bims-mepmim Biomed News
on Metabolites in pathological microenvironments and immunometabolism
Issue of 2022‒07‒03
twenty-two papers selected by
Erika Mariana Palmieri
NIH/NCI Laboratory of Cancer ImmunoMetabolism

  1. mBio. 2022 Jun 28. e0127422
      In response to Mycobacterium tuberculosis infection, macrophages mount proinflammatory and antimicrobial responses similar to those observed in M1 macrophages activated by lipopolysaccharide (LPS) and interferon gamma (IFN-γ). A metabolic reprogramming to hypoxia-inducible-factor 1 (HIF-1)-mediated uptake of glucose and its metabolism by glycolysis is required for M1-like polarization, but little is known about other metabolic programs driving the M1-like polarization during infection. We report that glutamine serves as a carbon and nitrogen source for the metabolic reprogramming to M1-like macrophages. Widely targeted metabolite screening identified an association of glutamine and/or glutamate with highly affected metabolic pathways of M1-like macrophages. Moreover, stable isotope-assisted metabolomics of U13C glutamine and U13C glucose revealed that glutamine, rather than glucose, is catabolized in both the oxidative and reductive tricarboxylic acid (TCA) cycles of M1-like macrophages, thereby generating signaling molecules that include succinate, biosynthetic precursors such as aspartate, and itaconate. U15N glutamine-tracing metabolomics further revealed participation of glutamine nitrogen in synthesis of intermediates of purine and pyrimidine metabolism plus amino acids, including aspartate. These findings were corroborated by diminished M1 polarization from chemical inhibition of glutaminase (GLS), the key enzyme in the glutaminolysis pathway, and by genetic deletion of GLS in infected macrophages. Thus, the catabolism of glutamine is an integral component of metabolic reprogramming in activating macrophages and it coordinates with elevated cytosolic glycolysis to satisfy the cellular demand for bioenergetic and biosynthetic precursors of M1-like macrophages. Knowledge of these new immunometabolic features of M1-like macrophages should advance the development of host-directed therapies for tuberculosis. IMPORTANCE Macrophages play essential roles in determining the progression and final outcome of human infection by Mycobacterium tuberculosis. While upregulation of hypoxia-inducible-factor 1 (HIF-1) and a metabolic reprogramming to the Warburg Effect-like state are known to be critical for immune cell activation in response to M. tuberculosis infection, our overall knowledge about the immunometabolism of M1-like macrophages is poor. Using widely targeted small-metabolite screening, stable isotope tracing metabolomics, and pharmacological and genetic approaches, we report that, in addition to enhanced glucose catabolism by glycolysis, glutamine is utilized as an important carbon and nitrogen source for the generation of biosynthetic precursors, signaling molecules, and itaconate in M. tuberculosis-induced M1-like macrophages. Recognizing this novel contribution of glutamine to the immunometabolic properties of M. tuberculosis-infected macrophages may facilitate the development of treatments for tuberculosis and stimulate comparable studies with other pathogen-macrophage interactions.
    Keywords:  M1-like polarization; Mycobacterium tuberculosis; TCA cycle; glutaminolysis; immunometabolism; isotope tracing metabolomics
  2. Cell Rep. 2022 Jun 28. pii: S2211-1247(22)00801-4. [Epub ahead of print]39(13): 111012
      Ovarian cancer (OC) is the most lethal gynecological malignancy, with aggressive metastatic disease responsible for the majority of OC-related deaths. In particular, OC tumors preferentially metastasize to and proliferate rapidly in the omentum. Here, we show that metastatic OC cells experience increased oxidative stress in the omental microenvironment. Metabolic reprogramming, including upregulation of the pentose phosphate pathway (PPP), a key cellular redox homeostasis mechanism, allows OC cells to compensate for this challenge. Inhibition of glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the PPP, reduces tumor burden in pre-clinical models of OC, suggesting that this adaptive metabolic dependency is important for OC omental metastasis.
