolism.
  63. Braz J Med Biol Res. 2021 ;pii: S0100-879X2021001000605. [Epub ahead of print]54(10): e11028
      Engeletin is a natural derivative of Smilax glabra rhizomilax that exhibits anti-inflammatory activity and suppresses lipid peroxidation. In the present study, we sought to elucidate the mechanistic basis for the neuroprotective and pro-angiogenic activity of engeltin in a human umbilical vein endothelial cells (HUVECs) oxygen-glucose deprivation and reoxygenation (OGD/R) model system and a middle cerebral artery occlusion (MCAO) rat model of cerebral ischemia and reperfusion injury. These analyses revealed that engeletin (10, 20, or 40 mg/kg) was able to reduce the infarct volume, increase cerebral blood flow, improve neurological function, and bolster the expression of vascular endothelial growth factor (VEGF), vasohibin-2 (Vash-2), angiopoietin-1 (Ang-1), phosphorylated human angiopoietin receptor tyrosine kinase 2 (p-Tie2), and platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in MCAO rats. Similarly, engeletin (100, 200, or 400 nM) markedly enhanced the migration, tube formation, and VEGF expression of HUVECs in an OGD/R model system, while the VEGF receptor (R) inhibitor axitinib reversed the observed changes in HUVEC tube formation activity and Vash-2, VEGF, and CD31 expression. These data suggested that engeletin exhibited significant neuroprotective effects against cerebral ischemia and reperfusion injury in rats, and improved cerebrovascular angiogenesis by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways.
  64. PLoS One. 2021 ;16(7): e0254921
      AIM: Diabetic foot ulcer (DFU) is a major concern in diabetes and its control requires in-depth molecular investigation. The present study aimed to screen the expression of microRNA-210 (miR-210) and its association in hypoxic pathway in DFU patients.METHODS: The study consists of 3 groups of circulation samples (50 in each group of: healthy volunteers, T2DM and T2DM with DFU) and 2 groups of tissue samples (10 in each group of: control and T2DM with DFU). Expression of miR-210 and hypoxia inducible factor-1 alpha (HIF-1α), and its responsive genes such as VEGF, TNF-α, IL-6, BCl2, Bax and Caspase 3 were analyzed by RT-PCR, Western blot and ELISA analyses.
    RESULTS: The HIF-1α expression decreased in DFU patients with increased miR-210 expression in both circulation and tissue biopsies. The circulatory IL-6 and inflammatory gene TNF-α expression was increased in DFU compared to healthy controls and T2DM subjects. Further, we found there was no alteration in the angiogenic marker, VEGF expression. In comparison, anti-apoptotic BCl2 was decreased and Bax and Caspase 3 was increased in DFU tissues relative to control.
    CONCLUSIONS: The study showed that there was an inverse relationship between miR-210 and HIF-1α expression in patients with DFU, indicating that miR-210 may regulate the expression of the hypoxic gene.
  65. Sci Rep. 2021 Jul 20. 11(1): 14789
      To compare lupus pathogenesis in disparate tissues, we analyzed gene expression profiles of human discoid lupus erythematosus (DLE) and lupus nephritis (LN). We found common increases in myeloid cell-defining gene sets and decreases in genes controlling glucose and lipid metabolism in lupus-affected skin and kidney. Regression models in DLE indicated increased glycolysis was correlated with keratinocyte, endothelial, and inflammatory cell transcripts, and decreased tricarboxylic (TCA) cycle genes were correlated with the keratinocyte signature. In LN, regression models demonstrated decreased glycolysis and TCA cycle genes were correlated with increased endothelial or decreased kidney cell transcripts, respectively. Less severe glomerular LN exhibited similar alterations in metabolism and tissue cell transcripts before monocyte/myeloid cell infiltration in some patients. Additionally, changes to mitochondrial and peroxisomal transcripts were associated with specific cells rather than global signal changes. Examination of murine LN gene expression demonstrated metabolic changes were not driven by acute exposure to type I interferon and could be restored after immunosuppression. Finally, expression of HAVCR1, a tubule damage marker, was negatively correlated with the TCA cycle signature in LN models. These results indicate that altered metabolic dysfunction is a common, reversible change in lupus-affected tissues and appears to reflect damage downstream of immunologic processes.
  66. Diabetes Care. 2021 Jul 23. pii: dc210162. [Epub ahead of print]
      OBJECTIVE: To compare the clinical effects of a personalized postprandial-targeting (PPT) diet versus a Mediterranean (MED) diet on glycemic control and metabolic health in prediabetes.RESEARCH DESIGN AND METHODS: We randomly assigned adults with prediabetes (n = 225) to follow a MED diet or a PPT diet for a 6-month dietary intervention and additional 6-month follow-up. The PPT diet relies on a machine learning algorithm that integrates clinical and microbiome features to predict personal postprandial glucose responses. During the intervention, all participants were connected to continuous glucose monitoring (CGM) and self-reported dietary intake using a smartphone application.
    RESULTS: Among 225 participants randomized (58.7% women, mean ± SD age 50 ± 7 years, BMI 31.3 ± 5.8 kg/m2, HbA1c, 5.9 ± 0.2% [41 ± 2.4 mmol/mol], fasting plasma glucose 114 ± 12 mg/dL [6.33 ± 0.67 mmol/L]), 200 (89%) completed the 6-month intervention. A total of 177 participants also contributed 12-month follow-up data. Both interventions reduced the daily time with glucose levels >140 mg/dL (7.8 mmol/L) and HbA1c levels, but reductions were significantly greater in PPT compared with MED. The mean 6-month change in "time above 140" was -0.3 ± 0.8 h/day and -1.3 ± 1.5 h/day for MED and PPT, respectively (95% CI between-group difference -1.29 to -0.66, P < 0.001). The mean 6-month change in HbA1c was -0.08 ± 0.19% (-0.9 ± 2.1 mmol/mol) and -0.16 ± 0.24% (-1.7 ± 2.6 mmol/mol) for MED and PPT, respectively (95% CI between-group difference -0.14 to -0.02, P = 0.007). The significant between-group differences were maintained at 12-month follow-up. No significant differences were noted between the groups in a CGM-measured oral glucose tolerance test.
    CONCLUSIONS: In this clinical trial in prediabetes, a PPT diet improved glycemic control significantly more than a MED diet as measured by daily time of glucose levels >140 mg/dL (7.8 mmol/L) and HbA1c. These findings may have implications for dietary advice in clinical practice.
  67. Folia Neuropathol. 2021 ;pii: 44444. [Epub ahead of print]59(2): 121-130
      Dysregulated microRNAs (miRNAs) are crucial regulators of cerebrovascular conditions, including ischemic stroke. Circulating miR-125a-5p is associated with ischemic stroke and may have clinical utility as an early diagnostic biomarker. This study conducted a series of experiments that were designed to elucidate the regulatory action of miR-125a-5p in ischemic brain injury and its underlying mechanisms. The results of this study found that the expression of miR-125a-5p was increased in BV2 microglial cells under oxygen-glucose deprivation/reoxygenation (OGD/R) setting, as well as in rat brain tissue after middle cerebral artery occlusion (MCAO). OGD/R triggered BV2 microglial cell apoptosis, whereas downregulation of miRNA-125a-5p suppressed the apoptosis rate in OGD/R-induced BV2 microglial cells. Subsequently, insulin-like growth factor binding protein 3 (IGFBP3) is a molecular target of miR-125a-5p, and IGFBP3 knockdown reversed the effects of miR-125a-5p inhibitor on BV2 microglial cells in vitro. These data supported the fact that miR-125a-5p silencing protects against cerebral ischemia-induced injury by targeting IGFBP3.
    Keywords:   IGFBP3; apoptosis; ischemic stroke.; miR-125a-5p
  68. J Med Food. 2021 Jul;24(7): 686-696
      Nitraria tangutorun Bobr. has been used for thousands of years as a native folk medicine to alleviate dizziness and neurasthenia due to oxygen. In our previous study, natural antioxidant components (namely, NJBE) were isolated from industrial N. tangutorun Bobr. juice byproducts (NJBE) from the Qinghai-Tibet plateau. The current investigation assessed the effects of NJBE on ischemic stroke in mice and the potential mechanisms. C57BL/6 mice received NJBE (25, 50, or 100 mg/Kg) by gavage for 14 days and then stroke was induced by the middle cerebral artery occlusion (MCAO) model, followed by reperfusion for 72 h. The evaluation of brain infarct size, behavioral tests, and functional assessments was conducted to assess the effects of NJBE after MCAO. Our results suggested that NJBE significantly decreases infarct size, improves neurological deficits, as well as reduces the number of GFAP+ and Iba-1+ cells after MCAO. NJBE inhibited nitric oxide and malondialdehyde production in the ischemic brain. Meanwhile, it attenuated the expressions of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Also, NJBE significantly attenuated the expression levels of proinflammatory indicators, including TNF-α, IL-1β, IL-6, and IL-12. This process was accompanied by the downregulation of TLR4, TRAF6, pIκB/pIκB, and MMP9 expression and the upregulation of claudin-5 expression. NJBE induced improvements in brain injury. The neuroprotective effect of NJBE provides evidence for its potential application in stroke treatment.
    Keywords:  Nitraria tangutorun Bobr.; anti-inflammatory; blood–brain barrier; focal cerebral ischemia; neuroprotection; oxidative stress
  69. Adv Exp Med Biol. 2021 ;1302 113-132
      Chemokines are a group of small proteins which play an important role in leukocyte migration and invasion. They are also involved in the cellular proliferation and migration of tumor cells.Chemokine CCL27 (cutaneous T cell-attracting chemokine, CTACK) is mainly expressed by keratinocytes of the normal epidermis. It is well known that this chemokine plays an important role in several inflammatory diseases of the skin, such as atopic dermatitis, contact dermatitis, and psoriasis. Moreover, several studies have shown an association between CCL27 expression and a variety of neoplasms including skin cancer.In this chapter, we address the role of chemokine CCL27 in the tumor microenvironment in the most relevant cancers of the skin and other anatomical locations. We also make a brief comment on future perspectives and the potential relation of CCL27 with different immunotherapeutic modalities.
    Keywords:  Angiogenesis; Breast cancer; CCL27; CCR10; Chemokine receptors; Chemokines; Colorectal cancer; Glioblastoma; Immunotherapy; Melanoma, mycosis fungoides; Metastasis; Pericytes; Skin cancer; Tumor microenvironment
  70. Free Radic Res. 2021 Jul 19. 1-11
      Cachexic condition due to malignant tumors has been a challenging problem. The aim of this study is to analyze effects of febuxostat on both in vitro and in vivo models of the wasting of skeletal muscles, due to LM8 osteosarcoma cells. C2C12 myotubes were incubated in the conditioned medium of LM8. Febuxostat was added at a concentration of 3 µM and 30 µM, and ROS, diameter of myotubes, and expression of atrogin-1 were analyzed. Furthermore, an in vivo study was performed by subcutaneous injection of LM8 on C3H mice. Febuxostat was administered in the drinking water at 5 µg/ml, and 25 µg/ml. In addition, tumor-bearing mice without febuxostat (group TB) and control mice (group C) were established. At 4 weeks, body weight, wet weights of the gastrocnemius muscles, XO activity, 8-OHdG, and expression of TNF-α and IL-6 were evaluated. ROS generation, atrophy of myotubes, and upregulation of atrogin-1 were clearly observed in C2C12 myotubes following incubation in the conditioned medium. These pathological conditions were significantly inhibited by febuxostat administration. Furthermore, mice in group TB showed significant loss of body weight and muscle weight in which XO activity, 8-OHdG, and expression of IL-6 were significantly increased compared to those in group C. Febuxostat administration not only significantly improved the body weight and muscleweight, but also reduced markers of oxidative stress and pro-inflammatory cytokines. Febuxostat did not show anti-tumor effects. Febuxostat, which is clinically used for treatment of hyperuricemia, is effective against the wasting of the skeletal muscles induced by LM8 osteosarcoma cells.
    Keywords:  Oxidaive stress; cachexia; reactive oxygen species (ROS); skeletal muscle; xanthine dehydrogenase/xanthine oxidase
  71. Oncogene. 2021 Jul 23.
      In response to oncogenic signals, Alternative Splicing (AS) regulators such as SR and hnRNP proteins show altered expression levels, subnuclear distribution and/or post-translational modification status, but the link between signals and these changes remains unknown. Here, we report that a cytosolic scaffold protein, IQGAP1, performs this task in response to heat-induced signals. We show that in gastric cancer cells, a nuclear pool of IQGAP1 acts as a tethering module for a group of spliceosome components, including hnRNPM, a splicing factor critical for the response of the spliceosome to heat-shock. IQGAP1 controls hnRNPM's sumoylation, subnuclear localisation and the relevant response of the AS machinery to heat-induced stress. Genome-wide analyses reveal that IQGAP1 and hnRNPM co-regulate the AS of a cell cycle-related RNA regulon in gastric cancer cells, thus favouring the accelerated proliferation phenotype of gastric cancer cells. Overall, we reveal a missing link between stress signals and AS regulation.
  72. Front Cell Neurosci. 2021 ;15 683769
      Microglial phagocytosis benefits neurological recovery after stroke. Large-conductance Ca2+-activated K+ currents are expressed in activated microglia, and BK channel knockout aggravates cerebral ischemic injury. However, the effect of BK channels on microglial phagocytosis after ischemic stroke remains unknown. Here, we explored whether BK channel activation is beneficial for neurological outcomes through microglial phagocytosis after ischemic stroke. ICR mice after transient middle cerebral artery occlusion (tMCAO) were treated with dimethyl sulfoxide (DMSO), BK channel activator NS19504, and inhibitor Paxilline. The results showed a decrease in BK channel expression after tMCAO. BK channel activator NS19504 alleviates neurological deficit after experimental modeling of tMCAO in mice compared to the control. Furthermore, we treated primary microglia with DMSO, NS19504, and Paxilline after oxygen glucose deprivation (OGD). NS19504 promoted primary microglial phagocytosing fluorescent beads and neuronal debris, which reduced neuronal apoptosis after stroke. These effects could be reversed by BK channel inhibitor Paxilline. Finally, NS19504 increased relative phosphorylated extracellular signal-regulated kinase 1/2 expression compared to the Paxilline group at the third day after stroke. Our findings indicate that microglial BK channels are a potential target for acute stage of ischemic stroke therapy.
