scholarly journals UK5099 inhibits macrophage activation independent of mitochondrial pyruvate carrier mediated metabolism

2021 ◽  
Author(s):  
Linyu Ran ◽  
Song Zhang ◽  
Pei Zhao ◽  
Jiaqi Zhou ◽  
Haiyun Gan ◽  
...  
Keyword(s):  
Macrophage Activation ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Tca Cycle ◽  
Metabolic Reprogramming ◽  
M1 Macrophages ◽  
Inflammatory Cytokine Production ◽  
The Tca Cycle ◽  
Mitochondrial Pyruvate Carrier ◽  
High Doses

Abstract Glycolysis is essential for the classical activation of macrophages (M1), but how glycolytic pathway metabolites engage in this process remains to be elucidated. Glycolysis culminates in the production of pyruvate, which can be transported into the mitochondria by the mitochondrial pyruvate carrier (MPC) followed by conversion to citrate and utilization in the TCA cycle. Alternatively, pyruvate can be metabolized to lactate under aerobic conditions, which had been considered to be the dominant route in the setting of classical macrophage activation. However, based on studies that used UK5099 as a MPC inhibitor and showed reduction in key inflammatory cytokines, the mitochondrial route has been considered to be of significance for M1 activation as well. Herein, using a genetic depletion model, we found that MPC is dispensable for metabolic reprogramming and the activation of M1. While UK5099 reaches maximal MPC inhibitory capacity at approximately 2–5µM, higher concentrations are required to inhibit inflammatory cytokine production in M1 and this is independent of MPC expression. Apart from MPC inhibition, UK5099 at high doses impairs glutamate oxidation, mitochondrial membrane potential and HIF-1α stabilization. Taken together, UK5099 inhibits inflammatory responses in M1 macrophages due to effects other than MPC inhibition.

scholarly journals Leishmania donovani infection suppresses Allograft Inflammatory Factor-1 in monocytes and macrophages to inhibit inflammatory responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ricardo Louzada da Silva ◽  
Diana M. Elizondo ◽  
Nailah Z. D. Brandy ◽  
Naomi L. Haddock ◽  
Thomas A. Boddie ◽  
...  
Keyword(s):  
Immune Evasion ◽  
Inflammatory Cytokine ◽  
Leishmania Donovani ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Bone Marrow Cells ◽  
Parasitic Infections ◽  
Inflammatory Factor ◽  
Immune Functions ◽  
Inflammatory Cytokine Production

AbstractMacrophages and monocytes are important for clearance of Leishmania infections. However, immune evasion tactics employed by the parasite results in suppressed inflammatory responses, marked by deficient macrophage functions and increased accumulation of monocytes. This results in an ineffective ability to clear parasite loads. Allograft Inflammatory Factor-1 (AIF1) is expressed in myeloid cells and serves to promote immune responses. However, AIF1 involvement in monocyte and macrophage functions during parasitic infections has not been explored. This study now shows that Leishmania donovani inhibits AIF1 expression in macrophages to block pro-inflammatory responses. Mice challenged with the parasite had markedly reduced AIF1 expression in splenic macrophages. Follow-up studies using in vitro approaches confirmed that L. donovani infection in macrophages suppresses AIF1 expression, which correlated with reduction in pro-inflammatory cytokine production and increased parasite load. Ectopic overexpression of AIF1 in macrophages provided protection from infection, marked by robust pro-inflammatory cytokine production and efficient pathogen clearance. Further investigations found that inhibiting AIF1 expression in bone marrow cells or monocytes impaired differentiation into functional macrophages. Collectively, results show that AIF1 is a critical regulatory component governing monocyte and macrophage immune functions and that L. donovani infection can suppress the gene as an immune evasion tactic.

scholarly journals β-Hydroxybutyrate Oxidation Promotes the Accumulation of Immunometabolites in Activated Microglia Cells

Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 346
Author(s):  
Adrian Benito ◽  
Nabil Hajji ◽  
Kevin O’Neill ◽  
Hector C. Keun ◽  
Nelofer Syed
Keyword(s):  
Metabolic Regulation ◽  
Marker Gene ◽  
Tca Cycle ◽  
Metabolic Reprogramming ◽  
Glycolytic Flux ◽  
Dihydroxyacetone Phosphate ◽  
Glycolytic Intermediate ◽  
Critical Set ◽  
The Tca Cycle ◽  
Bv2 Cells