    Keywords:  CP: Cancer; CP: Metabolism; metabolism; metastasis; ovarian cancer
  3. Mol Cell. 2022 Jun 24. pii: S1097-2765(22)00544-5. [Epub ahead of print]
      Bicarbonate (HCO3-) ions maintain pH homeostasis in eukaryotic cells and serve as a carbonyl donor to support cellular metabolism. However, whether the abundance of HCO3- is regulated or harnessed to promote cell growth is unknown. The mechanistic target of rapamycin complex 1 (mTORC1) adjusts cellular metabolism to support biomass production and cell growth. We find that mTORC1 stimulates the intracellular transport of HCO3- to promote nucleotide synthesis through the selective translational regulation of the sodium bicarbonate cotransporter SLC4A7. Downstream of mTORC1, SLC4A7 mRNA translation required the S6K-dependent phosphorylation of the translation factor eIF4B. In mTORC1-driven cells, loss of SLC4A7 resulted in reduced cell and tumor growth and decreased flux through de novo purine and pyrimidine synthesis in human cells and tumors without altering the intracellular pH. Thus, mTORC1 signaling, through the control of SLC4A7 expression, harnesses environmental bicarbonate to promote anabolic metabolism, cell biomass, and growth.
    Keywords:  SLC4A7/NBCn1; bicarbonate metabolism; mTOR signaling; purine metabolism; pyrimidine metabolism
  4. J Cell Sci. 2022 Jul 01. pii: jcs.259090. [Epub ahead of print]
      Accelerated aerobic glycolysis is a distinctive metabolic property of cancer cells that confers dependency on glucose for survival. However, the therapeutic strategies targeting this vulnerability are still inefficient and have unacceptable side effects in clinical trials. Therefore, developing biomarkers to predict therapeutic efficacy would be essential to improve the selective targeting of cancer cells. Here, we found that the cell lines sensitive to glucose deprivation have high expression of cystine/glutamate antiporter xCT. We found that cystine uptake and glutamate export through xCT contributed to rapid NADPH depletion under glucose deprivation. This collapse of the redox system oxidized and inactivated AMPK, a major regulator of metabolic adaptation, resulting in a metabolic catastrophe and cell death. While this phenomenon was prevented by pharmacological or genetic inhibition of xCT, overexpression of xCT sensitized resistant cancer cells to glucose deprivation. Taken together, these findings suggest a novel cross-talk between AMPK and xCT for the metabolism and signal transduction and reveal a metabolic vulnerability in xCT-high expressing cancer cells to glucose deprivation.
    Keywords:  AMPK; Cystine; Glucose starvation; NADPH; SLC7A11; xCT
  5. Mol Metab. 2022 Jun 22. pii: S2212-8778(22)00101-6. [Epub ahead of print] 101532
      Bone marrow mesenchymal stromal cells (MSCs) have immunomodulatory and regenerative potential. However, culture conditions govern their metabolic processes and therapeutic efficacy. Here we show that culturing donor-derived MSCs in Plasmax™, a physiological medium with the concentrations of nutrients found in human plasma, supports their proliferation and stemness, and prevents the nutritional stress induced by the conventional medium DMEM. The quantification of the exchange rates of metabolites between cells and medium, untargeted metabolomics, stable isotope tracing and transcriptomic analysis, performed at physiologically relevant oxygen concentrations (1%O2), reveal that MSCs rely on high rate of glucose to lactate conversion, coupled with parallel anaplerotic fluxes from glutamine and glutamate to support citrate synthesis and secretion. These distinctive traits of MSCs shape the metabolic microenvironment of bone marrow niche and can influence nutrient cross-talks under physiological and pathological conditions.
