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International Journal of Biological... 2022Emerging evidence suggests that metabolic adaptation is a vital hallmark and prerequisite for macrophage phenotype transition. Pyruvate kinase M2 (PKM2) is an essential...
Emerging evidence suggests that metabolic adaptation is a vital hallmark and prerequisite for macrophage phenotype transition. Pyruvate kinase M2 (PKM2) is an essential molecular determinant of metabolic adaptions in pro-inflammatory macrophages. Post-translational modifications play a central role in the regulation of PKM2. However, doubt remains on whether lactylation in PKM2 exists and how lactylation modulates the function of PKM2. For the first time, our study reports that lactate inhibits the Warburg effect by activating PKM2, promoting the transition of pro-inflammatory macrophages towards a reparative phenotype. We identify PKM2 as a lactylation substrate and confirm that lactylation occurs mainly at the K62 site. We find that lactate increases the lactylation level of PKM2, which inhibits its tetramer-to-dimer transition, promoting its pyruvate kinase activity and reducing nuclear distribution. In short, our study reports a novel post-translational modification type in PKM2 and clarifies its potential role in regulating inflammatory metabolic adaptation in pro-inflammatory macrophages.
Topics: Pyruvate Kinase; Macrophages; Glycolysis; Phosphorylation; Lactates
PubMed: 36439872
DOI: 10.7150/ijbs.75434 -
Seminars in Cell & Developmental Biology Jul 2015Pyruvate kinase is an enzyme that catalyzes the conversion of phosphoenolpyruvate and ADP to pyruvate and ATP in glycolysis and plays a role in regulating cell... (Review)
Review
Pyruvate kinase is an enzyme that catalyzes the conversion of phosphoenolpyruvate and ADP to pyruvate and ATP in glycolysis and plays a role in regulating cell metabolism. There are four mammalian pyruvate kinase isoforms with unique tissue expression patterns and regulatory properties. The M2 isoform of pyruvate kinase (PKM2) supports anabolic metabolism and is expressed both in cancer and normal tissue. The enzymatic activity of PKM2 is allosterically regulated by both intracellular signaling pathways and metabolites; PKM2 thus integrates signaling and metabolic inputs to modulate glucose metabolism according to the needs of the cell. Recent advances have increased our understanding of metabolic regulation by pyruvate kinase, raised new questions, and suggested the possibility of non-canonical PKM2 functions to regulate gene expression and cell cycle progression via protein-protein interactions and protein kinase activity. Here we review the structure, function, and regulation of pyruvate kinase and discuss how these properties enable regulation of PKM2 for cell proliferation and tumor growth.
Topics: Animals; Cell Cycle; Cell Proliferation; Gene Expression Regulation; Glucose; Glycolysis; Humans; Neoplasms; Protein Isoforms; Pyruvate Kinase; Signal Transduction
PubMed: 26277545
DOI: 10.1016/j.semcdb.2015.08.004 -
EMBO Reports Dec 2016A major metabolic aberration associated with cancer is a change in glucose metabolism. Isoform selection of the glycolytic enzyme pyruvate kinase has been implicated in... (Review)
Review
A major metabolic aberration associated with cancer is a change in glucose metabolism. Isoform selection of the glycolytic enzyme pyruvate kinase has been implicated in the metabolic phenotype of cancer cells, and specific pyruvate kinase isoforms have been suggested to support divergent energetic and biosynthetic requirements of cells in tumors and normal tissues. PKM2 isoform expression has been closely linked to embryogenesis, tissue repair, and cancer. In contrast, forced expression of the PKM1 isoform has been associated with reduced tumor cell proliferation. Here, we discuss the role that PKM2 plays in cells and provide a historical perspective for how the study of PKM2 has contributed to understanding cancer metabolism. We also review recent studies that raise important questions with regard to the role of PKM2 in both normal and cancer cell metabolism.
