{"title":"转酮醇酶通过限制肌苷诱导的线粒体活性来促进 MAFLD。","authors":"Lingfeng Tong, Zhangbing Chen, Yangyang Li, Xinxia Wang, Changjie Yang, Yakui Li, Yemin Zhu, Ying Lu, Qi Liu, Nannan Xu, Sijia Shao, Lifang Wu, Ping Zhang, Guangyu Wu, Xiaoyu Wu, Xiaosong Chen, Junwei Fang, Renbing Jia, Tianle Xu, Bin Li, Liang Zheng, Junling Liu, Xuemei Tong","doi":"10.1016/j.cmet.2024.03.003","DOIUrl":null,"url":null,"abstract":"<p><p>Metabolic dysfunction-associated fatty liver disease (MAFLD) has a global prevalence of about 25% and no approved therapy. Using metabolomic and proteomic analyses, we identified high expression of hepatic transketolase (TKT), a metabolic enzyme of the pentose phosphate pathway, in human and mouse MAFLD. Hyperinsulinemia promoted TKT expression through the insulin receptor-CCAAT/enhancer-binding protein alpha axis. Utilizing liver-specific TKT overexpression and knockout mouse models, we demonstrated that TKT was sufficient and required for MAFLD progression. Further metabolic flux analysis revealed that Tkt deletion increased hepatic inosine levels to activate the protein kinase A-cAMP response element binding protein cascade, promote phosphatidylcholine synthesis, and improve mitochondrial function. Moreover, insulin induced hepatic TKT to limit inosine-dependent mitochondrial activity. Importantly, N-acetylgalactosamine (GalNAc)-siRNA conjugates targeting hepatic TKT showed promising therapeutic effects on mouse MAFLD. Our study uncovers how hyperinsulinemia regulates TKT-orchestrated inosine metabolism and mitochondrial function and provides a novel therapeutic strategy for MAFLD prevention and treatment.</p>","PeriodicalId":93927,"journal":{"name":"Cell metabolism","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Transketolase promotes MAFLD by limiting inosine-induced mitochondrial activity.\",\"authors\":\"Lingfeng Tong, Zhangbing Chen, Yangyang Li, Xinxia Wang, Changjie Yang, Yakui Li, Yemin Zhu, Ying Lu, Qi Liu, Nannan Xu, Sijia Shao, Lifang Wu, Ping Zhang, Guangyu Wu, Xiaoyu Wu, Xiaosong Chen, Junwei Fang, Renbing Jia, Tianle Xu, Bin Li, Liang Zheng, Junling Liu, Xuemei Tong\",\"doi\":\"10.1016/j.cmet.2024.03.003\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Metabolic dysfunction-associated fatty liver disease (MAFLD) has a global prevalence of about 25% and no approved therapy. Using metabolomic and proteomic analyses, we identified high expression of hepatic transketolase (TKT), a metabolic enzyme of the pentose phosphate pathway, in human and mouse MAFLD. Hyperinsulinemia promoted TKT expression through the insulin receptor-CCAAT/enhancer-binding protein alpha axis. Utilizing liver-specific TKT overexpression and knockout mouse models, we demonstrated that TKT was sufficient and required for MAFLD progression. Further metabolic flux analysis revealed that Tkt deletion increased hepatic inosine levels to activate the protein kinase A-cAMP response element binding protein cascade, promote phosphatidylcholine synthesis, and improve mitochondrial function. Moreover, insulin induced hepatic TKT to limit inosine-dependent mitochondrial activity. Importantly, N-acetylgalactosamine (GalNAc)-siRNA conjugates targeting hepatic TKT showed promising therapeutic effects on mouse MAFLD. Our study uncovers how hyperinsulinemia regulates TKT-orchestrated inosine metabolism and mitochondrial function and provides a novel therapeutic strategy for MAFLD prevention and treatment.</p>\",\"PeriodicalId\":93927,\"journal\":{\"name\":\"Cell metabolism\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-05-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Cell metabolism\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1016/j.cmet.2024.03.003\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2024/3/27 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cell metabolism","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1016/j.cmet.2024.03.003","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/3/27 0:00:00","PubModel":"Epub","JCR":"","JCRName":"","Score":null,"Total":0}
Transketolase promotes MAFLD by limiting inosine-induced mitochondrial activity.
Metabolic dysfunction-associated fatty liver disease (MAFLD) has a global prevalence of about 25% and no approved therapy. Using metabolomic and proteomic analyses, we identified high expression of hepatic transketolase (TKT), a metabolic enzyme of the pentose phosphate pathway, in human and mouse MAFLD. Hyperinsulinemia promoted TKT expression through the insulin receptor-CCAAT/enhancer-binding protein alpha axis. Utilizing liver-specific TKT overexpression and knockout mouse models, we demonstrated that TKT was sufficient and required for MAFLD progression. Further metabolic flux analysis revealed that Tkt deletion increased hepatic inosine levels to activate the protein kinase A-cAMP response element binding protein cascade, promote phosphatidylcholine synthesis, and improve mitochondrial function. Moreover, insulin induced hepatic TKT to limit inosine-dependent mitochondrial activity. Importantly, N-acetylgalactosamine (GalNAc)-siRNA conjugates targeting hepatic TKT showed promising therapeutic effects on mouse MAFLD. Our study uncovers how hyperinsulinemia regulates TKT-orchestrated inosine metabolism and mitochondrial function and provides a novel therapeutic strategy for MAFLD prevention and treatment.