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Acta Biochimica Et Biophysica Sinica Aug 2023Tumor metabolic reprogramming and epigenetic modification work together to promote tumorigenesis and development. Protein lysine acetylation, which affects a variety of...
Tumor metabolic reprogramming and epigenetic modification work together to promote tumorigenesis and development. Protein lysine acetylation, which affects a variety of biological functions of proteins, plays an important role under physiological and pathological conditions. Here, through immunoprecipitation and mass spectrum data, we show that phosphoglycerate mutase 5 (PGAM5) deacetylation enhances malic enzyme 1 (ME1) metabolic enzyme activity to promote lipid synthesis and proliferation of liver cancer cells. Mechanistically, we demonstrate that the deacetylase SIRT2 mediates PGAM5 deacetylation to activate ME1 activity, leading to ME1 dephosphorylation, subsequent lipid accumulation and the proliferation of liver cancer cells. Taken together, our study establishes an important role for the SIRT2-PGAM5-ME1 axis in the proliferation of liver cancer cells, suggesting a potential innovative cancer therapy.
Topics: Humans; Sirtuin 2; Lipid Metabolism; Phosphoglycerate Mutase; Liver Neoplasms; Cell Proliferation; Lipids; Acetylation; Phosphoprotein Phosphatases; Mitochondrial Proteins
PubMed: 37580952
DOI: 10.3724/abbs.2023155 -
Frontiers in Immunology 2023Macrophages play a critical role in the regulation of inflammation and tissue homeostasis. In addition to their vital functions for cell survival and physiology,...
Macrophages play a critical role in the regulation of inflammation and tissue homeostasis. In addition to their vital functions for cell survival and physiology, mitochondria play a crucial role in innate immunity as a platform for the induction of inflammatory responses by regulating cell signaling and dynamics. Dynamin-related protein 1 (Drp1) plays a role in the induction of inflammatory responses and the subsequent development of various diseases. PGAM5 (phosphoglycerate mutase member 5) is a mitochondrial outer membrane phosphatase that dephosphorylates its substrate, Drp1. Previous studies showed that PGAM5 regulates the phosphorylation of Drp1 for the activation of NKT cells and T cells. However, it is not clear how PGAM5 regulates Drp1 activity for the induction of inflammation in macrophages. Here, we demonstrate that PGAM5 activity regulates the dephosphorylation of Drp1 in macrophages, leading to the induction of proinflammatory responses in macrophages. In TLR signaling, PGAM5 regulates the expression and production of inflammatory cytokines by regulating the activation of downstream signaling pathways, including the NF-κB and MAPK pathways. Upon LPS stimulation, PGAM5 interacts with Drp1 to form a complex, leading to the production of mtROS. Furthermore, PGAM5-Drp1 signaling promotes the polarization of macrophages toward a proinflammatory phenotype. Our study further demonstrates that PGAM5-Drp1 signaling promotes metabolic reprogramming by upregulating glycolysis and mitochondrial metabolism in macrophages. Altogether, PGAM5 signaling is a linker between alterations in Drp1-mediated mitochondrial dynamics and inflammatory responses in macrophages and may be a target for the treatment of inflammatory diseases.
Topics: Humans; Dynamins; Inflammation; Macrophages; Mitochondrial Proteins; Phosphoprotein Phosphatases; Signal Transduction; Animals
PubMed: 37771598
DOI: 10.3389/fimmu.2023.1243548 -
Cell & Bioscience Aug 2023Phosphoglycerate mutase 5 (PGAM5), a phosphatase involved in mitochondrial homeostasis, is reported to be closely related to the metabolic stress induced by high-fat...
BACKGROUND
Phosphoglycerate mutase 5 (PGAM5), a phosphatase involved in mitochondrial homeostasis, is reported to be closely related to the metabolic stress induced by high-fat diet (HFD) or cold. In this study, we aimed to investigate the effects of PGAM5 on hepatic steatosis, inflammation and fibrosis in nonalcoholic steatohepatitis (NASH).
