bims-mepmim 2022-09-11 papers

bims-mepmim

Biomed News

on Metabolites in pathological microenvironments and immunometabolism

Issue of 2022–09–11
thirty-one papers selected by
Erika Mariana Palmieri, NIH/NCI Laboratory of Cancer ImmunoMetabolism

Dietary lipids inhibit mitochondria transfer to macrophages to divert adipocyte-derived mitochondria into the blood.
Adipocyte-derived lactate is a signalling metabolite that potentiates adipose macrophage inflammation via targeting PHD2.
miR‑382 inhibits breast cancer progression and metastasis by affecting the M2 polarization of tumor‑associated macrophages by targeting PGC‑1α.
The amino acid transporter SLC7A11-mediated crosstalk implicated in cancer therapy and the tumor microenvironment.
An exercise-induced metabolic shield in distant organs blocks cancer progression and metastatic dissemination.
Methionine metabolism controls the B cell EBV epigenome and viral latency.
Lactate increases stemness of CD8 + T cells to augment anti-tumor immunity.
Spatially resolved characterization of tissue metabolic compartments in fasted and high-fat diet livers.
Assessment of lipid peroxidation in irradiated cells.
Nutritional Niches of Cancer Therapy-Induced Senescent Cells.
In situ mass spectrometry imaging reveals heterogeneous glycogen stores in human normal and cancerous tissues.
Methotrexate recognition by the human reduced folate carrier SLC19A1.
The Tumor Immune Microenvironment in Pancreatic Ductal Adenocarcinoma: Neither Hot nor Cold.
Evaluation of a Serum-Free Medium for Human Epithelial and Stromal Cell Culture.
Metabolic and Cellular Compartments of Acetyl-CoA in the Healthy and Diseased Brain.
Monocytes maintain central nervous system homeostasis following helminth-induced inflammation.
Increased glucose metabolism in TAMs fuels O-GlcNAcylation of lysosomal Cathepsin B to promote cancer metastasis and chemoresistance.
Iron Overload via Heme Degradation in the Endoplasmic Reticulum Triggers Ferroptosis in Myocardial Ischemia-Reperfusion Injury.
GATA3 as an immunomodulator in obesity-related metabolic dysfunction associated with fatty liver disease, insulin resistance, and type 2 diabetes.
Chenodeoxycholic acid suppresses AML progression through promoting lipid peroxidation via ROS/p38 MAPK/DGAT1 pathway and inhibiting M2 macrophage polarization.
In Situ Dendritic Cell Recruitment and T Cell Activation for Cancer Immunotherapy.
Cardiac immune cell infiltration associates with abnormal lipid metabolism.
Sphingosine-1-Phosphate (S1P) Lyase Inhibition Aggravates Atherosclerosis and Induces Plaque Rupture in ApoE-/- &nbsp;Mice.
Peroxisomal very long-chain fatty acid transport is targeted by herpesviruses and the antiviral host response.
GPX4 regulates cellular necrosis and host resistance in Mycobacterium tuberculosis infection.
Integrated analysis of the tumor microenvironment using a reconfigurable microfluidic cell culture platform.
Advances in mass spectrometry imaging for spatial cancer metabolomics.
Crosstalk between Pancreatic Cancer Cells and Cancer-Associated Fibroblasts in the Tumor Microenvironment Mediated by Exosomal MicroRNAs.
Role of plasma membrane dicarboxylate transporters in the uptake and toxicity of diglycolic acid, a metabolite of diethylene glycol, in human proximal tubule cells.
Dynamics of hepatocyte-cholangiocyte cell-fate decisions during liver development and regeneration.
In vivo tumor immune microenvironment phenotypes correlate with inflammation and vasculature to predict immunotherapy response.

Cell Metab. 2022 Aug 30. pii: S1550-4131(22)00353-9. [Epub ahead of print]

Dietary lipids inhibit mitochondria transfer to macrophages to divert adipocyte-derived mitochondria into the blood.

Nicholas Borcherding, Wentong Jia, Rocky Giwa, Rachael L Field, John R Moley, Benjamin J Kopecky, Mandy M Chan, Bin Q Yang, Jessica M Sabio, Emma C Walker, Omar Osorio, Andrea L Bredemeyer, Terri Pietka, Jennifer Alexander-Brett, Sharon Celeste Morley, Maxim N Artyomov, Nada A Abumrad, Joel Schilling, Kory Lavine, Clair Crewe, Jonathan R Brestoff.

  Adipocytes transfer mitochondria to macrophages in white and brown adipose tissues to maintain metabolic homeostasis. In obesity, adipocyte-to-macrophage mitochondria transfer is impaired, and instead, adipocytes release mitochondria into the blood to induce a protective antioxidant response in the heart. We found that adipocyte-to-macrophage mitochondria transfer in white adipose tissue is inhibited in murine obesity elicited by a lard-based high-fat diet, but not a hydrogenated-coconut-oil-based high-fat diet, aging, or a corn-starch diet. The long-chain fatty acids enriched in lard suppress mitochondria capture by macrophages, diverting adipocyte-derived mitochondria into the blood for delivery to other organs, such as the heart. The depletion of macrophages rapidly increased the number of adipocyte-derived mitochondria in the blood. These findings suggest that dietary lipids regulate mitochondria uptake by macrophages locally in white adipose tissue to determine whether adipocyte-derived mitochondria are released into systemic circulation to support the metabolic adaptation of distant organs in response to nutrient stress.

Keywords:  CD36; EXT1; aging; beige fat; brown adipose tissue; cell-free mitochondria; fatty acids; heparan sulfate; horizontal mitochondria transfer; intercellular mitochondria transfer; lipids; macrophage; mitochondria; obesity; palmitate; white adipose tissue

DOI:  https://doi.org/10.1016/j.cmet.2022.08.010
Nat Commun. 2022 Sep 05. 13(1): 5208

Adipocyte-derived lactate is a signalling metabolite that potentiates adipose macrophage inflammation via targeting PHD2.

Tianshi Feng, Xuemei Zhao, Ping Gu, Wah Yang, Cunchuan Wang, Qingyu Guo, Qiaoyun Long, Qing Liu, Ying Cheng, Jin Li, Cynthia Kwan Yui Cheung, Donghai Wu, Xinyu Kong, Yong Xu, Dewei Ye, Shuang Hua, Kerry Loomes, Aimin Xu, Xiaoyan Hui.

Adipose tissue macrophage (ATM) inflammation is involved with meta-inflammation and pathology of metabolic complications. Here we report that in adipocytes, elevated lactate production, previously regarded as the waste product of glycolysis, serves as a danger signal to promote ATM polarization to an inflammatory state in the context of obesity. Adipocyte-selective deletion of lactate dehydrogenase A (Ldha), the enzyme converting pyruvate to lactate, protects mice from obesity-associated glucose intolerance and insulin resistance, accompanied by a lower percentage of inflammatory ATM and reduced production of pro-inflammatory cytokines such as interleukin 1β (IL-1β). Mechanistically, lactate, at its physiological concentration, fosters the activation of inflammatory macrophages by directly binding to the catalytic domain of prolyl hydroxylase domain-containing 2 (PHD2) in a competitive manner with α-ketoglutarate and stabilizes hypoxia inducible factor (HIF-1α). Lactate-induced IL-1β was abolished in PHD2-deficient macrophages. Human adipose lactate level is positively linked with local inflammatory features and insulin resistance index independent of the body mass index (BMI). Our study shows a critical function of adipocyte-derived lactate in promoting the pro-inflammatory microenvironment in adipose and identifies PHD2 as a direct sensor of lactate, which functions to connect chronic inflammation and energy metabolism.

