Ulcerative colitis is an idiopathic,chronic inflammatory bowel disease.Its pathogenesis is multifactorial involving inflammation and immune dysregulation.Proinflammatory TNFα/NFκB signaling is believed to play a car...Ulcerative colitis is an idiopathic,chronic inflammatory bowel disease.Its pathogenesis is multifactorial involving inflammation and immune dysregulation.Proinflammatory TNFα/NFκB signaling is believed to play a cardinal role in ulcerative colitis.Growing evidence indicates the molecular interactions between the cellular metabolites and different phases of inflammation.This study aims to identify the metabolites that can inhibit TNFα/NFκB signaling and are potentially therapeutic against various TNFα-associated inflammatory diseases,particularly inflammatory bowel diseases.We performed in vitro and in vivo screening of cellular metabolites to inhibit TNFα/NFκB signaling.Multiple confirmation assays,including NFκB translocation,quantitative real-time PCR,ELISA,immunofluorescence staining,and RNA sequencing analysis were executed.Drug affinity-responsive target stability assay with proteomics was utilized for target identification.cPLA2 ablated mice with dextran sodium sulfate-induced colitis were employed to assess pyruvate's dependence on its molecular target in attenuating ulcerative colitis pathogenesis.Metabolite screening and subsequent validation with multiple approaches led to the isolation of pyruvate,a glycolytic metabolite,and a critical node in several metabolic pathways,as a novel inhibitor of TNFα/NFκB signaling.Importantly,pyruvate suppressed inflammation,preserved colonic histology,maintained tight junction proteins,and regulated permeability in the ulcerative colitis model.Additionally,cPLA2 was identified as a previously unknown target of pyruvate and pyruvate largely lost its therapeutic effects against ulcerative colitis in cPLA2-deficient mice.Conclusively,this study not only unveils pyruvate as an antagonist of TNFα/NFκB signaling and therapeutic intervention against colitis but also provides mechanistic insight into the mode of action of pyruvate.展开更多
Obesity has a multifactorial etiology and is known to be a state of chronic low-grade inflammation,known as meta-inflammation.This state is associated with the development of metabolic disorders such as glucose intole...Obesity has a multifactorial etiology and is known to be a state of chronic low-grade inflammation,known as meta-inflammation.This state is associated with the development of metabolic disorders such as glucose intolerance and nonalcoholic fatty liver disease.Pyruvate is a glycolytic metabolite and a crucial node in various metabolic pathways.However,its role and molecular mechanism in obesity and associated complications are obscure.In this study,we reported that pyruvate substantially inhibited adipogenic differentiation in vitro and its administration significantly prevented HFD-induced weight gain,white adipose tissue inflammation,and metabolic dysregulation.To identify the target proteins of pyruvate,drug affinity responsive target stability was employed with proteomics,cellular thermal shift assay,and isothermal drug response to detect the interactions between pyruvate and its molecular targets.Consequently,we identified cytosolic phospholipase A2(cPLA2)as a novel molecular target of pyruvate and demonstrated that pyruvate restrained diet-induced obesity,white adipose tissue inflammation,and hepatic steatosis in a cPLA2-dependent manner.Studies with global ablation of cPLA2 in mice showed that the protective effects of pyruvate were largely abrogated,confirming the importance of pyruvate/cPLA2 interaction in pyruvate attenuation of inflammation and obesity.Overall,our study not only establishes pyruvate as an antagonist of cPLA2 signaling and a potential therapeutic option for obesity but it also sheds light on the mechanism of its action.Pyruvate’s prior clinical use indicates that it can be considered a safe and viable alternative for obesity,whether consumed as a dietary supplement or as part of a regular diet.展开更多
基金supported by the US National Institutes of Health(NIH)research grants R01AR062207,R01AR061484,R01AR076900,R01AR078035,and R01NS070328.
文摘Ulcerative colitis is an idiopathic,chronic inflammatory bowel disease.Its pathogenesis is multifactorial involving inflammation and immune dysregulation.Proinflammatory TNFα/NFκB signaling is believed to play a cardinal role in ulcerative colitis.Growing evidence indicates the molecular interactions between the cellular metabolites and different phases of inflammation.This study aims to identify the metabolites that can inhibit TNFα/NFκB signaling and are potentially therapeutic against various TNFα-associated inflammatory diseases,particularly inflammatory bowel diseases.We performed in vitro and in vivo screening of cellular metabolites to inhibit TNFα/NFκB signaling.Multiple confirmation assays,including NFκB translocation,quantitative real-time PCR,ELISA,immunofluorescence staining,and RNA sequencing analysis were executed.Drug affinity-responsive target stability assay with proteomics was utilized for target identification.cPLA2 ablated mice with dextran sodium sulfate-induced colitis were employed to assess pyruvate's dependence on its molecular target in attenuating ulcerative colitis pathogenesis.Metabolite screening and subsequent validation with multiple approaches led to the isolation of pyruvate,a glycolytic metabolite,and a critical node in several metabolic pathways,as a novel inhibitor of TNFα/NFκB signaling.Importantly,pyruvate suppressed inflammation,preserved colonic histology,maintained tight junction proteins,and regulated permeability in the ulcerative colitis model.Additionally,cPLA2 was identified as a previously unknown target of pyruvate and pyruvate largely lost its therapeutic effects against ulcerative colitis in cPLA2-deficient mice.Conclusively,this study not only unveils pyruvate as an antagonist of TNFα/NFκB signaling and therapeutic intervention against colitis but also provides mechanistic insight into the mode of action of pyruvate.
基金supported by National Institutes of Health(NIH)research grants R01AR062207,R01AR061484,R01AR076900,R01AR078035 and R01NS070328.
文摘Obesity has a multifactorial etiology and is known to be a state of chronic low-grade inflammation,known as meta-inflammation.This state is associated with the development of metabolic disorders such as glucose intolerance and nonalcoholic fatty liver disease.Pyruvate is a glycolytic metabolite and a crucial node in various metabolic pathways.However,its role and molecular mechanism in obesity and associated complications are obscure.In this study,we reported that pyruvate substantially inhibited adipogenic differentiation in vitro and its administration significantly prevented HFD-induced weight gain,white adipose tissue inflammation,and metabolic dysregulation.To identify the target proteins of pyruvate,drug affinity responsive target stability was employed with proteomics,cellular thermal shift assay,and isothermal drug response to detect the interactions between pyruvate and its molecular targets.Consequently,we identified cytosolic phospholipase A2(cPLA2)as a novel molecular target of pyruvate and demonstrated that pyruvate restrained diet-induced obesity,white adipose tissue inflammation,and hepatic steatosis in a cPLA2-dependent manner.Studies with global ablation of cPLA2 in mice showed that the protective effects of pyruvate were largely abrogated,confirming the importance of pyruvate/cPLA2 interaction in pyruvate attenuation of inflammation and obesity.Overall,our study not only establishes pyruvate as an antagonist of cPLA2 signaling and a potential therapeutic option for obesity but it also sheds light on the mechanism of its action.Pyruvate’s prior clinical use indicates that it can be considered a safe and viable alternative for obesity,whether consumed as a dietary supplement or as part of a regular diet.
