Regulatory Mechanisms of Insulin Secretion

胰岛素分泌的调节机制

• 批准号: 9274952
• 负责人: MEGAN A RIZZO
• 金额: $ 36.46万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9274952
• 关键词: Adaptor Signaling Protein; Affect; Beta Cell; Biochemical; Biosensor; Blood Glucose; Cell model; Cells; Cellular Stress; Complex; Data; Defect; Depressed mood; Diabetes Mellitus; Diet; Endoplasmic Reticulum; Event; Failure; Fluorescence Resonance Energy Transfer; Funding; Gene Mutation; Genetic; Glucokinase; Glucose; Hormonal; Hormones; Human; ITPR1 gene; Impairment; Inositol; Insulin; Insulin Resistance; Lead; Mediating; Molecular; Molecular Conformation; Molecular Structure; Mus; Nature; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Peripheral; Phase; Post-Translational Regulation; Proteins; Reaction; Regulation; Role; Stress; Structure of beta Cell of islet; Testing; Time; Tissues; Work; alpha helix; base; biochemical model; chemical reaction; design; diabetic; endoplasmic reticulum stress; experimental study; glucose metabolism; glucose sensor; insulin secretion; islet; mouse model; new therapeutic target; novel; novel therapeutics; protein protein interaction; public health relevance; quantitative imaging; receptor; structural biology

DESCRIPTION (provided by applicant): Progression of type 2 diabetes mellitus tracks with the failure of pancreatic beta cells to compensate for peripheral insulin resistance. Loss of glucose sensitivity, particularly during the sharp rise in blood glucose that follows a meal, is strongly associated with peripheral tissue damage during diabetes. Yet the molecular mechanisms underlying defects in beta-cell glucose sensing during type 2 diabetes are not well understood. This proposal seeks critical information regarding the regulation of glucokinase, which is the glucose sensing protein in insulin-secreting beta cells. Work in the previous funding period focused on hormonal activation of glucokinase through chemical reaction with nitric oxide. These studies revealed important new connections between defects in glucokinase regulation and a genetic form of human diabetes. Even so, major questions remain concerning the mechanism of glucokinase activation and the impact of diabetes-related cell stress on glucokinase function. Three aims are proposed. Aim 1 will utilize a newly developed glucokinase biosensor to reveal the connection between cellular activation by nitric oxide and the underlying biochemical states suggested by its molecular structure. Aim 2 will focus on understanding the molecular mechanism that leads to glucokinase association with nitric oxide synthase, which is a critical interaction required for cellular activation of glucokinase. Experiments in this aim wil also reveal whether defects in glucokinase regulation may explain the association of NOS1AP gene mutations with human diabetes. Aim 3 will focus on the impact of diabetes-related cell stress on glucokinase activation. Our preliminary data show that impaired endoplasmic reticulum function disrupts glucokinase regulation. The planned studies seek to identify the mechanism behind this disruption, and test whether diet-related obesity can similarly disrupt glucokinase regulation. If so, these studies will provide a molecular explanation for inhibited glucose sensing during type 2 diabetes. In summary, these studies have the potential to unify cellular and biochemical models of glucokinase function, identify new molecular regulators of glucokinase activity, and will lead to new ideas about the molecular causes underlying the deficit in ß-cell glucose sensing observed in type 2 diabetes mellitus. Understanding the molecular events that worsen type 2 diabetes mellitus is vital for designing new therapies that target beta-cell glucose sensing.

描述（由申请人提供）：2型糖尿病的进展伴随胰腺β细胞无法补偿外周胰岛素抵抗。葡萄糖敏感性的丧失，特别是在餐后血糖急剧上升期间，与糖尿病期间的外周组织损伤密切相关。然而，2型糖尿病期间β细胞葡萄糖感知缺陷的分子机制尚未得到很好的理解。该提案寻求关于葡萄糖激酶调节的关键信息，葡萄糖激酶是胰岛素分泌β细胞中的葡萄糖敏感蛋白。上一个资助期的工作重点是通过与一氧化氮的化学反应来激素激活葡萄糖激酶。这些研究揭示了葡萄糖激酶调节缺陷与人类糖尿病遗传形式之间重要的新联系。即便如此，有关葡萄糖激酶激活机制以及糖尿病相关细胞应激对葡萄糖激酶功能的影响的主要问题仍然存在。提出了三个目标。目的1将利用一种新开发的葡萄糖激酶生物传感器来揭示一氧化氮激活细胞与其分子结构所暗示的潜在生化状态之间的联系。目的2将集中于了解导致葡萄糖激酶与一氧化氮合酶结合的分子机制，这是葡萄糖激酶细胞活化所需的关键相互作用。本实验也将揭示葡萄糖激酶调节的缺陷是否可以解释NOS1AP基因突变与人类糖尿病的关系。目标3将集中在糖尿病相关的细胞应激对葡萄糖激酶激活的影响。我们的初步数据表明，受损的内质网功能破坏葡萄糖激酶的调节。计划中的研究试图确定这种破坏背后的机制，并测试饮食相关的肥胖是否会同样破坏葡萄糖激酶的调节。如果是这样，这些研究将为2型糖尿病期间葡萄糖感知抑制提供分子解释。总之，这些研究有可能统一葡萄糖激酶功能的细胞和生物化学模型，鉴定葡萄糖激酶活性的新分子调节剂，并将导致关于2型糖尿病中观察到的β细胞葡萄糖感知缺陷的分子原因的新想法。了解使2型糖尿病恶化的分子事件对于设计针对β细胞葡萄糖传感的新疗法至关重要。