DOI: https://doi.org/10.1038/s41467-022-32871-3
Int J Oncol. 2022 Oct;pii: 126. [Epub ahead of print]61(4):

miR‑382 inhibits breast cancer progression and metastasis by affecting the M2 polarization of tumor‑associated macrophages by targeting PGC‑1α.

Hua Zhou, Mingyu Gan, Xin Jin, Meng Dai, Yuanyuan Wang, Youyang Lei, Zijing Lin, Jia Ming.

  Macrophages are principal immune cells with a high plasticity in the human body that can differentiate under different conditions in the tumor microenvironment to adopt two polarized phenotypes with opposite functions. Therefore, converting macrophages from the immunosuppressive phenotype (M2) to the inflammatory phenotype (M1) is considered a promising therapeutic strategy for cancer. However, the molecular mechanisms underlying this conversion process have not yet been completely elucidated. In recent years, microRNAs (miRNAs or miRs) have been shown to play key roles in regulating macrophage polarization through their ability to modulate gene expression. In the present study, it was found that miR‑382 expression was significantly downregulated in tumor‑associated macrophages (TAMs) and M2‑polarized macrophages in breast cancer. In vitro, macrophage polarization toward the M2 phenotype and M2‑type cytokine release were inhibited by transfection with miR‑382‑overexpressing lentivirus. Similarly, the overexpression of miR‑382 inhibited the ability of TAMs to promote the malignant behaviors of breast cancer cells. In addition, peroxisome proliferator‑activated receptor γ coactivator‑1α (PGC‑1α) was identified as the downstream target of miR‑382 and it was found that PGC‑1α affected macrophage polarization by altering the metabolic status. The ectopic expression of PGC‑1α restored the phenotype and cytokine secretion of miR‑382‑overexpressing macrophages. Furthermore, PGC‑1α expression reversed the miR‑382‑induced changes in the metabolic state of TAMs and the effects of TAMs on breast cancer cells. Of note, the in vivo growth and metastasis of 4T1 cells were inhibited by miR‑382‑overexpressing TAMs. Taken together, the results of the present study suggest that miR‑382 may alter the metabolic status of macrophages by targeting PGC‑1α, thereby decreasing the proportion of TAMs with the M2 phenotype, and inhibiting the progression and metastasis of breast cancer.

Keywords:  breast cancer; metabolic reprogramming; microRNA; tumor microenvironment; tumor‑associated macrophages

DOI:  https://doi.org/10.3892/ijo.2022.5416
Biochem Pharmacol. 2022 Sep 06. pii: S0006-2952(22)00335-5. [Epub ahead of print] 115241

The amino acid transporter SLC7A11-mediated crosstalk implicated in cancer therapy and the tumor microenvironment.

Jiaqin He, Xiaomeng Wang, Keying Chen, Mei Zhang, Juan Wang.

  The solute carrier family 7 member 11 (SLC7A11), an amino acid transporter protein is frequently overexpressed in human malignancies. The expression and activity of SLC7A11 is finely regulated by oncogenes and tumor suppressors in tumor cells through various mechanisms and is highly specific for cystine and glutamate. Cystine is mainly transported intracellularly by SLC7A11 in the tumor microenvironment (TME) and is involved in GSH synthesis, which leads to ferroptosis resistance in tumor cells and promotes tumorigenesis and progression. The downregulation of SLC7A11 presents a unique drug discovery opportunity for ferroptosis-related diseases. Experimental work has shown that targeting SLC7A11 and tumor immunotherapy combine to trigger ferroptosis more potently. Moreover, immunotargeting of SLC7A11 increases the chemosensitivity of cancer stem cells to doxorubicin, suggesting that it may act as an adjuvant to chemotherapy. Thus, SLC7A11 could be a promising target to overcome resistance mechanisms in conventional cancer treatments. This review provides an overview of the regulatory network of SLC7A11 in the TME and progress in the development of SLC7A11 inhibitors. In addition, we summarize the cytotoxic effects of blocking SLC7A11 in cancer cells, cancer stem cells and immune cells.

Keywords:  Anticancer; Ferroptosis; Immunotherapy; SLC7A11; SLC7A11 inhibitors

DOI:  https://doi.org/10.1016/j.bcp.2022.115241
Cancer Res. 2022 Sep 09. pii: CAN-22-0237. [Epub ahead of print]

An exercise-induced metabolic shield in distant organs blocks cancer progression and metastatic dissemination.

Danna Sheinboim, Shivang Parikh, Paulee Manich, Irit Markus, Sapir Dahan, Roma Parikh, Elisa Stubbs, Gali Cohen, Valentina Zemser-Werner, Rachel E Bell, Sara Arciniegas Ruiz, Ruth Percik, Ronen Brenner, Stav Leibou, Hananya Vaknine, Gali Arad, Yariv Gerber, Lital Keinan Boker, Tal Shimony, Lior Bikovski, Nir Goldstein, Keren Constantini, Sapir Labes, Shimonov Mordechai, Hila Doron, Ariel Ionescu, Tamar Ziv, Eran Nizri, Guy Choshen, Hagit Eldar-Finkelman, Yuval Tabach, Aharon Helman, Shamgar Ben-Eliyahu, Neta Erez, Eran Perlson, Tamar Geiger, Danny Ben-Zvi, Mehdi Khaled, Yftach Gepner, Carmit Levy.

Exercise prevents cancer incidence and recurrence, yet the underlying mechanism behind this relationship remains mostly unknown. Here we report that exercise induces metabolic reprogramming of internal organs that increases nutrient demand and protects against metastatic colonization by limiting nutrient availability to the tumor, generating an exercise-induced metabolic shield. Proteomic and ex vivo metabolic capacity analyses of murine internal organs revealed that exercise induces catabolic processes, glucose uptake, mitochondrial activity, and GLUT expression. Proteomic analysis of routinely active human subject plasma demonstrated increased carbohydrate utilization following exercise. Epidemiological data from a 20-year prospective study of a large human cohort of initially cancer-free participants revealed that exercise prior to cancer initiation had a modest impact on cancer incidence in low metastatic stages but significantly reduced the likelihood of highly metastatic cancer. In three models of melanoma in mice, exercise prior to cancer injection significantly protected against metastases in distant organs. The protective effects of exercise were dependent on mTOR activity, and inhibition of the mTOR pathway with rapamycin treatment ex vivo reversed the exercise-induced metabolic shield. Under limited glucose conditions, active stroma consumed significantly more glucose at the expense of the tumor. Collectively, these data suggest a clash between the metabolic plasticity of cancer and exercise-induced metabolic reprogramming of the stroma, raising an opportunity to block metastasis by challenging the metabolic needs of the tumor.

DOI: https://doi.org/10.1158/0008-5472.CAN-22-0237
Cell Metab. 2022 Sep 06. pii: S1550-4131(22)00351-5. [Epub ahead of print]34(9): 1280-1297.e9

Methionine metabolism controls the B cell EBV epigenome and viral latency.

Rui Guo, Jin Hua Liang, Yuchen Zhang, Michael Lutchenkov, Zhixuan Li, Yin Wang, Vicenta Trujillo-Alonso, Rishi Puri, Lisa Giulino-Roth, Benjamin E Gewurz.

