Role of pH-mediated metabolic reprogramming in β cell failure in Type 2 Diabetes Mellitus

pH 介导的代谢重编程在 2 型糖尿病β细胞衰竭中的作用

• 批准号: 10724745
• 负责人: ALEKSEY V MATVEYENKO
• 金额: $ 14.19万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10724745
• 关键词: Acids; Address; Alkalinization; Animal Model; Attenuated; Autopsy; Beta Cell; Bicarbonates; Buffers; Cell physiology; Cells; Collection; Compensation; Coupled; Development; Diabetes Mellitus; Etiology; Exposure to; Failure; Family; Fasting; Functional disorder; Genes; Genetic; Glucose; Goals; Health; Healthcare Systems; Human; Hyperglycemia; Impairment; Insulin; Insulin Resistance; Ion Pumps; Islets of Langerhans; Knock-out; Longevity; Measures; Mediating; Metabolic; Mitochondria; Molecular; Mus; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Pancreas; Persons; Phenotype; Physiological; Physiology; Prediabetes syndrome; Prevalence; Prevention strategy; Production; Proteins; Regulation; Role; Structure of beta Cell of islet; Testing; Training; Work; cancer cell; combat; diabetogenic; functional decline; gain of function; glucose metabolism; improved; insulin secretion; islet; loss of function; mitochondrial metabolism; novel; novel therapeutic intervention; obese patients; overexpression; parent project; preservation; public health relevance; response; sensor; stressor; symporter; therapeutic evaluation; tool; treatment strategy

DEI Supplement R01-DK128844: Supplement abstract Type 2 diabetes mellitus (T2DM) manifests through the development of fasting and postprandial hyperglycemia the etiology of which can be distilled to failure of pancreatic β cells to maintain appropriate glucose-stimulated insulin secretion (i.e., β cell function) to compensate for the decline in insulin action (i.e. insulin resistance). Part of our ongoing studies indicate that SLC4A4 and its protein product (electrogenic Na+ -coupled HCO3- cotransporter, NBCe1) in β cells contributes to β cell functional decline in T2DM. As this NBCe1 protein is inappropriately activated in T2D and should elicit changes of intracellular buffering and intracellular pH (pHi) regulation, this Supplement training vehicle seeks to directly measure pHi in β cells that have NBCe1 knocked out or overexpressed. This work should not only reveal the metabolic state of the β cells but also allow us to more directly determine if altered intracellular pH-regulation, intracellular buffering or some other aspect of NBCe1 physiology changes the β cell phenotype to a T2D-state. To address this hypothesis, we will focus on parts of the original Specific Aims 2 (cellular pH regulation with genetic gain-of-function tools) and 3 (utilize novel genetic loss-of-function animal models) to test therapeutic potential of inhibiting SLC4A4/NBCe1 expression/activity in β cells as means to attenuate β cell failure and improve overall glucose metabolism under diabetogenic conditions. From Specific Aim 2, INS1 cells with a genetically encoded pH-sensor will be evaluated with and without NBCe1 genetic gain-of-function to document pH-changes and determine if pHi changes per se leads to β cell functional failure through impairment of mitochondrial metabolism and function. Similarly for Specific Aim 3, novel genetic loss-of-function animal models (NBCe1-loss in β cells) will be crosses with a novel pH-sensor mouse to determine pH and buffering of β cells within intact pancreatic islets. The current project will uncover novel molecular/physiological mechanisms underlying induction of β cell dysfunction and test a potentially novel therapeutic strategy to attenuate of β cell failure in T2DM. Parent PROJECT SUMMARY/ABSTRACT Type 2 diabetes mellitus (T2DM) manifests through the development of fasting and postprandial hyperglycemia the etiology of which can be distilled to failure of pancreatic β cells to maintain appropriate glucose-stimulated insulin secretion (i.e. β cell function) to compensate for the decline in insulin action (i.e. insulin resistance). Thus preservation of β cell function has been identified as a critical barrier for the development of successful preventative and treatment strategies to combat the rise in T2DM prevalence. Studies suggest that β cell dysfunction in T2DM is associated with metabolic reprogramming/shift toward increased non-oxidative glucose metabolism and reduced mitochondrial function similar to an adaptive features observed in cancer cells. Accordingly, cancer cells facilitate increased glycolytic flux and subsequent rise in metabolic acid production by upregulating expression of ion pumps/transporters that enhance cellular buffering capacity and promote cellular alkalinization (increased pHi), such as SLC4 family of bicarbonate transporters. Although, previous studies have confirmed importance of pHi for proper β cell functionality, it is unknown whether intracellular alkalinization or increased pHi buffering contributes to β cell functional decline in T2DM. Thus, the key objective of the current proposal is to test the hypothesis that aberrant induction of a novel T2DM gene SLC4A4 and its protein product (electrogenic Na+ -coupled HCO3- cotransporter, NBCe1) in β cells contributes to β cell functional decline in T2DM. To address this hypothesis, Specific Aim 1 will 1) perform detailed examination of SLC4A4/NBCe1 expression using our unique collection of autopsy-derived human pancreas from patients with obesity, pre-diabetes and T2DM and 2) elucidate molecular mechanisms mediating aberrant β cell induction of SLC4A4/NBCe1 in response to diabetogenic stressors. Specific Aim 2 will utilize novel genetic gain-of-function tools to test the hypothesis that intracellular alkalinization mediated by increased β cell expression of SLC4A4/NBCe1 leads to β cell functional failure through impairment of mitochondrial metabolism and function. Finally, Specific aim 3 will utilize novel genetic loss-of-function animal models and T2DM human islets to test therapeutic potential of inhibiting SLC4A4/NBCe1 expression/activity in β cells as means to attenuate β cell failure and improve overall glucose metabolism under diabetogenic conditions. The current project will uncover novel molecular/physiological mechanisms underlying induction of β cell dysfunction and test a potentially novel therapeutic strategy to attenuate of β cell failure in T2DM.