METHODS AND RESULTS
We generated PGAM5 global knockout (GKO) mice and their wildtype (WT) littermates using CRISPR/CAS9. The mice were fed with a high fat high fructose (HFHF) diet for 12 weeks or a methionine choline-deficient (MCD) diet (methionine choline supplemented (MCS) as control) for 6 weeks. Hepatic PGAM5 expression was up-regulated in humans with NASH and WT mice fed with HFHF and MCS, and reduced in WT mice fed with MCD diet. In HFHF-fed mice, GKO had reduced body weight, hepatic triglyceride (TG) content and serum transaminase along with decreased hepatic pro-inflammatory and pro-fibrotic responses compared with their WT control. GKO had increased expression of antioxidative gene glutathione peroxidase-6 (GPX6) and activation of mammalian target of rapamycin (mTOR). In mice fed with MCS diet, GKO significantly increased serum TNF-α and IL-6 and decreased hepatic GPX6 mRNA expression. There was no difference in hepatic steatosis, inflammation or fibrosis between GKO and WT mice fed with MCD diet. We investigated the role of PGAM5 deficiency in a variety of cell types. In differentiated THP-1 cells, PGAM5 silencing significantly increased pro-inflammatory cytokine secretion and decreased antioxidative proteins, including nuclear factor erythroid 2- related factors (NRF2), heme oxygenase-1 (HO-1) and GPX6 without affecting mTOR activity. In HepG2 cells with steatosis, PGAM5 knockdown reduced insulin sensitivity, increased mTOR phosphorylation and reduced the expression of NRF2, catalase (CAT), HO-1 and GPX6. Conversely, PGAM5 knockdown reduced TG accumulation, increased insulin sensitivity, and increased antioxidative genes in 3T3-L1 cells, despite the up-regulation in mTOR phosphorylation.
CONCLUSIONS
PGAM5-KO relieved hepatic steatosis and inflammation in HFHF model, promoted inflammation in MCS-fed mice and had no effects on the MCD-fed model. The distinct effects may be owing to the different effects of PGAM5-KO on anti-oxidative pathways in energy-dependent, possible involves mTOR, and/or cell type-dependent manner. Our findings suggest that PGAM5 can be a potential therapeutic target for NASH.
PubMed: 37605246
DOI: 10.1186/s13578-023-01095-3 -
International Journal of Biological... 2023Numerous mitochondrial abnormalities are reported to result from excessive inflammation during endotoxemia. Prohibitin 2 (PHB2) and phosphoglycerate mutase 5 (Pgam5)...
Numerous mitochondrial abnormalities are reported to result from excessive inflammation during endotoxemia. Prohibitin 2 (PHB2) and phosphoglycerate mutase 5 (Pgam5) have been associated with altered mitochondrial homeostasis in several cardiovascular diseases; however, their role in endotoxemia-related myocardial dysfunction has not been explored. Our experiments were aimed to evaluate the potential contribution of Pgam5 and PHB2 to endotoxemia-induced mitochondrial dysfunction in cardiomyocytes, with a focus on two endogenous protective programs that sustain mitochondrial integrity, namely mitophagy and the mitochondrial unfolded protein response (UPR). We found that PHB2 transgenic mice are resistant to endotoxemia-mediated myocardial depression and mitochondrial damage. Our assays indicated that PHB2 overexpression activates mitophagy and the UPR, which maintains mitochondrial metabolism, prevents oxidative stress injury, and enhances cardiomyocyte viability. Molecular analyses further showed that Pgam5 binds to and dephosphorylates PHB2, resulting in cytosolic translocation of mitochondrial PHB2. Silencing of Pgam5 or transfection of a phosphorylated PHB2 mutant in mouse HL-1 cardiomyocytes prevented the loss of mitochondrially-localized PHB2 and activated mitophagy and UPR in the presence of LPS. Notably, cardiomyocyte-specific deletion of Pgam5 attenuated LPS-mediated myocardial dysfunction and preserved cardiomyocyte viability. These findings suggest that Pgam5/PHB2 signaling and mitophagy/UPR are potential targets for the treatment of endotoxemia-related cardiac dysfunction.
