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Showing papers on "Pyruvate kinase published in 2021"


Journal ArticleDOI
18 Aug 2021-Nature
TL;DR: In this paper, the authors show that dietary fructose improves the survival of intestinal cells and increases intestinal villus length in several mouse models, which leads to an increase in gut surface area, enhanced absorption of lipids and the promotion of tumour growth and obesity.
Abstract: Fructose consumption is linked to the rising incidence of obesity and cancer, which are two of the leading causes of morbidity and mortality globally1,2. Dietary fructose metabolism begins at the epithelium of the small intestine, where fructose is transported by glucose transporter type 5 (GLUT5; encoded by SLC2A5) and phosphorylated by ketohexokinase to form fructose 1-phosphate, which accumulates to high levels in the cell3,4. Although this pathway has been implicated in obesity and tumour promotion, the exact mechanism that drives these pathologies in the intestine remains unclear. Here we show that dietary fructose improves the survival of intestinal cells and increases intestinal villus length in several mouse models. The increase in villus length expands the surface area of the gut and increases nutrient absorption and adiposity in mice that are fed a high-fat diet. In hypoxic intestinal cells, fructose 1-phosphate inhibits the M2 isoform of pyruvate kinase to promote cell survival5–7. Genetic ablation of ketohexokinase or stimulation of pyruvate kinase prevents villus elongation and abolishes the nutrient absorption and tumour growth that are induced by feeding mice with high-fructose corn syrup. The ability of fructose to promote cell survival through an allosteric metabolite thus provides additional insights into the excess adiposity generated by a Western diet, and a compelling explanation for the promotion of tumour growth by high-fructose corn syrup. A high-fructose diet in mice improves the survival of intestinal epithelial cells, which leads to an increase in gut surface area, enhanced absorption of lipids and the promotion of tumour growth and obesity.

82 citations


Journal ArticleDOI
TL;DR: In this paper, a HIF-1α anti-sense lncRNA, HIFAL, is demonstrated to be essential for maintaining and enhancing HIF1α-mediated transactivation and glycolysis.
Abstract: Hypoxia-inducible factor-1 (HIF-1) is a master driver of glucose metabolism in cancer cells. Here, we demonstrate that a HIF-1α anti-sense lncRNA, HIFAL, is essential for maintaining and enhancing HIF-1α-mediated transactivation and glycolysis. Mechanistically, HIFAL recruits prolyl hydroxylase 3 (PHD3) to pyruvate kinase 2 (PKM2) to induce its prolyl hydroxylation and introduces the PKM2/PHD3 complex into the nucleus via binding with heterogeneous nuclear ribonucleoprotein F (hnRNPF) to enhance HIF-1α transactivation. Reciprocally, HIF-1α induces HIFAL transcription, which forms a positive feed-forward loop to maintain the transactivation activity of HIF-1α. Clinically, high HIFAL expression is associated with aggressive breast cancer phenotype and poor patient outcome. Furthermore, HIFAL overexpression promotes tumor growth in vivo, while targeting both HIFAL and HIF-1α significantly reduces their effect on cancer growth. Overall, our results indicate a critical regulatory role of HIFAL in HIF-1α-driven transactivation and glycolysis, identifying HIFAL as a therapeutic target for cancer treatment.

69 citations


Journal ArticleDOI
03 Jan 2021-Cancers
TL;DR: In this article, the authors discuss the results of most recent studies evaluating the impact of flavonoids on HIF-1 accompanied by the regulation of critical enzymes contributing to the Warburg phenotype.
Abstract: Tumor hypoxia is described as an oxygen deprivation in malignant tissue. The hypoxic condition is a consequence of an imbalance between rapidly proliferating cells and a vascularization that leads to lower oxygen levels in tumors. Hypoxia-inducible factor 1 (HIF-1) is an essential transcription factor contributing to the regulation of hypoxia-associated genes. Some of these genes modulate molecular cascades associated with the Warburg effect and its accompanying pathways and, therefore, represent promising targets for cancer treatment. Current progress in the development of therapeutic approaches brings several promising inhibitors of HIF-1. Flavonoids, widely occurring in various plants, exert a broad spectrum of beneficial effects on human health, and are potentially powerful therapeutic tools against cancer. Recent evidences identified numerous natural flavonoids and their derivatives as inhibitors of HIF-1, associated with the regulation of critical glycolytic components in cancer cells, including pyruvate kinase M2(PKM2), lactate dehydrogenase (LDHA), glucose transporters (GLUTs), hexokinase II (HKII), phosphofructokinase-1 (PFK-1), and pyruvate dehydrogenase kinase (PDK). Here, we discuss the results of most recent studies evaluating the impact of flavonoids on HIF-1 accompanied by the regulation of critical enzymes contributing to the Warburg phenotype. Besides, flavonoid effects on glucose metabolism via regulation of HIF-1 activity represent a promising avenue in cancer-related research. At the same time, only more-in depth investigations can further elucidate the mechanistic and clinical connections between HIF-1 and cancer metabolism.