Metabolic regulation of immune cells has arisen as a critical set of processes required for appropriate response to immunological signals. While our knowledge in this area has rapidly expanded in leukocytes, much less is known about the metabolic regulation of brain-resident microglia. In particular, the role of alternative nutrients to glucose remains poorly understood. Here, we use stable-isotope (13C) tracing strategies and metabolomics to characterize the oxidative metabolism of β-hydroxybutyrate (BHB) in human (HMC3) and murine (BV2) microglia cells and the interplay with glucose in resting and LPS-activated BV2 cells. We found that BHB is imported and oxidised in the TCA cycle in both cell lines with a subsequent increase in the cytosolic NADH:NAD+ ratio. In BV2 cells, stimulation with LPS upregulated the glycolytic flux, increased the cytosolic NADH:NAD+ ratio and promoted the accumulation of the glycolytic intermediate dihydroxyacetone phosphate (DHAP). The addition of BHB enhanced LPS-induced accumulation of DHAP and promoted glucose-derived lactate export. BHB also synergistically increased LPS-induced accumulation of succinate and other key immunometabolites, such as α-ketoglutarate and fumarate generated by the TCA cycle. Finally, BHB upregulated the expression of a key pro-inflammatory (M1 polarisation) marker gene, NOS2, in BV2 cells activated with LPS. In conclusion, we identify BHB as a potentially immunomodulatory metabolic substrate for microglia that promotes metabolic reprogramming during pro-inflammatory response.

scholarly journals Metabolic Constants and Plasticity of Cancer Cells in a Limiting Glucose and Glutamine Microenvironment—A Pyruvate Perspective

2020 ◽  
Vol 10 ◽  
Author(s):  
Angela M. Otto
Keyword(s):  
Cancer Cells ◽  
Metabolic Network ◽  
Metabolic Pathways ◽  
Cancer Cell Line ◽  
Tca Cycle ◽  
Reaction Rates ◽  
Diagnostic Methods ◽  
Metabolic Reprogramming ◽  
Amino Acid Synthesis ◽  
The Tca Cycle

The metabolism of cancer cells is an issue of dealing with fluctuating and limiting levels of nutrients in a precarious microenvironment to ensure their vitality and propagation. Glucose and glutamine are central metabolites for catabolic and anabolic metabolism, which is in the limelight of numerous diagnostic methods and therapeutic targeting. Understanding tumor metabolism in conditions of nutrient depletion is important for such applications and for interpreting the readouts. To exemplify the metabolic network of tumor cells in a model system, the fate 13C6-glucose was tracked in a breast cancer cell line growing in variable low glucose/low glutamine conditions. 13C-glucose-derived metabolites allowed to deduce the engagement of metabolic pathways, namely glycolysis, the TCA-cycle including glutamine and pyruvate anaplerosis, amino acid synthesis (serine, glycine, aspartate, glutamate), gluconeogenesis, and pyruvate replenishment. While the metabolic program did not change, limiting glucose and glutamine supply reduced cellular metabolite levels and enhanced pyruvate recycling as well as pyruvate carboxylation for entry into the TCA-cycle. Otherwise, the same metabolic pathways, including gluconeogenesis, were similarly engaged with physiologically saturating as with limiting glucose and glutamine. Therefore, the metabolic plasticity in precarious nutritional microenvironment does not require metabolic reprogramming, but is based on dynamic changes in metabolite quantity, reaction rates, and directions of the existing metabolic network.

scholarly journals BCAT1 affects mitochondrial metabolism independently of leucine transamination in activated human macrophages

2020 ◽  
Vol 133 (22) ◽  
pp. jcs247957
Author(s):  
Jeong-Hun Ko ◽  
Antoni Olona ◽  
Adonia E. Papathanassiu ◽  
Norzawani Buang ◽  
Kwon-Sik Park ◽  
...  
Keyword(s):  
Macrophage Activation ◽  
Polarization State ◽  
Tca Cycle ◽  
Metabolic Adaptation ◽  
Human Macrophages ◽  
Relative Contribution ◽  
The Tca Cycle ◽  
Nutrient Consumption ◽  
Anti Oxidant ◽  
Branched Chain

