Inhibiting SHP2 reduces glycolysis, promotes microglial M1 polarization, and alleviates secondary inflammation following spinal cord injury in a mouse model

Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.

The Epstein-Barr virus-miRNA-BART6-5p regulates TGF-β/SMAD4 pathway to induce glycolysis and enhance proliferation and metastasis of gastric cancer cells

Background:EBV-miR-BARTs exhibit significant relevance in epithelial tumors,particularly in EBVassociated gastric and nasopharyngeal cancers.However,their specific mechanisms in the initiation and progression of gastric cancer remain insufficiently explored.Material and Methods:Initially,EBV-miRNA-BART6-5p and its target gene SMAD4 expression were assessed in EBV-associated gastric cancer tissues and cell lines.Subsequent transfection induced overexpression of EBV-miRNA-BART6-5p in AGS and MKN-45,and downregulation in EBVpositive cells(SUN-719).The subsequent evaluation aimed to observe their impact on gastric cancer cell proliferation,migration,and glycolytic processes,with the TGF-β/SMAD4 signaling pathway value clarified using a TGF-βinhibitor.Results:EBV-miRNA-BART6-5p exhibits pronounced upregulation in EBV-associated gastric cancer tissues and EBV-positive cells,while its target gene SMAD4 demonstrates downregulated expression.Upregulation of it can promote the proliferation and migration of gastric cancer cells.Additionally,We found EBV-miRNA-BART6-5p promotes glycolysis of gastric cancer cells.Inhibition of the TGF-β/SMAD4 signaling pathway resulted in suppressed proliferation and migration of gastric cancer cells,concomitant with a diminished glycolytic capacity.Conclusion:In this study,we found that EBV-miRNA-BART6-5p can target SMAD4,effectively increasing glycolysis in gastric cancer cells by regulating the TGF-β/SMAD4 signaling pathway,thereby enhancing the proliferation and metastasis of gastric cancer cells.Our findings may offer new insights into the metabolic aspects of gastric cancer.

IL13RA2 promotes progression of infantile haemangioma by activating glycolysis and the Wnt/β-catenin signaling pathway

Background:Interleukin 13 receptor subunit alpha 2(IL13RA2)plays an essential role in the progression of many cancers.However,the role of IL13RA2 in infantile haemangioma(IH)is still unknown.Materials and Methods:IL13RA2 expression in IH tissues was analyzed using western blot,qRT-PCR,and immunofluorescence.The role of IL13RA2 in haemangioma-derived endothelial cells(HemECs)was determined following knockdown or overexpression of IL13RA2 using CCK-8,colony formation,apoptosis,wound healing,tubule formation,Transwell,and western blot.Results:IL13RA2 expression was upregulated in IH tissues.IL13RA2 overexpression promoted proliferation,migration,and invasion of HemECs and induced glycolysis,which was confirmed with a glycolysis inhibitor.Specifically,IL13RA2 interacted withβ-catenin and activated the Wnt/β-catenin pathway in HemECs,which were involved in the above-mentioned effects of IL13RA2.Conclusions:These findings revealed that targeting IL13RA2 is a potential therapeutic approach for IH.

Complement factor Ⅰ knockdown inhibits colon cancer development by affecting Wnt/β-catenin/c-Myc signaling pathway and glycolysis