41 citations


Journal ArticleDOI
TL;DR: The aim of the research is to study the effect of PKM2 tetramer activation on preventing kidney fibrosis via suppression of aberrant glycolysis and the EMT program.
Abstract: Aims/introduction Tubulointerstitial fibrosis is a hallmark of diabetic nephropathy and is associated with an epithelial-to-mesenchymal transition (EMT) program and aberrant glycolysis. Dimeric pyruvate kinase (PK) M2 (PKM2) acts as a key protein kinase in aberrant glycolysis by promoting the accumulation of hypoxia-inducible factor (HIF)-1α, while tetrameric PKM2 functions as a pyruvate kinase in oxidative phosphorylation. The aim of the research is to study the effect of PKM2 tetramer activation on preventing kidney fibrosis via suppression of aberrant glycolysis and the EMT program. Materials and methods In vivo: Streptozotocin (STZ) was utilized to induce diabetes in 8-week-old CD-1 mice; 4 weeks after diabetes induction, proteinuria-induced kidney fibrosis was developed by intraperitoneal injection of bovine serum albumin (BSA: 0.3 g/30 g BW) for 14 days; The PKM2 activator TEPP-46 was also administered orally simultaneously. In vitro: HK2 cells were co-treated with high-glucose media or/and TGF-β1 and TEPP46 for 48 h, cellular protein was extracted for evaluation. Results Diabetic mice developed kidney fibrosis associated with aberrant glycolysis and EMT; BSA injection accelerated kidney fibrosis in both the control and diabetic mice; TEPP-46 rescued the kidney fibrosis. In HK2 cells, TEPP-46 suppressed the EMT program induced by TGF-β1 and/or high-glucose incubation. TEPP-46-induced PKM2 tetramer formation and PK activity resulted in suppression of HIF-1α and lactate accumulation. Specific siRNA-mediated knockdown of HIF-1α expression diminished high glucose-induced mesenchymal protein levels. Conclusion PKM2 activation could restore the tubular phenotype via suppression of the EMT program and aberrant glycolysis, providing an alternative target to mitigate fibrosis in diabetic kidneys.

32 citations


Journal ArticleDOI
TL;DR: In this article, mitapivat (AG-348) was shown to reduce ineffective erythropoiesis and anemia in β-thalassemia in Hbbth3/- mice.
Abstract: Anemia in β-thalassemia is related to ineffective erythropoiesis and reduced red cell survival. Excess free heme and accumulation of unpaired α-globin chains impose substantial oxidative stress on β-thalassemic erythroblasts and erythrocytes, impacting cell metabolism. We hypothesized that increased pyruvate kinase activity induced by mitapivat (AG-348) in the Hbbth3/+ mouse model for β-thalassemia would reduce chronic hemolysis and ineffective erythropoiesis through stimulation of red cell glycolytic metabolism. Oral mitapivat administration ameliorated ineffective erythropoiesis and anemia in Hbbth3/+ mice. Increased ATP, reduced reactive oxygen species production, and reduced markers of mitochondrial dysfunction associated with improved mitochondrial clearance suggested enhanced metabolism following mitapivat administration in β-thalassemia. The amelioration of responsiveness to erythropoietin resulted in reduced soluble erythroferrone, increased liver Hamp expression, and diminished liver iron overload. Mitapivat reduced duodenal Dmt1 expression potentially by activating the pyruvate kinase M2-HIF2α axis, representing a mechanism additional to Hamp in controlling iron absorption and preventing β-thalassemia-related liver iron overload. In ex vivo studies on erythroid precursors from patients with β-thalassemia, mitapivat enhanced erythropoiesis, promoted erythroid maturation, and decreased apoptosis. Overall, pyruvate kinase activation as a treatment modality for β-thalassemia in preclinical model systems had multiple beneficial effects in the erythropoietic compartment and beyond, providing a strong scientific basis for further clinical trials.