DEI补充R01-DK128844：补充摘要 2型糖尿病（T2DM）通过禁食和餐后高血糖的发展表现出来 该病因可以蒸馏至胰腺β细胞的失败以维持适当的葡萄糖刺激 胰岛素分泌（即β细胞功能）以补偿胰岛素作用下降（即胰岛素抵抗）。 我们正在进行的研究的一部分表明SLC4A4及其蛋白质产物（电源Na+耦合 β细胞中的HCO3-共转运蛋白，NBCE1）有助于T2DM的β细胞功能下降。作为NBCE1蛋白 在T2D中被不适当地激活，应引起细胞内缓冲和细胞内pH的变化（PHI） 调节，这种补充训练工具试图直接测量具有NBCE1敲击的β细胞中的PHI 外出或过表达。这项工作不仅应揭示β细胞的代谢状态，而且还可以使我们能够 更直接地确定是否改变了细胞内pH调节，细胞内缓冲或其他方面 NBCE1生理学将β细胞表型更改为T2D状态。 为了解决这一假设，我们将重点关注原始特定目的2的各个部分（蜂窝pH调节， 遗传功能获得工具）和3（利用新型遗传功能丧失动物模型）来测试治疗 抑制β细胞中SLC4A4/NBCE1表达/活性作为减弱β细胞衰竭和 改善糖尿病生成条件下的总体葡萄糖代谢。从特定的目标2中，INS1单元具有 遗传编码的pH传感器将在有没有NBCE1遗传功能的情况下进行评估以记录 pH变化并确定pHI本质上是否会导致β细胞功能衰竭通过损害 线粒体代谢和功能。类似地，对于特定目标3，新型遗传功能丧失动物 模型（β细胞中的NBCE1损伤）将与新型pH传感器小鼠交叉，以确定pH和缓冲 完整胰岛中的β细胞。当前的项目将发现新颖的分子/生理 β细胞功能障碍诱导的基础机制，并测试一种潜在的新型治疗策略 T2DM中β细胞衰竭的衰减。 父项目摘要/摘要 2型糖尿病（T2DM）通过禁食和餐后高血糖的发展表现出来 该病因可以蒸馏至胰腺β细胞的失败以维持适当的葡萄糖刺激 胰岛素分泌（即β细胞功能）可以补偿胰岛素作用下降（即胰岛素抵抗）。 保留β细胞功能已被确定为成功发展的关键障碍 预防性和治疗策略以应对T2DM患病率上升。研究表明β细胞 T2DM中功能障碍与代谢重编程/转移朝着增加非氧化葡萄糖有关 代谢和降低的线粒体功能类似于在癌细胞中观察到的适应性特征。 彼此之间，癌细胞促进糖酵解通量增加，随后代谢产生升高 上调离子泵/转运蛋白的表达，以增强细胞缓冲能力并促进 细胞碱化（PHI增加），例如碳酸氢盐转运蛋白的SLC4家族。虽然，以前 研究已经证实了PHI对于适当β细胞功能的重要性，尚不清楚细胞内是否 碱化或增加的PHI缓冲导致T2DM的β细胞功能下降。那，关键 当前建议的目的是检验以下假设，即新型T2DM基因的异常诱导 SLC4A4及其蛋白质产物（电基质Na+耦合的HCO3-共转运蛋白，NBCE1）在β细胞中有助于 T2DM的β细胞功能下降。为了解决这一假设，具体目的1将1）执行详细的 使用我们独特的尸检衍生的人类胰腺来检查SLC4A4/NBCE1表达 来自肥胖，糖尿病前和T2DM的患者以及2）阐明了介导异常的分子机制 SLC4A4/NBCE1的β细胞诱导响应糖尿病性应激源。特定目标2将利用小说 遗传功能获取工具以检验以下假设：β细胞增加的细胞内碱化 SLC4A4/NBCE1的表达通过线粒体代谢损害导致β细胞功能衰竭 和功能。最后，特定目标3将利用新型遗传功能丧失动物模型和T2DM人类 测试抑制β细胞中SLC4A4/NBCE1表达/活性的治疗潜力的胰岛 减弱β细胞衰竭并改善糖尿病生成条件下的总体葡萄糖代谢。电流 项目将揭示β细胞功能障碍诱导的基础的新分子/生理机制 测试一种潜在的新型治疗策略，以减轻T2DM中β细胞衰竭的衰减。