BACKGROUND Colon cancer(CC)occurrence and progression are considerably influenced by the tumor microenvironment.However,the exact underlying regulatory mechanisms remain unclear.AIM To investigate immune infiltration-related differentially expressed genes(DEGs)in CC and specifically explored the role and potential molecular mechanisms of complement factor I(CFI).METHODS Immune infiltration-associated DEGs were screened for CC using bioinformatics.Quantitative reverse transcription polymerase chain reaction was used to examine hub DEGs expression in the CC cell lines.Stable CFI-knockdown HT29 and HCT116 cell lines were constructed,and the diverse roles of CFI in vitro were assessed using CCK-8,5-ethynyl-2’-deoxyuridine,wound healing,and transwell assays.Hematoxylin and eosin staining and immunohistochemistry staining were employed to evaluate the influence of CFI on the tumorigenesis of CC xenograft models constructed using BALB/c male nude mice.Key proteins associated with glycolysis and the Wnt pathway were measured using western blotting.RESULTS Six key immune infiltration-related DEGs were screened,among which the expression of CFI,complement factor B,lymphoid enhancer binding factor 1,and SRY-related high-mobility-group box 4 was upregulated,whereas that of fatty acid-binding protein 1,and bone morphogenic protein-2 was downregulated.Furthermore,CFI could be used as a diagnostic biomarker for CC.Functionally,CFI silencing inhibited CC cell proliferation,migration,invasion,and tumor growth.Mechanistically,CFI knockdown downregulated the expression of key glycolysis-related proteins(glucose transporter type 1,hexokinase 2,lactate dehydrogenase A,and pyruvate kinase M2)and the Wnt pathway-related proteins(β-catenin and c-Myc).Further investigation indicated that CFI knockdown inhibited glycolysis in CC by blocking the Wnt/β-catenin/c-Myc pathway.CONCLUSION The findings of the present study demonstrate that CFI plays a crucial role in CC development by influencing glycolysis and the Wnt/β-catenin/c-Myc pathway,indicating that it could serve as a promising target for therapeutic intervention in CC.

Role of aerobic glycolysis in alzheimer's disease and research progress of traditional Chinese medicine

Alzheimer's disease (AD) is an irreversible neurodegenerative disease with a variety of pathogenic factors and complex pathogenesis, so that the disease has a high prevalence and mortality in the world. Although the current diagnosis and treatment equipment and drug research and development keep pace with the times, the current medical technology still can not completely cure the disease, so it is of great significance to explore the pathogenesis and treatment target of AD. The disorder of energy metabolism is one of the characteristic changes in the pathological process of AD. Aerobic glycolysis (AEG) is a special metabolic pathway in the brain, which can rapidly consume glucose to produce energy and substrate for neurons, improve synaptic plasticity, neuroinflammation and oxidative damage, and contribute to the recovery of memory and cognitive function. In recent years, many literatures have reported the mechanism of AEG in AD and the intervention of Tradit Chin Med on this mechanism. The purpose of this paper is to summarize the role of AEG in AD and the related research on the regulation and control of AEG in the treatment of AD by Tradit Chin Med, in order to provide reference and ideas for the prevention and treatment of AD with Tradit Chin Med in the future.

Xiaojianzhong decoction prevents gastric precancerous lesions in rats by inhibiting autophagy and glycolysis in gastric mucosal cells

BACKGROUND Gastric precancerous lesions(GPL)precede the development of gastric cancer(GC).They are characterized by gastric mucosal intestinal metaplasia and dysplasia caused by various factors such as inflammation,bacterial infection,and injury.Abnormalities in autophagy and glycolysis affect GPL progression,and their effective regulation can aid in GPL treatment and GC prevention.Xiaojianzhong decoction(XJZ)is a classic compound for the treatment of digestive system diseases in ancient China which can inhibit the progression of GPL.However,its specific mechanism of action is still unclear.AIM To investigate the therapeutic effects of XJZ decoction on a rat GPL model and the mechanisms underlying its effects on autophagy and glycolysis regulation in GPLs.METHODS Wistar rats were randomly divided into six groups of five rats each and all groups except the control group were subjected to GPL model construction for 18 wk.The rats’body weight was monitored every 2 wk starting from the beginning of modeling.Gastric histopathology was examined using hematoxylin-eosin staining and Alcian blue-periodic acid-Schiff staining.Autophagy was observed using transmission electron microscopy.The expressions of autophagy,hypoxia,and glycolysis related proteins in gastric mucosa were detected using immunohistochemistry and immunofluorescence.The expressions of the following proteins in gastric tissues:B cell lymphoma/Leukemia-2 and adenovirus E1B19000 interacting protein 3(Bnip-3),microtubule associated protein 1 light chain 3(LC-3),moesin-like BCL2-interacting protein 1(Beclin-1),phosphatidylinositol 3-kimase(PI3K),protein kinase B(AKT),mammalian target of rapamycin(mTOR),p53,AMP-activated protein kinase(AMPK),and Unc-51 like kinase 1(ULK1)were detected using western blot.The relative expressions of autophagy,hypoxia,and glycolysis related mRNA in gastric tissues was detected using reverse transcription-polymerase chain reaction.RESULTS Treatment with XJZ increased the rats’body weight and improved GPL-related histopathological manifestations.It also decreased autophagosome and autolysosome formation in gastric tissues and reduced Bnip-3,Beclin-1,and LC-3II expressions,resulting in inhibition of autophagy.Moreover,XJZ down-regulated glycolysis-related monocarboxylate transporter(MCT1),MCT4,and CD147 expressions.XJZ prevented the increase of autophagy level by decreasing gastric mucosal hypoxia,activating the PI3K/AKT/mTOR pathway,inhibiting the p53/AMPK pathway activation and ULK1 Ser-317 and Ser-555 phosphorylation.In addition,XJZ improved abnormal gastric mucosal glucose metabolism by ameliorating gastric mucosal hypoxia and inhibiting ULK1 expression.CONCLUSION This study demonstrates that XJZ may inhibit autophagy and glycolysis in GPL gastric mucosal cells by improving gastric mucosal hypoxia and regulating PI3K/AKT/mTOR and p53/AMPK/ULK1 signaling pathways,providing a feasible strategy for the GPL treatment.