28 citations


Journal ArticleDOI
Haili Wu1, Mimi Cui1, Chenglu Li1, Hanqing Li1, Yuhao Dai1, Kaili Cui1, Zhuoyu Li1 
TL;DR: In this paper, the authors found that kaempferol inhibited the proliferation of human colon cancer cells HCT116 and DLD1 in a dose-dependent manner, and the IC50 values were 63.0 ± 12.9 and 98.3 ± 15.9 μM, respectively.
Abstract: Colon cancer is an aggressive malignancy with very limited therapeutic approaches. The available therapeutic agents for colon cancer show strong adverse effects and poor effectiveness, indicating the urgent need to identify new therapeutic drugs for this malignancy. Kaempferol, a flavonoid found in a variety of natural foods, exhibits significant inhibitory effects on colon cancer. Here, it was found that kaempferol inhibited the proliferation of human colon cancer cells HCT116 and DLD1 in a dose-dependent manner, and the IC50 values were 63.0 ± 12.9 and 98.3 ± 15.9 μM, respectively. Also, kaempferol treatment delayed G1 phase progression of cell cycle and induced apoptosis. Aerobic glycolysis is the major energy source for various tumor growths, including colon cancer. Indeed, kaempferol treatment impaired glucose consumption, which subsequently led to reduced lactic acid accumulation and ATP production. Mechanistically, kaempferol promoted the expression of miR-339-5p. Further studies identified hnRNPA1 and PTBP1 as two direct targets of miR-339-5p. By directly targeting hnRNPA1 and PTBP1, miR-339-5p reduced the expression of M2-type pyruvate kinase (PKM2) but induced that of PKM1. In conclusion, these data demonstrate that by modulating miR-339-5p-hnRNPA1/PTBP1-PKM2 axis, kaempferol inhibits glycolysis and colon cancer growth, which reveals a new explanation for the molecular mechanism underlying kaempferol anti-tumor.

28 citations


Journal ArticleDOI
Yang Wu1, Wu Jing1, Qiuting Shen1, Xiong Zheng1, Yinguang Chen1 
TL;DR: In this paper, the authors showed that copper nanoparticles (Cu NPs) were able to cause cell membrane oxidative damage and inhibit the growth and metabolism of Moorella thermoacetica (a model acetogen).

27 citations


Journal ArticleDOI
TL;DR: Bioinformatics analysis of the proteome showed that PSE was related to glycolysis, TCA cycle, oxidative phosphorylation, muscle tissue structure, signal transduction, and molecular chaperones as well as to proteins such as troponin T slow skeletal muscle isoform X, GADPH, L-lactate dehydrogenase A chain, and gamma-enolase iso Form X1.

27 citations


Journal ArticleDOI
TL;DR: It is demonstrated that L-PK silencing in male mice reduced both liver steatosis and fibrosis, accompanied by reduced de novo lipogenesis and improved mitochondrial function, which has important implications for the development of personalized therapeutics.
Abstract: Background & Aims The etiology of nonalcoholic fatty liver disease (NAFLD) is poorly understood, with males and certain populations exhibiting markedly increased susceptibility. Using a systems genetics approach involving multi-omic analysis of ∼100 diverse inbred strains of mice, we recently identified several candidate genes driving NAFLD. We investigated the role of one of these, liver pyruvate kinase (L-PK or Pklr), in NAFLD by using patient samples and mouse models. Methods We examined L-PK expression in mice of both sexes and in a cohort of bariatric surgery patients. We used liver-specific loss- and gain-of-function strategies in independent animal models of diet-induced steatosis and fibrosis. After treatment, we measured several metabolic phenotypes including obesity, insulin resistance, dyslipidemia, liver steatosis, and fibrosis. Liver tissues were used for gene expression and immunoblotting, and liver mitochondria bioenergetics was characterized. Results In both mice and humans, L-PK expression is up-regulated in males via testosterone and is strongly associated with NAFLD severity. In a steatosis model, L-PK silencing in male mice improved glucose tolerance, insulin sensitivity, and lactate/pyruvate tolerance compared with controls. Furthermore, these animals had reduced plasma cholesterol levels and intrahepatic triglyceride accumulation. Conversely, L-PK overexpression in male mice resulted in augmented disease phenotypes. In contrast, female mice overexpressing L-PK were unaffected. Mechanistically, L-PK altered mitochondrial pyruvate flux and its incorporation into citrate, and this, in turn, increased liver triglycerides via up-regulated de novo lipogenesis and increased PNPLA3 levels accompanied by mitochondrial dysfunction. Also, L-PK increased plasma cholesterol levels via increased PCSK9 levels. On the other hand, L-PK silencing reduced de novo lipogenesis and PNPLA3 and PCSK9 levels and improved mitochondrial function. Finally, in fibrosis model, we demonstrate that L-PK silencing in male mice reduced both liver steatosis and fibrosis, accompanied by reduced de novo lipogenesis and improved mitochondrial function. Conclusions L-PK acts in a male-specific manner in the development of liver steatosis and fibrosis. Because NAFLD/nonalcoholic steatohepatitis exhibit sexual dimorphism, our results have important implications for the development of personalized therapeutics.