    Keywords:  BK channels; ERK; ischemic stroke; microglia; phagocytosis
  73. Cell Rep. 2021 Jul 20. pii: S2211-1247(21)00825-1. [Epub ahead of print]36(3): 109412
      In this study, we investigate mechanisms leading to inflammation and immunoreactivity in ovarian tumors with homologous recombination deficiency (HRD). BRCA1 loss is found to lead to transcriptional reprogramming in tumor cells and cell-intrinsic inflammation involving type I interferon (IFN) and stimulator of IFN genes (STING). BRCA1-mutated (BRCA1mut) tumors are thus T cell inflamed at baseline. Genetic deletion or methylation of DNA-sensing/IFN genes or CCL5 chemokine is identified as a potential mechanism to attenuate T cell inflammation. Alternatively, in BRCA1mut cancers retaining inflammation, STING upregulates VEGF-A, mediating immune resistance and tumor progression. Tumor-intrinsic STING elimination reduces neoangiogenesis, increases CD8+ T cell infiltration, and reverts therapeutic resistance to dual immune checkpoint blockade (ICB). VEGF-A blockade phenocopies genetic STING loss and synergizes with ICB and/or poly(ADP-ribose) polymerase (PARP) inhibitors to control the outgrowth of Trp53-/-Brca1-/- but not Brca1+/+ ovarian tumors in vivo, offering rational combinatorial therapies for HRD cancers.
    Keywords:  BRCA1; CTLA-4; DNA sensing; ICB; PARPi; PD-L1; STING; T cells; VEGF-A; angiogenesis; dual immune checkpoint blockade; ovarian cancer; type I IFN
  74. Dev Comp Immunol. 2021 Jul 14. pii: S0145-305X(21)00215-9. [Epub ahead of print] 104207
      Infectious bacterial and viral diseases that cause hemolysis are considered life-threatening to grass carp (Ctenopharyngodon idellus), which is a species used in aquaculture worldwide. After heme and hemeproteins (Hb) are released as a result of hemolysis, the effect of excess Hb and heme on tissues remains to be characterized. To decipher the mechanisms, after incubation with Hb, we showed that lipopolysaccharide (LPS), Hb, and heme increased the cytotoxicity and secretion of inflammatory cytokines such as interleukin (IL)-6, chemokine (C-C motif) ligand 1 (CCL1), tumor necrosis factor (TNF)-α, IL-6, and IL-1β in vitro, which was due to stimulation of the expression of innate immune receptors, such as nucleotide-binding oligomerization domain (NOD2), toll-like receptor 2 (TLR2), TLR 4, and TLR3. The formation of reactive oxygen species (ROS) and the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-κB were important for increasing the cytokine production to induce heme, Hb, and LPS. Moreover, we confirmed that after LPS, Hb, and heme challenge, superoxide dismutase (SOD) and glutathione (GSH) synthetase (GSS) also caused remarkable destruction. However, catalase (CAT) and heme oxygenase-1 (HO-1) were strongly activated. In summary, our research findings present a framework through which heme and Hb concentrations amplify the secretions of inflammatory cytokines, which are induced by pattern recognition receptor (PRR) activation and present possible paths for immune intervention during infection with viral diseases and hemolytic bacterial.
    Keywords:  CIK cells; Ctenopharyngodon idellus; Hemeprotein; Inflammatory cytokine; MAPK; NF-κB; ROS
  75. Int J Immunogenet. 2021 Jul 21.
      With this investigation, we investigated on the contribution of lncRNA MALAT1 to inflammation disorder in Parkinson's Disease (PD). Serum samples were gathered from sporadic PD patients and healthy controls, and single nucleotide polymorphisms (SNPs) of MALAT1, including rs11227209, rs3200401, rs4102217, rs591291, rs619586 and rs664589, were identified. Serum level of MALAT1 was quantified using RT-PCR, and IL-1β, IL-6, TNF-α and IFN-γ levels in serum were measured with ELISA kits. Inflammation cell models were established by treating PC12 cells with LPS, and cytokine production of pcDNA3.1-MALAT1/si-MALAT1-transfected PC12 cells was evaluated. The results showed that PD patients with high serum level of MALAT1 were associated with lower MMSE score and higher serum levels of IL-1β, IL-6, TNF-α and IFN-γ than patients carrying low serum level of MALAT1 (p < .05). Mutant alleles of SNPs in MALAT1, including rs3200401 (C>T) and rs4102217 (G>C), tended to elevate PD susceptibility and facilitate cytokine production, as compared with their wild alleles (p < .05). And LPS-exposed PC12 cells secreted larger amounts of inflammation cytokines in the pcDNA3.1-MALAT1 group than in the Mock group (p < .05). In conclusion, MALAT1 participated in modifying inflammation disorder underlying PD aetiology, suggesting that it might be a promising therapeutic target for PD.
    Keywords:  PC12 cell line; Parkinson's disease; inflammation; lncRNA MALAT1; prognosis; single nucleotide polymorphism
  76. Oncoimmunology. 2021 ;10(1): 1940675
      The success of immune checkpoint therapy shows tumor-reactive T cells can eliminate cancer cells but are restrained by immunosuppression within the tumor micro-environment (TME). Cancer associated fibroblasts (CAFs) are the dominant stromal cell in the TME and co-localize with T cells in non-small cell lung cancer. We demonstrate the bidirectional nature of CAF/T cell interactions; T cells promote expression of co-inhibitory ligands, MHC molecules and CD73 on CAFs, increasing their production of IL-6 and eliciting production of IL-27. In turn CAFs upregulate co-inhibitory receptors on T cells including the ectonucleotidase CD39 promoting development of an exhausted but highly cytotoxic phenotype. Our results highlight the bidirectional interaction between T cells and CAFs in promoting components of the immunosuppressive CD39, CD73 adenosine pathway and demonstrate IL-27 production can be induced in CAF by activated T cells.
    Keywords:  Non-small cell lung cancer; T cells; cancer-associated fibroblasts; crosstalk
  77. Cancer Res. 2021 Jul 23. pii: canres.0468.2021. [Epub ahead of print]
      N6-methyladenosine (m6A) has been reported as an important mechanism of post-transcriptional regulation. Programmed death-ligand 1 (PD-L1) is a primary immune inhibitory molecule expressed on tumor cells that promotes immune evasion. Here we report ALKBH5 as an important m6A demethylase that orchestrates PD-L1 expression in intrahepatic cholangiocarcinoma (ICC). Regulation of PD-L1 expression by ALKBH5 was confirmed in human ICC cell lines. Sequencing of the m6A methylome identified PD-L1 mRNA as a direct target of m6A modification whose levels were regulated by ALKBH5. Furthermore, ALKBH5 and PD-L1 mRNA were shown to interact. ALKBH5 deficiency enriched m6A modification in the 3'UTR region of PD-L1 mRNA, thereby promoting its degradation in a YTHDF2-dependent manner. In vitro and in vivo, tumor-intrinsic ALKBH5 inhibited the expansion and cytotoxicity of T cells by sustaining tumor cell PD-L1 expression. The ALKBH5-PD-L1-regulating axis was further confirmed in human ICC specimens. Single-cell mass cytometry analysis unveiled a complex role of ALKBH5 in the tumor immune microenvironment by promoting the expression of PD-L1 on monocytes/macrophages and decreasing the infiltration of myeloid-derived suppressor-like cells. Analysis of specimens from patients receiving anti-PD1 immunotherapy suggested that tumors with strong nuclear expression patterns of ALKBH5 are more sensitive to anti-PD1 immunotherapy. Collectively, these results describe a new regulatory mechanism of PD-L1 by mRNA epigenetic modification by ALKBH5 and the potential role of ALKBH5 in immunotherapy response, which might provide insights for cancer immunotherapies.
  78. Physiol Rep. 2021 Jul;9(14): e14855
      The influence of glucose and palmitic acid (PA) on mitochondrial respiration and emission of hydrogen peroxide (H2 O2 ) was determined in skeletal muscle-derived microvascular endothelial cells. Measurements were assessed in intact and permeabilized (cells treated with 0.025% saponin) low passage endothelial cells with acute-or prolonged (3 days) incubation with regular (1.7 mM) or elevated (2.2 mM) PA concentrations and regular (5 mM) or elevated (11 mM) glucose concentrations. In intact cells, acute incubation with 1.7 mM PA alone or with 1.7 mM PA + 5 mM glucose (p < .001) led to a lower mitochondrial respiration (p < 0.01) and markedly higher H2 O2 /O2 emission (p < 0.05) than with 5 mM glucose alone. Prolonged incubation of intact cells with 1.7 mM PA +5 mM glucose led to 34% (p < 0.05) lower respiration and 2.5-fold higher H2 O2 /O2 emission (p < 0.01) than incubation with 5 mM glucose alone. Prolonged incubation of intact cells with elevated glucose led to 60% lower (p < 0.05) mitochondrial respiration and 4.6-fold higher H2 O2 /O2 production than incubation with 5 mM glucose in intact cells (p < 0.001). All effects observed in intact cells were present also in permeabilized cells (State 2). In conclusion, our results show that acute and prolonged lipid availability, as well as prolonged hyperglycemia, induces mitochondrial dysfunction as evidenced by lower mitochondrial respiration and enhanced H2 O2/ O2 emission. Elevated plasma substrate availability may lead to microvascular dysfunction in skeletal muscle by impairing endothelial mitochondrial function.
    Keywords:  glucose; mitochondria; palmitic acid; reactive oxygen species; respirometry; vascular
  79. Front Oncol. 2021 ;11 682217
      The stroma-rich, immunosuppressive microenvironment is a hallmark of pancreatic ductal adenocarcinoma (PDA). Tumor cells and other cellular components of the tumor microenvironment, such as cancer associated fibroblasts, CD4+ T cells and myeloid cells, are linked by a web of interactions. Their crosstalk not only results in immune evasion of PDA, but also contributes to pancreatic cancer cell plasticity, invasiveness, metastasis, chemo-resistance, immunotherapy-resistance and radiotherapy-resistance. In this review, we characterize several prevalent populations of stromal cells in the PDA microenvironment and describe how the crosstalk among them drives and maintains immune suppression. We also summarize therapeutic approaches to target the stroma. With a better understanding of the complex cellular and molecular networks in PDA, strategies aimed at sensitizing PDA to chemotherapy or immunotherapy through re-programing the tumor microenvironment can be designed, and in turn lead to improved clinical treatment for pancreatic cancer patients.
    Keywords:  T cells; cancer-associated fibroblasts; immune suppression; myeloid cells; pancreatic cancer; tumor microenvironment
  80. Int J Mol Sci. 2021 Jul 13. pii: 7516. [Epub ahead of print]22(14):
      Adiponectin and leptin are two abundant adipokines with different properties but both described such as potent factors regulating angiogenesis. AdipoRon is a small-molecule that, binding to AdipoRs receptors, acts as an adiponectin agonist. Here, we investigated the effects of AdipoRon and leptin on viability, migration and tube formation on a human in vitro model, the human umbilical vein endothelial cells (HUVEC) focusing on the expression of the main endothelial angiogenic factors: hypoxia-inducible factor 1-alpha (HIF-1α), C-X-C motif chemokine ligand 1 (CXCL1), vascular endothelial growth factor A (VEGF-A), matrix metallopeptidase 2 (MMP-2) and matrix metallopeptidase 9 (MMP-9). Treatments with VEGF-A were used as positive control. Our data revealed that, at 24 h treatment, proliferation of HUVEC endothelial cells was not influenced by AdipoRon or leptin administration; after 48 h longer exposure time, the viability was negatively influenced by AdipoRon while leptin treatment and the combination of AdipoRon+leptin produced no effects. In addition, AdipoRon induced a significant increase in complete tubular structures together with induction of cell migration while, on the contrary, leptin did not induce tube formation and inhibited cell migration; interestingly, the co-treatment with both AdipoRon and leptin determined a significant decrease of the tubular structures and cell migration indicating that leptin antagonizes AdipoRon effects. Finally, we found that the effects induced by AdipoRon administration are accompanied by an increase in the expression of CXCL1, VEGF-A, MMP-2 and MMP-9. In conclusion, our data sustain the active role of adiponectin and leptin in linking adipose tissue with the vascular endothelium encouraging the further deepening of the role of adipokines in new vessel's formation, to candidate them as therapeutic targets.
    Keywords:  AdipoRon; HUVEC endothelial cells; angiogenesis; cell migration; leptin
  81. Trends Endocrinol Metab. 2021 Jul 20. pii: S1043-2760(21)00133-8. [Epub ahead of print]
      There has been an explosion of interest in the signaling capacity of energy metabolites. A prime example is the Krebs cycle substrate succinate, an archetypal respiratory substrate with functions beyond energy production as an intracellular and extracellular signaling molecule. Long associated with inflammation, emerging evidence supports a key role for succinate in metabolic processes relating to energy management. As the natural ligand for SUCNR1, a G protein-coupled receptor, succinate is akin to hormones and likely functions as a reporter of metabolism and stress. In this review, we reconcile new and old observations to outline a regulatory role for succinate in metabolic homeostasis. We highlight the importance of the succinate-SUCNR1 axis in metabolic diseases as an integrator of macrophage immune response, and we discuss new metabolic functions recently ascribed to succinate in specific tissues. Because circulating succinate has emerged as a promising biomarker in chronic metabolic diseases, a better understanding of the physiopathological role of the succinate-SUCNR1 axis in metabolism might open new avenues for clinical use in patients with obesity or diabetes.
    Keywords:  SUCNR1; energy metabolite; metabolic diseases; metabolic function; succinate
  82. Commun Biol. 2021 Jul 21. 4(1): 893
      Immunotherapy has emerged as a promising approach to treating several forms of cancer. Use of immune cells, such as natural killer (NK) cells, along with small molecule drugs and antibodies through antibody dependent cell-mediated cytotoxicity (ADCC) has been investigated as a potential combination therapy for some difficult to treat solid tumors. Nevertheless, there remains a need to develop tools that support co-culture of target cancer cells and effector immune cells in a contextually relevant three-dimensional (3D) environment to provide a rapid means to screen for and optimize ADCC-drug combinations. To that end, here we have developed a high throughput 330 micropillar-microwell sandwich platform that enables 3D co-culture of NK92-CD16 cells with pancreatic (MiaPaCa-2) and breast cancer cell lines (MCF-7 and MDA-MB-231). The platform successfully mimicked hypoxic conditions found in a tumor microenvironment and was used to demonstrate NK-cell mediated cell cytotoxicity in combination with two monoclonal antibodies; Trastuzumab and Atezolizumab. The platform was also used to show dose response behavior of target cancer cells with reduced EC50 values for paclitaxel (an anti-cancer chemotherapeutic) when treated with both NK cells and antibody. Such a platform may be used to develop more personalized cancer therapies using patient-derived cancer cells.