ABSTRACTIn response to environmental stimuli, macrophages change their nutrient consumption and undergo an early metabolic adaptation that progressively shapes their polarization state. During the transient, early phase of pro-inflammatory macrophage activation, an increase in tricarboxylic acid (TCA) cycle activity has been reported, but the relative contribution of branched-chain amino acid (BCAA) leucine remains to be determined. Here, we show that glucose but not glutamine is a major contributor of the increase in TCA cycle metabolites during early macrophage activation in humans. We then show that, although uptake of BCAAs is not altered, their transamination by BCAT1 is increased following 8 h lipopolysaccharide (LPS) stimulation. Of note, leucine is not metabolized to integrate into the TCA cycle in basal or stimulated human macrophages. Surprisingly, the pharmacological inhibition of BCAT1 reduced glucose-derived itaconate, α-ketoglutarate and 2-hydroxyglutarate levels without affecting succinate and citrate levels, indicating a partial inhibition of the TCA cycle. This indirect effect is associated with NRF2 (also known as NFE2L2) activation and anti-oxidant responses. These results suggest a moonlighting role of BCAT1 through redox-mediated control of mitochondrial function during early macrophage activation.

scholarly journals Metformin Suppresses Monocyte Immunometabolic Activation by SARS-CoV-2 Spike Protein Subunit 1

2021 ◽  
Vol 12 ◽  
Author(s):  
Theodore J. Cory ◽  
Russell S. Emmons ◽  
Johnathan R. Yarbro ◽  
Kierstin L. Davis ◽  
Brandt D. Pence
Keyword(s):  
Inflammatory Cytokines ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Hypoxia Inducible Factor ◽  
Glucose Deprivation ◽  
Metabolic Reprogramming ◽  
Spike Protein ◽  
Glycolytic Metabolism ◽  
Protein Subunit ◽  
Pre Treatment

A hallmark of COVID-19 is a hyperinflammatory state associated with severity. Monocytes undergo metabolic reprogramming and produce inflammatory cytokines when stimulated with SARS-CoV-2. We hypothesized that binding by the viral spike protein mediates this effect, and that drugs which regulate immunometabolism could inhibit the inflammatory response. Monocytes stimulated with recombinant SARS-CoV-2 spike protein subunit 1 showed a dose-dependent increase in glycolytic metabolism associated with production of pro-inflammatory cytokines. This response was dependent on hypoxia-inducible factor-1α, as chetomin inhibited glycolysis and cytokine production. Inhibition of glycolytic metabolism by 2-deoxyglucose (2-DG) or glucose deprivation also inhibited the glycolytic response, and 2-DG strongly suppressed cytokine production. Glucose-deprived monocytes rescued cytokine production by upregulating oxidative phosphorylation, an effect which was not present in 2-DG-treated monocytes due to the known effect of 2-DG on suppressing mitochondrial metabolism. Finally, pre-treatment of monocytes with metformin strongly suppressed spike protein-mediated cytokine production and metabolic reprogramming. Likewise, metformin pre-treatment blocked cytokine induction by SARS-CoV-2 strain WA1/2020 in direct infection experiments. In summary, the SARS-CoV-2 spike protein induces a pro-inflammatory immunometabolic response in monocytes that can be suppressed by metformin, and metformin likewise suppresses inflammatory responses to live SARS-CoV-2. This has potential implications for the treatment of hyperinflammation during COVID-19.

scholarly journals Functionally distinct subsets of human FOXP3+ Treg cells that phenotypically mirror effector Th cells

Blood ◽  
2012 ◽  
Vol 119 (19) ◽  
pp. 4430-4440 ◽  
Author(s):  
Thomas Duhen ◽  
Rebekka Duhen ◽  
Antonio Lanzavecchia ◽  
Federica Sallusto ◽  
Daniel J. Campbell
Keyword(s):  
Inflammatory Cytokine ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Treg Cells ◽  
Receptor Expression ◽  
Inflammatory Cytokine Production ◽  
Th Cell ◽  
Different Types ◽  
Anti Inflammatory ◽  
Anti Inflammatory Cytokine