27 citations


Journal ArticleDOI
TL;DR: It is suggested that ammonia induced autophagy via miR-99a-3p, the reduction of ATPase activity, and the alteration of autophophagy-related factors, and energy metabolism mediation in BF.

26 citations


Journal ArticleDOI
TL;DR: Wang et al. as discussed by the authors found that the miR-125b-5p inhibition promoted the aggressive phenotypes and glycolysis of pancreatic cancer cells, including proliferation, invasion, migration, and gly colysis.
Abstract: Pancreatic cancer has the worst prognosis of all common cancers. Pancreatic cancer cells have a metabolic advantage due to their swiftly adaptive responses to hypoxic and low-nutrient medium. This advantage contributes to the aggressivity of pancreatic cancer. In this study, lncRNA MIR210HG was abnormally upregulated within pancreatic cancer. It acted as a key oncogenic regulator of pancreatic cancer aggressiveness and glycolysis. Knockdown of MIR210HG significantly inhibited the aggressive phenotype of pancreatic cancer cells and inhibited the growth of xenograft tumours. More importantly, MIR210HG knockdown inhibited pancreatic cancer cell glycolysis via regulating the glycolysis-related hexokinase 2 (HK2) and Pyruvate kinase muscle isozyme M2 (PKM2) expression. Compared with the MIR210HG knockdown group, miR-125b-5p inhibition promoted the aggressive phenotypes and glycolysis of pancreatic cancer cells. Furthermore, the effects of MIR210HG knockdown on HK2 and PKM2 expression, pancreatic cancer cell aggressive phenotypes, and glycolysis were significantly reversed by miR-125b-5p inhibition. In tissue samples, MIR210HG expression was negatively correlated with miR-125b-5p levels and positively correlated with HK2 and PKM2 expression. miR-125b-5p expression was negatively correlated with HK2 and PKM2 expression. In conclusion, MIR210HG affected the phenotypes of pancreatic cancer cells, including proliferation, invasion, migration, and glycolysis, via modulating the miR-125b-5p/HK2/PKM2 axis.

Journal ArticleDOI
Ran Gu, Rui Liu, Lu Wang, Man Tang, Shirong Li, Xiao Hu 
TL;DR: Aβ25-35-induced ERS and apoptosis in SH-SY5Y cells can be attenuated by lncRNA RPPH1 through regulating miR-326/PKM2 axis, providing therapeutic options for AD patients.
Abstract: The durative endoplasmic reticulum stress (ERS) and subsequent apoptosis contributes to the development and progression of Alzheimer’s disease (AD). MiR-326 can reduce pyruvate kinase M2 (PKM2) exp...

Journal ArticleDOI
TL;DR: Recently, a vast plethora of research has focused on identifying therapeutic strategies for targeting pyruvate kinase isoenzyme type M2 (PKM2) in various isoforms that can exhibit diverse biological functions and outcomes.
Abstract: Pyruvate kinase is a key regulator in glycolysis through the conversion of phosphoenolpyruvate (PEP) into pyruvate. Pyruvate kinase exists in various isoforms that can exhibit diverse biological functions and outcomes. The pyruvate kinase isoenzyme type M2 (PKM2) controls cell progression and survival through the regulation of key signaling pathways. In cancer cells, the dimer form of PKM2 predominates and plays an integral role in cancer metabolism. This predominance of the inactive dimeric form promotes the accumulation of phosphometabolites, allowing cancer cells to engage in high levels of synthetic processing to enhance their proliferative capacity. PKM2 has been recognized for its role in regulating gene expression and transcription factors critical for health and disease. This role enables PKM2 to exert profound regulatory effects that promote cancer cell metabolism, proliferation, and migration. In addition to its role in cancer, PKM2 regulates aspects essential to cellular homeostasis in non-cancer tissues and, in some cases, promotes tissue-specific pathways in health and diseases. In pursuit of understanding the diverse tissue-specific roles of PKM2, investigations targeting tissues such as the kidney, liver, adipose, and pancreas have been conducted. Findings from these studies enhance our understanding of PKM2 functions in various diseases beyond cancer. Therefore, there is substantial interest in PKM2 modulation as a potential therapeutic target for the treatment of multiple conditions. Indeed, a vast plethora of research has focused on identifying therapeutic strategies for targeting PKM2. Recently, targeting PKM2 through its regulatory microRNAs, long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) has gathered increasing interest. Thus, the goal of this review is to highlight recent advancements in PKM2 research, with a focus on PKM2 regulatory microRNAs and lncRNAs and their subsequent physiological significance.

