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Molecular Cell May 2021Oxidative phosphorylation (OXPHOS) and glycolysis are the two major pathways for ATP production. The reliance on each varies across tissues and cell states, and can...
Oxidative phosphorylation (OXPHOS) and glycolysis are the two major pathways for ATP production. The reliance on each varies across tissues and cell states, and can influence susceptibility to disease. At present, the full set of molecular mechanisms governing the relative expression and balance of these two pathways is unknown. Here, we focus on genes whose loss leads to an increase in OXPHOS activity. Unexpectedly, this class of genes is enriched for components of the pre-mRNA splicing machinery, in particular for subunits of the U1 snRNP. Among them, we show that LUC7L2 represses OXPHOS and promotes glycolysis by multiple mechanisms, including (1) splicing of the glycolytic enzyme PFKM to suppress glycogen synthesis, (2) splicing of the cystine/glutamate antiporter SLC7A11 (xCT) to suppress glutamate oxidation, and (3) secondary repression of mitochondrial respiratory supercomplex formation. Our results connect LUC7L2 expression and, more generally, the U1 snRNP to cellular energy metabolism.
Topics: Amino Acid Transport System y+; Electron Transport Chain Complex Proteins; Gene Expression Regulation; Genome-Wide Association Study; Glutamic Acid; Glycogen; Glycolysis; HEK293 Cells; HeLa Cells; Humans; K562 Cells; Mitochondria; Oxidation-Reduction; Oxidative Phosphorylation; Phosphofructokinase-1, Muscle Type; RNA Precursors; RNA Splicing; RNA, Messenger; RNA-Binding Proteins; Ribonucleoprotein, U1 Small Nuclear
PubMed: 33852893
DOI: 10.1016/j.molcel.2021.02.033 -
Cell Aug 2021In neutrophils, nicotinamide adenine dinucleotide phosphate (NADPH) generated via the pentose phosphate pathway fuels NADPH oxidase NOX2 to produce reactive oxygen...
In neutrophils, nicotinamide adenine dinucleotide phosphate (NADPH) generated via the pentose phosphate pathway fuels NADPH oxidase NOX2 to produce reactive oxygen species for killing invading pathogens. However, excessive NOX2 activity can exacerbate inflammation, as in acute respiratory distress syndrome (ARDS). Here, we use two unbiased chemical proteomic strategies to show that small-molecule LDC7559, or a more potent designed analog NA-11, inhibits the NOX2-dependent oxidative burst in neutrophils by activating the glycolytic enzyme phosphofructokinase-1 liver type (PFKL) and dampening flux through the pentose phosphate pathway. Accordingly, neutrophils treated with NA-11 had reduced NOX2-dependent outputs, including neutrophil cell death (NETosis) and tissue damage. A high-resolution structure of PFKL confirmed binding of NA-11 to the AMP/ADP allosteric activation site and explained why NA-11 failed to agonize phosphofructokinase-1 platelet type (PFKP) or muscle type (PFKM). Thus, NA-11 represents a tool for selective activation of PFKL, the main phosphofructokinase-1 isoform expressed in immune cells.
Topics: Adenosine Diphosphate; Adenosine Monophosphate; Allosteric Regulation; Enzyme Activation; Epithelial Cells; Glycolysis; Humans; Intracellular Signaling Peptides and Proteins; Kinetics; Microbial Viability; Models, Molecular; NADPH Oxidases; Neutrophils; Phagocytosis; Phosphate-Binding Proteins; Phosphofructokinase-1, Liver Type; Protein Kinase Inhibitors; Recombinant Proteins; Respiratory Burst; Tetradecanoylphorbol Acetate
PubMed: 34320407
DOI: 10.1016/j.cell.2021.07.004 -
American Journal of Respiratory and... Sep 2019Glycolytic shift is implicated in the pathogenesis of pulmonary arterial hypertension (PAH). It remains unknown how glycolysis is increased and how increased glycolysis...