  Epstein-Barr virus (EBV) subverts host epigenetic pathways to switch between viral latency programs, colonize the B cell compartment, and reactivate. Within memory B cells, the reservoir for lifelong infection, EBV genomic DNA and histone methylation marks restrict gene expression. But this epigenetic strategy also enables EBV-infected tumors, including Burkitt lymphomas, to evade immune detection. Little is known about host cell metabolic pathways that support EBV epigenome landscapes. We therefore used amino acid restriction, metabolomic, and CRISPR approaches to identify that an abundant methionine supply and interconnecting methionine and folate cycles maintain Burkitt EBV gene silencing. Methionine restriction, or methionine cycle perturbation, hypomethylated EBV genomes and de-repressed latent membrane protein and lytic gene expression. Methionine metabolism also shaped EBV latency gene regulation required for B cell immortalization. Dietary methionine restriction altered murine Burkitt xenograft metabolomes and de-repressed EBV immunogens in vivo. These results highlight epigenetic/immunometabolism crosstalk supporting the EBV B cell life cycle and suggest therapeutic approaches.

Keywords:  dietary amino acid restriction; folate metabolism; gamma-herpesvirus; immunometabolism; lytic reactivation; methionine cycle; methionine metabolism; one-carbon metabolism; tumor virus; viral latency

DOI:  https://doi.org/10.1016/j.cmet.2022.08.008
Nat Commun. 2022 Sep 06. 13(1): 4981

Lactate increases stemness of CD8 + T cells to augment anti-tumor immunity.

Qiang Feng, Zhida Liu, Xuexin Yu, Tongyi Huang, Jiahui Chen, Jian Wang, Jonathan Wilhelm, Suxin Li, Jiwon Song, Wei Li, Zhichen Sun, Baran D Sumer, Bo Li, Yang-Xin Fu, Jinming Gao.

Lactate is a key metabolite produced from glycolytic metabolism of glucose molecules, yet it also serves as a primary carbon fuel source for many cell types. In the tumor-immune microenvironment, effect of lactate on cancer and immune cells can be highly complex and hard to decipher, which is further confounded by acidic protons, a co-product of glycolysis. Here we show that lactate is able to increase stemness of CD8+ T cells and augments anti-tumor immunity. Subcutaneous administration of sodium lactate but not glucose to mice bearing transplanted MC38 tumors results in CD8+ T cell-dependent tumor growth inhibition. Single cell transcriptomics analysis reveals increased proportion of stem-like TCF-1-expressing CD8+ T cells among intra-tumoral CD3+ cells, a phenotype validated by in vitro lactate treatment of T cells. Mechanistically, lactate inhibits histone deacetylase activity, which results in increased acetylation at H3K27 of the Tcf7 super enhancer locus, leading to increased Tcf7 gene expression. CD8+ T cells in vitro pre-treated with lactate efficiently inhibit tumor growth upon adoptive transfer to tumor-bearing mice. Our results provide evidence for an intrinsic role of lactate in anti-tumor immunity independent of the pH-dependent effect of lactic acid, and might advance cancer immune therapy.

DOI: https://doi.org/10.1038/s41467-022-32521-8
PLoS One. 2022 ;17(9): e0261803

Spatially resolved characterization of tissue metabolic compartments in fasted and high-fat diet livers.

Sylwia A Stopka, Jiska van der Reest, Walid M Abdelmoula, Daniela F Ruiz, Shakchhi Joshi, Alison E Ringel, Marcia C Haigis, Nathalie Y R Agar.

Cells adapt their metabolism to physiological stimuli, and metabolic heterogeneity exists between cell types, within tissues, and subcellular compartments. The liver plays an essential role in maintaining whole-body metabolic homeostasis and is structurally defined by metabolic zones. These zones are well-understood on the transcriptomic level, but have not been comprehensively characterized on the metabolomic level. Mass spectrometry imaging (MSI) can be used to map hundreds of metabolites directly from a tissue section, offering an important advance to investigate metabolic heterogeneity in tissues compared to extraction-based metabolomics methods that analyze tissue metabolite profiles in bulk. We established a workflow for the preparation of tissue specimens for matrix-assisted laser desorption/ionization (MALDI) MSI that can be implemented to achieve broad coverage of central carbon, nucleotide, and lipid metabolism pathways. Herein, we used this approach to visualize the effect of nutrient stress and excess on liver metabolism. Our data revealed a highly organized metabolic tissue compartmentalization in livers, which becomes disrupted under high fat diet. Fasting caused changes in the abundance of several metabolites, including increased levels of fatty acids and TCA intermediates while fatty livers had higher levels of purine and pentose phosphate-related metabolites, which generate reducing equivalents to counteract oxidative stress. This spatially conserved approach allowed the visualization of liver metabolic compartmentalization at 30 μm pixel resolution and can be applied more broadly to yield new insights into metabolic heterogeneity in vivo.

DOI: https://doi.org/10.1371/journal.pone.0261803
Methods Cell Biol. 2022 ;pii: S0091-679X(22)00062-0. [Epub ahead of print]172 37-50

Assessment of lipid peroxidation in irradiated cells.

Chao Mao, Guang Lei, Amber Horbath, Boyi Gan.

  Lipid peroxidation occurs under conditions where reactive oxygen species (ROS) readily react with vulnerable lipids on cell membranes. Polyunsaturated fatty acids (PUFAs) are highly susceptible to lipid peroxidation because of their unstable double bonds. Because the cell membrane is particularly rich in PUFAs, it is often the site at which many lipid peroxidation chain reactions occur. Lipid peroxidation is considered the ultimate trigger of ferroptosis, an iron-dependent form of non-apoptotic cell death. Radiotherapy is a common cancer treatment that uses high-energy ionizing radiation to kill cancer cells, and radiation-induced cell death is partially attributed to lipid peroxidation-driven ferroptosis. Here, we describe methods to assess lipid peroxidation in irradiated cells. The same techniques can be applied to a variety of lipid peroxidation measurements under different treatment conditions.

Keywords:  Cell death; Ferroptosis; Lipid peroxidation; Radiation; Reactive oxygen species

DOI:  https://doi.org/10.1016/bs.mcb.2022.05.003
Nutrients. 2022 Sep 02. pii: 3636. [Epub ahead of print]14(17):

Nutritional Niches of Cancer Therapy-Induced Senescent Cells.

Àngela Llop-Hernández, Sara Verdura, Elisabet Cuyàs, Javier A Menendez.

  Therapy-induced senescence (TIS) is a state of stable proliferative arrest of both normal and neoplastic cells that is triggered by exposure to anticancer treatments. TIS cells acquire a senescence-associated secretory phenotype (SASP), which is pro-inflammatory and actively promotes tumor relapse and adverse side-effects in patients. Here, we hypothesized that TIS cells adapt their scavenging and catabolic ability to overcome the nutritional constraints in their microenvironmental niches. We used a panel of mechanistically-diverse TIS triggers (i.e., bleomycin, doxorubicin, alisertib, and palbociclib) and Biolog Phenotype MicroArrays to identify (among 190 different carbon and nitrogen sources) candidate metabolites that support the survival of TIS cells in limiting nutrient conditions. We provide evidence of distinguishable TIS-associated nutrient consumption profiles involving a core set of shared (e.g., glutamine) and unique (e.g., glucose-1-phosphate, inosine, and uridine) nutritional sources after diverse senescence-inducing interventions. We also observed a trend for an inverse correlation between the intensity of the pro-inflammatory SASP provoked by different TIS agents and diversity of compensatory nutritional niches utilizable by senescent cells. These findings support the detailed exploration of the nutritional niche as a new metabolic dimension to understand and target TIS in cancer.

Keywords:  cancer; glutamine; metabolism; miR146a; nutrition; senescence

DOI:  https://doi.org/10.3390/nu14173636
EMBO Mol Med. 2022 Sep 05. e16029

In situ mass spectrometry imaging reveals heterogeneous glycogen stores in human normal and cancerous tissues.