Journal ArticleDOI
TL;DR: The role of glycolytic enzyme PKM (pyruvate kinase M) 2 in smooth muscle cell phenotype switching and neointimal hyperplasia is poorly understood as discussed by the authors.
Abstract: Objective: The role of glycolytic enzyme PKM (pyruvate kinase M) 2 in smooth muscle cell (SMC) phenotype switching and neointimal hyperplasia is poorly understood. We determined the role of PKM2 in...

Journal ArticleDOI
TL;DR: The elevation of glucose utilization has been recognized as a hallmark of metabolic remodeling during cardiac hypertrophic growth under hemodynamic stress as mentioned in this paper, and it has been shown that metabolic remodeling precedes most alterations during cardiac hypertension.
Abstract: Background: Metabolic remodeling precedes most alterations during cardiac hypertrophic growth under hemodynamic stress. The elevation of glucose utilization has been recognized as a hallmark of met...

Journal ArticleDOI
TL;DR: Upregulated glycolysis in the lesioned muscle tissues of DM/PM was revealed, which activated the NLRP3 inflammasome and leaded to pyroptosis in muscle cells.
Abstract: Objectives Muscle cell necrosis is the most common pathological manifestation of idiopathic inflammatory myopathies. Evidence suggests that glycolysis might participate in it. However, the mechanism is unclear. This study aimed to determine the role of glycolysis in the muscle damage that occurs in DM/PM. Methods Mass spectrometry was performed on muscle lesions from DM/PM and control subjects. The expression levels of pyruvate kinase isozyme M2 (PKM2), the nucleotide-binding and oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and pyroptosis-related genes in muscle tissues or plasma were determined by real-time PCR, western blot analysis, IF and ELISA. In addition, IFNγ was used to stimulate myotubes, and the relationships among PMK2 expression, NLRP3 inflammasome activation and pyroptosis were investigated. Results Mass spectrometry and bioinformatics analysis suggested that multiple glycolysis processes, the NLRP3 inflammasome and programmed cell death pathway-related proteins were dysregulated in the muscle tissues of DM/PM. PKM2 and the NLRP3 inflammasome were upregulated and positively correlated in the muscle fibres of DM/PM. Moreover, the pyroptosis-related proteins were increased in muscle tissues of DM/PM and were further increased in PM. The levels of PKM2 in muscle tissues and IL-1β in plasma were high in patients with anti-signal recognition particle autoantibody expression. The pharmacological inhibition of PKM2 in IFNγ-stimulated myotubes attenuated NLRP3 inflammasome activation and subsequently inhibited pyroptosis. Conclusion Our study revealed upregulated glycolysis in the lesioned muscle tissues of DM/PM, which activated the NLRP3 inflammasome and leaded to pyroptosis in muscle cells. The levels of PKM2 and IL-1β were high in patients with anti-signal recognition particle autoantibody expression. These proteins might be used as new biomarkers for muscle damage.

Journal ArticleDOI
TL;DR: FA induces ferroptosis in hippocampal neuronal cells by upregulation of the Warburg effect and the inhibition of the warburg effect by dichloroacetate protected HT22 cells against FA-induced ferroPTosis and cell death.

Journal ArticleDOI
TL;DR: The homeostatic oxygen sensing system (HOSS) optimizes systemic oxygen delivery by converting reactive oxygen species (ROS) to a diffusible signaling molecule, hydrogen peroxide (H2O2), by superoxide dismutase (SOD2).

Journal ArticleDOI
TL;DR: In this article, the pyruvate kinase activator TEPP-46 bound PKM2pS37 and reduced its nuclear localization in triple negative breast cancer patients.
Abstract: Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with low survival rate and a lack of biomarkers and targeted treatments. Here we target pyruvate kinase M2 (PKM2), a key metabolic component of oncogenesis. In TNBC patients, PKM2pS37 was identified as a prominent phosphoprotein corresponding to the aggressive breast cancer phenotype that showed a characteristic nuclear staining pattern and prognostic value. Phosphorylation of PKM2 at S37 was connected with a cyclin-dependent kinase (CDK) pathway in TNBC cells. In parallel, pyruvate kinase activator TEPP-46 bound PKM2pS37 and reduced its nuclear localization. In a TNBC mouse xenograft model, treatment with either TEPP-46 or the potent CDK inhibitor Dinaciclib reduced tumor growth and diminished PKM2pS37. Combinations of Dinaciclib with TEPP-46 reduced cell invasion, impaired redox balance, and triggered cancer cell death. Collectively, these data support an approach to identify PKM2pS37-positive TNBC and target the PKM2 regulatory axis as a potential treatment.