    Keywords:  Citrate; Glutamate; Glutamine; Hypoxia; Mesenchymal stromal cells; Metabolism; Physiological medium; Plasmax; Primary cells; Stable isotope tracing
  6. Front Mol Biosci. 2022 ;9 893846
      Altered metabolism, such as aerobic glycolysis or the Warburg effect, has been recognized as characteristics of tumor cells for almost a century. Since then, there is accumulating evidence to demonstrate the metabolic reprogramming of tumor cells, addiction to excessive uptake and metabolism of key nutrients, to support rapid proliferation and invasion under tumor microenvironment. The solute carrier (SLC) superfamily transporters are responsible for influx or efflux of a wide variety of xenobiotic and metabolites that are needed for the cells to function, as well as some medications. To meet the increased demand for nutrients and energy, SLC transporters are frequently dysregulated in cancer cells. The SLCs responsible for the transport of key nutrients for cancer metabolism and energetics, such as glucose and amino acids, are of particular interest for their roles in tumor progression and metastasis. Meanwhile, rewired metabolism is accompanied by the dysregulation of microRNAs (miRNAs or miRs) that are small, noncoding RNAs governing posttranscriptional gene regulation. Studies have shown that many miRNAs directly regulate the expression of specific SLC transporters in normal or diseased cells. Changes of SLC transporter expression and function can subsequently alter the uptake of nutrients or therapeutics. Given the important role for miRNAs in regulating disease progression, there is growing interest in developing miRNA-based therapies, beyond serving as potential diagnostic or prognostic biomarkers. In this article, we discuss how miRNAs regulate the expression of SLC transporters and highlight potential influence on the supply of essential nutrients for cell metabolism and drug exposure toward desired efficacy.
    Keywords:  cancer; microRNA; nutrient; regulation; solute carrier; therapy; xenobiotic
  7. STAR Protoc. 2022 Sep 16. 3(3): 101480
      The communication between macrophage and adipocyte plays a critical role in the initiation and development of metabolic inflammation, which is difficult to study in vivo. Here, we provide a step-by-step protocol using differentiated cells to investigate the paracrine effects of classically activated macrophage on beige adipocyte metabolism in vitro. This protocol uses bone-marrow-derived macrophage and SVF-derived UCP1+ beige adipocyte in a culture model to study immune regulation of adipocyte metabolism by western blot analyses. For complete details on the use and execution of this protocol, please refer to Yao et al. (2021).
    Keywords:  Immunology; Metabolism
  8. J Biol Chem. 2022 Jun 22. pii: S0021-9258(22)00620-2. [Epub ahead of print] 102178
      The Solute Carrier 1A (SLC1A) family comprises a group of membrane proteins that act as dual-function amino acid transporters and chloride channels and includes the alanine serine cysteine transporters (ASCTs) as well as the excitatory amino acid transporters (EAATs). ASCT2 is regarded as a promising target for cancer therapy, as it can transport glutamine and other neutral amino acids into cells and is upregulated in a range of solid tumors. The compound L-γ-glutamyl-p-nitroanilide (GPNA) is widely used in studies probing the role of ASCT2 in cancer biology; however, the mechanism by which GPNA inhibits ASCT2 is not entirely clear. Here, we used electrophysiology and radiolabelled flux assays to demonstrate that GPNA activates the chloride conductance of ASCT2 to the same extent as a transported substrate, whilst not undergoing the full transport cycle. This is a previously unreported phenomenon for inhibitors of the SLC1A family but corroborates a body of literature suggesting that the structural requirements for transport are distinct from those for chloride channel formation. We also show that in addition to its currently known targets, GPNA inhibits several of the EAATs. Together, these findings raise questions about the true mechanisms of its anticancer effects.
    Keywords:  ASCT; Amino acid transport; EAAT; GPNA; SLC1A; cancer biology; chloride channel; glutamate; glutamine; inhibition mechanism
  9. Elife. 2022 06 27. pii: e71929. [Epub ahead of print]11
      Hyperactivation of oncogenic pathways downstream of RAS and PI3K/AKT in normal cells induces a senescence-like phenotype that acts as a tumor-suppressive mechanism that must be overcome during transformation. We previously demonstrated that AKT-induced senescence (AIS) is associated with profound transcriptional and metabolic changes. Here, we demonstrate that human fibroblasts undergoing AIS display upregulated cystathionine-β-synthase (CBS) expression and enhanced uptake of exogenous cysteine, which lead to increased hydrogen sulfide (H2S) and glutathione (GSH) production, consequently protecting senescent cells from oxidative stress-induced cell death. CBS depletion allows AIS cells to escape senescence and re-enter the cell cycle, indicating the importance of CBS activity in maintaining AIS. Mechanistically, we show this restoration of proliferation is mediated through suppressing mitochondrial respiration and reactive oxygen species (ROS) production by reducing mitochondrial localized CBS while retaining antioxidant capacity of transsulfuration pathway. These findings implicate a potential tumor-suppressive role for CBS in cells with aberrant PI3K/AKT pathway activation. Consistent with this concept, in human gastric cancer cells with activated PI3K/AKT signaling, we demonstrate that CBS expression is suppressed due to promoter hypermethylation. CBS loss cooperates with activated PI3K/AKT signaling in promoting anchorage-independent growth of gastric epithelial cells, while CBS restoration suppresses the growth of gastric tumors in vivo. Taken together, we find that CBS is a novel regulator of AIS and a potential tumor suppressor in PI3K/AKT-driven gastric cancers, providing a new exploitable metabolic vulnerability in these cancers.