Glycolysis and acute lung injury:A review

Acute lung injury is featured as diffuse pulmonary edema and persistent hypoxemia caused by lung or systemic injury.It is believed that these pathological changes are associated with damage to the alveolar epithelium and vascular endothelium,recruitment of inflammatory cells,and inflammatory factor storms.In recent years,the metabolic reprogramming of lung parenchymal cells and immune cells,particularly alterations in glycolysis,has been found to occur in acute lung injury.Inhibition of glycolysis can reduce the severity of acute lung injury.Thus,this review focuses on the interconnection between acute lung injury and glycolysis and the mechanisms of interaction,which may bring hope for the treatment of acute lung injury.

Predicting the Activity of Oral Lichen Planus with Glycolysis-related Molecules:A Scikit-learn-based Function

Objective Oral lichen planus(OLP)is one of the most common oral mucosa diseases,and is mainly mediated by T lymphocytes.The metabolic reprogramming of activated T cells has been shown to transform from oxidative phosphorylation to aerobic glycolysis.The present study investigated the serum levels of glycolysis-related molecules(lactate dehydrogenase,LDH;pyruvic acid,PA;lactic acid,LAC)in OLP,and the correlation with OLP activity was assessed using the reticular,atrophic and erosive lesion(RAE)scoring system.Methods Univariate and multivariate linear regression functions based on scikit-learn were designed to predict the RAE scores in OLP patients,and the performance of these two machine learning functions was compared.Results The results revealed that the serum levels of PA and LAC were upregulated in erosive OLP(EOLP)patients,when compared to healthy volunteers.Furthermore,the LDH and LAC levels were significantly higher in the EOLP group than in the nonerosive OLP(NEOLP)group.All glycolysis-related molecules were positively correlated to the RAE scores.Among these,LAC had a strong correlation.The univariate function that involved the LAC level and the multivariate function that involved all glycolysis-related molecules presented comparable prediction accuracy and stability,but the latter was more time-consuming.Conclusion It can be concluded that the serum LAC level can be a user-friendly biomarker to monitor the OLP activity,based on the univariate function developed in the present study.The intervention of the glycolytic pathway may provide a potential therapeutic strategy.