Journal ArticleDOI
TL;DR: LBP suppressed the LPS-induced inflammation by altering glycolysis and the M1 differentiation of macrophages and the effects of LBP were mediated by the downregulation of PKM2 via enhanced ubiquitination.
Abstract: Lipopolysaccharide (LPS)-induced inflammation is the leading cause of multiple organ failure in sepsis. Pyruvate kinase 2 (PKM2) is a protein kinase and transcriptional coactivator that plays an important role in glycolysis. Recent studies have confirmed that glycolysis maintains the M1 differentiation and induces immune activation in macrophages. Lycium barbarum polysaccharide (LBP), the main bioactive component of Chinese wolfberry, suppresses glycolysis and inflammation. Here, RAW264.7 macrophages were treated with LBP for evaluating its effects against LPS-induced inflammation. The differentiation of M1/M2 macrophages was assessed by flow cytometry for assessing the cell surface markers, CD86 and CD206. The enrichment of hypoxia inducible factor (HIF)-1α and ubiquitin in the PKM2 protein complex was determined by co-immunoprecipitation. LBP suppressed LPS-induced glycolysis, differentiation of M1 macrophages, and the production of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and high mobility group (HMG) 1 proteins. The suppressive effects of LBP were similar to those of PKM2 knockdown, but were abolished by the overexpression of PKM2. LPS elevated the mRNA and protein levels of PKM2. LBP reduced the LPS-induced expression of PKM2 protein, but had no effects on the expression of PKM2 mRNA. LPS inhibited the ubiquitination of PKM2, probably by downregulating the expression of ubiquitin ligases, including Nedd4L, Nedd4, and Gnb2. LBP interfered with the inhibition of PKM2 ubiquitination by upregulating the expression of Nedd4L, Nedd4, and Gnb2. In conclusion, LBP suppressed the LPS-induced inflammation by altering glycolysis and the M1 differentiation of macrophages. The effects of LBP were mediated by the downregulation of PKM2 via enhanced ubiquitination.

Journal ArticleDOI
TL;DR: In this paper, the βThal+ units exhibited better levels of storage haemolysis and susceptibility to lysis following osmotic, oxidative and mechanical insults, while the β-thal+ RBCs had a lower percentage of surface removal signaling, reactive oxygen species and oxidative defects to membrane components at late stages of storage.
Abstract: Blood donor genetics and lifestyle affect the quality of red blood cell (RBC) storage. Heterozygotes for beta-thalassaemia (βThal+) constitute a non-negligible proportion of blood donors in the Mediterranean and other geographical areas. The unique haematological profile of βThal+ could affect capacity of enduring storage stress, however, the storability of βThal+ RBCs is largely unknown. In this study, RBCs from 18 βThal+ donors were stored in the cold and profiled for primary (haemolysis) and secondary (phosphatidylserine exposure, potassium leakage, oxidative stress) quality measures, and metabolomics, versus sex- and age-matched controls. The βThal+ units exhibited better levels of storage haemolysis and susceptibility to lysis following osmotic, oxidative and mechanical insults. Moreover, βThal+ RBCs had a lower percentage of surface removal signaling, reactive oxygen species and oxidative defects to membrane components at late stages of storage. Lower potassium accumulation and higher urate-dependent antioxidant capacity were noted in the βThal+ supernatant. Full metabolomics analyses revealed alterations in purine and arginine pathways at baseline, along with activation of pentose phosphate pathway and glycolysis upstream to pyruvate kinase in βThal+ RBCs. Upon storage, substantial changes were observed in arginine, purine and vitamin B6 metabolism, as well as in the hexosamine pathway. A high degree of glutamate generation in βThal+ RBCs was accompanied by low levels of purine oxidation products (IMP, hypoxanthine, allantoin). The βThal mutations impact the metabolism and the susceptibility to haemolysis of stored RBCs, suggesting good post-transfusion recovery. However, haemoglobin increment and other clinical outcomes of βThal+ RBC transfusion deserve elucidation by future studies.