    Keywords:  PI3K/AKT signaling; cancer biology; cell biology; cystathionine-β-synthase; gastric cancer; glutathione; human; mouse; oxidative stress; senescence
  10. Free Radic Biol Med. 2022 Jun 23. pii: S0891-5849(22)00462-2. [Epub ahead of print]
      5-methoxy tryptophan (5-MTP) is an anti-fibrotic metabolite made by fibroblasts and epithelial cells, present in a micromolar concentrations in human blood, and is associated with the progression of fibrotic kidney disease, but the mechanism is unclear. Here, we show by microscopy and functional assays that 5-MTP influences mitochondria in human peripheral blood monocyte-derived macrophages. As a result, the mitochondrial membranes are more rigid, more branched, and are protected against oxidation. The macrophages also change their metabolism by reducing mitochondrial import of acyl-carnitines, intermediates of fatty acid metabolism, driving glucose import. Moreover, 5-MTP increases the endocytosis of collagen by macrophages, and experiments with inhibition of glucose uptake showed that this is a direct result of their altered metabolism. However, 5-MTP does not affect the macrophages following pathogenic stimulation, due to 5-MTP degradation by induced expression of indole-amine oxygenase-1 (IDO-1). Thus, 5-MTP is a fibrosis-protective metabolite that, in absence of pathogenic stimulation, promotes collagen uptake by anti-inflammatory macrophages by altering the physicochemical properties of their mitochondrial membranes.
    Keywords:  5-Methoxy tryptophan; Fibrosis; IDO; Inflammation; Macrophage; Metabolism; Mitochondria
  11. Front Cell Dev Biol. 2022 ;10 856243
      Mast cells are specialized, tissue resident, immune effector cells able to respond to a wide range of stimuli. MCs are involved in the regulation of a variety of physiological functions, including vasodilation, angiogenesis and pathogen elimination. In addition, MCs recruit and regulate the functions of many immune cells such as dendritic cells, macrophages, T cells, B cells and eosinophils through their selective production of multiple cytokines and chemokines. MCs generate and release multi-potent molecules, such as histamine, proteases, prostanoids, leukotrienes, heparin, and many cytokines, chemokines, and growth factors through both degranulation dependent and independent pathways. Recent studies suggested that metabolic shifts dictate the activation and granule content secretion by MCs, however the metabolic signaling promoting these events is at its infancy. Lipid metabolism is recognized as a pivotal immunometabolic regulator during immune cell activation. Peroxisomes are organelles found across all eukaryotes, with a pivotal role in lipid metabolism and the detoxification of reactive oxygen species. Peroxisomes are one of the emerging axes in immunometabolism. Here we identified the peroxisome as an essential player in MCs activation. We determined that lack of functional peroxisomes in murine MCs causes a significant reduction of interleukin-6, Tumor necrosis factor and InterleukinL-13 following immunoglobulin IgE-mediated and Toll like receptor 2 and 4 activation compared to the Wild type (WT) BMMCs. We linked these defects in cytokine release to defects in free fatty acids homeostasis. In conclusion, our study identified the importance of peroxisomal fatty acids homeostasis in regulating mast cell-mediated immune functions.