Lyndsay E A Young, Lindsey R Conroy, Harrison A Clarke, Tara R Hawkinson, Kayli E Bolton, William C Sanders, Josephine E Chang, Madison B Webb, Warren J Alilain, Craig W Vander Kooi, Richard R Drake, Douglas A Andres, Tom C Badgett, Lars M Wagner, Derek B Allison, Ramon C Sun, Matthew S Gentry.

  Glycogen dysregulation is a hallmark of aging, and aberrant glycogen drives metabolic reprogramming and pathogenesis in multiple diseases. However, glycogen heterogeneity in healthy and diseased tissues remains largely unknown. Herein, we describe a method to define spatial glycogen architecture in mouse and human tissues using matrix-assisted laser desorption/ionization mass spectrometry imaging. This assay provides robust and sensitive spatial glycogen quantification and architecture characterization in the brain, liver, kidney, testis, lung, bladder, and even the bone. Armed with this tool, we interrogated glycogen spatial distribution and architecture in different types of human cancers. We demonstrate that glycogen stores and architecture are heterogeneous among diseases. Additionally, we observe unique hyperphosphorylated glycogen accumulation in Ewing sarcoma, a pediatric bone cancer. Using preclinical models, we correct glycogen hyperphosphorylation in Ewing sarcoma through genetic and pharmacological interventions that ablate in vivo tumor growth, demonstrating the clinical therapeutic potential of targeting glycogen in Ewing sarcoma.

Keywords:  Ewing sarcoma; MALDI imaging; glycogen; glycogen storage disease; spatial metabolism

DOI:  https://doi.org/10.15252/emmm.202216029
Nature. 2022 Sep 07.

Methotrexate recognition by the human reduced folate carrier SLC19A1.

Nicholas J Wright, Justin G Fedor, Han Zhang, Pyeonghwa Jeong, Yang Suo, Jiho Yoo, Jiyong Hong, Wonpil Im, Seok-Yong Lee.

Folates are essential nutrients with important roles as cofactors in one-carbon transfer reactions, being heavily utilized in the synthesis of nucleic acids and the metabolism of amino acids during cell division1,2. Mammals lack de novo folate synthesis pathways and thus rely on folate uptake from the extracellular milieu3. The human reduced folate carrier (hRFC, also known as SLC19A1) is the major importer of folates into the cell1,3, as well as chemotherapeutic agents such as methotrexate4-6. As an anion exchanger, RFC couples the import of folates and antifolates to anion export across the cell membrane and it is a major determinant in methotrexate (antifolate) sensitivity, as genetic variants and its depletion result in drug resistance4-8. Despite its importance, the molecular basis of substrate specificity by hRFC remains unclear. Here we present cryo-electron microscopy structures of hRFC in the apo state and captured in complex with methotrexate. Combined with molecular dynamics simulations and functional experiments, our study uncovers key determinants of hRFC transport selectivity among folates and antifolate drugs while shedding light on important features of anion recognition by hRFC.

DOI: https://doi.org/10.1038/s41586-022-05168-0
Cancers (Basel). 2022 Aug 31. pii: 4236. [Epub ahead of print]14(17):

The Tumor Immune Microenvironment in Pancreatic Ductal Adenocarcinoma: Neither Hot nor Cold.

Samuel J S Rubin, Raoul S Sojwal, John Gubatan, Stephan Rogalla.

  Pancreatic ductal adenocarcinoma (PDAC) is the most common pancreatic tumor and is associated with poor prognosis and treatment response. The tumor microenvironment (TME) is recognized as an important factor in metastatic progression across cancers. Despite extensive study of the TME in PDAC, the cellular and molecular signaling networks remain poorly understood, largely due to the tremendous heterogeneity across tumors. While earlier work characterized PDAC as an immunologically privileged tumor poorly recognized by the immune system, recent studies revealed the important and nuanced roles of immune cells in the pathogenesis of PDAC. Distinct lymphoid, myeloid, and stromal cell types in the TME exert opposing influences on PDAC tumor trajectory, suggesting a more complex organization than the classical "hot" versus "cold" tumor distinction. We review the pro- and antitumor immune processes found in PDAC and briefly discuss their leverage for the development of novel therapeutic approaches in the field.

Keywords:  T cell; fibroblast; macrophage; myeloid-derived suppressor cell; neutrophil; pancreatic ductal adenocarcinoma; tumor microenvironment

DOI:  https://doi.org/10.3390/cancers14174236
Int J Mol Sci. 2022 Sep 02. pii: 10035. [Epub ahead of print]23(17):

Evaluation of a Serum-Free Medium for Human Epithelial and Stromal Cell Culture.

Christophe Caneparo, Stéphane Chabaud, Julie Fradette, Stéphane Bolduc.

  Over the past decade, growing demand from many domains (research, cosmetics, pharmaceutical industries, etc.) has given rise to significant expansion of the number of in vitro cell cultures. Despite the widespread use of fetal bovine serum, many issues remain. Among them, the whole constitution of most serums remains unknown and is subject to significant variations. Furthermore, the presence of potential contamination and xenogeny elements is challenging for clinical applications, while limited production is an obstacle to the growing demand. To circumvent these issues, a Serum-Free Medium (SFM) has been developed to culture dermal and vesical fibroblasts and their corresponding epithelial cells, namely, keratinocytes and urothelial cells. To assess the impact of SFM on these cells, proliferation, clonogenic and metabolic assays have been compared over three passages to conditions associated with the use of a classic Fetal Bovine Serum-Containing Medium (FBSCM). The results showed that the SFM enabled fibroblast and epithelial cell proliferation while maintaining a morphology, cell size and metabolism similar to those of FBSCM. SFM has repeatedly been found to be better suited for epithelial cell proliferation and clonogenicity. Fibroblasts and epithelial cells also showed more significant mitochondrial metabolism in the SFM compared to the FBSCM condition. However, the SFM may need further optimization to improve fibroblast proliferation.

Keywords:  cell culture; cellular morphology; clonogenicity; metabolism; proliferation; serum-containing medium; serum-free medium

DOI:  https://doi.org/10.3390/ijms231710035
Int J Mol Sci. 2022 Sep 03. pii: 10073. [Epub ahead of print]23(17):

Metabolic and Cellular Compartments of Acetyl-CoA in the Healthy and Diseased Brain.

Agnieszka Jankowska-Kulawy, Joanna Klimaszewska-Łata, Sylwia Gul-Hinc, Anna Ronowska, Andrzej Szutowicz.

  The human brain is characterised by the most diverse morphological, metabolic and functional structure among all body tissues. This is due to the existence of diverse neurons secreting various neurotransmitters and mutually modulating their own activity through thousands of pre- and postsynaptic interconnections in each neuron. Astroglial, microglial and oligodendroglial cells and neurons reciprocally regulate the metabolism of key energy substrates, thereby exerting several neuroprotective, neurotoxic and regulatory effects on neuronal viability and neurotransmitter functions. Maintenance of the pool of mitochondrial acetyl-CoA derived from glycolytic glucose metabolism is a key factor for neuronal survival. Thus, acetyl-CoA is regarded as a direct energy precursor through the TCA cycle and respiratory chain, thereby affecting brain cell viability. It is also used for hundreds of acetylation reactions, including N-acetyl aspartate synthesis in neuronal mitochondria, acetylcholine synthesis in cholinergic neurons, as well as divergent acetylations of several proteins, peptides, histones and low-molecular-weight species in all cellular compartments. Therefore, acetyl-CoA should be considered as the central point of metabolism maintaining equilibrium between anabolic and catabolic pathways in the brain. This review presents data supporting this thesis.

Keywords:  acetyl-CoA metabolism; aging; neurodegenerative diseases; thiamine deficiency; zinc dyshomeostasis

DOI:  https://doi.org/10.3390/ijms231710073
Proc Natl Acad Sci U S A. 2022 Sep 13. 119(37): e2201645119

Monocytes maintain central nervous system homeostasis following helminth-induced inflammation.