Topics: Animals; Mice; Endotoxemia; Lipopolysaccharides; Mitophagy; Phosphoprotein Phosphatases; Prohibitins; Unfolded Protein Response
PubMed: 37781037
DOI: 10.7150/ijbs.85767 -
The EMBO Journal Jun 2024Phosphoglycerate mutase 1 (PGAM1) is a key node enzyme that diverts the metabolic reactions from glycolysis into its shunts to support macromolecule biosynthesis for...
Phosphoglycerate mutase 1 (PGAM1) is a key node enzyme that diverts the metabolic reactions from glycolysis into its shunts to support macromolecule biosynthesis for rapid and sustainable cell proliferation. It is prevalent that PGAM1 activity is upregulated in various tumors; however, the underlying mechanism remains unclear. Here, we unveil that pyruvate kinase M2 (PKM2) moonlights as a histidine kinase in a phosphoenolpyruvate (PEP)-dependent manner to catalyze PGAM1 H11 phosphorylation, that is essential for PGAM1 activity. Moreover, monomeric and dimeric but not tetrameric PKM2 are efficient to phosphorylate and activate PGAM1. In response to epidermal growth factor signaling, Src-catalyzed PGAM1 Y119 phosphorylation is a prerequisite for PKM2 binding and the subsequent PGAM1 H11 phosphorylation, which constitutes a discrepancy between tumor and normal cells. A PGAM1-derived pY119-containing cell-permeable peptide or Y119 mutation disrupts the interaction of PGAM1 with PKM2 and PGAM1 H11 phosphorylation, dampening the glycolysis shunts and tumor growth. Together, these results identify a function of PKM2 as a histidine kinase, and illustrate the importance of enzyme crosstalk as a regulatory mode during metabolic reprogramming and tumorigenesis.
Topics: Glycolysis; Humans; Phosphoglycerate Mutase; Phosphorylation; Animals; Thyroid Hormones; Mice; Thyroid Hormone-Binding Proteins; Neoplasms; Membrane Proteins; Cell Line, Tumor; Carrier Proteins
PubMed: 38750259
DOI: 10.1038/s44318-024-00110-8 -
Cell Stress & Chaperones Jun 2024Heart failure (HF) refers to a group of clinical syndromes in which various heart diseases lead to the inability of cardiac output to meet the metabolic needs of the... (Review)
Review
Heart failure (HF) refers to a group of clinical syndromes in which various heart diseases lead to the inability of cardiac output to meet the metabolic needs of the body's tissues. Cardiac metabolism requires enormous amounts of energy; thus, impaired myocardial energy metabolism is considered a key factor in the occurrence and development of HF. Mitochondria serve as the primary energy source for cardiomyocytes, and their regular functionality underpins healthy cardiac function. The mitochondrial quality control system is a crucial mechanism for regulating the functionality of cardiomyocytes, and any abnormality in this system can potentially impact the morphology and structure of mitochondria, as well as the energy metabolism of cardiomyocytes. Phosphoglycerate mutase 5 (PGAM5), a multifunctional protein, plays a key role in the regulation of mitochondrial quality control through multiple pathways. Therefore, abnormal PGAM5 function is closely related to mitochondrial damage. This article reviews the mechanism of PGAM5's involvement in the regulation of the mitochondrial quality control system in the occurrence and development of HF, thereby providing a theoretical basis for future in-depth research.
Topics: Humans; Heart Failure; Animals; Mitochondria, Heart; Phosphoprotein Phosphatases; Mitochondrial Proteins; Myocytes, Cardiac; Mitochondria; Energy Metabolism
PubMed: 38821173
DOI: 10.1016/j.cstres.2024.05.004 -
Biochemistry and Biophysics Reports Sep 2023A growing body of evidence indicated that Alantolactone (ALT) promotes Reactive Oxygen Species (ROS) generation exclusively in cancer cells. Therefore, the aim of this...
INTRODUCTION
A growing body of evidence indicated that Alantolactone (ALT) promotes Reactive Oxygen Species (ROS) generation exclusively in cancer cells. Therefore, the aim of this study was to investigate the effect of ALT on the molecular mechanism of oxeiptosis, as a novel cell death pathway due to the high levels of intracellular ROS in ovarian cancer.