Thioridazine reverses trastuzumab resistance in gastric cancer by inhibiting S-phase kinase associated protein 2-mediated aerobic glycolysis

BACKGROUND Trastuzumab constitutes the fundamental component of initial therapy for patients with advanced human epidermal growth factor receptor 2(HER-2)-positive gastric cancer(GC).However,the efficacy of this treatment is hindered by substantial challenges associated with both primary and acquired drug resistance.While S-phase kinase associated protein 2(Skp2)overexpression has been implicated in the malignant progression of GC,its role in regulating trastuzumab resistance in this context remains uncertain.Despite the numerous studies investigating Skp2 inhibitors among small molecule compounds and natural products,there has been a lack of successful commercialization of drugs specifically targeting Skp2.AIM To discover a Skp2 blocker among currently available medications and develop a therapeutic strategy for HER2-positive GC patients who have experienced progression following trastuzumab-based treatment.METHODS Skp2 exogenous overexpression plasmids and small interfering RNA vectors were utilized to investigate the correlation between Skp2 expression and trastuzumab resistance in GC cells.Q-PCR,western blot,and immunohistochemical analyses were conducted to evaluate the regulatory effect of thioridazine on Skp2 expression.A cell counting kit-8 assay,flow cytometry,a amplex red glucose/glucose oxidase assay kit,and a lactate assay kit were utilized to measure the proliferation,apoptosis,and glycolytic activity of GC cells in vitro.A xenograft model established with human GC in nude mice was used to assess thioridazine's effectiveness in vivo.RESULTS The expression of Skp2 exhibited a negative correlation with the sensitivity of HER2-positive GC cells to trastuzumab.Thioridazine demonstrated the ability to directly bind to Skp2,resulting in a reduction in Skp2 expression at both the transcriptional and translational levels.Moreover,thioridazine effectively inhibited cell proliferation,exhibited antiapoptotic properties,and decreased the glucose uptake rate and lactate production by suppressing Skp2/protein kinase B/mammalian target of rapamycin/glucose transporter type 1 signaling pathways.The combination of thioridazine with either trastuzumab or lapatinib exhibited a more pronounced anticancer effect in vivo,surpassing the efficacy of either monotherapy.CONCLUSION Thioridazine demonstrates promising outcomes in preclinical GC models and offers a novel therapeutic approach for addressing trastuzumab resistance,particularly when used in conjunction with lapatinib.This compound has potential benefits for patients with Skp2-proficient tumors.

Prognostic model for prostate cancer based on glycolysis-related genes and non-negative matrix factorization analysis

Background:Establishing an appropriate prognostic model for PCa is essential for its effective treatment.Glycolysis is a vital energy-harvesting mechanism for tumors.Developing a prognostic model for PCa based on glycolysis-related genes is novel and has great potential.Methods:First,gene expression and clinical data of PCa patients were downloaded from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO),and glycolysis-related genes were obtained from the Molecular Signatures Database(MSigDB).Gene enrichment analysis was performed to verify that glycolysis functions were enriched in the genes we obtained,which were used in nonnegative matrix factorization(NMF)to identify clusters.The correlation between clusters and clinical features was discussed,and the differentially expressed genes(DEGs)between the two clusters were investigated.Based on the DEGs,we investigated the biological differences between clusters,including immune cell infiltration,mutation,tumor immune dysfunction and exclusion,immune function,and checkpoint genes.To establish the prognostic model,the genes were filtered based on univariable Cox regression,LASSO,and multivariable Cox regression.Kaplan–Meier analysis and receiver operating characteristic analysis validated the prognostic value of the model.A nomogram of the risk score calculated by the prognostic model and clinical characteristics was constructed to quantitatively estimate the survival probability for PCa patients in the clinical setting.Result:The genes obtained from MSigDB were enriched in glycolysis functions.Two clusters were identified by NMF analysis based on 272 glycolysis-related genes,and a prognostic model based on DEGs between the two clusters was finally established.The prognostic model consisted of LAMPS,SPRN,ATOH1,TANC1,ETV1,TDRD1,KLK14,MESP2,POSTN,CRIP2,NAT1,AKR7A3,PODXL,CARTPT,and PCDHGB2.All sample,training,and test cohorts from The Cancer Genome Atlas(TCGA)and the external validation cohort from GEO showed significant differences between the high-risk and low-risk groups.The area under the ROC curve showed great performance of this prognostic model.Conclusion:A prognostic model based on glycolysis-related genes was established,with great performance and potential significance to the clinical application.