Abstract FOXP3+ regulatory T (Treg) cells are a broadly acting and potent anti-inflammatory population of CD4+ T cells essential for maintaining immune homeostasis and preventing debilitating autoimmunity. Based on chemokine receptor expression, we identified distinct populations of Treg cells in human blood expected to colocalize with different Th cell subsets. Although each population was functionally suppressive, they displayed unique patterns of pro- and anti-inflammatory cytokine production, differentially expressed lineage-specifying transcription factors, and responded differently to antigens associated with Th1 and Th17 responses. These results highlight a previously unappreciated degree of phenotypic and functional diversity in human Treg cells that allows subsets with unique specificities and immunomodulatory functions to be targeted to defined immune environments during different types of inflammatory responses.

scholarly journals Glycolysis-dependent histone deacetylase 4 degradation regulates inflammatory cytokine production

2014 ◽  
Vol 25 (21) ◽  
pp. 3300-3307 ◽  
Author(s):  
Bin Wang ◽  
Ting-yu Liu ◽  
Chun-Hsiang Lai ◽  
Yan-hua Rao ◽  
Moon-Chang Choi ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Response ◽  
Histone Deacetylase ◽  
Inflammatory Cytokine ◽  
Caspase 3 ◽  
Cytokine Production ◽  
Metabolic Reprogramming ◽  
Inflammatory Cytokine Production ◽  
Histone Deacetylase 4 ◽  
Lps Treatment

Activation of the inflammatory response is accompanied by a metabolic shift to aerobic glycolysis. Here we identify histone deacetylase 4 (HDAC4) as a new component of the immunometabolic program. We show that HDAC4 is required for efficient inflammatory cytokine production activated by lipopolysaccharide (LPS). Surprisingly, prolonged LPS treatment leads to HDAC4 degradation. LPS-induced HDAC4 degradation requires active glycolysis controlled by GSK3β and inducible nitric oxide synthase (iNOS). Inhibition of GSK3β or iNOS suppresses nitric oxide (NO) production, glycolysis, and HDAC4 degradation. We present evidence that sustained glycolysis induced by LPS treatment activates caspase-3, which cleaves HDAC4 and triggers its degradation. Of importance, a caspase-3–resistant mutant HDAC4 escapes LPS-induced degradation and prolongs inflammatory cytokine production. Our findings identify the GSK3β-iNOS-NO axis as a critical signaling cascade that couples inflammation to metabolic reprogramming and a glycolysis-driven negative feedback mechanism that limits inflammatory response by triggering HDAC4 degradation.

scholarly journals Mycobacterium tuberculosis induces decelerated bioenergetic metabolism in human macrophages

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Bridgette M Cumming ◽  
Kelvin W Addicott ◽  
John H Adamson ◽  
Adrie JC Steyn
Keyword(s):  
Fatty Acids ◽  
Mycobacterium Tuberculosis ◽  
Human Monocyte ◽  
Tca Cycle ◽  
Metabolic Reprogramming ◽  
Flux Analysis ◽  
Human Macrophages ◽  
Extracellular Flux ◽  
The Tca Cycle ◽  
Bioenergetic Metabolism

How Mycobacterium tuberculosis (Mtb) rewires macrophage energy metabolism to facilitate survival is poorly characterized. Here, we used extracellular flux analysis to simultaneously measure the rates of glycolysis and respiration in real time. Mtb infection induced a quiescent energy phenotype in human monocyte-derived macrophages and decelerated flux through glycolysis and the TCA cycle. In contrast, infection with the vaccine strain, M. bovis BCG, or dead Mtb induced glycolytic phenotypes with greater flux. Furthermore, Mtb reduced the mitochondrial dependency on glucose and increased the mitochondrial dependency on fatty acids, shifting this dependency from endogenous fatty acids in uninfected cells to exogenous fatty acids in infected macrophages. We demonstrate how quantifiable bioenergetic parameters of the host can be used to accurately measure and track disease, which will enable rapid quantifiable assessment of drug and vaccine efficacy. Our findings uncover new paradigms for understanding the bioenergetic basis of host metabolic reprogramming by Mtb.