Glycolytic shift is implicated in the pathogenesis of pulmonary arterial hypertension (PAH). It remains unknown how glycolysis is increased and how increased glycolysis contributes to pulmonary vascular remodeling in PAH. To determine whether increased glycolysis is caused by 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) and how PFKFB3-driven glycolysis induces vascular remodeling in PAH. PFKFB3 levels were measured in pulmonary arteries of patients and animals with PAH. Lactate levels were assessed in lungs of animals with PAH and in pulmonary artery smooth muscle cells (PASMCs). Genetic and pharmacologic approaches were used to investigate the role of PFKFB3 in PAH. Lactate production was elevated in lungs of PAH rodents and in platelet-derived growth factor-treated PASMCs. PFKFB3 protein was higher in pulmonary arteries of patients and rodents with PAH, in PASMCs of patients with PAH, and in platelet-derived growth factor-treated PASMCs. PFKFB3 inhibition by genetic disruption and chemical inhibitor attenuated phosphorylation/activation of extracellular signal-regulated kinase (ERK1/2) and calpain-2, and vascular remodeling in PAH rodent models, and reduced platelet-derived growth factor-induced phosphorylation/activation of ERK1/2 and calpain-2, collagen synthesis and proliferation of PASMCs. ERK1/2 inhibition attenuated phosphorylation/activation of calpain-2, and vascular remodeling in Sugen/hypoxia PAH rats, and reduced lactate-induced phosphorylation/activation of calpain-2, collagen synthesis, and proliferation of PASMCs. Calpain-2 inhibition reduced lactate-induced collagen synthesis and proliferation of PASMCs. Upregulated PFKFB3 mediates collagen synthesis and proliferation of PASMCs, contributing to vascular remodeling in PAH. The mechanism is through the elevation of glycolysis and lactate that results in the activation of calpain by ERK1/2-dependent phosphorylation of calpain-2.
Topics: Animals; Cell Proliferation; Disease Models, Animal; Humans; Male; Mice; Muscle, Smooth, Vascular; Phosphofructokinase-2; Pulmonary Arterial Hypertension; Rats; Vascular Remodeling
PubMed: 30817168
DOI: 10.1164/rccm.201812-2290OC -
Cell Death & Disease Apr 2022Renal inflammation is a critical pathophysiological characteristic of diabetic kidney disease (DKD). The mechanism of the inflammatory response is complicated, and there...
Renal inflammation is a critical pathophysiological characteristic of diabetic kidney disease (DKD). The mechanism of the inflammatory response is complicated, and there are few effective treatments for renal inflammation that can be used clinically. Insulin-like growth factor-binding protein 5 (IGFBP5) is an important secretory protein that is related to inflammation and fibrosis in several tissues. Studies have shown that the IGFBP5 level is significantly upregulated in DKD. However, the function of IGFBP5 and its mechanism in DKD remain unclear. Here, we showed that IGFBP5 levels were significantly increased in the kidneys of diabetic mice. Ablation of IGFBP5 alleviated kidney inflammation in DKD mice. Mechanistically, IGFBP5 increased glycolysis, which was characterized by increases in lactic acid and the extracellular acidification rate, by activating the transcription factor early growth response 1 (EGR1) and enhancing the expression of PFKFB3 in endothelial cells. Furthermore, a mutation in PFKFB3 attenuated renal inflammation in DKD mice. Taken together, we provided evidence that IGFBP5 enhanced kidney inflammation through metabolic reprogramming of glomerular endothelial cells. Our results provide new mechanistic insights into the effect of IGFBP5 on kidney and highlight potential therapeutic opportunities for IGFBP5 and the metabolic regulators involved in DKD.