NR4A1 enhances glycolysis in hypoxia-exposed pulmonary artery smooth muscle cells by upregulating HIF-1αexpression

Background:Pulmonary arterial hypertension(PAH)is a chronic and progressive disease that is strongly associated with dysregulation of glucose metabolism.Alterations in nuclear receptor subfamily 4 group A member 1(NR4A1)activity alter the outcome of PAH.This study aimed to investigate the effects of NR4A1 on glycolysis in PAH and its underlying mechanisms.Methods:This study included twenty healthy volunteers and twenty-three PAH patients,and plasma samples were collected from the participants.To mimic the conditions of PAH in vitro,a hypoxia-induced model of pulmonary artery smooth muscle cell(PASMC)model was established.The proliferation of PASMCs was assessed using CCK8 assays.Results:Levels of NR4A1,hypoxia-inducible factor-1α(HIF-1α),and various glycolysis-related enzymes were measured.In addition,extracellular glucose and lactate production were assessed.The interaction between NR4A1 and HIF-1αwas evaluated by co-immunoprecipitation assays.Levels of NR4A1 and HIF-1αwas increased in PAH patients,and exposure to hypoxia resulted in increased levels of NR4A1 and HIF-1αin PASMCs.NR4A1 interacted with HIF-1α.NR4A1 overexpression enhanced hypoxia-induced expression of HIF-1α,GLUT1,PKM2,HK2,and CD36,decreased glucose levels,increased lactate levels and promoted hypoxic PASMC viability.Conversely,silencing NR4A1 decreased hypoxia-induced expression of HIF-1α,GLUT1,PKM2,HK2,and CD36,promoted glucose production,reduced lactate levels and inhibited hypoxic PASMC viability.Furthermore,overexpression of HIF-1αreversed the regulation of glycolysis caused by NR4A1 knockdown.Conclusion:NR4A1 enhances glycolysis in hypoxia-induced PASMCs by upregulating HIF-1α.Our findings indicate that the management of NR4A1 activity may be a promising strategy for PAH therapy.

Physcion increases the sensitivity of hepatocellular carcinoma to sorafenib through miRNA-370/PIM1 axis-regulated glycolysis

BACKGROUND Resistance to sorafenib has become a challenge in clinical treatment of hepatocellular carcinoma(HCC).Physcion is a common bioactive anthraquinone that has potential as an anticancer agent.AIM To study the effect of physcion on sensitizing HCC cells to sorafenib.METHODS Sorafenib-resistant HCC cells were established and treated with sorafenib and/or physcion.The cell viability,proliferation and apoptosis were measured by cell counting kit-8,colony formation,flow cytometry,and in vivo xenograft model.Glucose uptake,lactate acid production,extracellular acidification rate(ECAR),and oxygen consumption rate(OCR)were measured to analyze glycolysis.Expression of glycolysis-related regulators was assessed by western blotting.RESULTS The addition of physcion significantly enhanced the antitumor effects of sorafenib on sorafenib-resistant HCC cells,manifested by enhanced apoptosis and suppressed cell growth.The glucose uptake,lactate acid production,and ECAR were elevated,and OCR was suppressed by physcion treatment.The level of PIM1 was elevated and miR-370 was suppressed in sorafenib-resistant HCC cells compared with the parental cells,which was suppressed by physcion treatment.Inhibition of miR-370 notably reversed the effects of physcion on sorafenib-resistant HCC cells.CONCLUSION Our data indicated that physcion enhanced the sensitivity of HCC cells to sorafenib by enhancing miR-370 to suppress PIM1-promoted glycolysis.

推广的简化Glycolysis模型存在一个正的不变区域(英文)

研究了一个以周期函数为系数的非线性常微分方程系统———一个推广的简化Glycolysis模型.证明了这个模型存在一个严格的正的不变区域,给出该模型的线性化在不变区域内的一些性质.