scholarly journals Evaluation of Immunologic Function of Peripheral Blood Monocytes from Schizophrenic Patients in Response to Toxoplasma Gondii

2020 ◽  
pp. 1-8
Author(s):  
Ahmad Zavaran Hosseini ◽  
Ahmad Ali Noorbala ◽  
Ahmad Zavaran Hosseini ◽  
Esfandiar Azizi ◽  
Saiyad Bastaminejad ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Toxoplasma Gondii ◽  
Cytokine Production ◽  
Inflammatory Responses ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Inflammatory Cytokine Production ◽  
Tnf Α ◽  
Schizophrenic Patients

Background: It has been suggested that the function of myeloid immune cells, especially macrophages in schizophrenia patients (SCZ), is impaired. Considering the role of macrophages in induction of inflammatory responses, the purpose of this study is to examine the response of monocyte-derived macrophages (MDM) of schizophrenia patients to Toxoplasma gondii (T. gondii) challenge. Materials and Methods: MDMs were generated from 20 SCZ and 10 healthy controls (HC). The cells were exposed to T. gondii. The Cytokine (IL-10, IL-12, IL-6, and TNF-α) and nitric oxide (NO) productions were measured. The expression of miR146a and miR155 was examined using qPCR. Results: The level of NO was significantly higher in the supernatant of MDMs of SCZ compared with the HC (P≤0.05) in response to T. gondii. There was no difference in cytokine (IL-10, IL-12, IL-6, and TNF-α) production of SCZ compared to the controls. The effect of miR-155/ miR-146a on inflammatory cytokine production was confirmed using anti-miRNAs. There were no significant effect in miR-155/ miR-146a expression of macrophages of schizophrenia patients to T. gondii compared to control. Conclusion: In this study, although the cytokine response and the amount of miR-155/ miR-146a expression of macrophages to T. gondii was not significantly different between the schizophrenia patients and the healthy subjects, the significant differences in the production of nitric oxide strengthen the hypothesis of the functional failure of these cells.

scholarly journals Glutamine is required for M1-like polarization in response to Mycobacterium tuberculosis infection

2022 ◽  
Author(s):  
Lanbo Shi ◽  
Qingkui Jiang ◽  
Yunping Qiu ◽  
Irwin J. Kurland ◽  
Karl Drlica ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Tca Cycle ◽  
Metabolic Reprogramming ◽  
Tuberculosis Infection ◽  
Mycobacterium Tuberculosis Infection ◽  
M1 Macrophages ◽  
M1 Polarization ◽  
Key Enzyme ◽  
Antimicrobial Metabolite

In response to Mycobacterium tuberculosis infection, macrophages mount early proinflammatory and antimicrobial responses similar to those observed in M1 macrophages classically activated by LPS and IFN-γ. A metabolic reprogramming to 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 M1-like polarization during M. tuberculosis infection. Identification and quantification of labeling patterns of U 13 C glutamine and U 13 C glucose-derived metabolites demonstrated that glutamine, rather than glucose, is catabolized in both the oxidative and reductive TCA cycle of M1-like macrophages, thereby generating signaling molecules that include succinate, biosynthetic precursors such as aspartate, and the antimicrobial metabolite itaconate. This conclusion is corroborated by diminished M1 polarization via chemical inhibition of glutaminase (GLS), the key enzyme of the glutaminolysis pathway, and by genetic deletion of GLS in infected macrophages. Furthermore, characterization of the labeling distribution pattern of U 15 N glutamine in M1-like macrophages indicates that glutamine serves as a nitrogen source for the synthesis of intermediates of purine and pyrimidine metabolism plus amino acids including aspartate. Thus, the catabolism of glutamine, as an integral component of metabolic reprogramming in activating macrophages, fulfills the cellular demand for bioenergetic and biosynthetic precursors of M1-like macrophages. Knowledge of these new immunometabolic features of M1-like macrophages is expected to advance the development of host-directed therapies that will enhance bacterial clearance and prevent immunopathology during tuberculosis.

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