Jianya Peng, Chandler B Sy, John J Ponessa, Alexander D Lemenze, Christina M Hernandez, Juan M Inclan-Rico, Arman Sawhney, Hannah G Federman, Krupa Chavan, Vanessa Espinosa, Sergei V Kotenko, Amariliz Rivera, Mark C Siracusa.

  Neuroimmune interactions are crucial for regulating immunity and inflammation. Recent studies have revealed that the central nervous system (CNS) senses peripheral inflammation and responds by releasing molecules that limit immune cell activation, thereby promoting tolerance and tissue integrity. However, the extent to which this is a bidirectional process, and whether peripheral immune cells also promote tolerance mechanisms in the CNS remains poorly defined. Here we report that helminth-induced type 2 inflammation promotes monocyte responses in the brain that are required to inhibit excessive microglial activation and host death. Mechanistically, infection-induced monocytes express YM1 that is sufficient to inhibit tumor necrosis factor production from activated microglia. Importantly, neuroprotective monocytes persist in the brain, and infected mice are protected from subsequent lipopolysaccharide-induced neuroinflammation months after infection-induced inflammation has resolved. These studies demonstrate that infiltrating monocytes promote CNS homeostasis in response to inflammation in the periphery and demonstrate that a peripheral infection can alter the immunologic landscape of the host brain.

Keywords:  helminth; innate immune cells; monocyte; neuroimmune cross-talk

DOI:  https://doi.org/10.1073/pnas.2201645119
Cancer Cell. 2022 Aug 30. pii: S1535-6108(22)00376-2. [Epub ahead of print]

Increased glucose metabolism in TAMs fuels O-GlcNAcylation of lysosomal Cathepsin B to promote cancer metastasis and chemoresistance.

Qingzhu Shi, Qicong Shen, Yanfang Liu, Yang Shi, Wenwen Huang, Xi Wang, Zhiqing Li, Yangyang Chai, Hao Wang, Xiangjia Hu, Nan Li, Qian Zhang, Xuetao Cao.

  How glucose metabolism remodels pro-tumor functions of tumor-associated macrophages (TAMs) needs further investigation. Here we show that M2-like TAMs bear the highest individual capacity to take up intratumoral glucose. Their increased glucose uptake fuels hexosamine biosynthetic pathway-dependent O-GlcNAcylation to promote cancer metastasis and chemoresistance. Glucose metabolism promotes O-GlcNAcylation of the lysosome-encapsulated protease Cathepsin B at serine 210, mediated by lysosome-localized O-GlcNAc transferase (OGT), elevating mature Cathepsin B in macrophages and its secretion in the tumor microenvironment (TME). Loss of OGT in macrophages reduces O-GlcNAcylation and mature Cathepsin B in the TME and disrupts cancer metastasis and chemoresistance. Human TAMs with high OGT are positively correlated with Cathepsin B expression, and both levels predict chemotherapy response and prognosis of individuals with cancer. Our study reports the biological and potential clinical significance of glucose metabolism in tumor-promoting TAMs and reveals insights into the underlying mechanisms.

Keywords:  O-GlcNAc transferase; O-GlcNAcylation; cathepsin B; glucose metabolism; lysosome; metastasis; tumor-associated macrophages

DOI:  https://doi.org/10.1016/j.ccell.2022.08.012
JACC Basic Transl Sci. 2022 Aug;7(8): 800-819

Iron Overload via Heme Degradation in the Endoplasmic Reticulum Triggers Ferroptosis in Myocardial Ischemia-Reperfusion Injury.

Hiroko Deguchi Miyamoto, Masataka Ikeda, Tomomi Ide, Tomonori Tadokoro, Shun Furusawa, Ko Abe, Kosei Ishimaru, Nobuyuki Enzan, Masashi Sada, Taishi Yamamoto, Shouji Matsushima, Tomoko Koumura, Ken-Ichi Yamada, Hirotaka Imai, Hiroyuki Tsutsui.

  Ischemia-reperfusion (I/R) injury is a promising therapeutic target to improve clinical outcomes after acute myocardial infarction. Ferroptosis, triggered by iron overload and excessive lipid peroxides, is reportedly involved in I/R injury. However, its significance and mechanistic basis remain unclear. Here, we show that glutathione peroxidase 4 (GPx4), a key endogenous suppressor of ferroptosis, determines the susceptibility to myocardial I/R injury. Importantly, ferroptosis is a major mode of cell death in I/R injury, distinct from mitochondrial permeability transition (MPT)-driven necrosis. This suggests that the use of therapeutics targeting both modes is an effective strategy to further reduce the infarct size and thereby ameliorate cardiac remodeling after I/R injury. Furthermore, we demonstrate that heme oxygenase 1 up-regulation in response to hypoxia and hypoxia/reoxygenation degrades heme and thereby induces iron overload and ferroptosis in the endoplasmic reticulum (ER) of cardiomyocytes. Collectively, ferroptosis triggered by GPx4 reduction and iron overload in the ER is distinct from MPT-driven necrosis in both in vivo phenotype and in vitro mechanism for I/R injury. The use of therapeutics targeting ferroptosis in conjunction with cyclosporine A can be a promising strategy for I/R injury.

Keywords:  AMI, acute myocardial infarction; CsA, cyclosporine A; CypD, cyclophilin D; DXZ, dexrazoxane; ER, endoplasmic reticulum; Fer-1, ferrostatin-1; GPx4, glutathione peroxidase 4; H/R, hypoxia-reoxygenation; HF, heart failure; HO-1, heme oxygenase 1; I/R, ischemia-reperfusion; LP, lipid peroxide; MPT, mitochondrial permeability transition; MPT-driven necrosis; RCD, regulated cell death; STEMI, ST-segment elevation myocardial infarction; cyclosporine A; ferroptosis; glutathione peroxidase 4; ischemia-reperfusion injury

DOI:  https://doi.org/10.1016/j.jacbts.2022.03.012
Chem Biol Interact. 2022 Sep 01. pii: S0009-2797(22)00346-5. [Epub ahead of print] 110141

GATA3 as an immunomodulator in obesity-related metabolic dysfunction associated with fatty liver disease, insulin resistance, and type 2 diabetes.

Amr Ahmed El-Arabey, Mohnad Abdalla.

  Obesity is the leading risk factor associated with Metabolic dysfunction Associated with Fatty Liver Disease (MAFLD), Insulin Resistance (IR), and type 2 diabetes (T2DM). Notably, MAFLD affects 25% of the world's adult population, ranging from 13.5% in Africa to 31.8% in the Middle East. The prevalence of MAFLD is 80-90% in obese adults and 30-50% in patients with diabetes. According to the recent WHO update, more than 400 million people will experience T2DM by 2025. Furthermore, the worldwide obesity incidence rate has risen in the preceding years. Adipogenesis deterioration is a critical step in the induction of obesity correlated with MAFLD, IR and T2DM. The well-known transcription factor GATA3 is highly expressed in the preadipocytes-adipocytes transition of embryonic stem cells and obese people with IR. In this regard, the reduction of GATA3 improves the differentiation of adipocytes. Omental adipose tissue inflammation by upregulation of macrophages infiltration is strongly linked with body mass index in insulin tolerance of obese people. In particular, the dynamic interaction between macrophages and adipocytes significantly regulates obese adipose tissue's inflammatory status and influences IR by reducing the differentiation of adipocytes, macrophage function, and glucose transport. Emerging evidence demonstrated that GATA3 is a master regulator for macrophage polarization and infiltration. Hence, we will shed light on GATA3 as an emerging target for immunomodulation in human obesity associated with MAFLD, IR, and T2DM by reducing macrophages' recruitment and inflammation of muscles and liver.