METHODS
MTT assay was used to evaluate the effect of ALT on SKOV3 cell viability. mRNA and protein expression levels of Nrf2 (nuclear factor erythroid 2-related factor 2), KEAP1 (Kelch-like ECH-associated protein 1), PGAM5 (phosphoglycerate mutase family member 5), AIFM1 (Mitochondrial Apoptosis-Inducing Factor), Glutathione synthetase (GSS) and glutathione peroxidase (GPX) were analyzed by real time PCR and western blotting methods respectively.
RESULTS
Our findings showed that ALT inhibits the proliferation of skov3 cells in a time and dose dependent manner and IC50 was 32 μM at 24h.A significant down-regulation of Nrf2, GSH and GPX mRNA levels was seen in skov3 cells incubated with 32 and 64 μM of ALT in comparison with control group, while, mRNA expression levels of PGAM5 and KEAP1 were increased.Western blot analysis showed that ALT significantly decreases protein levels of Nrf2 and increases PGAM5 and KEAP1.ALT dephosphorylated PS116-AIFM1 and total AIFM1 protein level was elevated.
CONCLUSION
Our results provided evidence that ALT could be a potential option for ovarian cancer treatment by ROS-mediated oxeiptosis.
PubMed: 37712005
DOI: 10.1016/j.bbrep.2023.101537 -
CNS Neuroscience & Therapeutics Apr 2024Despite extensive work to identify diagnostic plasma markers for Parkinson's disease (PD), there are still no accepted and validated surrogate biomarkers....
BACKGROUND
Despite extensive work to identify diagnostic plasma markers for Parkinson's disease (PD), there are still no accepted and validated surrogate biomarkers. Mitophagy-associated proteins (MAPs), including PTEN-induced putative kinase 1 (PINK1), Parkin, phosphoglycerate mutase 5 (PGAM5), BCL2 interacting protein 3 (BNIP3), and phosphorylated-TBK1 (p-TBK1), are, to our best knowledge, not well studied as a panel of biomarkers of neurodegeneration in PD.
METHODS
The study population comprised 116 age-matched controls (HC), 179 PD patients, alongside and 90 PD syndromes (PDs) divided between two cohorts: (i) the modeling cohort (cohort 1), including 150 PD, 97 HC, and 80 PDs; and (ii) the validated cohort (cohort 2), including 29 PD, 19 HC, and 10 PDs.
RESULTS
MAPs are elevated in the plasma of PD patients. PINK1, Parkin, and PGAM5 displayed the top three measurable increase trends in amplitude compared to BNIP3 and p-TBK1. Moreover, the area under the curve (AUC) values of PINK1, PGAM5, and Parkin were ranked the top three MAP candidates in diagnosis accuracy for PD from HC, but the MAPs make it hard to differentiate PD from PDs. In addition, there are higher plasma PINK1-Parkin levels and prominent diagnostic accuracy in A-synuclein (+) subjects than in A-synuclein (-) subjects.
CONCLUSIONS
These results uncover that plasma MAPs (PINK1, Parkin, and PGAM5) may be potentially useful diagnostic biomarkers for PD diagnosis. Studies on larger cohorts would be required to test whether elevated plasma MAP levels are related to PD risk or prognosis.
Topics: Humans; Parkinson Disease; Male; Female; Biomarkers; Aged; Middle Aged; Mitophagy; Protein Kinases; Ubiquitin-Protein Ligases; Cohort Studies; Mitochondrial Proteins; Membrane Proteins; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Phosphoprotein Phosphatases
PubMed: 37990436
DOI: 10.1111/cns.14532 -
International Journal of Medical... 2024This study aims to elucidate the roles of Phosphoglycerate Mutase Family Member 5 (Pgam5) and Prohibitin 2 (Phb2) in the context of hyperglycemia-induced myocardial...