    Keywords:  IgE; TLR; free fatty acids; mast cell; peroxisome
  12. FEBS Lett. 2022 Jul 01.
      Deregulated metabolism is a well-known feature of several challenging diseases, including diabetes, obesity and cancer. Besides their important role as intracellular bioenergetic molecules, dietary nutrients and metabolic intermediates are released in the extracellular environment. As such, they may achieve unconventional roles as hormone-like molecules by activating cell-surface G-protein-coupled receptors (GPCRs) that regulate several pathophysiological processes. In this review, we provide an insight into the role of lactate, succinate, fatty acids, amino acids, ketogenesis-derived and β-oxidation-derived intermediates as extracellular signalling molecules. Moreover, the mechanisms by which their cognate metabolite-sensing GPCRs integrate nutritional and metabolic signals with specific intracellular pathways will be described. A better comprehension of these aspects is of fundamental importance to identify GPCRs as novel druggable targets.
    Keywords:  G-protein-coupled receptors; extracellular signalling molecules; lactate; metabolites; nutrients; succinate
  13. Nat Metab. 2022 Jun;4(6): 693-710
      Elevated production of collagen-rich extracellular matrix is a hallmark of cancer-associated fibroblasts (CAFs) and a central driver of cancer aggressiveness. Here we find that proline, a highly abundant amino acid in collagen proteins, is newly synthesized from glutamine in CAFs to make tumour collagen in breast cancer xenografts. PYCR1 is a key enzyme for proline synthesis and highly expressed in the stroma of breast cancer patients and in CAFs. Reducing PYCR1 levels in CAFs is sufficient to reduce tumour collagen production, tumour growth and metastatic spread in vivo and cancer cell proliferation in vitro. Both collagen and glutamine-derived proline synthesis in CAFs are epigenetically upregulated by increased pyruvate dehydrogenase-derived acetyl-CoA levels. PYCR1 is a cancer cell vulnerability and potential target for therapy; therefore, our work provides evidence that targeting PYCR1 may have the additional benefit of halting the production of a pro-tumorigenic extracellular matrix. Our work unveils new roles for CAF metabolism to support pro-tumorigenic collagen production.
  14. Front Immunol. 2022 ;13 889875
      Reactive oxygen species (ROS), previously considered toxic by-products of aerobic metabolism, are increasingly recognized as regulators of cellular signaling. Keeping ROS levels low is essential to safeguard the self-renewal capacity of hematopoietic stem cells (HSC). HSC reside in a hypoxic environment and have been shown to be highly dependent on the glycolytic pathway to meet their energy requirements. However, when the differentiation machinery is activated, there is an essential enhancement of ROS together with a metabolic shift toward oxidative metabolism. Initiating and sustaining leukemia depend on the activity of leukemic stem cells (LSC). LSC also show low ROS levels, but unlike HSC, LSC rely on oxygen to meet their metabolic energetic requirements through mitochondrial respiration. In contrast, leukemic blasts show high ROS levels and great metabolic plasticity, both of which seem to sustain their invasiveness. Oxidative stress and metabolism rewiring are recognized as hallmarks of cancer that are intimately intermingled. Here we present a detailed overview of these two features, sustained at different levels, that support a two-way relationship in leukemia. Modifying ROS levels and targeting metabolism are interesting therapeutic approaches. Therefore, we provide the most recent evidence on the modulation of oxidative stress and metabolism as a suitable anti-leukemic approach.
    Keywords:  NADPH oxidases (NOX); hematopoietic stem cell (HSC); leukemia; leukemic stem cell (LSC); metabolism; reactive oxygen species
  15. J Cancer Res Clin Oncol. 2022 Jul 01.
      PURPOSE: Nicotinamide adenine dinucleotide (NAD+) is closely related to the pathogenesis of tumors. However, the effect of NAD+ metabolism of gastric cancer (GC) cells on immune cells remains unexplained. We targeted nicotinamide phosphoribosyltransferase (NAMPT), a rate-limiting enzyme in the NAD+ synthesis salvage pathway, to observe its effect in the immune microenvironment.METHODS: NAMPT of GC cell lines was inhibited by using the small molecule inhibitor (FK866) and short hairpin RNA (shRNA). CCK-8 test and flow cytometry were performed to detect cell viability and apoptosis. Immunofluorescence was used to observe changes in mitochondrial membrane potential (MMP).The transfected GC cells (AGS) and patient-derived organoids (PDOs) were cocultured with activated PBMCs, followed by flow cytometric analysis (FCA) for cytokines and inhibitory marker. The level of NAD and ATP of GC cells (AGS & MKN45) was tested combined with NMN and CD39 inhibitor.
