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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 -
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 Chemical Biology Oct 2012Cancer cells engage in a metabolic program to enhance biosynthesis and support cell proliferation. The regulatory properties of pyruvate kinase M2 (PKM2) influence...
Cancer cells engage in a metabolic program to enhance biosynthesis and support cell proliferation. The regulatory properties of pyruvate kinase M2 (PKM2) influence altered glucose metabolism in cancer. The interaction of PKM2 with phosphotyrosine-containing proteins inhibits enzyme activity and increases the availability of glycolytic metabolites to support cell proliferation. This suggests that high pyruvate kinase activity may suppress tumor growth. We show that expression of PKM1, the pyruvate kinase isoform with high constitutive activity, or exposure to published small-molecule PKM2 activators inhibits the growth of xenograft tumors. Structural studies reveal that small-molecule activators bind PKM2 at the subunit interaction interface, a site that is distinct from that of the endogenous activator fructose-1,6-bisphosphate (FBP). However, unlike FBP, binding of activators to PKM2 promotes a constitutively active enzyme state that is resistant to inhibition by tyrosine-phosphorylated proteins. These data support the notion that small-molecule activation of PKM2 can interfere with anabolic metabolism.
Topics: Animals; Biopolymers; Blotting, Western; Cell Proliferation; Cell Transformation, Neoplastic; Enzyme Activators; Humans; Mice; Neoplasms; Pyruvate Kinase
PubMed: 22922757
DOI: 10.1038/nchembio.1060 -
Redox Biology Sep 2020Nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease (NAFLD), is becoming a common chronic liver disease with the...
Nonalcoholic steatohepatitis (NASH), the progressive form of nonalcoholic fatty liver disease (NAFLD), is becoming a common chronic liver disease with the characteristics of steatosis, inflammation and fibrosis. Macrophage plays an important role in the development of NASH. In this study, Annexin A5 (Anx A5) is identified with the special effect on hepatic macrophage phenotype shift from M1 to M2. And it is further demonstrated that Anx A5 significantly switches metabolic reprogramming from glycolysis to oxidative phosphorylation in activated macrophages. Mechanistically, the main target of Anx A5 in energy metabolism is confirmed to be pyruvate kinase M2 (PKM2). And we following reveal that Anx A5 directly interacts with PKM2 at ASP101, LEU104 and ARG106, inhibits phosphorylation of Y105, and promotes PKM2 tetramer formation. In addition, based on the results of PKM2 inhibitor (compound 3k) and the phosphorylated mutation (PKM2 (Y105E)), it is proved that Anx A5 exhibits the function in macrophage polarization dependently on PKM2 activity. In vivo studies also show that Anx A5 improves steatosis, inflammation and fibrosis in NASH mice due to specially regulating hepatic macrophages via interaction with PKM2. Therefore, we have revealed a novel function of Anx A5 in hepatic macrophage polarization and HFD-induced NASH, providing important insights into the metabolic reprogramming, which is important for NASH therapy.
Topics: Animals; Annexin A5; Liver; Macrophage Activation; Macrophages; Mice; Non-alcoholic Fatty Liver Disease; Pyruvate Kinase
PubMed: 32863213
DOI: 10.1016/j.redox.2020.101634 -
Cell Death & Disease Oct 2023An important pathophysiological process of acute kidney injury (AKI) is mitochondrial fragmentation in renal tubular epithelial cells, which leads to cell death....
An important pathophysiological process of acute kidney injury (AKI) is mitochondrial fragmentation in renal tubular epithelial cells, which leads to cell death. Pyruvate kinase M2 (PKM2) is an active protein with various biological functions that participates in regulating glycolysis and plays a key role in regulating cell survival. However, the role and mechanism of PKM2 in regulating cell survival during AKI remain unclear. Here, we found that the phosphorylation of PKM2 contributed to the formation of the PKM2 dimer and translocation of PKM2 into the mitochondria after treatment with staurosporine or cisplatin. Mitochondrial PKM2 binds myosin heavy chain 9 (MYH9) to promote dynamin-related protein 1 (DRP1)-mediated mitochondrial fragmentation. Both in vivo and in vitro, PKM2-specific loss or regulation PKM2 activity partially limits mitochondrial fragmentation, alleviating renal tubular injury and cell death, including apoptosis, necroptosis, and ferroptosis. Moreover, staurosporine or cisplatin-induced mitochondrial fragmentation and cell death were reversed in cultured cells by inhibiting MYH9 activity. Taken together, our results indicate that the regulation of PKM2 abundance and activity to inhibit mitochondrial translocation may maintain mitochondrial integrity and provide a new therapeutic strategy for treating AKI.