Topics: Animals; Carrier Proteins; Cell Line, Tumor; Cell Proliferation; Glycolysis; Humans; Isoenzymes; Membrane Proteins; Metabolic Networks and Pathways; Mice; Neoplasms; Pyruvate Kinase; Thyroid Hormones; Thyroid Hormone-Binding Proteins
PubMed: 27856534
DOI: 10.15252/embr.201643300 -
Blood Sep 2020Pyruvate kinase deficiency (PKD) is an autosomal-recessive enzyme defect of the glycolytic pathway that causes congenital nonspherocytic hemolytic anemia. The diagnosis... (Review)
Review
Pyruvate kinase deficiency (PKD) is an autosomal-recessive enzyme defect of the glycolytic pathway that causes congenital nonspherocytic hemolytic anemia. The diagnosis and management of patients with PKD can be challenging due to difficulties in the diagnostic evaluation and the heterogeneity of clinical manifestations, ranging from fetal hydrops and symptomatic anemia requiring lifelong transfusions to fully compensated hemolysis. Current treatment approaches are supportive and include transfusions, splenectomy, and chelation. Complications, including iron overload, bilirubin gallstones, extramedullary hematopoiesis, pulmonary hypertension, and thrombosis, are related to the chronic hemolytic anemia and its current management and can occur at any age. Disease-modifying therapies in clinical development may decrease symptoms and findings associated with chronic hemolysis and avoid the complications associated with current treatment approaches. As these disease-directed therapies are approved for clinical use, clinicians will need to define the types of symptoms and findings that determine the optimal patients and timing for initiating these therapies. In this article, we highlight disease manifestations, monitoring approaches, strategies for managing complications, and novel therapies in development.
Topics: Adolescent; Adult; Anemia, Hemolytic, Congenital Nonspherocytic; Blood Transfusion; Chelation Therapy; Child; Child, Preschool; Cholelithiasis; Clinical Trials as Topic; Disease Management; Female; Fetal Diseases; Genetic Therapy; Genotype; Hematopoietic Stem Cell Transplantation; Humans; Infant; Infant, Newborn; Iron Chelating Agents; Iron Overload; Jaundice, Neonatal; Male; Mutation; Pregnancy; Prevalence; Pyruvate Kinase; Pyruvate Metabolism, Inborn Errors; Splenectomy; Splenomegaly
PubMed: 32702739
DOI: 10.1182/blood.2019000945 -
Cell Metabolism Jan 2015Macrophages activated by the TLR4 agonist LPS undergo dramatic changes in their metabolic activity. We here show that LPS induces expression of the key metabolic...
Macrophages activated by the TLR4 agonist LPS undergo dramatic changes in their metabolic activity. We here show that LPS induces expression of the key metabolic regulator Pyruvate Kinase M2 (PKM2). Activation of PKM2 using two well-characterized small molecules, DASA-58 and TEPP-46, inhibited LPS-induced Hif-1α and IL-1β, as well as the expression of a range of other Hif-1α-dependent genes. Activation of PKM2 attenuated an LPS-induced proinflammatory M1 macrophage phenotype while promoting traits typical of an M2 macrophage. We show that LPS-induced PKM2 enters into a complex with Hif-1α, which can directly bind to the IL-1β promoter, an event that is inhibited by activation of PKM2. Both compounds inhibited LPS-induced glycolytic reprogramming and succinate production. Finally, activation of PKM2 by TEPP-46 in vivo inhibited LPS and Salmonella typhimurium-induced IL-1β production, while boosting production of IL-10. PKM2 is therefore a critical determinant of macrophage activation by LPS, promoting the inflammatory response.
Topics: Animals; Bone Marrow Cells; Cells, Cultured; Enzyme Activators; Gene Expression; Glycolysis; Hypoxia-Inducible Factor 1, alpha Subunit; Interleukin-1beta; Lipopolysaccharides; Macrophage Activation; Macrophages; Mice; Mice, Inbred C57BL; Promoter Regions, Genetic; Protein Binding; Pyruvate Kinase; RNA, Messenger; Salmonella typhimurium; Toll-Like Receptor 4
PubMed: 25565206
DOI: 10.1016/j.cmet.2014.12.005 -
Gut Dec 2022Follistatin-like protein 1 (FSTL1) is widely recognised as a secreted glycoprotein, but its role in modulating macrophage-related inflammation during liver fibrosis has...