    RESULTS: Targeting NAD+ by FK866 obviously reduced MMP, which ultimately inhibited proliferation and increased the apoptosis of GC cells. NAMPT silencing reduced intracellular NAD and ATP,further decreased extracellular adenosine. Meawhile, the cytokines of CD8+T cells were significantly increased after cocultured with transfected AGS, and the expression of PD-1 was distinctly decreased. NMN reversed the effect of shNAMPT and enhanced the immunosuppression. Consistent results were obtained by coculturing PBMCs with PDOs.
    CONCLUSION: Restraining the function of NAMPT resulted in the functional improvement of effector CD8+ T cells by decreasing extracellular adenosine levels and inducing apoptosis of GC cells simultaneously. Therefore, this study demonstrates that NAMPT can be an effective target for gastric cancer immunotherapy.
    Keywords:  ATP-adenosine axis; Gastric cancer; NAD; NAMPT; Organoids; Tumor microenvironment
  16. Front Immunol. 2022 ;13 924775
      Environmental conditions greatly shape the phenotype and function of immune cells. Specifically, hypoxic conditions that exist within tissues and organs have been reported to affect both the adaptive and the innate immune system. Natural killer (NK) cells belong to the innate immune system. They are among the first immune cells responding to infections and are involved in tumor surveillance. NK cells produce cytokines that shape other innate and adaptive immune cells, and they produce cytolytic molecules leading to target cell killing. Therefore, they are not only involved in steady state tissue homeostasis, but also in pathogen and tumor clearance. Hence, understanding the role of NK cells in pathological and physiological immune biology is an emerging field. To date, it remains incompletely understood how the tissue microenvironment shapes NK cell phenotype and function. In particular, the impact of low oxygen concentrations in tissues on NK cell reactivity has not been systematically dissected. Here, we present a comprehensive review focusing on two highly compelling hypoxic tissue environments, the tumor microenvironment (pathological) and the decidua (physiological) and compare their impact on NK cell reactivity.
    Keywords:  NK cells; hypoxia; pregnancy; tumor microenvironment; vascularization
  17. Ups J Med Sci. 2022 ;127
      Background: Splenectomy impacts hematological, immunological, and metabolic functions of the patient. Since our understanding of its metabolic effects, in particular effects on lipid metabolism, is limited, this study aims to investigate the effects of splenectomy on lipid metabolism.Methods: The data from 316 patients undergoing splenectomy between 2009 and 2019 were retrospectively analyzed. Thirty-eight patients whose serum lipid values were measured both preoperatively and 1 year after surgery were included in this study.
    Results: Significantly higher levels of total cholesterol, low-density lipoprotein (LDL), and non-high-density lipoprotein (HDL) lipid profile were found in the postsplenectomy measurements. However, no significant differences were recorded in levels of triglyceride, HDL, or very-LDL.
    Conclusion: We determined that splenectomy does impact lipid metabolism, and that the metabolic effects of splenectomy should further be investigated.
    Keywords:  atherosclerosis; autotransplantation; coronary; homeostasis; hyperlipidemia; lipoprotein
  18. PLoS One. 2022 ;17(6): e0270418
      Thymidine kinase 2 (TK2) deficiency in humans leads to a myopathic form of mitochondrial DNA (mtDNA) deficiency. Here we present a skeletal and cardiac muscle specific TK2 knockout mouse (mTk2 KO). The mice showed dilated hearts and markedly reduced adipose tissue during week 12 to 16. A severe decrease of mtDNA was found only in skeletal muscle and heart tissue in mTk2 KO mice. Expression analysis of key metabolic genes of 16 weeks knockout mice showed significant changes of genes involved in lipid metabolism, with different patterns in heart and skeletal muscle. Our study further suggests that lipoprotein lipase (LPL) from liver supports the metabolism when heart and skeletal muscle were impaired due to mitochondrial dysfunction. The angiotensin-converting enzyme 2 (ACE2), which is involved in glucose homeostasis, was also affected by mtDNA deficiency in our study. Interestingly, both the gene and protein expression of ACE2 were increased in cardiac tissue of mTk2 KO mice. Since ACE2 is a receptor for the SARS-CoV-2 virus, its regulation in relation to mitochondrial function may have important clinical implications.