Thermogenic protein UCP1 and UCP3 expression in non- small cell lung cancer： relation with glycolysis and anaerobic metabolism

Uncoupling protein 1(UCP1)is a proton transporter/channel residing on the inner mitochondrial membrane and is involved in cellular heat production.Using immunohistochemistry,we investigated the expression of UCP1 and UCP3 in a series of 98 patients with non-small cell lung cancer(NSCLC)treated with surgery.Expression patterns were correlated with histopathological variables,prognosis,and the expression of enzymes/proteins related to cell metabolism.Bronchial epithelium did not express UCP1 or UCP3,while alveolar cells strongly expressed UCP1.In tumors,strong expression of UCP1 and UCP3 was recorded in43/98(43.8%)and 27/98(27.6%)cases,respectively.UCP1 was significantly associated with squamous cell histology(P=0.05),whilst UCP3 was more frequently overexpressed in large cell carcinomas(P=0.08),and was inversely related to necrosis(P=0.009).In linear regression analysis,UCP1 was directly related to markers of glycolysis[hexokinase(HXKII)and phosphofructokinase(PFK1)]and anaerobic glucose metabolism[pyruvate dehydrogenase kinase(PDK1)and lactate dehydrogenase(LDH5)].UCP3 was directly linked with a glucose transporter(GLUT2),monocarboxylate transporter(MCT2),glycolysis markers(PFK1 and aldolase),and with the phosphorylation of pyruvate dehydrogenase(p PDH).Kaplan-Meier survival analysis showed that UCP3 was significantly related to poor prognosis in squamous cell carcinomas(P=0.04).UCP1 and UCP3 are overexpressed in a large subgroup of non-small cell lung tumors and their expression coincides with increased glucose absorption,intensified glycolysis,and anaerobic glucose usage.Whether UCPs are targets for therapeutic interventions in lung cancer is a hypothesis that demands further investigation.

Wortmannin influences hypoxia-inducible factor-1 alpha expression and glycolysis in esophageal carcinoma cells

AIM: To investigate the influence of phosphatidylinositol-3-kinase protein kinase B(PI3K/AKT)-HIF-1α signaling pathway on glycolysis in esophageal carcinoma cells under hypoxia. METHODS: Esophageal carcinoma cell lines Eca109 and TE13 were cultured under hypoxia environment, and the protein, m RNA and activity levels of hypoxia inducible factor-1 alpha(HIF-1α), glucose transporter 1, hexokinase-Ⅱ, phosphofructokinase 2 and lactate dehydrogenase-A were determined. Supernatant lactic acid concentrations were also detected. The PI3K/AKT signaling pathway was then inhibited with wortmannin, and the effects of hypoxia on the expression or activities of HIF-1α, associated glycolytic enzymes and lactic acid concentrations were observed. Esophageal carcinoma cells were then transfected with interference plasmid with HIF-1α-targeting si RNA to assess impact of the high expression of HIF-1α on glycolysis.RESULTS: HIF-1α is highly expressed in the esophageal carcinoma cell lines tested, and with decreasing levels of oxygen, the expression of HIF-1α and the associated glycolytic enzymes and the extracellular lactic acid concentration were enhanced in the esophageal carcinoma cell lines Eca109 and TE13. In both normoxia and hypoxic conditions, the level of glycolytic enzymesand the secretion of lactic acid were both reduced by wortmannin. The expression and activities of glycolytic enzymes and the lactic acid concentration in cells were reduced by inhibiting HIF-1α, especially the decreasing level of glycolysis was significant under hypoxic conditions.CONCLUSION: The PI3K/AKT pathway and HIF-1α are both involved in the process of glycolysis in esophageal cancer cells.