OBJECTIVE
Follistatin-like protein 1 (FSTL1) is widely recognised as a secreted glycoprotein, but its role in modulating macrophage-related inflammation during liver fibrosis has not been documented. Herein, we aimed to characterise the roles of macrophage FSTL1 in the development of liver fibrosis.
DESIGN
Expression analysis was conducted with human liver samples obtained from 33 patients with liver fibrosis and 18 individuals without fibrosis serving as controls. Myeloid-specific FSTL1-knockout (FSTL1) mice were constructed to explore the function and mechanism of macrophage FSTL1 in 3 murine models of liver fibrosis induced by carbon tetrachloride injection, bile duct ligation or a methionine-deficient and choline-deficient diet.
RESULTS
FSTL1 expression was significantly elevated in macrophages from fibrotic livers of both humans and mice. Myeloid-specific FSTL1 deficiency effectively attenuated the progression of liver fibrosis. In FSTL1 mice, the microenvironment that developed during liver fibrosis showed relatively less inflammation, as demonstrated by attenuated infiltration of monocytes/macrophages and neutrophils and decreased expression of proinflammatory factors. FSTL1 macrophages exhibited suppressed proinflammatory M1 polarisation and nuclear factor kappa B pathway activation in vivo and in vitro. Furthermore, this study showed that, through its FK domain, FSTL1 bound directly to the pyruvate kinase M2 (PKM2). Interestingly, FSTL1 promoted PKM2 phosphorylation and nuclear translocation, reduced PKM2 ubiquitination to enhance PKM2-dependent glycolysis and increased M1 polarisation. Pharmacological activation of PKM2 (DASA-58) partially countered FSTL1-mediated glycolysis and inflammation.
CONCLUSION
Macrophage FSTL1 promotes the progression of liver fibrosis by inducing M1 polarisation and inflammation based on the intracellular PKM2 reprogramming function of macrophages.
Topics: Humans; Mice; Animals; Follistatin-Related Proteins; Pyruvate Kinase; Mice, Inbred C57BL; Macrophages; Liver Cirrhosis; Inflammation; Liver
PubMed: 35140065
DOI: 10.1136/gutjnl-2021-325150 -
Cell Metabolism Sep 2022The drivers of sporadic Alzheimer's disease (AD) remain incompletely understood. Utilizing directly converted induced neurons (iNs) from AD-patient-derived fibroblasts,...
The drivers of sporadic Alzheimer's disease (AD) remain incompletely understood. Utilizing directly converted induced neurons (iNs) from AD-patient-derived fibroblasts, we identified a metabolic switch to aerobic glycolysis in AD iNs. Pathological isoform switching of the glycolytic enzyme pyruvate kinase M (PKM) toward the cancer-associated PKM2 isoform conferred metabolic and transcriptional changes in AD iNs. These alterations occurred via PKM2's lack of metabolic activity and via nuclear translocation and association with STAT3 and HIF1α to promote neuronal fate loss and vulnerability. Chemical modulation of PKM2 prevented nuclear translocation, restored a mature neuronal metabolism, reversed AD-specific gene expression changes, and re-activated neuronal resilience against cell death.
Topics: Alzheimer Disease; Glycolysis; Humans; Neoplasms; Protein Isoforms; Pyruvate Kinase
PubMed: 35987203
DOI: 10.1016/j.cmet.2022.07.014 -
Military Medical Research May 2022Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported....
BACKGROUND
Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol (Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.
METHODS
We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide (LPS). We screened for potential protein targets of Cel using activity-based protein profiling (ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays (CETSA) and surface plasmon resonance (SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.