Topics: Humans; Acute Kidney Injury; Cisplatin; Homeostasis; Mitochondria; Pyruvate Kinase; Staurosporine
PubMed: 37816709
DOI: 10.1038/s41419-023-06195-z -
Trends in Molecular Medicine May 2023Mutations in the PKLR gene lead to pyruvate kinase (PK) deficiency, causing chronic hemolytic anemia secondary to reduced red cell energy, which is crucial for... (Review)
Review
Mutations in the PKLR gene lead to pyruvate kinase (PK) deficiency, causing chronic hemolytic anemia secondary to reduced red cell energy, which is crucial for maintenance of the red cell membrane and function. Heterogeneous clinical manifestations can result in significant morbidity and reduced health-related quality of life. Treatment options have historically been limited to supportive care, including red cell transfusions and splenectomy. Current disease-modifying treatment considerations include an oral allosteric PK activator, mitapivat, which was recently approved for adults with PK deficiency, and gene therapy, which is currently undergoing clinical trials. Studies evaluating the role of PK activators in other congenital hemolytic anemias are ongoing. The long-term effect of treatment with disease-modifying therapy in PK deficiency will require continued evaluation.
Topics: Adult; Humans; Pyruvate Kinase; Quality of Life; Anemia, Hemolytic, Congenital Nonspherocytic; Pyruvate Metabolism, Inborn Errors
PubMed: 36935283
DOI: 10.1016/j.molmed.2023.02.005 -
Nature Communications Jul 2023Neutrophils rely predominantly on glycolytic metabolism for their biological functions, including reactive oxygen species (ROS) production. Although pyruvate kinase M2...
Neutrophils rely predominantly on glycolytic metabolism for their biological functions, including reactive oxygen species (ROS) production. Although pyruvate kinase M2 (PKM2) is a glycolytic enzyme known to be involved in metabolic reprogramming and gene transcription in many immune cell types, its role in neutrophils remains poorly understood. Here, we report that PKM2 regulates ROS production and microbial killing by neutrophils. Zymosan-activated neutrophils showed increased cytoplasmic expression of PKM2. Pharmacological inhibition or genetic deficiency of PKM2 in neutrophils reduced ROS production and Staphylococcus aureus killing in vitro. In addition, this also resulted in phosphoenolpyruvate (PEP) accumulation and decreased dihydroxyacetone phosphate (DHAP) production, which is required for de novo synthesis of diacylglycerol (DAG) from glycolysis. In vivo, PKM2 deficiency in myeloid cells impaired the control of infection with Staphylococcus aureus. Our results fill the gap in the current knowledge of the importance of lower glycolysis for ROS production in neutrophils, highlighting the role of PKM2 in regulating the DHAP and DAG synthesis to promote ROS production in neutrophils.
Topics: Pyruvate Kinase; Reactive Oxygen Species; Neutrophils; Phosphorylation; Glycolysis
PubMed: 37460614
DOI: 10.1038/s41467-023-40021-6 -
European Journal of Haematology Apr 2021Pyruvate kinase (PK) deficiency is caused by PKLR gene mutations, leading to defective red blood cell glycolysis and hemolytic anemia. Rates of comorbidities and...
OBJECTIVES
Pyruvate kinase (PK) deficiency is caused by PKLR gene mutations, leading to defective red blood cell glycolysis and hemolytic anemia. Rates of comorbidities and complications by transfusion history and relative to the general population remain poorly quantified.
METHODS
Data for patients aged ≥ 18 years with two confirmed PKLR mutations were obtained from the PK deficiency Natural History Study (NCT02053480). Frequencies of select conditions were compared with an age- and sex-matched cohort from a general insured US population without PK deficiency.
RESULTS
Compared with the matched population (n = 1220), patients with PK deficiency (n = 122) had significantly higher lifetime rates of osteoporosis, liver cirrhosis, and pulmonary hypertension; splenectomy and cholecystectomy rates were also significantly higher in the 8 years before the index date. Sixty-five (53.3%) patients with PK deficiency were classified as regularly transfused, 30 (24.6%) as occasionally transfused, and 27 (22.1%) as never transfused. Regularly transfused patients were significantly more likely than never transfused patients to have had splenectomy, cholecystectomy, and/or thrombosis. Liver iron overload was reported in 62% of patients and occurred regardless of transfusion cohort.
CONCLUSIONS
Even never transfused patients with PK deficiency had higher rates of select comorbidities and complications than individuals without PK deficiency.
Topics: Adult; Alleles; Anemia, Hemolytic, Congenital Nonspherocytic; Comorbidity; Female; Genotype; Humans; Male; Middle Aged; Mutation; Prevalence; Pyruvate Kinase; Pyruvate Metabolism, Inborn Errors; Young Adult
PubMed: 33370479
DOI: 10.1111/ejh.13572