Glutamate Impairs Mitochondria Aerobic Respiration Capacity and Enhances Glycolysis in Cultured Rat Astrocytes

Objective To study the effect of glutamate on metabolism, shifts in glycolysis and lactate release in rat astrocytes. Methods After 10 days, secondary cultured astrocytes were treated with 1 mmol/L glutamate for 1 h, and the oxygen consumption rates （OCR） and extra cellular acidification rate （ECAR） was analyzed using a Seahorse XF 24 Extracellular Flux Analyzer. Cell viability was then evaluated by MTT assay. Moreover, changes in extracellular lactate concentration induced by glutamate were tested with a lactate detection kit. Results Compared with the control group, treatment with 1 mmol/L glutamate decreased the astrocytes’ maximal respiration and spare respiratory capacity but increased their glycolytic capacity and glycolytic reserve. Further analysis found that 1-h treatment with different concentrations of glutamate （0.1-1 mmol/L） increased lactate release from astrocytes, however the cell viability was not affected by the glutamate treatment. Conclusion The current study provided direct evidence that exogenous glutamate treatment impaired the mitochondrial respiration capacity of astrocytes and enhanced aerobic glycolysis, which could be involved in glutamate injury or protection mechanisms in response to neurological disorders.

Embryonic liver fordin is involved in glucose glycolysis of hepatic stellate cell by regulating PI3K/Akt signaling

AIM To investigate the role of embryonic liver fordin(ELF) in liver fibrosis by regulating hepatic stellate cells(HSCs) glucose glycolysis.METHODS The expression of ELF and the glucose glycolysisrelated proteins were evaluated in activated HSCs. si RNA was used to silence ELF expression in activated HSCs in vitro and the subsequent changes in PI3K/Akt signaling and glucose glycolysis-related proteins were observed.RESULTS The expression of ELF increased remarkably in HSCs of the fibrosis mouse model and HSCs that were cultured for 3 wk in vitro. Glucose glycolysis-related proteins showed an obvious increase in the activated HSCs, such as phosphofructokinase, platelet and glucose transporter 1. ELF-si RNA, which perfectly silenced the expression of ELF in activated HSCs, led to the induction of glucose glycolysis-related proteins and extracellular matrix(ECM) components. Moreover, p Akt, which is an important downstream factor in PI3K/Akt signaling, showed a significant change in response to the ELF silencing. The expression of glucose glycolysisrelated proteins and ECM components decreased remarkably when the PI3K/Akt signaling was blocked by Ly294002 in the activated HSCs. CONCLUSION ELF is involved in HSC glucose glycolysis by regulating PI3K/Akt signaling.

Metabolic interplay between glycolysis and mitochondrial oxidation: The reverse Warburg effect and its therapeutic implication

Aerobic glycolysis, i.e., the Warburg effect, may contribute to the aggressive phenotype of hepatocellular carcinoma. However, increasing evidence highlights the limitations of the Warburg effect, such as high mitochondrial respiration and low glycolysis rates in cancer cells. To explain such contradictory phenomena with regard to the Warburg effect, a metabolic interplay between glycolytic and oxidative cells was proposed, i.e., the "reverse Warburg effect". Aerobic glycolysis may also occur in the stromal compartment that surrounds the tumor; thus, the stromal cells feed the cancer cells with lactate and this interaction prevents the creation of an acidic condition in the tumor microenvironment. This concept provides great heterogeneity in tumors, which makes the disease difficult to cure using a single agent. Understanding metabolic flexibility by lactate shuttles offers new perspectives to develop treatments that target the hypoxic tumor microenvironment and overcome the limitations of glycolytic inhibitors.

Transforming growth factor beta-1 upregulates glucose transporter 1 and glycolysis through canonical and noncanonical pathways in hepatic stellate cells