RESULTS
Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS (P < 0.05). Cel bound to Cys424 of pyruvate kinase M2 (PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis (Warburg effect). Cel also bound to Cys106 in high mobility group box 1 (HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin (IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A (LDHA).
CONCLUSION
Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.
Topics: Animals; Anti-Inflammatory Agents; Cytokines; Endotoxemia; HMGB1 Protein; Humans; Inflammation; Lipopolysaccharides; Mice; Pentacyclic Triterpenes; Pyruvate Kinase; Sepsis
PubMed: 35596191
DOI: 10.1186/s40779-022-00381-4 -
Nature Communications Mar 2023Vascular endothelial cells (ECs) senescence correlates with the increase of cardiovascular diseases in ageing population. Although ECs rely on glycolysis for energy...
Vascular endothelial cells (ECs) senescence correlates with the increase of cardiovascular diseases in ageing population. Although ECs rely on glycolysis for energy production, little is known about the role of glycolysis in ECs senescence. Here, we report a critical role for glycolysis-derived serine biosynthesis in preventing ECs senescence. During senescence, the expression of serine biosynthetic enzyme PHGDH is significantly reduced due to decreased transcription of the activating transcription factor ATF4, which leads to reduction of intracellular serine. PHGDH prevents premature senescence primarily by enhancing the stability and activity of pyruvate kinase M2 (PKM2). Mechanistically, PHGDH interacts with PKM2, which prevents PCAF-catalyzed PKM2 K305 acetylation and subsequent degradation by autophagy. In addition, PHGDH facilitates p300-catalyzed PKM2 K433 acetylation, which promotes PKM2 nuclear translocation and stimulates its activity to phosphorylate H3T11 and regulate the transcription of senescence-associated genes. Vascular endothelium-targeted expression of PHGDH and PKM2 ameliorates ageing in mice. Our findings reveal that enhancing serine biosynthesis could become a therapy to promote healthy ageing.
Topics: Animals; Mice; Cellular Senescence; Endothelial Cells; Glycolysis; Histones; Phosphoglycerate Dehydrogenase; Pyruvate Kinase; Serine; Aging
PubMed: 36899022
DOI: 10.1038/s41467-023-37094-8 -
PKM2 promotes Th17 cell differentiation and autoimmune inflammation by fine-tuning STAT3 activation.The Journal of Experimental Medicine Oct 2020Th17 cell differentiation and pathogenicity depend on metabolic reprogramming inducing shifts toward glycolysis. Here, we show that the pyruvate kinase M2 (PKM2), a...
Th17 cell differentiation and pathogenicity depend on metabolic reprogramming inducing shifts toward glycolysis. Here, we show that the pyruvate kinase M2 (PKM2), a glycolytic enzyme required for cancer cell proliferation and tumor progression, is a key factor mediating Th17 cell differentiation and autoimmune inflammation. We found that PKM2 is highly expressed throughout the differentiation of Th17 cells in vitro and during experimental autoimmune encephalomyelitis (EAE) development. Strikingly, PKM2 is not required for the metabolic reprogramming and proliferative capacity of Th17 cells. However, T cell-specific PKM2 deletion impairs Th17 cell differentiation and ameliorates symptoms of EAE by decreasing Th17 cell-mediated inflammation and demyelination. Mechanistically, PKM2 translocates into the nucleus and interacts with STAT3, enhancing its activation and thereby increasing Th17 cell differentiation. Thus, PKM2 acts as a critical nonmetabolic regulator that fine-tunes Th17 cell differentiation and function in autoimmune-mediated inflammation.
Topics: Animals; Autoimmunity; Cell Differentiation; Encephalomyelitis, Autoimmune, Experimental; Flow Cytometry; Fluorescent Antibody Technique; Inflammation; Mice; Mice, Inbred C57BL; Pyruvate Kinase; Real-Time Polymerase Chain Reaction; STAT3 Transcription Factor; Th17 Cells
PubMed: 32697823
DOI: 10.1084/jem.20190613