  19. Front Med (Lausanne). 2022 ;9 815467
      Ascites is one of the most common complications of cirrhosis, and there is a dearth of knowledge about ascites-related pathologic metabolism. In this study, 122 alcoholic liver disease (ALD) patients, including 49 cases without ascites, 18 cases with mild-ascites, and 55 cases with large-ascites (1) were established according to the International Ascites Club (2), and untargeted metabolomics coupled with pattern recognition approaches were performed to profile and extract metabolite signatures. A total of 553 metabolites were uniquely discovered in patients with ascites, of which 136 metabolites had been annotated in the human metabolome database. Principal component analysis (PCA) analysis was used to further identify 21 ascites-related fingerprints. The eigenmetabolite calculated by reducing the dimensions of the 21 metabolites could be used to effectively identify those ALD patients with or without ascites. The eigenmetabolite showed a decreasing trend during ascites production and accumulation and was negatively related to the disease progress. These metabolic fingerprints mainly belong to the metabolites in lipid metabolism and the amino acid pathway. The results imply that lipid and amino acid metabolism disturbance may play a critical role in the development of ascites in ALD patients and could be a potent prognosis marker.
    Keywords:  alcohol liver disease; amino acid metabolism disturbance; ascites; lipid metabolism disturbance; untargeted metabolomic
  20. Nat Commun. 2022 Jul 01. 13(1): 3799
      Atherosclerosis is a chronic inflammatory disease driven by hypercholesterolemia. During aging, T cells accumulate cholesterol, potentially affecting inflammation. However, the effect of cholesterol efflux pathways mediated by ATP-binding cassette A1 and G1 (ABCA1/ABCG1) on T cell-dependent age-related inflammation and atherosclerosis remains poorly understood. In this study, we generate mice with T cell-specific Abca1/Abcg1-deficiency on the low-density-lipoprotein-receptor deficient (Ldlr-/-) background. T cell Abca1/Abcg1-deficiency decreases blood, lymph node, and splenic T cells, and increases T cell activation and apoptosis. T cell Abca1/Abcg1-deficiency induces a premature T cell aging phenotype in middle-aged (12-13 months) Ldlr-/- mice, reflected by upregulation of senescence markers. Despite T cell senescence and enhanced T cell activation, T cell Abca1/Abcg1-deficiency decreases atherosclerosis and aortic inflammation in middle-aged Ldlr-/- mice, accompanied by decreased T cells in atherosclerotic plaques. We attribute these effects to T cell apoptosis downstream of T cell activation, compromising T cell functionality. Collectively, we show that T cell cholesterol efflux pathways suppress T cell apoptosis and senescence, and induce atherosclerosis in middle-aged Ldlr-/- mice.
  21. Arch Pharm Res. 2022 Jun;45(6): 401-416
      Cancer creates a complex tumor microenvironment (TME) composed of immune cells, stromal cells, blood vessels, and various other cellular and extracellular elements. It is essential for the development of anti-cancer combination therapies to understand and overcome this high heterogeneity and complexity as well as the dynamic interactions between them within the TME. Recent treatment strategies incorporating immune-checkpoint inhibitors and anti-angiogenic agents have brought many changes and advances in clinical cancer treatment. However, there are still challenges for immune suppressive tumors, which are characterized by a lack of T cell infiltration and treatment resistance. In this review, we will investigate the crosstalk between immunity and angiogenesis in the TME. In addition, we will look at strategies designed to enhance anti-cancer immunity, to convert "immune suppressive tumors" into "immune activating tumors," and the mechanisms by which these strategies enhance effector immune cell infiltration.
    Keywords:  Angiogenesis; Immune suppressive tumor; Treg cells; Tumor microenvironment; Tumor-associated macrophage