Keywords:  GATA3; Immunomodulation; Insulin resistance; Metabolic dysfunction associated with fatty liver disease; Obesity; Type 2 diabetes

DOI:  https://doi.org/10.1016/j.cbi.2022.110141
Redox Biol. 2022 Aug 30. pii: S2213-2317(22)00224-5. [Epub ahead of print]56 102452

Chenodeoxycholic acid suppresses AML progression through promoting lipid peroxidation via ROS/p38 MAPK/DGAT1 pathway and inhibiting M2 macrophage polarization.

Jinting Liu, Yihong Wei, Wenbo Jia, Can Can, Ruiqing Wang, Xinyu Yang, Chaoyang Gu, Fabao Liu, Chunyan Ji, Daoxin Ma.

   PURPOSE: Bile acids are steroid synthesized in liver, which are essential for fat emulsification, cholesterol excretion and gut microbial homeostasis. However, the role of bile acids in leukemia progression remains unclear. We aim at exploring the effects and mechanisms of chenodeoxycholic acid (CDCA), a type of bile acids, on acute myeloid leukemia (AML) progression.
RESULTS: Here, we found that CDCA was decreased in feces and plasma of AML patients, positively correlated with the diversity of gut microbiota, and negatively associated with AML prognosis. We further demonstrated that CDCA suppressed AML progression both in vivo and in vitro. Mechanistically, CDCA bound to mitochondria to cause mitochondrial morphology damage containing swelling and reduction of cristae, decreased mitochondrial membrane potential and elevated mitochondrial calcium level, which resulted in the production of excessive reactive oxygen species (ROS). Elevated ROS further activated p38 MAPK signaling pathway, which collaboratively promoted the accumulation of lipid droplets (LDs) through upregulating the expression of the diacylglycerol O-acyltransferase 1 (DGAT1). As the consequence of the abundance of ROS and LDs, lipid peroxidation was enhanced in AML cells. Moreover, we uncovered that CDCA inhibited M2 macrophage polarization and suppressed the proliferation-promoting effects of M2 macrophages on AML cells in co-cultured experiments.
CONCLUSION: Our findings demonstrate that CDCA suppresses AML progression through synergistically promoting LDs accumulation and lipid peroxidation via ROS/p38 MAPK/DGAT1 pathway caused by mitochondrial dysfunction in leukemia cells and inhibiting M2 macrophage polarization.

Keywords:  Acute myeloid leukemia; Chenodeoxycholic acid; Lipid droplets; Mitochondria

DOI:  https://doi.org/10.1016/j.redox.2022.102452
Front Pharmacol. 2022 ;13 954955

In Situ Dendritic Cell Recruitment and T Cell Activation for Cancer Immunotherapy.

Joonsu Han, Rimsha Bhatta, Yusheng Liu, Yang Bo, Hua Wang.

  Cancer immunotherapy has shifted the paradigm for cancer treatment in the past decade, but new immunotherapies enabling the effective treatment of solid tumors are still greatly demanded. Here we report a pore-forming hydrogel-based immunotherapy that enables simultaneous recruitment of dendritic cells and in situ activation of T cells, for reshaping the immunosuppressive tumor microenvironment and amplifying cytotoxic T lymphocyte response. The injectable pore-forming hydrogel composed of porogen-dispersed alginate network can form a macroporous structure upon injection into mice, and enables controlled release of granulocyte-macrophage colony-stimulating factor (GM-CSF), a chemoattractant for recruiting dendritic cells, and epacadostat, an inhibitor of indoleamine 2, 3-dioxygenase for activating T cells. We show that gels loaded with GM-CSF and epacadostat, after peritumoral injection, can recruit massive dendritic cells in situ and activate effector T cells in the tumor tissues, resulting in enhanced frequency and activation status of dendritic cells, reduced numbers of regulatory T (Treg) cells, and increased CD8+/Treg ratios in the tumor microenvironment. This hydrogel-based immunotherapy holds great promise for treating poorly-immunogenic solid tumors.

Keywords:  T cell; cancer immunotherapy; dendritic cell; hydrogel; solid tumor

DOI:  https://doi.org/10.3389/fphar.2022.954955
Front Cardiovasc Med. 2022 ;9 948332

Cardiac immune cell infiltration associates with abnormal lipid metabolism.

Vincenza Cifarelli, Ondrej Kuda, Kui Yang, Xinping Liu, Richard W Gross, Terri A Pietka, Gyu Seong Heo, Deborah Sultan, Hannah Luehmann, Josie Lesser, Morgan Ross, Ira J Goldberg, Robert J Gropler, Yongjian Liu, Nada A Abumrad.

  CD36 mediates the uptake of long-chain fatty acids (FAs), a major energy substrate for the myocardium. Under excessive FA supply, CD36 can cause cardiac lipid accumulation and inflammation while its deletion reduces heart FA uptake and lipid content and increases glucose utilization. As a result, CD36 was proposed as a therapeutic target for obesity-associated heart disease. However, more recent reports have shown that CD36 deficiency suppresses myocardial flexibility in fuel preference between glucose and FAs, impairing tissue energy balance, while CD36 absence in tissue macrophages reduces efferocytosis and myocardial repair after injury. In line with the latter homeostatic functions, we had previously reported that CD36-/- mice have chronic subclinical inflammation. Lipids are important for the maintenance of tissue homeostasis and there is limited information on heart lipid metabolism in CD36 deficiency. Here, we document in the hearts of unchallenged CD36-/- mice abnormalities in the metabolism of triglycerides, plasmalogens, cardiolipins, acylcarnitines, and arachidonic acid, and the altered remodeling of these lipids in response to an overnight fast. The hearts were examined for evidence of inflammation by monitoring the presence of neutrophils and pro-inflammatory monocytes/macrophages using the respective positron emission tomography (PET) tracers, 64Cu-AMD3100 and 68Ga-DOTA-ECL1i. We detected significant immune cell infiltration in unchallenged CD36-/- hearts as compared with controls and immune infiltration was also observed in hearts of mice with cardiomyocyte-specific CD36 deficiency. Together, the data show that the CD36-/- heart is in a non-homeostatic state that could compromise its stress response. Non-invasive immune cell monitoring in humans with partial or total CD36 deficiency could help evaluate the risk of impaired heart remodeling and disease.

Keywords:  CD36; PET tracers; cardiac inflammation; eicosanoids; lipidomics; macrophage

DOI:  https://doi.org/10.3389/fcvm.2022.948332
Int J Mol Sci. 2022 Aug 24. pii: 9606. [Epub ahead of print]23(17):

Sphingosine-1-Phosphate (S1P) Lyase Inhibition Aggravates Atherosclerosis and Induces Plaque Rupture in ApoE-/- &nbsp;Mice.

Petra Keul, Susann Peters, Karin von Wnuck Lipinski, Nathalie H Schröder, Melissa K Nowak, Dragos A Duse, Amin Polzin, Sarah Weske, Markus H Gräler, Bodo Levkau.