  83. Cancer Res. 2021 Jul 21. pii: canres.3941.2020. [Epub ahead of print]
      Invasive lung adenocarcinoma (LADC) can be classified histologically as lepidic, acinar, papillary, micropapillary, or solid. Most LADC tumors manifest several of these histological subtypes, with heterogeneity being related to therapeutic resistance. We report here that in immunodeficient mice, human LADC cells form tumors with distinct histological features, MUC5AC-expressing solid-type or cytokeratin 7 (CK7)-expressing acinar-type tumors, depending on the site of development, and that a solid-to-acinar transition (SAT) could be induced by the tumor microenvironment. The TGF-β-Smad signaling pathway was activated in both tumor and stromal cells of acinar-type tumors. Immortalized cancer-associated fibroblasts (CAF) derived from acinar-type tumors induced SAT in 3D cocultures with LADC cells. Exogenous TGF-β1 or overexpression of an active form of TGF-β1 increased CK7 expression and reduced MUC5AC expression in LADC cells, and knockdown of Tgfb1 mRNA in CAFs attenuated SAT induction. RNA-sequencing analysis suggested that angiogenesis and neutrophil recruitment are associated with SAT in vivo. Our data indicate that CAF-mediated paracrine TGF-β signaling induces remodeling of tumor tissue and determines the histological pattern of LADC, thereby contributing to tumor heterogeneity.
  84. Am J Med Sci. 2021 Jul 15. pii: S0002-9629(21)00253-6. [Epub ahead of print]
    Keywords:  Diaphragmatic; Mesothelial Cyst
  85. Transl Lung Cancer Res. 2021 Jun;10(6): 2830-2841
      Metastatic lung cancer represents a significant global issue where it is responsible for the most cancer diagnoses and deaths worldwide. Treatment for advanced lung cancer has undergone a series of paradigm shifts from chemotherapy to targeted molecular agents to the most recent immunotherapy strategies. The most successful of the latter involves antibodies that block inhibitory receptors on tumor infiltrating T cells, thereby enhancing T cell activity against tumor cells. However, only a subset of patients demonstrate durable responses to these drugs and treatment resistance is common. Emerging evidence suggests that a critical role exists for B cells as more than a bystander immune cell in the tumor microenvironment (TME). However, this role is likely context-specific where B cells comprise distinct subtypes with unique effector functions that may result in anti- or pro-tumor effects. As such, the balance between various B cell subtypes affects the net B cell impact upon tumor immunity. To date, the factors needed to polarize B cell function toward anti-tumor activity are unclear. Understanding B cell biology in the lung cancer setting will help redefine and refine treatment strategies to augment anti-tumor immunity. This article presents a review of the literature describing the current knowledge of the development and function of B cells, and explores their role in lung cancer and potential as an immunotherapeutic strategy and as a predictive marker for response to immune checkpoint blockade.
    Keywords:  B cell; B lymphocyte; immune checkpoint inhibitors (ICIs); immunotherapy; lung cancer
  86. Amino Acids. 2021 Jul 20.
      The cyanobacterial non-protein amino acid α-amino-β-methylaminopropionic acid, more commonly known as BMAA, was first discovered in the seeds of the ancient gymnosperm Cycad circinalis (now Cycas micronesica Hill). BMAA was linked to the high incidence of neurological disorders on the island of Guam first reported in the 1950s. BMAA still attracts interest as a possible causative factor in amyotrophic lateral sclerosis (ALS) following the identification of ALS disease clusters associated with living in proximity to lakes with regular cyanobacterial blooms. Since its discovery, BMAA toxicity has been the subject of many in vivo and in vitro studies. A number of mechanisms of toxicity have been proposed including an agonist effect at glutamate receptors, competition with cysteine for transport system xc_ and other mechanisms capable of generating cellular oxidative stress. In addition, a wide range of studies have reported effects related to disturbances in proteostasis including endoplasmic reticulum stress and activation of the unfolded protein response. In the present studies we examine the effects of BMAA on the ubiquitin-proteasome system (UPS) and on chaperone-mediated autophagy (CMA) by measuring levels of ubiquitinated proteins and lamp2a protein levels in a differentiated neuronal cell line exposed to BMAA. The BMAA induced increases in oxidised proteins and the increase in CMA activity reported could be prevented by co-administration of L-serine but not by the two antioxidants examined. These data provide further evidence of a protective role for L-serine against the deleterious effects of BMAA.
    Keywords:  BMAA; L-serine; Lamp2a; Protein aggregation; Ubiquitin
  87. PLoS One. 2021 ;16(7): e0254712
      Ischemic preconditioning (IPC) is the most powerful endogenous cardioprotective form of cellular adaptation. However, the inhibitory or augmenting mechanism underlying cardioprotection via IPC remains largely unknown. Suppressor of cytokine signaling-3 (SOCS3) is a cytokine-inducible potent negative feedback regulator of the signal transducer and activator of transcription-3 (STAT3) signaling pathway. Here, we aimed to determine whether cardiac SOCS3 deficiency and IPC would synergistically reduce infarct size after myocardial ischemia reperfusion injury. We evaluated STAT3 activation and SOCS3 induction after ischemic conditioning (IC) using western blot analysis and real-time PCR, and found that myocardial IC alone transiently activated myocardial STAT3 and correspondingly induced SOCS3 expression in wild-type mice. Compared with wild-type mice, cardiac-specific SOCS3 knockout (SOCS3-CKO) mice showed significantly greater and more sustained IC-induced STAT3 activation. Following ischemia reperfusion, IPC substantially reduced myocardial infarct size and significantly enhanced STAT3 phosphorylation in SOCS3-CKO mice compared to in wild-type mice. Real-time PCR array analysis revealed that SOCS3-CKO mice after IC exhibited significantly increased expressions of several anti-apoptotic genes and SAFE pathway-related genes. Moreover, real-time PCR analysis revealed that myocardial IC alone rapidly induced expression of the STAT3-activating cytokine erythropoietin in the kidney at 1 h post-IC. We also found that the circulating erythropoietin level was promptly increased at 1 h after myocardial IC. Myocardial SOCS3 deficiency and IPC exert synergistic effects in the prevention of myocardial injury after ischemia reperfusion. Our present results suggest that myocardial SOCS3 is a potent inhibitor of IPC-induced cardioprotection, and that myocardial SOCS3 inhibition augment IPC-mediated cardioprotection during ischemia reperfusion injury.
  88. Immunity. 2021 Jul 13. pii: S1074-7613(21)00264-8. [Epub ahead of print]
      As substantial constituents of the multiple myeloma (MM) microenvironment, pro-inflammatory macrophages have emerged as key promoters of disease progression, bone destruction, and immune impairment. We identify beta-2-microglobulin (β2m) as a driver in initiating inflammation in myeloma-associated macrophages (MAMs). Lysosomal accumulation of phagocytosed β2m promotes β2m amyloid aggregation in MAMs, resulting in lysosomal rupture and ultimately production of active interleukin-1β (IL-1β) and IL-18. This process depends on activation of the NLRP3 inflammasome after β2m accumulation, as macrophages from NLRP3-deficient mice lack efficient β2m-induced IL-1β production. Moreover, depletion or silencing of β2m in MM cells abrogates inflammasome activation in a murine MM model. Finally, we demonstrate that disruption of NLRP3 or IL-18 diminishes tumor growth and osteolytic bone destruction normally promoted by β2m-induced inflammasome signaling. Our results provide mechanistic evidence for β2m's role as an NLRP3 inflammasome activator during MM pathogenesis. Moreover, inhibition of NLRP3 represents a potential therapeutic approach in MM.
    Keywords:  NLRP3; inflammation; macrophages; multiple myeloma; phagocytosis; tumor-associated macrophages
  89. J Biol Chem. 2021 Jul 20. pii: S0021-9258(21)00791-2. [Epub ahead of print] 100989
      Insulin-induced genes (INSIGs) encode endoplasmic reticulum (ER)-resident proteins that regulate intracellular cholesterol metabolism. Oxysterols are oxygenated derivatives of cholesterol, some of which orchestrate lipid metabolism via interaction with INSIGs. Recently, it was reported that expression of activating transcription factor-4 (ATF4) was induced by certain oxysterols; the precise of mechanism is unclear. Herein, we show that INSIGs mediate ATF4 upregulation upon interaction with oxysterol. Oxysterols that possess a high affinity for INSIG, such as 27- and 25-hydroxycholesterol (25HC), markedly induced the increase of ATF4 protein when compared with other oxysterols. In addition, ATF4 upregulation by these oxysterols was attenuated in INSIG1/2-deficient CHO cells and was recovered by either INSIG1 or INSIG2 rescue. Mechanistic studies revealed that the binding of 25HC to INSIG is critical for increased ATF4 protein via activation of PERK and eIF2α. Knockout of INSIG1 or INSIG2 in human hepatoma Huh7 cells attenuated ATF4 protein upregulation, indicating that only one of the endogenous INSIGs, unlike overexpression of intrinsic INSIG1 or INSIG2, was insufficient for ATF4 induction. Furthermore, ATF4 proactively upregulated the cell death inducible genes expression, such as Chop, Chac1, and Trb3, thereby markedly reducing cell viability with 25-hydroxycholesterol. These findings support a model whereby that INSIGs sense an increase in oxysterol in the ER and induce an increase of ATF4 protein via the PERK/eIF2α pathway, thereby promoting cell death.
    Keywords:  activating transcription factor-4 (ATF4); cell death; endoplasmic reticulum stress (ER stress); eukaryotic initiation factor 2 (eIF2); oxysterol; sterol; stress response
  90. Nat Commun. 2021 07 21. 12(1): 4434
      Dyslipidemia is a main driver of cardiovascular diseases. The ability of macrophages to scavenge excess lipids implicate them as mediators in this process and understanding the mechanisms underlying macrophage lipid metabolism is key to the development of new treatments. Here, we investigated how adipose tissue macrophages regulate post-prandial cholesterol transport. Single-cell RNA sequencing and protected bone marrow chimeras demonstrated that ingestion of lipids led to specific transcriptional activation of a population of resident macrophages expressing Lyve1, Tim4, and ABCA1. Blocking the phosphatidylserine receptor Tim4 inhibited lysosomal activation and the release of post-prandial high density lipoprotein cholesterol following a high fat meal. Both effects were recapitulated by chloroquine, an inhibitor of lysosomal function. Moreover, clodronate-mediated cell-depletion implicated Tim4+ resident adipose tissue macrophages in this process. Thus, these data indicate that Tim4 is a key regulator of post-prandial cholesterol transport and adipose tissue macrophage function and may represent a novel pathway to treat dyslipidemia.
  91. Immunology. 2021 Jul 20.
      Sepsis is a life-threatening condition involving a dysregulated immune response to infectious agents that causes injury to host tissues and organs. Current treatments are limited to early administration of antibiotics and supportive care. While appealing, the strategy of targeted inhibition of individual molecules in the inflammatory cascade has not proved beneficial. Non-targeted, systemic immunosuppression with steroids has shown limited efficacy and raises concern for secondary infection. Iminosugars are a class of small molecule glycomimetics with distinct inhibition profiles for glycan processing enzymes based on stereochemistry. Inhibition of host endoplasmic reticulum resident glycoprotein processing enzymes has demonstrated efficacy as a broad spectrum antiviral strategy, but limited consideration has been given to the effects on host glycoprotein production and consequent disruption of signaling cascades. This work demonstrates that iminosugars inhibit dengue virus, bacterial lipopolysaccharide, and fungal antigen stimulated cytokine responses in human macrophages. In spite of decreased inflammatory mediator production, viral replication is suppressed in the presence of iminosugar. Transcriptome analysis reveals the key interaction of pathogen-induced endoplasmic reticulum stress, the resulting unfolded protein response, and inflammation. Our work shows that iminosugars modulate these interactions. Based on these findings, we propose a new therapeutic role for iminosugars as treatment for sepsis related inflammatory disorders associated with excess cytokine secretion.
    Keywords:  Iminosugar; Inflammation; Sepsis; dengue virus; unfolded protein response
  92. Cancer Sci. 2021 Jul 22.
      Submucosal invasion and lymph node metastasis are important issues affecting treatment options for early colorectal cancer (CRC). In this study, we aimed to unravel the molecular mechanism underlying the invasiveness of early CRCs. We performed RNA-sequencing (RNA-seq) with poorly differentiated components (PORs) and their normal counterparts isolated from T1 CRC tissues, and detected significant upregulation of SAA1 in PORs. Immunohistochemical analysis revealed that SAA1 was specifically expressed in PORs at the invasive front of T1b CRCs. Upregulation of SAA1 in CRC cells promoted cell migration and invasion. Co-culture experiments using CRC cell lines and THP-1 cells suggested that interleukin 1β (IL-1β) produced by macrophages induces SAA1 expression in CRC cells. Induction of SAA1 and promotion of CRC cell migration and invasion by macrophages were inhibited by blocking IL-1β. These findings were supported by immunohistochemical analysis of primary T1 CRCs showing accumulation of M1-like/M2-like macrophages at SAA1-positive invasive front regions. Moreover, SAA1 produced by CRC cells stimulated upregulation of MMP-9 in macrophages. Our data suggest that tumor-associated macrophages at the invasive front of early CRCs promote cancer cell migration and invasion through induction of SAA1, and that SAA1 may be a predictive biomarker and a useful therapeutic target.
    Keywords:  colorectal cancer; serum amyloid A1; submucosal invasion; tumor microenvironment; tumor-associated macrophage
  93. Mol Biol Rep. 2021 Jul 22.
      OBJECTIVES: Tonsil tissue is a very important component of the human immunity system, contributing to the functioning of the cellular and humoral defence system, especially in childhood. The endoplasmic reticulum (ER) is an organelle that has a very important function in the balanced functioning of cells, in which the accumulation of a cellular protein called ER stress occurs in case of dysfunction. ER stress influences the pathogenesis of many diseases and immune system functions. We aimed to investigate the relation between the diseases of tonsil tissue and ER stress response to elucidate the mechanisms of diseases related with the immune system.METHODS: A prospective study was conducted in 46 children aged between 2 and 16 years who underwent tonsillectomy for chronic tonsillitis or tonsillar hypertrophy. Tonsil tissue was separated into two groups according to their size and evaluated in terms of ER stress markers and apoptosis markers by Real-time PCR and Western blot analysis.
    RESULTS: The ΔCT levels of ER stress markers (ATF4, ATF6, CHOP, GRP78, EIF2AK3, ERN1, GRP94) were greater in children with chronic tonsillitis (p < 0.005). In contrast, the tonsillar hypertrophy group had greater ΔCT levels of apoptosis markers (BAX, BCL-2) according to the Real-time PCR method (p < 0.005). According to the Western blot analysis, the normalized levels of ATF4, ATF6, CHOP, GRP78, and ERN1 genes were found greater in the chronic tonsillitis group than the tonsillar hypertrophy group. There was no difference between the two groups in terms of normalized BCL-2 and BAX levels by Western blot analysis.
    CONCLUSION: This is the first study in the literature investigating the effect of the ER stress pathway on the etiopathogenesis of tonsil diseases. It was concluded that the ER stress pathway plays a role in the etiopathogenesis of chronic tonsillitis. Investigating the relationship between ER stress and structures such as the tonsil tissue that make up the immune system can help create new treatment strategies.