This study aims to elucidate the roles of Phosphoglycerate Mutase Family Member 5 (Pgam5) and Prohibitin 2 (Phb2) in the context of hyperglycemia-induced myocardial dysfunction, a critical aspect of diabetic cardiomyopathy. The research employed primary cardiomyocytes, which were then subjected to hyperglycemia treatment to mimic diabetic conditions. We used siRNA transfection to knock down Pgam5 and overexpressed Phb2 using adenovirus transfection to assess their individual and combined effects on cardiomyocyte health. Mitochondrial function was evaluated through measurements of mitochondrial membrane potential using the JC-1 probe, and levels of mitochondrial reactive oxygen species (ROS) were assessed. Additionally, the study involved qPCR analysis to quantify the transcriptional changes in genes related to mitochondrial fission and mitophagy. Our findings indicate that hyperglycemia significantly reduces cardiomyocyte viability and impairs mitochondrial function, as evidenced by decreased mitochondrial membrane potential and increased ROS levels. Pgam5 knockdown was observed to mitigate these adverse effects, preserving mitochondrial function and cardiomyocyte viability. On the molecular level, Pgam5 was found to regulate genes associated with mitochondrial fission (such as Drp1, Mff, and Fis1) and mitophagy (including Parkin, Bnip3, and Fundc1). Furthermore, overexpression of Phb2 countered the hyperglycemia-induced mitochondrial dysfunction and normalized the levels of key mitochondrial antioxidant enzymes. The combined data suggest a protective role for both Pgam5 knockdown and Phb2 overexpression against hyperglycemia-induced cellular and mitochondrial damage. The study elucidates the critical roles of Pgam5 and Phb2 in regulating mitochondrial dynamics in the setting of hyperglycemia-induced myocardial dysfunction. By modulating mitochondrial fission and mitophagy, Pgam5 and Phb2 emerge as key players in preserving mitochondrial integrity and cardiomyocyte health under diabetic conditions. These findings contribute significantly to our understanding of the molecular mechanisms underlying diabetic cardiomyopathy and suggest potential therapeutic targets for mitigating myocardial dysfunction in diabetes.
Topics: Prohibitins; Myocytes, Cardiac; Mitochondrial Dynamics; Hyperglycemia; Humans; Membrane Potential, Mitochondrial; Diabetic Cardiomyopathies; Reactive Oxygen Species; Animals; Mitophagy; Phosphoprotein Phosphatases; Repressor Proteins; Mitochondria, Heart; Mitochondrial Proteins; Rats
PubMed: 38818468
DOI: 10.7150/ijms.92872 -
Journal of Cancer 2024Phosphoglycerate mutase 1 (PGAM1) is a key enzyme regulating cancer glycolysis. However, the expression and function of PGAM1 in uveal melanoma (UVM) are unknown and...
Phosphoglycerate mutase 1 (PGAM1) is a key enzyme regulating cancer glycolysis. However, the expression and function of PGAM1 in uveal melanoma (UVM) are unknown and systematic analysis is lacking. This study performed a comprehensive analysis of PGAM1 expression across 33 cancer types in multiple public databases. Results demonstrated PGAM1 is aberrantly overexpressed in most tumors compared to normal tissues, and this overexpression is associated with poor prognosis, advanced tumor staging, and aggressive clinical phenotypes in multiple cancers including UVM, lung, breast and bladder carcinomas. In addition, PGAM1 expression positively correlated with infiltration levels of tumor-promoting immune cells including macrophages, NK cells, myeloid dendritic cells, etc. Further experiments showed that PGAM1 was overexpressed in UVM cell lines and tissues, and it was positively associated with a poor prognosis of UVM patients. And knockdown of PGAM1 inhibited migration/invasion and induced apoptosis in UVM cells, followed by decreased levels of PD-L1, Snail, and BCl-2 and increased levels of E-cadherin. Additionally, the correlation analysis and molecular docking results suggest that PGAM1 could interact with PD-L1, Snail and BCl-2. Thus, PGAM1 may promote UVM pathogenesis via modulating immune checkpoint signaling, EMT and apoptosis. Collectively, this study reveals PGAM1 as a valuable prognostic biomarker and potential therapeutic target in aggressive cancers including UVM.
PubMed: 38434965
DOI: 10.7150/jca.93398