  Altered plasma sphingosine-1-phosphate (S1P) concentrations are associated with clinical manifestations of atherosclerosis. However, whether long-term elevation of endogenous S1P is pro- or anti-atherogenic remains unclear. Here, we addressed the impact of permanently high S1P levels on atherosclerosis in cholesterol-fed apolipoprotein E-deficient (ApoE-/-) mice over 12 weeks. This was achieved by pharmacological inhibition of the S1P-degrading enzyme S1P lyase with 4-deoxypyridoxine (DOP). DOP treatment dramatically accelerated atherosclerosis development, propagated predominantly unstable plaque phenotypes, and resulted in frequent plaque rupture with atherothrombosis. Macrophages from S1P lyase-inhibited or genetically deficient mice had a defect in cholesterol efflux to apolipoprotein A-I that was accompanied by profoundly downregulated cholesterol transporters ATP-binding cassette transporters ABCA1 and ABCG1. This was dependent on S1P signaling through S1PR3 and resulted in dramatically enhanced atherosclerosis in ApoE-/-/S1PR3-/- mice, where DOP treatment had no additional effect. Thus, high endogenous S1P levels promote atherosclerosis, compromise cholesterol efflux, and cause genuine plaque rupture.

Keywords:  atherosclerosis; cholesterol efflux; plaque rupture; sphingosine-1-phosphate; vascular biology

DOI:  https://doi.org/10.3390/ijms23179606
Commun Biol. 2022 Sep 09. 5(1): 944

Peroxisomal very long-chain fatty acid transport is targeted by herpesviruses and the antiviral host response.

Isabelle Weinhofer, Agnieszka Buda, Markus Kunze, Zsofia Palfi, Matthäus Traunfellner, Sarah Hesse, Andrea Villoria-Gonzalez, Jörg Hofmann, Simon Hametner, Günther Regelsberger, Ann B Moser, Florian Eichler, Stephan Kemp, Jan Bauer, Jörn-Sven Kühl, Sonja Forss-Petter, Johannes Berger.

Very long-chain fatty acids (VLCFA) are critical for human cytomegalovirus replication and accumulate upon infection. Here, we used Epstein-Barr virus (EBV) infection of human B cells to elucidate how herpesviruses target VLCFA metabolism. Gene expression profiling revealed that, despite a general induction of peroxisome-related genes, EBV early infection decreased expression of the peroxisomal VLCFA transporters ABCD1 and ABCD2, thus impairing VLCFA degradation. The mechanism underlying ABCD1 and ABCD2 repression involved RNA interference by the EBV-induced microRNAs miR-9-5p and miR-155, respectively, causing significantly increased VLCFA levels. Treatment with 25-hydroxycholesterol, an antiviral innate immune modulator produced by macrophages, restored ABCD1 expression and reduced VLCFA accumulation in EBV-infected B-lymphocytes, and, upon lytic reactivation, reduced virus production in control but not ABCD1-deficient cells. Finally, also other herpesviruses and coronaviruses target ABCD1 expression. Because viral infection might trigger neuroinflammation in X-linked adrenoleukodystrophy (X-ALD, inherited ABCD1 deficiency), we explored a possible link between EBV infection and cerebral X-ALD. However, neither immunohistochemistry of post-mortem brains nor analysis of EBV seropositivity in 35 X-ALD children supported involvement of EBV in the onset of neuroinflammation. Collectively, our findings indicate a previously unrecognized, pivotal role of ABCD1 in viral infection and host defence, prompting consideration of other viral triggers in cerebral X-ALD.

DOI: https://doi.org/10.1038/s42003-022-03867-y
J Exp Med. 2022 Nov 07. pii: e20220504. [Epub ahead of print]219(11):

GPX4 regulates cellular necrosis and host resistance in Mycobacterium tuberculosis infection.

Eduardo P Amaral, Taylor W Foreman, Sivaranjani Namasivayam, Kerry L Hilligan, Keith D Kauffman, Caio Cesar Barbosa Bomfim, Diego L Costa, Beatriz Barreto-Duarte, Clarissa Gurgel-Rocha, Monique Freire Santana, Marcelo Cordeiro-Santos, Elsa Du Bruyn, Catherine Riou, Kate Aberman, Robert John Wilkinson, Daniel L Barber, Katrin D Mayer-Barber, Bruno B Andrade, Alan Sher.

Cellular necrosis during Mycobacterium tuberculosis (Mtb) infection promotes both immunopathology and bacterial dissemination. Glutathione peroxidase-4 (Gpx4) is an enzyme that plays a critical role in preventing iron-dependent lipid peroxidation-mediated cell death (ferroptosis), a process previously implicated in the necrotic pathology seen in Mtb-infected mice. Here, we document altered GPX4 expression, glutathione levels, and lipid peroxidation in patients with active tuberculosis and assess the role of this pathway in mice genetically deficient in or overexpressing Gpx4. We found that Gpx4-deficient mice infected with Mtb display substantially increased lung necrosis and bacterial burdens, while transgenic mice overexpressing the enzyme show decreased bacterial loads and necrosis. Moreover, Gpx4-deficient macrophages exhibited enhanced necrosis upon Mtb infection in vitro, an outcome suppressed by the lipid peroxidation inhibitor, ferrostatin-1. These findings provide support for the role of ferroptosis in Mtb-induced necrosis and implicate the Gpx4/GSH axis as a target for host-directed therapy of tuberculosis.

DOI: https://doi.org/10.1084/jem.20220504
FASEB J. 2022 Oct;36(10): e22540

Integrated analysis of the tumor microenvironment using a reconfigurable microfluidic cell culture platform.

Nan Sethakorn, Erika Heninger, Matthew T Breneman, Emma Recchia, Adeline B Ding, David F Jarrard, Peiman Hematti, David J Beebe, David Kosoff.

  The tumor microenvironment (TME) is a complex network of non-malignant cells and stroma that perform a wide array of vital roles in tumor growth, immune evasion, metastasis, and therapeutic resistance. These highly diverse roles have been shown to be critically important to the progression of cancers and have already shown potential as therapeutic targets. Therefore, there has been a tremendous push to elucidate the pathways that underlie these roles and to develop new TME-directed therapies for cancer treatment. Unfortunately, TME-focused research has been limited by a lack of translational in vitro culture platforms that can model this highly complex niche and can support the integrated analysis of cell biology and function. In the current study, we investigate whether an independently developed reconfigurable microfluidic platform, known as Stacks, can address the critical need for translational multi-cellular tumor models and integrated analytics in TME research. We present data on multi-cellular culture of primary human cells in Stacks as well as the orthogonal analysis of cellular polarization, differentiation, migration, and cytotoxicity in this reconfigurable system. These expanded capabilities of Stacks are highly relevant to the cancer research community with the potential to enhance clinical translation of pre-clinical TME studies and to yield novel biological insight into TME crosstalk, metastasis, and responses to novel drug combinations or immune therapies.

Keywords:  high throughput; microfluidics; multi-culture; multiplex; organoid; primary cells; tumor microenvironment

DOI:  https://doi.org/10.1096/fj.202200684RR
Mass Spectrom Rev. 2022 Sep 06. e21804

Advances in mass spectrometry imaging for spatial cancer metabolomics.

Xin Ma, Facundo M Fernández.

  Mass spectrometry (MS) has become a central technique in cancer research. The ability to analyze various types of biomolecules in complex biological matrices makes it well suited for understanding biochemical alterations associated with disease progression. Different biological samples, including serum, urine, saliva, and tissues have been successfully analyzed using mass spectrometry. In particular, spatial metabolomics using MS imaging (MSI) allows the direct visualization of metabolite distributions in tissues, thus enabling in-depth understanding of cancer-associated biochemical changes within specific structures. In recent years, MSI studies have been increasingly used to uncover metabolic reprogramming associated with cancer development, enabling the discovery of key biomarkers with potential for cancer diagnostics. In this review, we aim to cover the basic principles of MSI experiments for the nonspecialists, including fundamentals, the sample preparation process, the evolution of the mass spectrometry techniques used, and data analysis strategies. We also review MSI advances associated with cancer research in the last 5 years, including spatial lipidomics and glycomics, the adoption of three-dimensional and multimodal imaging MSI approaches, and the implementation of artificial intelligence/machine learning in MSI-based cancer studies. The adoption of MSI in clinical research and for single-cell metabolomics is also discussed. Spatially resolved studies on other small molecule metabolites such as amino acids, polyamines, and nucleotides/nucleosides will not be discussed in the context.