    CLINICAL TRIAL REGISTRATION: Trial Registration Identifier: NCT04653376.
    Keywords:  Apoptosis; Children; Endoplasmic reticulum stress; Genetics; Palatine tonsil; Tonsillitis
  94. Neuro Endocrinol Lett. 2021 Jul 19. 42(3): 160-170
      Stroke is the second-leading cause of death worldwide and exhibits a high disability rate. Ischemic stroke accounts for approximately 80% of all stroke cases. Inflammatory responses induced by innate immunity are involved in all stages of stroke-related injury, including early cerebral-infarction tissue repair and regeneration after ischemia. Toll-like receptors are the main receptors involved in innate immunity. Toll-like receptors specific antagonists inhibit neuroinflammation by reducing overproduction of inflammatory mediators. But there are still some limitations, such as affecting protein clearance and myelination. Extracellular vesicles are widespread and distributed in various body fluids, carry and transmit important signal molecules, affect the physiological state of cells and are closely related to the occurrence and progress of many diseases. In the present review, we summarize recent findings regarding the mechanisms by which extracellular vesicles act as signaling vectors to regulate cellular crosstalk between neurovascular units and further discuss the therapeutic effects of extracellular vesicles derived from mesenchymal stem cells on brain injury. Collectively, our review may provide novel insights into further elucidating pathogenesis and cerebral-protective measures of ischemic stroke.
  95. Int J Mol Sci. 2021 Jul 14. pii: 7532. [Epub ahead of print]22(14):
      Coagulopathies common to patients with diabetes and chronic kidney disease (CKD) are not fully understood. Fibrin deposits in the kidney suggest the local presence of clotting factors including tissue factor (TF). In this study, we investigated the effect of glucose availability on the synthesis of TF by cultured human kidney tubular epithelial cells (HTECs) in response to activation of protease-activated receptor 2 (PAR2). PAR2 activation by peptide 2f-LIGRLO-NH2 (2F, 2 µM) enhanced the synthesis and secretion of active TF (~45 kDa) which was blocked by a PAR2 antagonist (I-191). Treatment with 2F also significantly increased the consumption of glucose from the cell medium and lactate secretion. Culturing HTECs in 25 mM glucose enhanced TF synthesis and secretion over 5 mM glucose, while addition of 5 mM 2-deoxyglucose (2DOG) significantly decreased TF synthesis and reduced its molecular weight (~40 kDa). Blocking glycosylation with tunicamycin also reduced 2F-induced TF synthesis while reducing its molecular weight (~36 kDa). In conclusion, PAR2-induced TF synthesis in HTECs is enhanced by culture in high concentrations of glucose and suppressed by inhibiting either PAR2 activation (I-191), glycolysis (2DOG) or glycosylation (tunicamycin). These results may help explain how elevated concentrations of glucose promote clotting abnormities in diabetic kidney disease. The application of PAR2 antagonists to treat CKD should be investigated further.
    Keywords:  PAR2; diabetes; glucose; kidney tubular epithelial cells; protease; tissue factor
  96. J Exp Med. 2021 Sep 06. pii: e20210108. [Epub ahead of print]218(9):
      Colorectal cancers (CRCs) deficient in DNA mismatch repair (dMMR) contain abundant CD8+ tumor-infiltrating lymphocytes (TILs) responding to the abundant neoantigens from their unstable genomes. Priming of such tumor-targeted TILs first requires recruitment of CD8+ T cells into the tumors, implying that this is an essential prerequisite of successful dMMR anti-tumor immunity. We have discovered that selective recruitment and activation of systemic CD8+ T cells into dMMR CRCs strictly depend on overexpression of CCL5 and CXCL10 due to endogenous activation of cGAS/STING and type I IFN signaling by damaged DNA. TIL infiltration into orthotopic dMMR CRCs is neoantigen-independent and followed by induction of a resident memory-like phenotype key to the anti-tumor response. CCL5 and CXCL10 could be up-regulated by common chemotherapies in all CRCs, indicating that facilitating CD8+ T cell recruitment underlies their efficacy. Induction of CCL5 and CXCL10 thus represents a tractable therapeutic strategy to induce TIL recruitment into CRCs, where local priming can be maximized even in neoantigen-poor CRCs.
  97. Front Physiol. 2021 ;12 687654
      The increased mass of airway smooth muscle (ASM) in the airways of asthmatic patients may contribute to the pathology of this disease by increasing the capacity for airway narrowing. Evidence for the airway epithelium as a participant in ASM remodeling is accruing. To investigate mechanisms by which airway epithelial cells induce ASM cell (ASMC) proliferation, we have employed a co-culture model to explore markers of ASMC proliferative phenotype. Co-culture with epithelial cells led to incorporation of bromodeoxyuridine into ASMCs, indicating augmented proliferation and an associated increase in mRNA of the pro-proliferative co-transcription factor Elk1. Although the mitogen heparin-binding epidermal growth factor (HB-EGF) was augmented in the co-culture supernatant, the ASMC epidermal growth factor receptor (EGFR), an effector of HB-EGF induced proliferation, did not mediate epithelial-induced proliferation. The co-culture increased the expression of ASMC mRNA for the pro-inflammatory cytokines IL-6 and IL-8 as well as the pro-proliferative microRNA miR-210. The transcriptional repressor Max-binding protein (Mnt), a putative target of miR-210, was transcriptionally repressed in co-cultured ASMCs. Together, these data indicate that the airway epithelium-induced proliferative phenotype of ASMCs is not driven by EGFR signaling, but rather may be dependent on miR210 targeting of tumor suppressor Mnt.
    Keywords:  airway smooth muscle cells; epithelial cells; miRNA-210; proinflammatory; proliferation
  98. Cell Mol Immunol. 2021 Jul 19.
      Kupffer cells (KCs), which are liver-resident macrophages, originate from the fetal yolk sac and represent one of the largest macrophage populations in the body. However, the current data on the origin of the cells that restore macrophages during liver injury and regeneration remain controversial. Here, we address the question of whether liver macrophage restoration results from circulating monocyte infiltration or local KC proliferation in regenerating livers after partial hepatectomy (PHx) and uncover the underlying mechanisms. By using several strains of genetically modified mice and performing immunohistochemical analyses, we demonstrated that local KC proliferation mainly contributed to the restoration of liver macrophages after PHx. Peak KC proliferation was impaired in Il6-knockout (KO) mice and restored after the administration of IL-6 protein, whereas KC proliferation was not affected in Il4-KO or Csf2-KO mice. The source of IL-6 was identified using hepatocyte- and myeloid-specific Il6-KO mice and the results revealed that both hepatocytes and myeloid cells contribute to IL-6 production after PHx. Moreover, peak KC proliferation was also impaired in myeloid-specific Il6 receptor-KO mice after PHx, suggesting that IL-6 signaling directly promotes KC proliferation. Studies using several inhibitors to block the IL-6 signaling pathway revealed that sirtuin 1 (SIRT1) contributed to IL-6-mediated KC proliferation in vitro. Genetic deletion of the Sirt1 gene in myeloid cells, including KCs, impaired KC proliferation after PHx. In conclusion, our data suggest that KC repopulation after PHx is mainly driven by local KC proliferation, which is dependent on IL-6 and SIRT1 activation in KCs.
    Keywords:  IL-6; Kupffer cells; Liver regeneration; Myeloid cells; Sirtuin 1
  99. Neurochem Res. 2021 Jul 20.
      Cerebral ischemic injury is a leading cause of death and long-term disability throughout the world. Peroxisome proliferator-activated receptor gamma (PPAR-ɣ) is a ligand-activated nuclear transcription factor that is a member of the PPAR family. PPAR-ɣ has been shown in several in vitro and in vivo models to prevent post-ischemic inflammation and neuronal damage by negatively controlling the expression of genes modulated by cerebral ischemic injury, indicating a neuroprotective effect during cerebral ischemic injury. A extensive literature review of PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out to understand the nature of the extensive work done on the mechanistic role of Peroxisome proliferator activated receptor gamma and its modulation in Cerebral ischemic injury. PPAR-ɣ can interact with specific DNA response elements to control gene transcription and expression when triggered by its ligand. It regulates lipid metabolism, improves insulin sensitivity, modulates antitumor mechanisms, reduces oxidative stress, and inhibits inflammation. This review article provides insights on the current state of research into the neuroprotective effects of PPAR-ɣ in cerebral ischemic injury, as well as the cellular and molecular mechanisms by which these effects are modulated, such as inhibition of inflammation, reduction of oxidative stress, suppression of pro-apoptotic production, modulation of transcription factors, and restoration of injured tissue through neurogenesis and angiogenesis.
    Keywords:  Angiogenesis; Cerebral ischemic injury; Insulin; Neurogenesis; Neuroinflammation; Peroxisome proliferator activated receptor gamma
  100. Cancers (Basel). 2021 Jul 15. pii: 3541. [Epub ahead of print]13(14):
      Arginine is an amino acid critically involved in multiple cellular processes including the syntheses of nitric oxide and polyamines, and is a direct activator of mTOR, a nutrient-sensing kinase strongly implicated in carcinogenesis. Yet, it is also considered as a non- or semi-essential amino acid, due to normal cells' intrinsic ability to synthesize arginine from citrulline and aspartate via ASS1 (argininosuccinate synthase 1) and ASL (argininosuccinate lyase). As such, arginine can be used as a dietary supplement and its depletion as a therapeutic strategy. Strikingly, in over 70% of tumors, ASS1 transcription is suppressed, rendering the cells addicted to external arginine, forming the basis of arginine-deprivation therapy. In this review, we will discuss arginine as a signaling metabolite, arginine's role in cancer metabolism, arginine as an epigenetic regulator, arginine as an immunomodulator, and arginine as a therapeutic target. We will also provide a comprehensive summary of ADI (arginine deiminase)-based arginine-deprivation preclinical studies and an update of clinical trials for ADI and arginase. The different cell killing mechanisms associated with various cancer types will also be described.
    Keywords:  ADI; arginase; arginine; arginine-deprivation therapy; cancer metabolism; epigenetics
  101. JPEN J Parenter Enteral Nutr. 2021 Jul 22.
      Muscle wasting is common and persistent in severely burned patients, worsened by immobilization during treatment. In this review, we posit two major phenotypes of muscle wasting after severe burn, cachexia and sarcopenia, each with distinguishing characteristics to result in muscle atrophy; these characteristics are also likely present in other critically ill populations. An online search was conducted from the PubMed database and other available online resources and we manually extracted published articles in a systematic mini review. We describe the current definitions and characteristics of cachexia and sarcopenia and relate these to muscle wasting after severe burn. We then discuss these putative mechanisms of muscle atrophy in this condition. Severe burn and immobilization have distinctive patterns in mediating muscle wasting and muscle atrophy. In considering these two pathological phenotypes (cachexia and sarcopenia), we propose two independent principal causes and mechanisms of muscle mass loss after burns: 1) inflammation-induced cachexia leading to proteolysis and protein degradation, and 2) sarcopenia/immobility that signals inhibition of expected increases in protein synthesis in response to protein loss. Because both are present following severe burn, these should be considered independently in devising treatments. Discussing cachexia and sarcopenia as independent mechanisms of severe burn-initiated muscle wasting is explored. Recognition of these associated mechanisms will likely improve outcomes. This article is protected by copyright. All rights reserved.
    Keywords:  cachexia; immobilization; muscle atrophy; sarcopenia; thermal injury
  102. Int J Mol Sci. 2021 Jul 15. pii: 7564. [Epub ahead of print]22(14):
      Hypoxia is a key component of the tumor microenvironment (TME) and promotes not only tumor growth and metastasis, but also negatively affects infiltrating immune cells by impairing host immunity. Dendritic cells (DCs) are the most potent antigen-presenting cells and their biology is weakened in the TME in many ways, including the modulation of their viability. RNASET2 belongs to the T2 family of extracellular ribonucleases and, besides its nuclease activity, it exerts many additional functions. Indeed, RNASET2 is involved in several human pathologies, including cancer, and it is functionally relevant in the TME. RNASET2 functions are not restricted to cancer cells and its expression could be relevant also in other cell types which are important players in the TME, including DCs. Therefore, this study aimed to unravel the effect of hypoxia (2% O2) on the expression of RNASET2 in DCs. Here, we showed that hypoxia enhanced the expression and secretion of RNASET2 in human monocyte-derived DCs. This paralleled the HIF-1α accumulation and HIF-dependent and -independent signaling, which are associated with DCs' survival/autophagy/apoptosis. RNASET2 expression, under hypoxia, was regulated by the PI3K/AKT pathway and was almost completely abolished by TLR4 ligand, LPS. Taken together, these results highlight how hypoxia- dependent and -independent pathways shape RNASET2 expression in DCs, with new perspectives on its implication for TME and, therefore, in anti-tumor immunity.
    Keywords:  RNASET2; dendritic cell; hypoxia
  103. Osteoarthritis Cartilage. 2021 Jul 20. pii: S1063-4584(21)00842-6. [Epub ahead of print]
      OBJECTIVE: Metabolic dysfunction can cause IL-1β mediated activation of the innate immune system, which could have important implications for the therapeutic efficacy of IL-1β neutralizing drugs as treatment for OA in the context of metabolic syndrome (MetS). In the present study, we investigated whether early treatment with a single dose of IL-1β blocking antibodies could prevent Western diet (WD) induced changes to systemic monocyte populations and their cytokine secretion profile and herewith modulate collagenase induced osteoarthritis (CiOA) pathology.METHODS: CiOA was induced in female C57Bl/6 mice fed either a standard diet (SD) or WD and treated with a single dose of either polyclonal anti-IL-1β antibodies or control. Monocyte subsets and granulocytes in bone marrow and blood were analyzed with flow cytometry, and cytokine expression by bone marrow cells was analyzed using qPCR. Synovial cellularity, cartilage damage and osteophyte formation were assessed on histology.
    RESULTS: WD feeding of C57Bl/6 mice led to increased serum levels of low-density lipoprotein (LDL) and innate immune activation in the form of an increased number of Ly6Chigh cells in bone marrow and blood and increased cytokine expression of especially IL-6 and TNF-α by bone marrow cells. The increase in monocyte number and activity was ameliorated by anti-IL-1β treatment. However, anti-IL-1β treatment did not significantly affect synovial lining thickness, cartilage damage and osteophyte formation during WD feeding.
    CONCLUSIONS: Single-dose systemic anti-IL-1β treatment prevented WD-induced innate immune activation during early stage CiOA in C57Bl/6 mice, but did not ameliorate joint pathology.