Topics: Animals; Carrier Proteins; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Endothelial Cells; Glycolysis; Humans; Inflammation; Mice; Phosphofructokinase-2
PubMed: 35418167
DOI: 10.1038/s41419-022-04803-y -
Revisited Metabolic Control and Reprogramming Cancers by Means of the Warburg Effect in Tumor Cells.International Journal of Molecular... Sep 2022Aerobic glycolysis is an emerging hallmark of many human cancers, as cancer cells are defined as a "metabolically abnormal system". Carbohydrates are metabolically... (Review)
Review
Aerobic glycolysis is an emerging hallmark of many human cancers, as cancer cells are defined as a "metabolically abnormal system". Carbohydrates are metabolically reprogrammed by its metabolizing and catabolizing enzymes in such abnormal cancer cells. Normal cells acquire their energy from oxidative phosphorylation, while cancer cells acquire their energy from oxidative glycolysis, known as the "Warburg effect". Energy-metabolic differences are easily found in the growth, invasion, immune escape and anti-tumor drug resistance of cancer cells. The glycolysis pathway is carried out in multiple enzymatic steps and yields two pyruvate molecules from one glucose (Glc) molecule by orchestral reaction of enzymes. Uncontrolled glycolysis or abnormally activated glycolysis is easily observed in the metabolism of cancer cells with enhanced levels of glycolytic proteins and enzymatic activities. In the "Warburg effect", tumor cells utilize energy supplied from lactic acid-based fermentative glycolysis operated by glycolysis-specific enzymes of hexokinase (HK), keto-HK-A, Glc-6-phosphate isomerase, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase, phosphofructokinase (PFK), phosphor-Glc isomerase (PGI), fructose-bisphosphate aldolase, phosphoglycerate (PG) kinase (PGK)1, triose phosphate isomerase, PG mutase (PGAM), glyceraldehyde-3-phosphate dehydrogenase, enolase, pyruvate kinase isozyme type M2 (PKM2), pyruvate dehydrogenase (PDH), PDH kinase and lactate dehydrogenase. They are related to glycolytic flux. The key enzymes involved in glycolysis are directly linked to oncogenesis and drug resistance. Among the metabolic enzymes, PKM2, PGK1, HK, keto-HK-A and nucleoside diphosphate kinase also have protein kinase activities. Because glycolysis-generated energy is not enough, the cancer cell-favored glycolysis to produce low ATP level seems to be non-efficient for cancer growth and self-protection. Thus, the Warburg effect is still an attractive phenomenon to understand the metabolic glycolysis favored in cancer. If the basic properties of the Warburg effect, including genetic mutations and signaling shifts are considered, anti-cancer therapeutic targets can be raised. Specific therapeutics targeting metabolic enzymes in aerobic glycolysis and hypoxic microenvironments have been developed to kill tumor cells. The present review deals with the tumor-specific Warburg effect with the revisited viewpoint of recent progress.
Topics: Glycolysis; Hexokinase; Humans; Neoplasms; Phosphofructokinase-1; Phosphoglycerate Kinase; Phosphoglycerate Mutase; Pyruvates; Tumor Microenvironment
PubMed: 36077431
DOI: 10.3390/ijms231710037 -
Circulation Research May 2022Mechanical forces play crucial roles in neointimal hyperplasia after vein grafting; yet, our understanding of their influences on vascular smooth muscle cell (VSMC)...
BACKGROUND
Mechanical forces play crucial roles in neointimal hyperplasia after vein grafting; yet, our understanding of their influences on vascular smooth muscle cell (VSMC) activation remains rudimentary.
METHODS
A cuff mouse model was used to study vein graft hyperplasia. Fifteen percent to 1 Hz uniaxial cyclic stretch (arterial strain), 5% to 1 Hz uniaxial cyclic stretch or a static condition (venous strain) were applied to the cultured VSMCs. Metabolomics analysis, cell proliferation and migration assays, immunoblotting, co-immunoprecipitation, mutagenesis, pull-down and surface plasmon resonance assays were employed to elucidate the potential molecular mechanisms.
RESULTS
RNA-sequencing in vein grafts and the controls identified changes in metabolic pathways and downregulation of mitochondrial protein MFN2 (mitofusin 2) in the vein grafts. Exposure of VSMCs to 15% stretch resulted in MFN2 downregulation, mitochondrial fragmentation, metabolic shift from mitochondrial oxidative phosphorylation to glycolysis, and cell proliferation and migration, as compared with that to a static condition or 5% stretch. Metabolomics analysis indicated an increased generation of fructose 1,6-bisphosphate, an intermediate in the glycolytic pathway converted by PFK1 (phosphofructokinase 1) from fructose-6-phosphate, in cells exposed to 15% stretch. Mechanistic study revealed that MFN2 physically interacts through its C-terminus with PFK1. MFN2 knockdown or exposure of cells to 15% stretch promoted stabilization of PFK1, likely through interfering the association between PFK1 and the E3 ubiquitin ligase TRIM21 (E3 ubiquitin ligase tripartite motif [TRIM]-containing protein 21), thus, decreasing the ubiquitin-protease-dependent PFK1 degradation. In addition, study of mechanotransduction utilizing pharmaceutical inhibition indicated that the MFN2 downregulation by 15% stretch was dependent on inactivation of the SP1 (specificity protein 1) and activation of the JNK (c-Jun N-terminal kinase) and ROCK (Rho-associated protein kinase). Adenovirus-mediated MFN2 overexpression or pharmaceutical inhibition of PFK1 suppressed the 15% stretch-induced VSMC proliferation and migration and alleviated neointimal hyperplasia in vein grafts.