Journal ArticleDOI
25 Mar 2021-Blood
TL;DR: It is reported that limiting PKM2 dimer formation, using a small molecule inhibitor ML265, negatively regulates lactate production and glucose uptake in human and murine stimulated platelets and implicatePKM2 as a potential target for antithrombotic therapeutic intervention.

Journal ArticleDOI
TL;DR: In this article, the authors observed that influenza A virus (H1N1), a single-stranded, negative-sense RNA virus with an eight-segmented genome, enhanced glycolysis both in mouse lung tissues and in human lung epithelial (A549) cells.

Journal ArticleDOI
TL;DR: In this article, the authors reviewed the evidence that the mitochondrial metabolic theory (MMT) can better explain the hallmarks of cancer than can the somatic mutation theory (SMT) where mutations in proto-oncogenes and tumor suppressor genes cause dysregulated cell growth.
Abstract: A theory that can best explain the facts of a phenomenon is more likely to advance knowledge than a theory that is less able to explain the facts. Cancer is generally considered a genetic disease based on the somatic mutation theory (SMT) where mutations in proto-oncogenes and tumor suppressor genes cause dysregulated cell growth. Evidence is reviewed showing that the mitochondrial metabolic theory (MMT) can better account for the hallmarks of cancer than can the SMT. Proliferating cancer cells cannot survive or grow without carbons and nitrogen for the synthesis of metabolites and ATP (Adenosine Triphosphate). Glucose carbons are essential for metabolite synthesis through the glycolysis and pentose phosphate pathways while glutamine nitrogen and carbons are essential for the synthesis of nitrogen-containing metabolites and ATP through the glutaminolysis pathway. Glutamine-dependent mitochondrial substrate level phosphorylation becomes essential for ATP synthesis in cancer cells that over-express the glycolytic pyruvate kinase M2 isoform (PKM2), that have deficient OxPhos, and that can grow in either hypoxia (0.1% oxygen) or in cyanide. The simultaneous targeting of glucose and glutamine, while elevating levels of non-fermentable ketone bodies, offers a simple and parsimonious therapeutic strategy for managing most cancers.

Journal ArticleDOI
Shuyu Yu1, Weicheng Zang1, Yuchong Qiu1, Liming Liao1, Xiaofeng Zheng1 
20 Oct 2021-Oncogene
TL;DR: In this paper, an OTU deubiquitinase was shown to be upregulated in colorectal cancer (CRC) and exacerbates the progression of CRC through modulating the aerobic glycolysis.
Abstract: Aberrant regulation of ubiquitination often leads to metabolic reprogramming in tumor cells. However, the underlying mechanisms are not fully understood. Here we demonstrate that OTUB2, an OTU deubiquitinase, is upregulated in colorectal cancer (CRC) and exacerbates the progression of CRC through modulating the aerobic glycolysis. Mechanistically, OTUB2 directly interacts with pyruvate kinase M2 (PKM2) and inhibits its ubiquitination by blocking the interaction between PKM2 and its ubiquitin E3 ligase Parkin, thereby enhancing PKM2 activity and promoting glycolysis. In response to glucose starvation stress, the effect of OTUB2 on PKM2 is enhanced, which confers metabolic advantage to CRC cells. Moreover, OTUB2 depletion reduces glucose consumption, lactate production, and cellular ATP production. OTUB2-knockout CRC cells exhibit attenuated proliferation and migration, as well as an elevated level of apoptosis and increased sensitivity to chemotherapy drugs. Furthermore, in vivo assays show that knockout of OTUB2 inhibits tumor growth in mice. Taken together, these findings reveal the critical role of OTUB2 in the regulation of glycolysis and illustrate the molecular mechanism underlying its role as a negative regulator of PKM2 ubiquitination in CRC, establishing a bridge between OTUB2-regulated PKM2 ubiquitination and altered metabolic patterns in CRC and suggesting that OTUB2 is a promising target for CRC treatment.