    Keywords:  CiOA; LDL; Metabolic syndrome; Western Diet; anti-IL-1β; inflammation
  104. J Gastroenterol. 2021 Jul 19.
      Pancreatic fibrosis (PF) is an essential component of the pathobiology of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC). Activated pancreatic myofibroblasts (PMFs) are crucial for the deposition of the extracellular matrix, and fibrotic reaction in response to sustained signaling. Consequently, understanding of the molecular mechanisms of PMF activation is not only critical for understanding CP and PDAC biology but is also a fertile area of research for the development of novel therapeutic strategies for pancreatic pathologies. This review analyzes the key signaling events that drive PMF activation including, initiating signals from transforming growth factor-β1, platelet derived growth factor, as well as other microenvironmental cues, like hypoxia and extracellular matrix rigidity. Further, we discussed the intracellular signal events contributing to PMF activation, and crosstalk with different components of tumor microenvironment. Additionally, association of epidemiologically established risk factors for CP and PDAC, like alcohol intake, tobacco exposure, and metabolic factors with PMF activation, is discussed to comprehend the role of lifestyle factors on pancreatic pathologies. Overall, this analysis provides insight into the biology of PMF activation and highlights salient features of this process, which offer promising therapeutic targets.
    Keywords:  Cell signaling; Chronic pancreatitis; Myofibroblast; Pancreatic cancer; Pancreatic fibrosis
  105. Front Immunol. 2021 ;12 681810
      Inflammation, which is induced by the immune response, is recognized as the driving factor in many diseases, including infections and inflammatory diseases, metabolic disorders and cancers. Genetic variations in pivotal genes associated with the immune response, particularly single nucleotide polymorphisms (SNPs), may account for predisposition and clinical outcome of diseases. Lipopolysaccharide (LPS)-binding protein (LBP) functions as an enhancer of the host response to LPS, the main component of the outer membrane of gram-native bacteria. Given the crucial role of LBP in inflammation, we will review the impact of SNPs in the LBP gene on infections and inflammatory diseases, metabolic disorders and cancers.
    Keywords:  cancers; infections; inflammation; inflammatory diseases; lipopolysaccharide-binding protein; metabolic disorders; single nucleotide polymorphisms
  106. J Cell Biochem. 2021 Jul 21.
      Multiple d-amino acids are present in mammalian cells, and these compounds have distinctive physiological functions. Among the free d-amino acids identified in mammals, d-aspartate plays critical roles in the neuroendocrine and endocrine systems, as well as in the central nervous system. Mammalian cells have the molecular apparatus necessary to take up, degrade, synthesize, and release d-aspartate. In particular, d-aspartate is degraded by d-aspartate oxidase (DDO), a peroxisome-localized enzyme that catalyzes the oxidative deamination of d-aspartate to generate oxaloacetate, hydrogen peroxide, and ammonia. However, little is known about the molecular mechanisms underlying d-aspartate homeostasis in cells. In this study, we established a cell line that overexpresses cytoplasm-localized DDO; this cell line cannot survive in the presence of high concentrations of d-aspartate, presumably because high levels of toxic hydrogen peroxide are produced by metabolism of abundant d-aspartate by DDO in the cytoplasm, where hydrogen peroxide cannot be removed due to the absence of catalase. Next, we transfected these cells with a complementary DNA library derived from the human brain and screened for clones that affected d-aspartate metabolism and improved cell survival, even when the cells were challenged with high concentrations of d-aspartate. The screen identified a clone of glyoxylate reductase/hydroxypyruvate reductase (GRHPR). Moreover, the GRHPR metabolites glyoxylate and hydroxypyruvate inhibited the enzymatic activity of DDO. Furthermore, we evaluated the effects of GRHPR and peroxisome-localized DDO on d- and l-aspartate levels in cultured mammalian cells. Our findings show that GRHPR contributes to the homeostasis of these amino acids in mammalian cells.
    Keywords:  d-amino acid; d-aspartate; d-aspartate oxidase; glyoxylate reductase/hydroxypyruvate reductase
  107. Plast Reconstr Surg. 2021 Jul 21.
      BACKGROUND: Fat grafting is commonly used in treating soft-tissue defects. However, the basic biology behind fat grafting is still not fully understood. Evidence of adipose browning into beige adipose tissue after fat grafting was revealed, but its role in fat grafting remains unclear.METHODS: Induced beige adipocytes and adipose-derived stem cells were obtained from human lipoaspirates and labeled with green fluorescent protein. Nude mice were each injected with 300 mg of human lipoaspirate containing green fluorescent protein-labeled adipose-derived stem cells, green fluorescent protein-labeled induced beige adipocytes, or phosphate-buffered saline. Grafted fat was harvested after 1, 4, 8, and 12 weeks for immunohistochemistry and histologic examination. Graft retention, vascularization, and adipogenic gene expression were compared.
    RESULTS: After 7 days' induction, adipocytes achieved browning with multilocular lipid droplets, increased mitochondria, and up-regulated browning gene expression. Fat graft retention rates at week 12 were significantly higher after injection of induced beige adipocytes than after injection of phosphate-buffered saline (46.0 ± 4.9 percent versus 31.0 ± 3.6 percent; p = 0.01), but were similar after injection of induced beige adipocytes and adipose-derived stem cells (p > 0.05). Induced beige adipocytes underwent rewhitening into white adipocytes and showed up-regulation of peroxisome proliferator-activated receptor-γ expression. Induced beige adipocytes enhanced angiogenesis, but were not active in forming vessel structures.
    CONCLUSIONS: Induced beige adipocytes and adipose-derived stem cells were comparable in improving fat graft retention rates. Induced beige adipocytes promote angiogenesis in a paracrine manner and are prone to rewhitening after fat grafting.
  108. J Clin Med. 2021 Jul 02. pii: 2977. [Epub ahead of print]10(13):
      To investigate the expression of vascular endothelial growth factor (VEGF)-C and vascular endothelial growth factor receptor (VEGFR)3 in the trabecular meshwork (TM) of patients with glaucoma and cultured TM cells. Methods: The expressions of VEGF-C in angle tissues collected by trabeculectomy from patients with glaucoma and non-glaucomatous choroidal malignant melanoma were analyzed by immunohistochemistry. Additionally, VEGF-C concentrations were determined in the aqueous humor of patients with glaucoma by ELISA. The expressions of VEGFR3, which is a receptor of VEGF-C in cultured TM cells, were analyzed by Western blot analysis and immunocytochemistry. Cultured TM cells were stimulated by oxidative stress, hypoxia, or high glucose conditions, and VEGF-C concentrations in supernatants and cell lysates were determined by ELISA. Results: VEGF-C immunoreactivity was positive in TM tissues of glaucoma patients, but not in those of non-glaucomatous controls. VEGF-C concentrations in the aqueous humor of patients with neovascular glaucoma and primary open-angle glaucoma were lower than those with non-glaucoma patients. VEGFR3 was expressed in cultured TM cells. VEGF-C concentrations in supernatants or cell lysates of TM cells cultured under oxidative stress and hypoxia were significantly elevated compared with those under steady conditions (p < 0.05). VEGF-C concentrations in supernatants and cell lysates of TM cells cultured in high glucose were significantly higher than those in low glucose (p < 0.01). Conclusions: VEGF-C was expressed in TM tissues of patients with glaucoma, which was secreted from cultured TM cells under various pathological conditions. These results suggest that VEGF-C may be involved in the pathology of glaucoma.
    Keywords:  VEGF-C; VEGFR3; neovascular glaucoma; primary open-angle glaucoma; trabecular meshwork
  109. Front Endocrinol (Lausanne). 2021 ;12 697120
      Glucagon-like peptide-1 (GLP-1) shows robust protective effects on β-cell survival and function and GLP-1 based therapies are successfully applied for type-2 diabetes (T2D) and obesity. Another cleavage product of pro-glucagon, Glucagon-like peptide-2 (GLP-2; both GLP-1 and GLP-2 are inactivated by DPP-4) has received little attention in its action inside pancreatic islets. In this study, we investigated GLP-2 production, GLP-2 receptor (GLP-2R) expression and the effect of GLP-2R activation in human islets. Isolated human islets from non-diabetic donors were exposed to diabetogenic conditions: high glucose, palmitate, cytokine mix (IL-1β/IFN-γ) or Lipopolysaccharide (LPS) in the presence or absence of the DPP4-inhibitor linagliptin, the TLR4 inhibitor TAK-242, the GLP-2R agonist teduglutide and/or its antagonist GLP-2(3-33). Human islets under control conditions secreted active GLP-2 (full-length, non-cleaved by DPP4) into the culture media, which was increased by combined high glucose/palmitate, the cytokine mix and LPS and highly potentiated by linagliptin. Low but reproducible GLP-2R mRNA expression was found in all analyzed human islet isolations from 10 donors, which was reduced by pro-inflammatory stimuli: the cytokine mix and LPS. GLP-2R activation by teduglutide neither affected acute or glucose stimulated insulin secretion nor insulin content. Also, teduglutide had no effect on high glucose/palmitate- or LPS-induced dysfunction in cultured human islets but dampened LPS-induced macrophage-dependent IL1B and IL10 expression, while its antagonist GLP-2(3-33) abolished such reduction. In contrast, the expression of islet macrophage-independent cytokines IL6, IL8 and TNF was not affected by teduglutide. Medium conditioned by teduglutide-exposed human islets attenuated M1-like polarization of human monocyte-derived macrophages, evidenced by a lower mRNA expression of pro-inflammatory cytokines, compared to vehicle treated islets, and a reduced production of itaconate and succinate, marker metabolites of pro-inflammatory macrophages. Our results reveal intra-islet production of GLP-2 and GLP-2R expression in human islets. Despite no impact on β-cell function, local GLP-2R activation reduced islet inflammation which might be mediated by a crosstalk between endocrine cells and macrophages.
    Keywords:  GLP-2; GLP-2R; alpha-cell; beta-cell; diabetes; inflammation; islets
  110. Am J Med Genet B Neuropsychiatr Genet. 2021 Jul 24.
      Hyperprolinemia Type I and II are genetic metabolic disorders caused by disrupted proline degradation. It has been suggested that hyperprolinemia is associated with increased risk of developmental and mental disorders but detailed information on the psychiatric phenotype in hyperprolinemic patients is limited. Following PRISMA guidelines, we carried out a systematic review to clarify psychiatric phenotypes in patients with hyperprolinemia. We screened 1753 studies and included 35 for analysis, including 20 case reports and 15 case-control and cohort studies. From these studies, a common psychiatric phenotype is observed with a high prevalence of developmental delay, intellectual disability, autism spectrum disorders, and psychosis spectrum disorders. In most cases, a genetic cause of hyperprolinemia was known, these included mutations in the PRODH and ALDH4A1 genes and deletions of chromosome 22q11.2. No evidence for a biochemical phenotype-clinical phenotype correlation was found; that is, no association between higher proline levels and specific psychiatric phenotypes was observed. This suggests that genomic and environmental factors are likely to contribute to clinical outcomes. More studies are needed to clarify whether hyperprolinemia is a primary causal factor underlying the increased risk of developing psychiatric disorders seen in patients with hyperprolinemia, or whether hyperprolinemia and psychiatric disorders are both consequences of a shared underlying mechanism.
    Keywords:  22q11 deletion syndrome; ALDH4A1; PRODH; hyperprolinemia; mental disorders
  111. Cancer Res. 2021 Jul 23. pii: canres.4028.2020. [Epub ahead of print]
      Castration-resistant prostate cancer (CRPC) is a lethal stage of disease in which androgen receptor (AR) signaling is persistent despite androgen deprivation therapy (ADT). Most studies have focused on investigating cell-autonomous alterations in CRPC, while the contributions of the tumor microenvironment are less well understood. Here we sought to determine the role of tumor-associated macrophages in CRPC, based upon their role in cancer progression and therapeutic resistance. In a syngeneic model that reflected the mutational landscape of CRPC, macrophage depletion resulted in a reduced transcriptional signature for steroid and bile acid synthesis, indicating potential perturbation of cholesterol metabolism. As cholesterol is the precursor of the five major types of steroid hormones, we hypothesized that macrophages were regulating androgen biosynthesis within the prostate tumor microenvironment. Macrophage depletion reduced androgen levels within prostate tumors and restricted androgen receptor (AR) nuclear localization in vitro and in vivo. Macrophages were also cholesterol-rich and were able to transfer cholesterol to tumor cells in vitro. AR nuclear translocation was inhibited by activation of Liver X Receptor (LXR)-β, the master regulator of cholesterol homeostasis. Consistent with these data, macrophage depletion extended survival during ADT and the presence of macrophages correlated with therapeutic resistance in patient-derived explants. Taken together, these findings support the therapeutic targeting of macrophages in CRPC.
  112. Front Immunol. 2021 ;12 691155
      AA amyloidosis belongs to the group of amyloid diseases which can follow chronic inflammatory conditions of various origin. The disease is characterized by the deposition of insoluble amyloid fibrils formed by serum amyloid A1 (SAA1) leading eventually to organ failure. Macrophages are intimately involved in the fibrillogenesis as well as in the clearance of amyloid fibrils. In vivo, macrophages may occur as classically (M1) or alternatively activated (M2) macrophages. We investigate here how SAA1 might affect the macrophage phenotype and function. Gene microarray analysis revealed upregulation of 64 M1-associated genes by SAA1. M1-like polarization was further confirmed by the expression of the M1-marker MARCO, activation of the NF-κB transcription factor, and secretion of the M1-cytokines TNF-α, IL-6, and MCP-1. Additionally, we demonstrate here that M1-polarized macrophages exhibit enhanced fibrillogenic activity towards SAA1. Based on our data, we propose reconsideration of the currently used cellular amyloidosis models towards an in vitro model employing M1-polarized macrophages. Furthermore, the data suggest macrophage repolarization as potential intervention strategy in AA amyloidosis.
    Keywords:  M1 subset; amyloidosis; inflammation; innate immunity; macrophage polarization; serum amyloid A
  113. Front Mol Biosci. 2021 ;8 643997
      Background/Aims: LncRNAs are a new modulator in the development of intervertebral disc degeneration. However, the functional role and mechanism of HOXC13-AS in intervertebral disc degeneration remain unclear. Methods: qRT-PCR analysis was performed to measure the relative expression levels of HOXC13-AS and miR-497-5p, and the levels of IL-1β, IL-6, and TNF-α in the medium supernatant were analyzed by ELISA. The related mechanism between HOXC13-AS and miR-497-5p was detected by luciferase assays. Results: The results revealed that TNF-α and IL-1β induced HOXC13-AS expression in NP cells. HOXC13-AS was overexpressed in IDD specimens compared to control specimens, and higher expression of HOXC13-AS was correlated with high Pfirrmann scores. Ectopic expression of HOXC13-AS promoted MMP-3 and ADAMTS4 and inhibited aggrecan and collagen II expression in NP cells. Furthermore, overexpression of HOXC13-AS increased the expression of inflammatory cytokines, including IL-1β, IL-6, and TNF-α. Our results demonstrated that TNF-α and IL-1β induced ADAMTS5 expression and suppressed miR-497-5p expression. miR-497-5p was downregulated in IDD specimens compared to control specimens, and the lower expression of miR-497-5p was correlated with high Pfirrmann scores. The miR-497-5p level was negatively proportional to HOXC13-AS expression in IDD specimens. Luciferase analysis data indicated that ADAMTS5 was a direct target gene of miR-497-5p. HOXC13-AS induced inflammatory cytokine expression and ECM degradation by modulating miR-497-5p/ADAMTS5. Conclusion: HOXC13-AS may be a treatment target for IDD.