CONCLUSIONS
MFN2 is a mechanoresponsive protein that interacts with PFK1 to mediate PFK1 degradation and therefore suppresses glycolysis in VSMCs.
Topics: Animals; Cell Proliferation; Cells, Cultured; GTP Phosphohydrolases; Hyperplasia; Mechanotransduction, Cellular; Mice; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Neointima; Phosphofructokinase-1; Ubiquitin-Protein Ligases
PubMed: 35450439
DOI: 10.1161/CIRCRESAHA.122.320846 -
Free Radical Biology & Medicine Nov 2023Hypoxia has long been considered to play an active role in the progression of fibrosis in chronic kidney disease, but its specific mechanism is not fully understood. The...
Hypoxia has long been considered to play an active role in the progression of fibrosis in chronic kidney disease, but its specific mechanism is not fully understood. The stimulator of interferon genes (STING) has been a research hotspot in the fields of tumor, immunity, and infection in recent years, and its role in immune and inflammatory responses related to kidney disease has gradually attracted attention. This study mainly explores the role and mechanism of STING in hypoxia-related renal fibrosis. To address this issue, we stimulated human proximal tubular epithelial (HK-2) cells with hypoxia for 48 h to construct cell models. Meanwhile, C57BL/6J male mice were used to establish a renal fibrosis model induced by renal ischemia-reperfusion injury (IRI). In our present study, we found that the GMP-AMP synthase (cGAS)-STING signaling pathway can promote the progression of renal fibrosis after hypoxic exposure, and this effect is closely related to 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3)-mediated glycolysis. Furthermore, inhibition of both STING and its downstream interferon regulatory factor 3 (IRF3) reversed elevated PFKFB3 expression, thereby attenuating hypoxia-induced renal fibrosis. Taken together, our data suggest that the cGAS-STING-IRF3-PFKFB3 signaling pathway activated under hypoxia may provide new ideas and targets for the treatment of early renal fibrosis.
Topics: Animals; Humans; Male; Mice; Fibrosis; Glycolysis; Hypoxia; Kidney Diseases; Mice, Inbred C57BL; Nucleotidyltransferases; Phosphofructokinase-2; Signal Transduction
PubMed: 37714438
DOI: 10.1016/j.freeradbiomed.2023.09.011 -
Cell Death & Disease Nov 2022Glioblastoma (GBM) is a highly vascular malignant brain tumor that overexpresses vascular endothelial growth factor (VEGF) and phosphofructokinase 1 platelet isoform...
Glioblastoma (GBM) is a highly vascular malignant brain tumor that overexpresses vascular endothelial growth factor (VEGF) and phosphofructokinase 1 platelet isoform (PFKP), which catalyzes a rate-limiting reaction in glycolysis. However, whether PFKP and VEGF are reciprocally regulated during GBM tumor growth remains unknown. Here, we show that PFKP can promote EGFR activation-induced VEGF expression in HIF-1α-dependent and -independent manners in GBM cells. Importantly, we demonstrate that EGFR-phosphorylated PFKP Y64 has critical roles in both AKT/SP1-mediated transcriptional expression of HIF-1α and in the AKT-mediated β-catenin S552 phosphorylation, to fully enhance VEGF transcription, subsequently promoting blood vessel formation and brain tumor growth. Levels of PFKP Y64 phosphorylation in human GBM specimens are positively correlated with HIF-1α expression, β-catenin S552 phosphorylation, and VEGF expression. Conversely, VEGF upregulates PFKP expression in a PFKP S386 phosphorylation-dependent manner, leading to increased PFK enzyme activity, aerobic glycolysis, and proliferation in GBM cells. These findings highlight a novel mechanism underlying the mutual regulation that occurs between PFKP and VEGF for promoting GBM tumor growth and also suggest that targeting the PFKP/VEGF regulatory loop might show therapeutic potential for treating GBM patients.