Journal ArticleDOI
TL;DR: A novel umami peptide, IPIPATKT, showed excellent dual dipeptidyl peptidase-IV (DPP-IV) and angiotensin I-converting enzyme (ACE) inhibitory activities, the IC50 values were 64 and 265 μM, respectively as discussed by the authors.
Abstract: A novel umami peptide, IPIPATKT, showed excellent dual dipeptidyl peptidase-IV (DPP-IV) and angiotensin I-converting enzyme (ACE) inhibitory activities, the IC50 values were 64 and 265 μM, respectively. Molecular docking displayed that IPIPATKT was docked into the S1 and S2 pockets of ACE, and it was close to the active site pocket of DPP-IV. The insulin-resistant-HepG2 (IR-HepG2) cell model and human umbilical vein endothelial cell (HUVEC) model showed that the peptide significantly increased the content of glucose, the activities of hexokinase, pyruvate kinase, and the concentration of nitric oxide (p < 0.01), while it reduced the content of endothelin-1 (ET-1). IPIPATKT exhibited a hypotensive effect (-23.5 ± 2.2 mmHg) and attenuated the increase in glucose levels in vivo, as demonstrated using spontaneous hypertensive rats (SHRs) and C57BL/6N mice. We reported the in vivo activities of the umami peptide with dual hypertensive and hypoglycemic effects for the first time.

Journal ArticleDOI
Wei Yang1, Jianhua Liu1, Lin Hou1, Qingmin Chen1, Yahui Liu1 
TL;DR: It is suggested that PKM2 rewires glucose metabolism, which explains the differential sensitivity to shikonin-induced apoptosis in HCC cells and indicates a theoretical basis for targeting glycolytic enzymes in refractory HCC.


Journal ArticleDOI
TL;DR: In this article, an affinity purification screen for host factors that interact with large viral surface antigens (LHBS) was set up to test a hypothesis if hepatitis B virus may govern intracellular biosynthesis to achieve a productive reproduction.
Abstract: As an intracellular pathogen, the reproduction of the hepatitis B virus (HBV) depends on the occupancy of host metabolism machinery. Here we test a hypothesis if HBV may govern intracellular biosynthesis to achieve a productive reproduction. To test this hypothesis, we set up an affinity purification screen for host factors that interact with large viral surface antigens (LHBS). This identified pyruvate kinase isoform M2 (PKM2), a key regulator of glucose metabolism, as a binding partner of viral surface antigens. We showed that the expression of viral LHBS affected oligomerization of PKM2 in hepatocytes, thereby increasing glucose consumption and lactate production, a phenomenon known as aerobic glycolysis. Reduction of PKM2 activity was also validated in several different models, including HBV-infected HepG2-NTCP-C4 cells, adenovirus mediated HBV gene transduction and transfection with a plasmid containing complete HBV genome on HuH-7 cells. We found the recovery of PKM2 activity in hepatocytes by chemical activators, TEPP-46 or DASA-58, reduced expressions of viral surface and core antigens. In addition, reduction of glycolysis by culturing in low-glucose condition or treatment with 2-deoxyglucose also decreased expressions of viral surface antigen, without affecting general host proteins. Finally, TEPP-46 largely suppressed proliferation of LHBS-positive cells on 3-dimensional agarose plates, but showed no effect on the traditional 2-dimensional cell culture. Taken together, these results indicate that HBV-induced metabolic switch may support its own translation in hepatocytes. In addition, aerobic glycolysis is likely essential for LHBS-mediated oncogenesis. Accordingly, restriction of glucose metabolism may be considered as a novel strategy to restrain viral protein synthesis and subsequent oncogenesis during chronic HBV infection.

Journal ArticleDOI
01 Jul 2021
TL;DR: Wiese et al. as mentioned in this paper showed that oxaloacetate (OAA) is a competitive inhibitor of human lactate dehydrogenase A (LDHA) and that elevated PKM2 activity increases de novo synthesis of OAA through glutaminolysis, thereby inhibiting LDHA in cancer cells.
Abstract: Pharmacological activation of the glycolytic enzyme PKM2 or expression of the constitutively active PKM1 isoform in cancer cells results in decreased lactate production, a phenomenon known as the PKM2 paradox in the Warburg effect. Here we show that oxaloacetate (OAA) is a competitive inhibitor of human lactate dehydrogenase A (LDHA) and that elevated PKM2 activity increases de novo synthesis of OAA through glutaminolysis, thereby inhibiting LDHA in cancer cells. We also show that replacement of human LDHA with rabbit LDHA, which is relatively resistant to OAA inhibition, eliminated the paradoxical correlation between the elevated PKM2 activity and the decreased lactate concentration in cancer cells treated with a PKM2 activator. Furthermore, rabbit LDHA-expressing tumours, compared to human LDHA-expressing tumours in mice, displayed resistance to the PKM2 activator. These findings describe a mechanistic explanation for the PKM2 paradox by showing that OAA accumulates and inhibits LDHA following PKM2 activation. Wiese et al. find that oxaloacetate generated through increased activation of PKM2 can inhibit lactate dehydrogenase A, shedding light on the long observed PKM2 paradox during Warburg metabolism in cancer cells.