    Keywords:  ADAMTS5; HOXC13-AS; intervertebral disc; lncRNA; miR-497-5p
  114. J Hematol Oncol. 2021 Jul 22. 14(1): 114
      Metabolic rewiring offers novel therapeutic opportunities in cancer. Until recently, there was scant information regarding soft tissue sarcomas, due to their heterogeneous tissue origin, histological definition and underlying genetic history. Novel large-scale genomic and metabolomics approaches are now helping stratify their physiopathology. In this review, we show how various genetic alterations skew activation pathways and orient metabolic rewiring in sarcomas. We provide an update on the contribution of newly described mechanisms of metabolic regulation. We underscore mechanisms that are relevant to sarcomagenesis or shared with other cancers. We then discuss how diverse metabolic landscapes condition the tumor microenvironment, anti-sarcoma immune responses and prognosis. Finally, we review current attempts to control sarcoma growth using metabolite-targeting drugs.
    Keywords:  Metabolism; Metabolite-targeted therapies; Metabolomics; Microenvironment; Sarcoma; Transcriptomics
  115. Acta Neuropathol Commun. 2021 Jul 17. 9(1): 125
      Peripheral nerve injury is a serious health problem and repairing long nerve deficits remains a clinical challenge nowadays. Nerve guidance conduit (NGC) serves as the most promising alternative therapy strategy to autografts but its repairing efficiency needs improvement. In this study, we investigated whether modulating the immune microenvironment by Interleukin-17F (IL-17F) could promote NGC mediated peripheral nerve repair. Chitosan conduits were used to bridge sciatic nerve defect in IL-17F knockout mice and wild-type mice with autografts as controls. Our data revealed that IL-17F knockout mice had improved functional recovery and axonal regeneration of sciatic nerve bridged by chitosan conduits comparing to the wild-type mice. Notably, IL-17F knockout mice had enhanced anti-inflammatory macrophages in the NGC repairing microenvironment. In vitro data revealed that IL-17F knockout peritoneal and bone marrow derived macrophages had increased anti-inflammatory markers after treatment with the extracts from chitosan conduits, while higher pro-inflammatory markers were detected in the Raw264.7 macrophage cell line, wild-type peritoneal and bone marrow derived macrophages after the same treatment. The biased anti-inflammatory phenotype of macrophages by IL-17F knockout probably contributed to the improved chitosan conduit guided sciatic nerve regeneration. Additionally, IL-17F could enhance pro-inflammatory factors production in Raw264.7 cells and wild-type peritoneal macrophages. Altogether, IL-17F may partially mediate chitosan conduit induced pro-inflammatory polarization of macrophages during nerve repair. These results not only revealed a role of IL-17F in macrophage function, but also provided a unique and promising target, IL-17F, to modulate the microenvironment and enhance the peripheral nerve regeneration.
    Keywords:  IL-17F; Immune microenvironment; Macrophage polarization; Nerve guidance conduit; Peripheral nerve regeneration
  116. Front Immunol. 2021 ;12 702785
      Inflammation is a fundamental physiological response orchestrated by innate immune cells to restore tissue homeostasis. Specialized pro-resolving mediators (SPMs) are involved in active resolution of inflammation but when inflammation is incomplete, chronic inflammation creates a favorable environment that fuels carcinogenesis and cancer progression. Conventional cancer therapy also strengthens cancer-related inflammation by inducing massive tumor cell death that activate surrounding immune-infiltrating cells such as tumor-associated macrophages (TAMs). Macrophages are key actors of both inflammation and its active resolution due to their plastic phenotype. In line with this high plasticity, macrophages can be hijacked by cancer cells to support tumor progression and immune escape, or therapy resistance. Impaired resolution of cancer-associated inflammation supported by TAMs may thus reinforces tumor progression. From this perspective, recent evidence suggests that stimulating macrophage's pro-resolving functions using SPMs can promote inflammation resolution in cancer and improve anticancer treatments. Thus, TAMs' re-education toward an antitumor phenotype by using SPMs opens a new line of attack in cancer treatment. Here, we review SPMs' anticancer capacities with special attention regarding their effects on TAMs. We further discuss how this new therapeutic approach could be envisioned in cancer therapy.
    Keywords:  cancer; inflammation; macrophages; phagocytosis; specialized pro-resolving mediators; tumor microenvironment
  117. Aging (Albany NY). 2021 Jul 21. 13
      Research on cerebral glucose metabolism has shown that the aging brain experiences a fall of aerobic glycolysis, and that the age-related loss of aerobic glycolysis may accelerate Alzheimer's disease pathology. In the healthy brain, aerobic glycolysis, namely the use of glucose outside oxidative phosphorylation, may cover energy demand and increase neuronal resilience to stressors at once. Currently, the drivers of aerobic glycolysis in neurons are unknown. We previously demonstrated that synthetic monomers of β-amyloid protein (Aβ) enhance glucose uptake in neurons, and that endogenous Aβ is required for depolarization-induced glucose uptake in cultured neurons. In this work, we show that cultured cortical neurons increased aerobic glycolysis in response to the inhibition of oxidative phosphorylation by oligomycin or to a kainate pulse. Such an increase was prevented by blocking the endogenous Aβ tone and re-established by the exogenous addition of synthetic Aβ monomers. The activity of mitochondria-bound hexokinase-1 appeared to be necessary for monomers-stimulated aerobic glycolysis during oxidative phosphorylation blockade or kainate excitation. Our data suggest that, through Aβ release, neurons coordinate glucose uptake with aerobic glycolysis in response to metabolic stressors. The implications of this new finding are that the age-related drop in aerobic glycolysis and the susceptibility to Alzheimer's disease could be linked to factors interfering with release and functions of Aβ monomers.
    Keywords:  AMPK; Alzheimer’s disease; aerobic glycolysis; default mode network; kainate; lactate; oligomycin; β-amyloid monomers
  118. Yonsei Med J. 2021 Aug;62(8): 734-742
      PURPOSE: The present study aimed to identify the physiological characteristics of cells by investigating the change in gene expression and protein levels during extracellular matrix (ECM) synthesis in the intervertebral disc (IVD) under hypoxic conditions.MATERIALS AND METHODS: To test the effect of oxygen on cell growth and ECM synthesis of chondrocyte-like cells, the cells from IVD were separated and cultured in two hypoxia-mimicking systems: chemical hypoxic conditions using deferoxamine (DFO), and physiological hypoxic conditions using a hypoxic chamber for 7 days. Chondrocyte like cells cultured without DFO and under the normal oxygen concentration (21% O₂ and 5% CO₂, 37°C) served as the controls.
    RESULTS: Chondrocyte-like cells cultured in the presence of 6% oxygen demonstrated a 100% increase in cellular proliferation compared to the control. The cells treated with chemical hypoxic conditions demonstrated a dose-dependent increase in the mRNA expression of glucose transporter-1, GAPDH, aggrecan, and type II collagen on Day 1. When treated with 100 µM DFO, the cells showed a 50% increase in the levels of proteoglycan protein on Day 7. The cells treated with chemical hypoxic condition demonstrated increase in sulfated glycosaminoglycan (GAG) protein levels on Day 7. Moreover, the cells cultured in the presence of 6% oxygen showed a 120% increase in sulfated GAG levels on Day 7.
    CONCLUSION: The oxygen concentration had an important role in the viability, proliferation, and maturation of chondrocyte-like cells in IVD. In addition, chondrocyte-like cells are sensitive to the concentration of oxygen.
    Keywords:  Intervertebral disc; chondrocyte-like cell; extracellular matrix; low oxygen; proteoglycan
  119. Transl Lung Cancer Res. 2021 Jun;10(6): 2806-2818
      It has long been recognized that cigarette smoking is a shared risk factor for lung cancer and the debilitating lung disease, chronic obstructive pulmonary disease (COPD). As the severity of COPD increases, so does the risk for developing lung cancer, independently of pack years smoked. Neutrophilic inflammation increases with COPD severity and anti-inflammatories such as non-steroidal anti-inflammatory drugs (NSAIDs) can modulate neutrophil function and cancer risk. This review discusses the biology of tumour associated neutrophils (TANs) in lung cancer, which increase in density with tumour progression, particularly in smokers with non-small cell lung cancer (NSCLC). It is now increasingly recognized that neutrophils are responsive to the tumour microenvironment (TME) and polarize into distinct phenotypes that operate in an anti- (N1) or pro-tumorigenic (N2) manner. Intriguingly, the emergence of the pro-tumorigenic N2 phenotype increases with tumour growth, to suggest that cancer cells and the surrounding stroma can re-educate neutrophils. The neutrophil itself is a potent source of reactive oxygen species (ROS), arginase, proteases and cytokines that paradoxically can exert a potent immunosuppressive effect on lymphocytes including cytotoxic T cells (CTLs). Indeed, the neutrophil to lymphocyte ratio (NLR) is a systemic biomarker that is elevated in lung cancer patients and prognostic for poor survival outcomes. Herein, we review the molecular mechanisms by which neutrophil derived mediators can suppress CTL function. Selective therapeutic strategies designed to suppress pathogenic neutrophils in NSCLC may cooperate with immune checkpoint inhibitors (ICI) to increase CTL killing of cancer cells in the TME.
    Keywords:  Lung cancer; chronic obstructive pulmonary disease (COPD); immunotherapy; neutrophils
  120. Zhonghua Kou Qiang Yi Xue Za Zhi. 2021 Jul 09. 56(7): 672-678
      Objective: To investigate the effect of low dose lipopolysaccharide (LPS)-treated human periodontal ligament stem cells (HPDLSC) on the expression of macrophage pro-inflammatory factors and the mechanism involved. Methods: The primary HPDLSCs were obtained from healthy third molar periodontal ligament tissue. Phosphate buffer saline (PBS), 100 μg/L or 10 mg/L of LPS were used to treat HPDLSCs for 48 h, and their conditioned media were respectively co-cultured with THP-1-derived macrophages for 48 h. The corresponding experimental groups were PBS-treated HPDLSC-derived conditioned medium (CM-C) group, low dose LPS-treated HPDLSC-derived conditioned medium (CM-L) group, and high dose LPS-treated HPDLSC-derived conditioned medium (CM-H) group. Quantitative real-time PCR was performed to explore the mRNA expressions of macrophage interleukin (IL)-6, IL-8, IL-12, tumor necrosis factor-α (TNF-α) in the CM-C, CM-L and CM-H groups, and the expressions of nuclear factor (erythroid-derived 2)-like 2 (NRF2), glutamate-cysteine ligase catalytic subunit (GCLC), NAD(P)H quinone dehydrogenase 1 (NQO1) and heme oxygenase 1 (HO-1) in the CM-C and CM-L groups. Meanwhile, Western blotting was used to detect the change of nuclear and cytoplasmic NRF2 and the levels of GCLC and HO-1 in the CM-C and CM-L groups. The 2', 7'-dichlorofluorescein probe was adopted to detect the reactive oxygen species (ROS) levels of macrophages in the CM-C and CM-L groups and the data were characterized by the mean fluorescent intensity (MFI). Results: The mRNA expressions of macrophage pro-inflammatory factors IL-6, IL-8, IL-12 and TNF-α in the CM-H group (2.332±0.594, 3.601±0.639, 2.120±0.677 and 2.468±0.236) were significantly upregulated compared with those in the CM-C group (1.000±0.321, 1.000±0.151, 1.000±0.059 and 1.000±0.095) (P<0.05); while the relative mRNA levels of IL-6, IL-12 and TNF-α in the CM-L group (0.056±0.002, 0.215±0.024 and 0.567±0.071) were much lower than those in the CM-C group (1.000±0.209, 1.000±0.220 and 1.000±0.220) (P<0.05). At the mRNA level, the expression of NRF2 was significantly increased in the CM-L group (1.864±0.198) compared with that in the CM-C group (1.000±0.094) (P<0.05). At the protein level, the cytoplasmic NRF2 and nuclear NRF2 were increased in CM-L group (1.175±0.104 and 1.308±0.082) compared with those in the CM-C group (1.000±0.025 and 1.000±0.049) (P<0.05). Furthermore, the antioxidative genes, i.e. GCLC and NQO1, localized in NRF2 downstream, were significantly upregulated in the CM-L group (1.786±0.278 and 1.444±0.078) compared with the CM-C group (1.000±0.139 and 1.000±0.226) (P<0.05). The protein levels of GCLC and HO-1 were augmented in the CM-L group (1.159±0.036 and 1.412±0.075) in contrast with those in the CM-C group (1.000±0.050 and 1.000±0.013) (P<0.05). In addition, the MFI in the CM-L group (123 419±1 302) was significantly lower than that in the CM-C group (139 193±1 241) (P<0.05). Conclusions: Low-dose LPS-treated HPDLSCs could regulate oxidative stress response through activating the NRF2 signaling pathway of macrophages and further downregulating the expressions of macrophage pro-inflammatory factors.
  121. Am J Physiol Cell Physiol. 2021 07 21.
      The peroxisome proliferator activated receptors (PPARs) are a group of transcription factors belonging to the nuclear receptor superfamily. Since most target genes of either PPARs are implicated in lipid and glucose metabolism, regulation by PPARs could be used as a screening tool to identify novel genes involved in lipid or glucose metabolism. Here, we identify Adtrp, a serine hydrolase enzyme that was reported to catalyze the hydrolysis of fatty acid esters of hydroxy fatty acids (FAHFAs), as a novel PPAR-regulated gene. Adtrp was significantly upregulated by PPARα activation in mouse primary hepatocytes, liver slices, and whole liver. In addition, Adtrp was upregulated by PPARγ activation in 3L3-L1 adipocytes and in white adipose tissue. ChIP-SEQ identified a strong PPAR binding site in the immediate upstream promoter of the Adtrp gene. Adenoviral-mediated hepatic overexpression of Adtrp in diet-induced obese mice caused a modest increase in plasma non-esterified fatty acids but did not influence diet-induced obesity, liver triglyceride levels, liver lipidomic profiles, liver transcriptomic profiles, and plasma cholesterol, triglycerides, glycerol, and glucose levels. Moreover, hepatic Adtrp overexpression did not lead to significant changes in FAHFA levels in plasma or liver and did not influence glucose and insulin tolerance. Finally, hepatic overexpression of Adtrp did not influence liver triglycerides and levels of plasma metabolites after a 24h fast. Taken together, our data suggest that despite being a PPAR-regulated gene, hepatic Adtrp does not seem to play a major role in lipid and glucose metabolism and does not regulate FAHFA levels.
