{"title":"葡萄糖对β细胞KATP通道的调控:是建立新模型的时候了","authors":"Matthew J. Merrins, Richard G. Kibbey","doi":"10.2337/dbi23-0032","DOIUrl":null,"url":null,"abstract":"An agreed-upon consensus model of glucose-stimulated insulin secretion from healthy β-cells is essential for understanding diabetes pathophysiology. Since the discovery of the KATP channel in 1984, an oxidative phosphorylation (OxPhos)–driven rise in ATP has been assumed to close KATP channels to initiate insulin secretion. This model lacks any evidence, genetic or otherwise, that mitochondria possess the bioenergetics to raise the ATP/ADP ratio to the triggering threshold, and conflicts with genetic evidence demonstrating that OxPhos is dispensable for insulin secretion. It also conflates the stoichiometric yield of OxPhos with thermodynamics, and overestimates OxPhos by failing to account for established features of β-cell metabolism, such as leak, anaplerosis, cataplerosis, and NADPH production that subtract from the efficiency of mitochondrial ATP production. We have proposed an alternative model, based on the spatial and bioenergetic specializations of β-cell metabolism, in which glycolysis initiates insulin secretion. The evidence for this model includes that 1) glycolysis has high control strength over insulin secretion; 2) glycolysis is active at the correct time to explain KATP channel closure; 3) plasma membrane–associated glycolytic enzymes control KATP channels; 4) pyruvate kinase has favorable bioenergetics, relative to OxPhos, for raising ATP/ADP; and 5) OxPhos stalls before membrane depolarization and increases after. Although several key experiments remain to evaluate this model, the 1984 model is based purely on circumstantial evidence and must be rescued by causal, mechanistic experiments if it is to endure.","PeriodicalId":11376,"journal":{"name":"Diabetes","volume":null,"pages":null},"PeriodicalIF":6.2000,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Glucose Regulation of β-Cell KATP Channels: It Is Time for a New Model!\",\"authors\":\"Matthew J. Merrins, Richard G. Kibbey\",\"doi\":\"10.2337/dbi23-0032\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"An agreed-upon consensus model of glucose-stimulated insulin secretion from healthy β-cells is essential for understanding diabetes pathophysiology. Since the discovery of the KATP channel in 1984, an oxidative phosphorylation (OxPhos)–driven rise in ATP has been assumed to close KATP channels to initiate insulin secretion. This model lacks any evidence, genetic or otherwise, that mitochondria possess the bioenergetics to raise the ATP/ADP ratio to the triggering threshold, and conflicts with genetic evidence demonstrating that OxPhos is dispensable for insulin secretion. It also conflates the stoichiometric yield of OxPhos with thermodynamics, and overestimates OxPhos by failing to account for established features of β-cell metabolism, such as leak, anaplerosis, cataplerosis, and NADPH production that subtract from the efficiency of mitochondrial ATP production. We have proposed an alternative model, based on the spatial and bioenergetic specializations of β-cell metabolism, in which glycolysis initiates insulin secretion. The evidence for this model includes that 1) glycolysis has high control strength over insulin secretion; 2) glycolysis is active at the correct time to explain KATP channel closure; 3) plasma membrane–associated glycolytic enzymes control KATP channels; 4) pyruvate kinase has favorable bioenergetics, relative to OxPhos, for raising ATP/ADP; and 5) OxPhos stalls before membrane depolarization and increases after. Although several key experiments remain to evaluate this model, the 1984 model is based purely on circumstantial evidence and must be rescued by causal, mechanistic experiments if it is to endure.\",\"PeriodicalId\":11376,\"journal\":{\"name\":\"Diabetes\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":6.2000,\"publicationDate\":\"2024-04-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Diabetes\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.2337/dbi23-0032\",\"RegionNum\":1,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENDOCRINOLOGY & METABOLISM\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Diabetes","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.2337/dbi23-0032","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
Glucose Regulation of β-Cell KATP Channels: It Is Time for a New Model!
An agreed-upon consensus model of glucose-stimulated insulin secretion from healthy β-cells is essential for understanding diabetes pathophysiology. Since the discovery of the KATP channel in 1984, an oxidative phosphorylation (OxPhos)–driven rise in ATP has been assumed to close KATP channels to initiate insulin secretion. This model lacks any evidence, genetic or otherwise, that mitochondria possess the bioenergetics to raise the ATP/ADP ratio to the triggering threshold, and conflicts with genetic evidence demonstrating that OxPhos is dispensable for insulin secretion. It also conflates the stoichiometric yield of OxPhos with thermodynamics, and overestimates OxPhos by failing to account for established features of β-cell metabolism, such as leak, anaplerosis, cataplerosis, and NADPH production that subtract from the efficiency of mitochondrial ATP production. We have proposed an alternative model, based on the spatial and bioenergetic specializations of β-cell metabolism, in which glycolysis initiates insulin secretion. The evidence for this model includes that 1) glycolysis has high control strength over insulin secretion; 2) glycolysis is active at the correct time to explain KATP channel closure; 3) plasma membrane–associated glycolytic enzymes control KATP channels; 4) pyruvate kinase has favorable bioenergetics, relative to OxPhos, for raising ATP/ADP; and 5) OxPhos stalls before membrane depolarization and increases after. Although several key experiments remain to evaluate this model, the 1984 model is based purely on circumstantial evidence and must be rescued by causal, mechanistic experiments if it is to endure.
期刊介绍:
Diabetes is a scientific journal that publishes original research exploring the physiological and pathophysiological aspects of diabetes mellitus. We encourage submissions of manuscripts pertaining to laboratory, animal, or human research, covering a wide range of topics. Our primary focus is on investigative reports investigating various aspects such as the development and progression of diabetes, along with its associated complications. We also welcome studies delving into normal and pathological pancreatic islet function and intermediary metabolism, as well as exploring the mechanisms of drug and hormone action from a pharmacological perspective. Additionally, we encourage submissions that delve into the biochemical and molecular aspects of both normal and abnormal biological processes.
However, it is important to note that we do not publish studies relating to diabetes education or the application of accepted therapeutic and diagnostic approaches to patients with diabetes mellitus. Our aim is to provide a platform for research that contributes to advancing our understanding of the underlying mechanisms and processes of diabetes.