Topics: Humans; Glioblastoma; Vascular Endothelial Growth Factor A; Phosphorylation; beta Catenin; Proto-Oncogene Proteins c-akt; Phosphofructokinase-1; Vascular Endothelial Growth Factors; Brain Neoplasms; Protein Isoforms; ErbB Receptors
PubMed: 36435833
DOI: 10.1038/s41419-022-05449-6 -
Cell Death & Disease Oct 2022Renal fibrosis is a common pathological feature and outcome of almost all chronic kidney diseases, and it is characterized by metabolic reprogramming toward aerobic...
Renal fibrosis is a common pathological feature and outcome of almost all chronic kidney diseases, and it is characterized by metabolic reprogramming toward aerobic glycolysis. Mesenchymal stem cell-derived exosomes (MSC-Exos) have been proposed as a promising therapeutic approach for renal fibrosis. In this study, we investigated the effect of MSC-Exos on glycolysis and the underlying mechanisms. We demonstrated that MSC-Exos significantly ameliorated unilateral ureter obstruction (UUO)-induced renal fibrosis by inhibiting glycolysis in tubular epithelial cells (TECs). miRNA sequencing showed that miR-21a-5p was highly enriched in MSC-Exos. Mechanistically, miR-21a-5p repressed the expression of phosphofructokinase muscle isoform (PFKM), a rate-limiting enzyme of glycolysis, thereby attenuating glycolysis in TECs. Additionally, knockdown of miR-21a-5p abolished the renoprotective effect of MSC-Exos. These findings revealed a novel role for MSC-Exos in the suppression of glycolysis, providing a new insight into the treatment of renal fibrosis.
Topics: Humans; Exosomes; Fibrosis; Glycolysis; Kidney Diseases; Mesenchymal Stem Cells; MicroRNAs; Muscles; Phosphofructokinase-1, Muscle Type; Protein Isoforms
PubMed: 36253358
DOI: 10.1038/s41419-022-05305-7 -
Redox Biology Feb 2023The accumulation of DNA damage induced by oxidative stress is a crucial pathogenic factor of endothelial loss in diabetic vascular complications, but it is still unknown...
The accumulation of DNA damage induced by oxidative stress is a crucial pathogenic factor of endothelial loss in diabetic vascular complications, but it is still unknown whether aberrant glucose metabolism leads to defective DNA repair and accounts for hyperglycemia-induced endothelial oxidative stress injury. Here, we showed that Foxo1 knockdown alleviated diabetes-associated retinal DNA damage and vascular dysfunction. Mechanistically, FOXO1 knockdown avoided persistent DNA damage and cellular senescence under high glucose in endothelial cells by promoting DNA repair mediated by the MRN (MRE11-RAD50-NBS1 complex)-ATM pathway in response to oxidative stress injury. Moreover, FOXO1 knockdown mediated robust DNA repair by restoring glycolysis capacity under high glucose. During this process, the key glycolytic enzyme PFKFB3 was stimulated and, in addition to its promoting effect on glycolysis, directly participated in DNA repair. Under genotoxic stress, PFKFB3 relocated into oxidative stress-induced DNA damage sites and promoted DNA repair by interaction with the MRN-ATM pathway. Our study proposed that defective glycolysis-dependent DNA repair is present in diabetic endothelial cells and contributes to hyperglycemia-induced vascular dysfunction, which could provide novel therapeutic targets for diabetic vascular complications.
Topics: Humans; Cell Cycle Proteins; Endothelial Cells; DNA Repair; Glycolysis; DNA Damage; Oxidative Stress; Hyperglycemia; Glucose; Diabetic Angiopathies; Forkhead Box Protein O1; Phosphofructokinase-2
PubMed: 36577299
DOI: 10.1016/j.redox.2022.102589