    Keywords:  ADTRP; FAHFAs; PPAR; liver; metabolism
  122. Shock. 2021 Aug 01. 56(2): 268-277
      ABSTRACT: Leukocyte Nox2 is recognized to have a fundamental microbicidal function in sepsis but the specific role of Nox2 in endothelial cells (EC) remains poorly elucidated. Here, we tested the hypothesis that endothelial Nox2 participates in the pathogenesis of systemic inflammation and hypotension induced by LPS. LPS was injected intravenously in mice with Tie2-targeted deficiency or transgenic overexpression of Nox2. Mice with Tie2-targeted Nox2 deficiency had increased circulating levels of TNF-α, enhanced numbers of neutrophils trapped in lungs, and aggravated hypotension after LPS injection, as compared to control LPS-injected animals. In contrast, Tie2-driven Nox2 overexpression attenuated inflammation and prevented the hypotension induced by LPS. Because Tie2-Cre targets both EC and myeloid cells we generated bone marrow chimeric mice with Nox2 deletion restricted to leukocytes or ECs. Mice deficient in Nox2 either in leukocytes or ECs had reduced LPS-induced neutrophil trapping in the lungs and lower plasma TNF-α levels as compared to control LPS-injected mice. However, the pronounced hypotensive response to LPS was present only in mice with EC-specific Nox2 deletion. Experiments in vitro with human vein or aortic endothelial cells (HUVEC and HAEC, respectively) treated with LPS revealed that EC Nox2 controls NF-κB activation and the transcription of toll-like receptor 4 (TLR4), which is the recognition receptor for LPS. In conclusion, these results suggest that endothelial Nox2 limits NF-κB activation and TLR4 expression, which in turn attenuates the severity of hypotension and systemic inflammation induced by LPS.
  123. Clin Immunol. 2021 Jul 16. pii: S1521-6616(21)00135-2. [Epub ahead of print] 108798
      Inflammatory response in patients with COPD secondary to organic dust exposure (OD-COPD) is poorly understood. We therefore aimed to characterize inflammatory and immune profile from peripheral blood mononuclear cells (PBMC) in a group of patients with mild-to-moderate COPD secondary to organic dust exposure (OD-COPD), tobacco smoking (T-COPD), or both. We compared T, B and NK cells distribution and inflammatory (TNF-α, Il-1β, IL-6), type 1 (IFN-γ), type 2 (IL-4, IL-13) and type 3 (IL-17) immunity related cytokines at baseline, and after stimulation with LPS, flagellin and CD3/CD28 beads in all COPD groups. OD-COPD displayed significantly lower NK cells and CD8+ T cells compared with controls. After flagellin stimulation, T-COPD had significantly lower IL-13 levels than OD-COPD and controls (p < 0.05) whereas IFN-γ tended to be lower in OD-COPD. All COPD groups displayed higher IL-1β and IL-17 than controls after CD3/CD28 stimulation. Inflammatory responses in OD-COPD were different from T-COPD. OD-COPD displayed higher levels of type 2 immunity related cytokines.
    Keywords:  Chronic obstructive pulmonary disease; Cytokines; Inflammation; Organic dust
  124. J Biol Chem. 2021 Jul 17. pii: S0021-9258(21)00778-X. [Epub ahead of print] 100976
      Muscle glycogen depletion has been proposed as one of the main causes of fatigue during exercise. However, few studies have addressed the contribution of liver glycogen to exercise performance. Using a low-intensity running protocol, here we analyzed exercise capacity in mice overexpressing protein targeting to glycogen (PTG) specifically in the liver (PTGOE mice), which show a high concentration of glycogen in this organ. PTGOE mice showed improved exercise capacity, as determined by the distance covered and time ran in an extenuating endurance exercise compared to control mice. Moreover, fasting decreased exercise capacity in control mice but not in PTGOE mice. After exercise, liver glycogen stores were totally depleted in control mice, but PTGOE mice maintained significant glycogen levels even in fasting conditions. Additionally, PTGOE mice displayed an increased hepatic energy state after exercise compared to control mice. Exercise caused a reduction in blood glucose concentration in control mice that was less pronounced in PTGOE mice. No changes were found in the levels of blood lactate, plasma free fatty acids, or ß-hydroxybutyrate. Plasma glucagon was elevated after exercise in control mice, but not in PTGOE mice. Exercise-induced changes in skeletal muscle were similar in both genotypes. These results identify hepatic glycogen as a key regulator of endurance capacity in mice, an effect that may be exerted through the maintenance of blood glucose levels.
    Keywords:  ATP; Exercise; glucose; glycogen; liver metabolism; protein targeting to glycogen (PTG)
  125. Food Funct. 2021 Jul 21.
      Alcohol induces inflammation and oxidative stress with the dysregulation of proinflammatory cytokines, which are implicated in the pathogenesis of alcoholic liver injury. Melanoidins are known to exert an antioxidant effect, however, their function in inhibiting alcohol-induced inflammation is unclear. In this study, we examined the role of melanoidins from Chinese traditional vinegar powder in terms of their anti-inflammatory and antioxidant properties in RAW 264.7 macrophages and elucidated their mechanisms of function. In macrophages, melanoidins significantly suppress the mRNA expression of interleukin (Il)-6, Il-1β and tumor necrosis factor α (Tnf-α) with a concomitant inhibitory effect on IL-1β, IL-6 and TNFα secretion, which are increased by ethanol. In addition, ethanol significantly increases the cellular reactive oxygen species (ROS) levels and the expression of cytochrome β-245 and beta polypeptide (Cybb), which are repressed by melanoidins to basal level. However, the expression of genes related to oxidative stress significantly decreases in response to ethanol, while it is significantly increased by melanoidins. Importantly, treatment with ethanol led to significant decreases in SIRT1 and SIRT3 transcription, translation, and activation, as well as the nicotinamide adenine dinucleotide (NAD+) levels. Interestingly, all the decreases were markedly attenuated by melanoidins. Ethanol promoted the expression of proinflammatory genes, whereas coincubation with resveratrol (a potent SIRT agonist) inhibited this effect. Conversely, the addition of sirtinol (a known SIRT inhibitor) augmented the proinflammatory gene expression. Taken together, our findings suggest that melanoidins exert anti-inflammatory and antioxidant functions via abolishing decreases in SIRT1 and SIRT3 expression and cellular NAD+ levels in ethanol-induced macrophages and may serve as a new therapeutic agent for the prevention of alcohol-induced cell damage.
  126. Cryobiology. 2021 Jul 15. pii: S0011-2240(21)00119-X. [Epub ahead of print]
      Mammalian hibernation is a period that involves substantial metabolic change in order to promote survival in harsh conditions, with animals typically relying on non-carbohydrate fuel stores during long bouts of torpor. However, the use and maintenance of carbohydrate fuel stores remains important during periods of arousal from torpor as well as when exiting hibernation. Gluconeogenesis plays a key role in maintaining glucose stores; however, little is known about this process within the muscles of hibernating mammals. Here, we used 13-lined ground squirrels (Ictidomys tridecemlineatus) as our model for mammalian hibernation, and showed that skeletal muscle fructose-1,6-bisphosphatse (FBPase; EC, the rate-limiting enzyme for the gluconeogenic pathway, was suppressed during torpor as compared to the euthermic control. A physical assessment of partially purified FBPase via exposure to increasing concentrations of the denaturant urea indicated that FBPase from the two conditions were structurally distinct. Western blot analysis suggests that the kinetic and physical differences between euthermic and torpid FBPase may be derived from differential acetylation, whereby increased acetylation of the torpid enzyme makes FBPase more rigid and less active. This study increases our understanding of skeletal muscle carbohydrate metabolism during mammalian hibernation and sets forth a potentially novel mechanism for the regulation of FBPase during environmental stress.
    Keywords:  gluconeogenesis; glucose metabolism; mammalian hibernation; muscle metabolism; posttranslational acetylation; torpor
  127. Zhonghua Kou Qiang Yi Xue Za Zhi. 2021 Jul 09. 56(7): 679-686
      Objective: To study the relationship between zoledronic acid (ZOL) and vascular endothelial growth factor (VEGF) conformation so as to reveal the mechanism of bisphosphonates inhibiting angiogenesis. Methods: The binding structures of ZOL and VEGF were preprocessed and the molecular dockings were simulated through AutoDockTools, Discovery studio4 and AutoDockVina. The best binding conformation was accurately screened. The effects of various concentrations of ZOL (group A was 0 μmol/L, groups B, C and D were 25, 50 and 100 μmol/L, respectively) on human umbilical vein endothelial cell (HUVEC) proliferation, angiogenesis and angiogenic molecules were detected by using cell counting kit-8 (CCK-8) in vivo and in vitro angiogenesis, immunofluorescence and Western blotting. Results: There was a ZOL binding site on the target protein VEGF conformation. The affinity was -5.2 kcal/mol. This binding site consisted of the hydrophobic region composed of amino acids Cys26, 51, 57, etc. and the hydrogen bond binding region of the A chain (ASP34, SER50) and B chain (CYS61, 68, LEU66, GLY59). The results of CCK-8 showed that the levels of value A in groups B, C and D were significantly lower than that in group A at each time point from 3 to 6 days (P<0.05). In vitro vascular experiments demonstrated that the numbers of budding in groups B, C and D [(208±28), (151±21) and (62±9), respectively] were significantly lower than that in group A (276±30) (P<0.05). In vivo vascular experiments displayed that the ratio of Matrigel gel/plasma fluorescence in group A (0.003 1±0.000 3) was significantly higher than those in group B (0.002 1±0.000 2), group C (0.001 6±0.000 2) and group D (0.000 6±0.000 1) (P<0.05). The results of Western blotting revealed that the expression of VEGF in groups B, C and D [(0.72±0.11), (0.41±0.07) and (0.24±0.04), respectively] were significantly lower than that in group A (1.01±0.02) (P<0.05), and the expression levels of hypoxia-inducible factor-1α (HIF-1α) in groups B, C and D [(0.68±0.09), (0.55±0.06) and (0.43±0.08), respectively] were significantly lower than that in group A (0.96±0.04) (P<0.05). Conclusions: ZOL could inhibit cell proliferation, in vivo and in vitro vascularization and expression of VEGF/HIF-1α. The binding site of ZOL with the conformation of VEGF was located in the hydrophobic region and hydrogen-bonding region of amino acids. Designing an antagonist targeting this site might potentially alleviate the effect of ZOL in inhibiting angiogenesis.
  128. Proc Natl Acad Sci U S A. 2021 Jul 27. pii: e2101759118. [Epub ahead of print]118(30):
      The opportunistic pathogen Pseudomonas aeruginosa explores surfaces using twitching motility powered by retractile extracellular filaments called type IV pili (T4P). Single cells twitch by sequential T4P extension, attachment, and retraction. How single cells coordinate T4P to efficiently navigate surfaces remains unclear. We demonstrate that P. aeruginosa actively directs twitching in the direction of mechanical input from T4P in a process called mechanotaxis. The Chp chemotaxis-like system controls the balance of forward and reverse twitching migration of single cells in response to the mechanical signal. Collisions between twitching cells stimulate reversals, but Chp mutants either always or never reverse. As a result, while wild-type cells colonize surfaces uniformly, collision-blind Chp mutants jam, demonstrating a function for mechanosensing in regulating group behavior. On surfaces, Chp senses T4P attachment at one pole, thereby sensing a spatially resolved signal. As a result, the Chp response regulators PilG and PilH control the polarization of the extension motor PilB. PilG stimulates polarization favoring forward migration, while PilH inhibits polarization, inducing reversal. Subcellular segregation of PilG and PilH efficiently orchestrates their antagonistic functions, ultimately enabling rapid reversals upon perturbations. The distinct localization of response regulators establishes a signaling landscape known as local excitation-global inhibition in higher-order organisms, identifying a conserved strategy to transduce spatially resolved signals.
    Keywords:  chemotaxis; mechanosensing; motility; twitching; type IV pili
  129. PLoS Comput Biol. 2021 Jul;17(7): e1009140
      The metabolic capabilities of the species and the local environment shape the microbial interactions in a community either through the exchange of metabolic products or the competition for the resources. Cells are often arranged in close proximity to each other, creating a crowded environment that unevenly reduce the diffusion of nutrients. Herein, we investigated how the crowding conditions and metabolic variability among cells shape the dynamics of microbial communities. For this, we developed CROMICS, a spatio-temporal framework that combines techniques such as individual-based modeling, scaled particle theory, and thermodynamic flux analysis to explicitly incorporate the cell metabolism and the impact of the presence of macromolecular components on the nutrients diffusion. This framework was used to study two archetypical microbial communities (i) Escherichia coli and Salmonella enterica that cooperate with each other by exchanging metabolites, and (ii) two E. coli with different production level of extracellular polymeric substances (EPS) that compete for the same nutrients. In the mutualistic community, our results demonstrate that crowding enhanced the fitness of cooperative mutants by reducing the leakage of metabolites from the region where they are produced, avoiding the resource competition with non-cooperative cells. Moreover, we also show that E. coli EPS-secreting mutants won the competition against the non-secreting cells by creating less dense structures (i.e. increasing the spacing among the cells) that allow mutants to expand and reach regions closer to the nutrient supply point. A modest enhancement of the relative fitness of EPS-secreting cells over the non-secreting ones were found when the crowding effect was taken into account in the simulations. The emergence of cell-cell interactions and the intracellular conflicts arising from the trade-off between growth and the secretion of metabolites or EPS could provide a local competitive advantage to one species, either by supplying more cross-feeding metabolites or by creating a less dense neighborhood.
  130. Ann Thorac Surg. 2021 Jul 20. pii: S0003-4975(21)01262-5. [Epub ahead of print]
  131. Front Immunol. 2021 ;12 702527
      Inflammasomes comprise a family of cytosolic multi-protein complexes that modulate the activation of cysteine-aspartate-specific protease 1 (caspase-1) and promote the maturation and secretion of interleukin (IL)-1β and IL-18, leading to an inflammatory response. Different types of inflammasomes are defined by their sensor protein which recognizes pathogenic ligands and then directs inflammasome assembly. Although the specific molecular mechanisms underlying the activation of most inflammasomes are still unclear, NLRC4 inflammasomes have emerged as multifaceted agents of the innate immune response, playing important roles in immune defense against a variety of pathogens. Other studies have also expanded the scope of NLRC4 inflammasomes to include a range of inherited human autoimmune diseases as well as proposed roles in cancer. In this review article, we provide an updated overview of NLRC4 inflammasomes, describing their composition, activation mechanisms and roles in both microbial infections and other disease conditions.