BACKGROUND Hepatic stellate cells(HSCs)are the key effector cells mediating the occurrence and development of liver fibrosis,while aerobic glycolysis is an important metabolic characteristic of HSC activation.Transforming growth factor-β1(TGF-β1)induces aerobic glycolysis and is a driving factor for metabolic reprogramming.The occurrence of glycolysis depends on a high glucose uptake level.Glucose transporter 1(GLUT1)is the most widely distributed glucose transporter in the body and mainly participates in the regulation of carbohydrate metabolism,thus affecting cell proliferation and growth.However,little is known about the relationship between TGF-β1 and GLUT1 in the process of liver fibrosis and the molecular mechanism underlying the promotion of aerobic glycolysis in HSCs.AIM To investigate the mechanisms of action of GLUT1,TGF-β1 and aerobic glycolysis in the process of HSC activation during liver fibrosis.METHODS Immunohistochemical staining and immunofluorescence assays were used to examine GLUT1 expression in fibrotic liver tissue.A Seahorse extracellular flux(XF)analyzer was used to examine changes in aerobic glycolytic flux,lactate production levels and glucose consumption levels in HSCs upon TGF-β1 stimulation.The mechanism by which TGF-β1 induces GLUT1 protein expression in HSCs was further explored by inhibiting/promoting the TGF-β1/mothersagainst-decapentaplegic-homolog 2/3(Smad2/3)signaling pathway and inhibiting the p38 and phosphoinositide 3-kinase(PI3K)/AKT signaling pathways.In addition,GLUT1 expression was silenced to observe changes in the growth and proliferation of HSCs.Finally,a GLUT1 inhibitor was used to verify the in vivo effects of GLUT1 on a mouse model of liver fibrosis.RESULTS GLUT1 protein expression was increased in both mouse and human fibrotic liver tissues.In addition,immunofluorescence staining revealed colocalization of GLUT1 and alpha-smooth muscle actin proteins,indicating that GLUT1 expression was related to the development of liver fibrosis.TGF-β1 caused an increase in aerobic glycolysis in HSCs and induced GLUT1 expression in HSCs by activating the Smad,p38 MAPK and P13K/AKT signaling pathways.The p38 MAPK and Smad pathways synergistically affected the induction of GLUT1 expression.GLUT1 inhibition eliminated the effect of TGF-β1 on HSC proliferation and migration.A GLUT1 inhibitor was administered in a mouse model of liver fibrosis,and GLUT1 inhibition reduced the degree of liver inflammation and liver fibrosis.CONCLUSION TGF-β1 induces GLUT1 expression in HSCs,a process related to liver fibrosis progression.In vitro experiments revealed that TGF-β1-induced GLUT1 expression might be one of the mechanisms mediating the metabolic reprogramming of HSCs.In addition,in vivo experiments also indicated that the GLUT1 protein promotes the occurrence and development of liver fibrosis.

Focal adhesion kinase-related non-kinase ameliorates liver fibrosis by inhibiting aerobic glycolysis via the FAK/Ras/c-myc/ENO1 pathway

BACKGROUND Hepatic stellate cell(HSC)hyperactivation is a central link in liver fibrosis development.HSCs perform aerobic glycolysis to provide energy for their activation.Focal adhesion kinase(FAK)promotes aerobic glycolysis in cancer cells or fibroblasts,while FAK-related non-kinase(FRNK)inhibits FAK phosphorylation and biological functions.AIM To elucidate the effect of FRNK on liver fibrosis at the level of aerobic glycolytic metabolism in HSCs.METHODS Mouse liver fibrosis models were established by administering CCl4,and the effect of FRNK on the degree of liver fibrosis in the model was evaluated.Transforming growth factor-β1 was used to activate LX-2 cells.Tyrosine phosphorylation at position 397(pY397-FAK)was detected to identify activated FAK,and the expression of the glycolysis-related proteins monocarboxylate transporter 1(MCT-1)and enolase1(ENO1)was assessed.Bioinformatics analysis was performed to predict putative binding sites for c-myc in the ENO1 promoter region,which were validated with chromatin immunoprecipitation(ChIP)and dual luciferase reporter assays.RESULTS The pY397-FAK level was increased in human fibrotic liver tissue.FRNK knockout promoted liver fibrosis in mouse models.It also increased the activation,migration,proliferation and aerobic glycolysis of primary hepatic stellate cells(pHSCs)but inhibited pHSC apoptosis.Nevertheless,opposite trends for these phenomena were observed after exogenous FRNK treatment in LX-2 cells.Mechanistically,the FAK/Ras/c-myc/ENO1 pathway promoted aerobic glycolysis,which was inhibited by exogenous FRNK.CONCLUSION FRNK inhibits aerobic glycolysis in HSCs by inhibiting the FAK/Ras/c-myc/ENO1 pathway,thereby improving liver fibrosis.FRNK might be a potential target for liver fibrosis treatment.