Keywords:  DESI; MALDI; SIMS; cancer; glycans; lipids; mass spectrometry imaging; spatial metabolomics

DOI:  https://doi.org/10.1002/mas.21804
Int J Mol Sci. 2022 Aug 23. pii: 9512. [Epub ahead of print]23(17):

Crosstalk between Pancreatic Cancer Cells and Cancer-Associated Fibroblasts in the Tumor Microenvironment Mediated by Exosomal MicroRNAs.

Xiangyu Chu, Yinmo Yang, Xiaodong Tian.

  Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant digestive tumors, characterized by a low rate of early diagnosis, strong invasiveness, and early metastasis. The abundant stromal cells, dense extracellular matrix, and lack of blood supply in PDAC limit the penetration of chemotherapeutic drugs, resulting in poor efficacy of the current treatment regimens. Cancer-associated fibroblasts (CAFs) are the major stromal cells in the tumor microenvironment. Tumor cells can secrete exosomes to promote the generation of activated CAFs, meanwhile exosomes secreted by CAFs help promote tumor progression. The aberrant expression of miRNAs in exosomes is involved in the interaction between tumor cells and CAFs, which provides the possibility for the application of exosomal miRNAs in the diagnosis and treatment of PDAC. The current article reviews the mechanism of exosomal miRNAs in the crosstalk between PDAC cells and CAFs in the tumor microenvironment, in order to improve the understanding of TME regulation and provide evidence for designing diagnostic and therapeutic targets against exosome miRNA in human PDAC.

Keywords:  PDAC; cancer-associated fibroblasts; exosomal miRNAs; tumor microenvironment

DOI:  https://doi.org/10.3390/ijms23179512
Toxicol Sci. 2022 Sep 10. pii: kfac091. [Epub ahead of print]

Role of plasma membrane dicarboxylate transporters in the uptake and toxicity of diglycolic acid, a metabolite of diethylene glycol, in human proximal tubule cells.

Julie D Tobin, Corie N Robinson, Elliot S Luttrell-Williams, Greg M Landry, Donard Dwyer, Kenneth E McMartin.

  Diethylene glycol (DEG) mass poisonings have resulted from ingestion of pharmaceuticals mistakenly adulterated with DEG, typically leading to proximal tubular necrosis and acute kidney injury. The metabolite, diglycolic acid (DGA) accumulates greatly in kidney tissue and its direct administration results in toxicity identical to that in DEG-treated rats. DGA is a dicarboxylic acid, similar in structure to metabolites like succinate. These studies have assessed the mechanism for cellular accumulation of DGA, specifically whether DGA is taken into primary cultures of human proximal tubule (HPT) cells via sodium dicarboxylate transporters (NaDC-1 or NaDC-3) like those responsible for succinate uptake. When HPT cells were cultured on membrane inserts, sodium dependent succinate uptake was observed from both apical and basolateral directions. Pretreatment with the NaDC-1 inhibitor N-(p-amylcinnamoyl)anthranilic acid (ACA) markedly reduced apical uptakes of both succinate and DGA. Basolateral uptake of both succinate and DGA were decreased similarly following combined treatment with ACA and the NaDC-3 inhibitor 2,3-dimethylsuccinate. When the cells were pre-treated with siRNA to knockdown NaDC-1 function, apical uptake of succinate and toxicity of apically applied DGA were reduced, while the reduction in basolateral succinate uptake and basolateral DGA toxicity was marginal with NaDC-3 knockdown. DGA reduced apical uptake of succinate, but not basolateral uptake. This study confirmed that primary HPT cells retain sodium dicarboxylate transport functionality and that DGA was taken up by these transporters. This study identified NaDC-1 as a likely and NaDC-3 as a possible molecular target to reduce uptake of this toxic metabolite by the kidney.

Keywords:  NaDC-1; NaDC-3; diethylene glycol toxicity; diglycolic acid uptake; kidney cells; succinate transport

DOI:  https://doi.org/10.1093/toxsci/kfac091
iScience. 2022 Sep 16. 25(9): 104955

Dynamics of hepatocyte-cholangiocyte cell-fate decisions during liver development and regeneration.

Sarthak Sahoo, Ashutosh Mishra, Anna Mae Diehl, Mohit Kumar Jolly.

  The immense regenerative potential of the liver is attributed to the ability of its two key cell types - hepatocytes and cholangiocytes - to trans-differentiate to one another either directly or through intermediate progenitor states. However, the dynamic features of decision-making between these cell-fates during liver development and regeneration remains elusive. Here, we identify a core gene regulatory network comprising c/EBPα, TGFBR2, and SOX9 which is multistable in nature, enabling three distinct cell states - hepatocytes, cholangiocytes, and liver progenitor cells (hepatoblasts/oval cells) - and stochastic switching among them. Predicted expression signature for these three states are validated through multiple bulk and single-cell transcriptomic datasets collected across developmental stages and injury-induced liver repair. This network can also explain the experimentally observed spatial organization of phenotypes in liver parenchyma and predict strategies for efficient cellular reprogramming. Our analysis elucidates how the emergent dynamics of underlying regulatory networks drive diverse cell-fate decisions in liver development and regeneration.

Keywords:  Cell biology; In silico biology; Systems biology

DOI:  https://doi.org/10.1016/j.isci.2022.104955
Nat Commun. 2022 Sep 09. 13(1): 5312

In vivo tumor immune microenvironment phenotypes correlate with inflammation and vasculature to predict immunotherapy response.

Aditi Sahu, Kivanc Kose, Lukas Kraehenbuehl, Candice Byers, Aliya Holland, Teguru Tembo, Anthony Santella, Anabel Alfonso, Madison Li, Miguel Cordova, Melissa Gill, Christi Fox, Salvador Gonzalez, Piyush Kumar, Amber Weiching Wang, Nicholas Kurtansky, Pratik Chandrani, Shen Yin, Paras Mehta, Cristian Navarrete-Dechent, Gary Peterson, Kimeil King, Stephen Dusza, Ning Yang, Shuaitong Liu, William Phillips, Pascale Guitera, Anthony Rossi, Allan Halpern, Liang Deng, Melissa Pulitzer, Ashfaq Marghoob, Chih-Shan Jason Chen, Taha Merghoub, Milind Rajadhyaksha.

Response to immunotherapies can be variable and unpredictable. Pathology-based phenotyping of tumors into 'hot' and 'cold' is static, relying solely on T-cell infiltration in single-time single-site biopsies, resulting in suboptimal treatment response prediction. Dynamic vascular events (tumor angiogenesis, leukocyte trafficking) within tumor immune microenvironment (TiME) also influence anti-tumor immunity and treatment response. Here, we report dynamic cellular-level TiME phenotyping in vivo that combines inflammation profiles with vascular features through non-invasive reflectance confocal microscopic imaging. In skin cancer patients, we demonstrate three main TiME phenotypes that correlate with gene and protein expression, and response to toll-like receptor agonist immune-therapy. Notably, phenotypes with high inflammation associate with immunostimulatory signatures and those with high vasculature with angiogenic and endothelial anergy signatures. Moreover, phenotypes with high inflammation and low vasculature demonstrate the best treatment response. This non-invasive in vivo phenotyping approach integrating dynamic vasculature with inflammation serves as a reliable predictor of response to topical immune-therapy in patients.

DOI: https://doi.org/10.1038/s41467-022-32738-7