    Keywords:  NLRC4; PANoptosis; autoimmune disease; cancer; inflammasome
  132. Cancer Discov. 2021 Jul;11(7): 1623-1625
      In this issue, Du and colleagues uncover that optineurin functions as a key regulator of IFNγ receptor (IFNGR1) stability in malignant cells. Loss of optineurin in colorectal cancer cells causes IFNGR1 degradation, leading to impaired IFNγ signaling, decreased MHC-I expression, and enhanced ability to evade adaptive immune control.See related article by Du et al., p. 1826.
  133. Brief Bioinform. 2021 Jul 20. pii: bbaa317. [Epub ahead of print]22(4):
      The accurate quantification of tumor-infiltrating immune cells turns crucial to uncover their role in tumor immune escape, to determine patient prognosis and to predict response to immune checkpoint blockade. Current state-of-the-art methods that quantify immune cells from tumor biopsies using gene expression data apply computational deconvolution methods that present multicollinearity and estimation errors resulting in the overestimation or underestimation of the diversity of infiltrating immune cells and their quantity. To overcome such limitations, we developed MIXTURE, a new ν-support vector regression-based noise constrained recursive feature selection algorithm based on validated immune cell molecular signatures. MIXTURE provides increased robustness to cell type identification and proportion estimation, outperforms the current methods, and is available to the wider scientific community. We applied MIXTURE to transcriptomic data from tumor biopsies and found relevant novel associations between the components of the immune infiltrate and molecular subtypes, tumor driver biomarkers, tumor mutational burden, microsatellite instability, intratumor heterogeneity, cytolytic score, programmed cell death ligand 1 expression, patients' survival and response to anti-cytotoxic T-lymphocyte-associated antigen 4 and anti-programmed cell death protein 1 immunotherapy.
    Keywords:  RNA sequencing; cancer; deconvolution; digital cytometry; immune infiltrate; immunotherapy
  134. Int J Mol Sci. 2021 Jul 01. pii: 7151. [Epub ahead of print]22(13):
      The placental tissue, due to its angiogenic, anti-inflammatory, antioxidative, antimicrobial, and anti-fibrotic properties, has become a compelling source towards a solution for several indications in regenerative medicine. However, methods to enhance and capture the therapeutic properties with formulations that can further the applications of viable placental tissue have not been explored. In this study, we investigated the regenerative effects of a hypoxia primed flowable placental formulation (FPF), composed of amnion/chorion and umbilical tissue, in two in vivo injury models. Laser Doppler data from rodent ischemia hindlimbs treated with FPF revealed significant tissue perfusion improvements compared to control ischemic hindlimbs. To further corroborate FPF's effects, we used a rodent ischemic bipedicle skin flap wound model. FPF treatment significantly increased the rate of wound closure and the quality of wound healing. FPF-treated wounds displayed reduced inflammation and an increase in angiogenesis. Furthermore, quantitative PCR and next-generation sequencing analysis confirmed these changes in the FPF-treated group at both the gene and transcriptional level. The observed modulation in miRNAs was associated with angiogenesis, regulation of inflammatory microenvironment, cell migration and apoptosis, reactive oxygen species generation, and restoring epithelial barrier function, all processes involved in impaired tissue healing. Taken together, these data validate the tissue regenerative properties of the flowable placental formulation configuration tested.
    Keywords:  amnion; chorion; chronic wounds; ischemia; umbilical cord
  135. Cancers (Basel). 2021 Jul 15. pii: 3550. [Epub ahead of print]13(14):
      Three-dimensional (3D) cancer cell culture systems have been developed to aid the study of molecular mechanisms in cancer development, identify therapeutic targets, and test drug candidates. In this study, we developed a strategy for mimicking the hypoxic tumor microenvironment in a 3D cancer cell culture system using multi-layer, nanofibrous poly(ε-caprolactone) (PCL) scaffold (pNFS)-based cancer cell cultures. We found that human colon cancer cells infiltrated pNFS within 3 days and could be cultured three-dimensionally within the NFS. When incubated in four stacks of 30 µm-thick pNFS for 3 days, colon cancer cells in layer three showed partially reduced entry into the S phase, whereas those in layer four, located farthest from the media, showed a marked reduction in S-phase entry. As a consequence, cells in layer four exhibited hypoxia-induced disorganization of F-actin on day 3, and those in layers three and four showed an increase in the expression of the hypoxia-induced transcription factor HIF-1α and its target genes, Glut1, CA9, VEGF, and LDHA. Consistent with these results, doxorubicin- and ionizing radiation-induced cell death was reduced in colon cancer cells cultured in layers three and four. These results suggest that pNFS-based multi-layer colon cancer cell cultures mimic the hypoxic tumor microenvironment and are useful for bioassays.
    Keywords:  PCL; cancer cell culture; hypoxia; nanofibrous scaffold; three-dimensional
  136. Int J Mol Sci. 2021 Jul 01. pii: 7121. [Epub ahead of print]22(13):
      Seizures are common in newborn infants with hypoxic-ischemic encephalopathy and are highly associated with adverse neurodevelopmental outcomes. The impact of seizure activity on the developing brain and the most effective way to manage these seizures remain surprisingly poorly understood, particularly in the era of therapeutic hypothermia. Critically, the extent to which seizures exacerbate brain injury or merely reflect the underlying evolution of injury is unclear. Current anticonvulsants, such as phenobarbital and phenytoin have poor efficacy and preclinical studies suggest that most anticonvulsants are associated with adverse effects on the developing brain. Levetiracetam seems to have less potential neurotoxic effects than other anticonvulsants but may not be more effective. Given that therapeutic hypothermia itself has significant anticonvulsant effects, randomized controlled trials of anticonvulsants combined with therapeutic hypothermia, are required to properly determine the safety and efficacy of these drugs. Small clinical studies suggest that prophylactic phenobarbital administration may improve neurodevelopmental outcomes compared to delayed administration; however, larger high-quality studies are required to confirm this. In conclusion, there is a distinct lack of high-quality evidence for whether and to what extent neonatal seizures exacerbate brain damage after hypoxia-ischemia and how best to manage them in the era of therapeutic hypothermia.
    Keywords:  anticonvulsants; antiepileptic drugs; asphyxia; hypoxic-ischemic encephalopathy; levetiracetam; phenobarbital; seizures; therapeutic hypothermia
  137. Front Immunol. 2021 ;12 651049
      Objective: Autoantibodies are detected in most patients with rheumatoid arthritis (RA) and can be of the IgM, IgG or IgA subclass. Correlations between IgA autoantibodies and more severe disease activity have been previously reported, but the functional role of IgA autoantibodies in the pathogenesis of RA is ill understood. In this study, we explored the effect of IgA immune complexes on osteoclast mediated bone resorption.Methods: Anti-citrullinated peptide antibody (ACPA) and anti-carbamylated protein (anti-CarP) antibody levels of the IgA and IgG isotype and rheumatoid factor (RF) IgA were determined in synovial fluid (SF) of RA patients. Monocytes, neutrophils, and osteoclasts were stimulated with precipitated immune complexes from SF of RA patients or IgA- and IgG-coated beads. Activation was determined by neutrophil extracellular trap (NET) release, cytokine secretion, and bone resorption.
    Results: NET formation by neutrophils was enhanced by SF immune complexes compared to immune complexes from healthy or RA serum. Monocytes stimulated with isolated SF immune complexes released IL-6 and IL-8, which correlated with the levels of ACPA IgA levels in SF. Osteoclasts cultured in the presence of supernatant of IgA-activated monocytes resorbed significantly more bone compared to osteoclasts that were cultured in supernatant of IgG-activated monocytes (p=0.0233). Osteoclasts expressed the Fc receptor for IgA (FcαRI; CD89) and Fc gamma receptors. IgA-activated osteoclasts however produced significantly increased levels of IL-6 (p<0.0001) and IL-8 (p=0.0007) compared to IgG-activated osteoclasts. Both IL-6 (p=0.03) and IL-8 (p=0.0054) significantly enhanced bone resorption by osteoclasts.
    Conclusion: IgA autoantibodies induce release of IL-6 and IL-8 by immune cells as well as osteoclasts, which enhances bone resorption by osteoclasts. We anticipate that this will result in more severe disease activity in RA patients. Targeting IgA-FcαRI interactions therefore represents a promising novel therapeutic strategy for RA patients with IgA autoantibodies.
    Keywords:  ACPA; IgA; autoantibodies; bone resorption; osteoclast; rheumatoid arthritis
  138. Acta Trop. 2021 Jul 14. pii: S0001-706X(21)00222-9. [Epub ahead of print] 106043
      BACKGROUND: Adjuvants are essential in the induction of immunity by vaccines and interact with receptors, including the Toll-like receptors (TLRs). Responsiveness of these receptors differs between and within populations, which impacts vaccine effectiveness.OBJECTIVE: Here we examine how the innate cytokine response towards TLR ligands differs between high and low socioeconomic status (SES) school-aged children from Makassar, Indonesia.
    METHODS: We stimulated whole blood from children, of which 27 attended a high SES school and 27 children a low SES school, with ligands for TLR-2/1, -2/6, -3, -4, -5, -7, -9 and measured pro- (TNF) and anti-inflammatory (IL-10) cytokines released.
    RESULTS: In the low SES there is an increased pro-inflammatory response after 24 h stimulation with TLR-2/1 ligand Pam3 and TLR-4 ligand LPS compared to the high SES. Comparison of the response to LPS after 24 h versus 72 h stimulation revealed that the pro-inflammatory response in the low SES after 24 h shifts to an anti-inflammatory response, whereas in the high SES the initial anti-inflammatory response shifts to a strong pro-inflammatory response after 72 h stimulation.
    CONCLUSION: We observed differences in the TLR-mediated innate immune response between children attending low and high SES schools, which can have important implications for vaccine development.
    Keywords:  IL-10; TLR; TNF
  139. Proc Natl Acad Sci U S A. 2021 Jul 27. pii: e2026307118. [Epub ahead of print]118(30):
      "Taste-like" tuft cells in the intestine trigger type 2 immunity in response to worm infection. The secretion of interleukin-13 (IL-13) from type 2 innate lymphoid cells (ILC2) represents a key step in the tuft cell-ILC2 cell-intestinal epithelial cell circuit that drives the clearance of worms from the gut via type 2 immune responses. Hallmark features of type 2 responses include tissue remodeling, such as tuft and goblet cell expansion, and villus atrophy, yet it remains unclear if additional molecular changes in the gut epithelium facilitate the clearance of worms from the gut. Using gut organoids, we demonstrated that IL-4 and IL-13, two type 2 cytokines with similar functions, not only induced the classical type 2 responses (e.g., tuft cell expansion) but also drastically up-regulated the expression of gasdermin C genes (Gsdmcs). Using an in vivo worm-induced type 2 immunity model, we confirmed the up-regulation of Gsdmcs in Nippostrongylus brasiliensis-infected wild-type C57BL/6 mice. Consistent with gasdermin family members being principal effectors of pyroptosis, overexpression of Gsdmc2 in human embryonic kidney 293 (HEK293) cells triggered pyroptosis and lytic cell death. Moreover, in intestinal organoids treated with IL-4 or IL-13, or in wild-type mice infected with N. brasiliensis, lytic cell death increased, which may account for villus atrophy observed in worm-infected mice. Thus, we propose that the up-regulated Gsdmc family may be major effectors for type 2 responses in the gut and that Gsdmc-mediated pyroptosis may provide a conduit for the release of antiparasitic factors from enterocytes to facilitate the clearance of worms.
    Keywords:  IL-4/IL-13; gasdermin; helminth; pyroptosis; type 2 immunity
  140. Front Physiol. 2021 ;12 668330
      Long-chain fatty acids are molecules that act as metabolic intermediates and constituents of membranes; however, their novel role as signaling molecules in immune function has also been demonstrated. The presence of free fatty acid (FFA) receptors on immune cells has contributed to the understanding of this new role of long-chain fatty acids (LCFAs) in immune function, showing their role as anti-inflammatory or pro-inflammatory molecules and elucidating their intracellular mechanisms. The FFA1 and FFA4 receptors, also known as GPR40 and GPR120, respectively, have been described in macrophages and neutrophils, two key cells mediating innate immune response. Ligands of the FFA1 and FFA4 receptors induce the release of a myriad of cytokines through well-defined intracellular signaling pathways. In this review, we discuss the cellular responses and intracellular mechanisms activated by LCFAs, such as oleic acid, linoleic acid, palmitic acid, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), in T-cells, macrophages, and neutrophils, as well as the role of the FFA1 and FFA4 receptors in immune cells.
    Keywords:  FFA1; FFA4; T-cells; fatty acids; immune; macrophages; neutrophils
  141. Front Surg. 2021 ;8 692734
      Objective: Inflammatory cytokines are increased during one-lung ventilation in patients undergoing lung resection, and this increase can be fatal. Propofol and sevoflurane are the main anesthetics used for these patients. Unfortunately, there is no consensus on the best choice of an anesthetic agent concerning an inflammatory response in patients undergoing lung resection. This meta-analysis aimed to compare the effects of propofol and sevoflurane on the inflammatory response in patients undergoing lung resection. Methods: We searched electronic databases to identify randomized controlled trials comparing the effects of different anesthetics (sevoflurane vs. propofol) on the inflammatory response. The primary outcome concerned the concentration of systemic inflammatory cytokines. The secondary outcomes concerned the concentrations of inflammatory cytokines in the bronchoalveolar lavage (BAL) fluid from the dependent and independent lung. Random effects analysis of the meta-analyses were performed to synthesize the evidence and to assess the concentrations of inflammatory factors in the sevoflurane and propofol groups. Results: Eight trials involving 488 participants undergoing lung resection with one-lung ventilation were included. There was no significant difference in the concentrations of systemic interleukin (IL)-6, IL-10, or tumor necrosis factor α between the sevoflurane and propofol groups. Compared with the propofol group, BAL levels of IL-6 in the dependent ventilated lung were decreased in the sevoflurane group (three trials, 256 participants; standardized mean difference [SMD], -0.51; 95% confidence interval [CI], -0.90 to -0.11; p = 0.01; I 2 = 46%). The BAL levels of IL-6 in the independent ventilated lung were also decreased by sevoflurane (four trials, 362 participants; SMD, -0.70; 95% [CI], -0.93 to -0.47; p < 0.00001; I 2 = 0%). Conclusions: There was no difference in the systemic inflammatory response between the sevoflurane and propofol groups. However, compared with propofol, sevoflurane can reduce the local alveolar inflammatory response. Additional research is necessary to confirm whether the inflammatory response is direct or indirect.
    Keywords:  OLV; inflammatory response; meta-analysis; propofol; sevoflurane