TRANSGENIC MOUSE MODEL FOR FAMILIAL HYPERINSULINISM

家族性高胰岛素血症转基因小鼠模型

• 批准号: 6381037
• 负责人: Joseph Bryan
• 金额: $ 20.37万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 2003-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6381037
• 关键词: B lymphocyte; calcium channel; diabetes mellitus genetics; disease /disorder model; drug receptors; electrophysiology; gene mutation; gene targeting; genetic disorder; genetically modified animals; glucagon; glucose metabolism; hyperinsulinism; hypoglycemia; insulin; laboratory mouse; membrane potentials; neurons; noninsulin dependent diabetes mellitus; pancreatic islet function; pancreatic islets; potassium channel; somatostatin; sulfonylurea; tissue /cell culture

The objective of this proposal is to understand how beta-cells couple metabolism to membrane activity using SUR1 null mice. We have reconstituted the beta-cell ATP-sensitive K+ channel, KATP, from the high affinity sulfonylurea receptor (SUR1) and a silent member of the small inward rectifier family (KIR6.2). KATP is the target for the sulfonylureas used to treat non-insulin dependent diabetes mellitus, NIDDM, and for K+ channel openers (KCOs) used to treat hyperinsulinism. SUR1 is a member of the ATP-binding cassette superfamily with multiple transmembrane domains and two nucleotide binding folds (NBFs). KATP channels play a key role in regulating insulin secretion. Glucose metabolism alters the ATP/ADP ratio in beta-cells, particularly MgADP levels that stimulate openings of KATP, which set the beta-cell resting membrane potential. SUR1 senses changes in nucleotide levels and reduces K+ flux through KATP thus depolarizing the beta-cell membrane. Depolarization activates voltage-gated Ca2+ channels; the resulting Ca2+ transients trigger insulin exocytosis. Mutations in SUR1 that inactivate KATP, or affect its regulation by MgADP, cause persistent hyperinsulinemic hypoglycemia of infancy (PHHI), an autosomal recessive disease of newborns characterized by high insulin levels despite severe hypoglycemia. We have made SUR1 null mice in order to characterize the PHHI phenotype and study the functions of KATP channels in insulin secretion. We propose to characterize these animals, specifically, the levels of glucose, insulin, glucagon and somatostatin will be assayed to determine if homozygotic SUR1 null mice are hyperinsulinemic and hypoglycemic and to characterize heterozygotic animals. Pancreatic islets will be cultured and used for electrophysiological characterization of KATP. These mice will provide research material for the study of the most common cause of persistent hypoglycemia in newborns, and will provide insight into the physiology and pathology of insulin secretion. We will correct the pancreatic defect by expressing SUR1 cDNA in the pancreas under control of the rat insulin II promoter. The resulting animals will be used to study extra-pancreatic functions of the SUR/KIR6.2 ATP-sensitive potassium channels, particularly in neurons.

该提案的目的是了解 β 细胞如何耦合 使用 SUR1 缺失小鼠进行代谢至膜活性。 我们有 重建了 β 细胞 ATP 敏感的 K+ 通道 KATP， 高亲和力磺酰脲受体 (SUR1) 和沉默成员 小型内向整流器系列（KIR6.2）。 KATP 的目标是 用于治疗非胰岛素依赖型糖尿病的磺酰脲类药物， NIDDM，以及用于治疗高胰岛素血症的 K+ 通道开放剂 (KCO)。 SUR1 是 ATP 结合盒超家族的成员，具有多个 跨膜结构域和两个核苷酸结合折叠（NBF）。 钾ATP 通道在调节胰岛素分泌方面发挥着关键作用。 葡萄糖 代谢改变 β 细胞中的 ATP/ADP 比率，特别是 MgADP 刺激 KATP 开放的水平，从而使 β 细胞休息 膜电位。 SUR1 感知核苷酸水平的变化并减少 K+ 通过 KATP 通量，从而使 β 细胞膜去极化。 去极化激活电压门控 Ca2+ 通道；生成的Ca2+ 瞬态触发胰岛素胞吐作用。 SUR1 的突变 使 KATP 失活，或影响 MgADP 对其的调节，导致持续存在 婴儿期高胰岛素性低血糖症（PHHI），一种常染色体隐性遗传病 尽管病情严重，但仍以高胰岛素水平为特征的新生儿疾病 低血糖。 我们制作了 SUR1 缺失小鼠以表征 PHHI表型及胰岛素KATP通道功能研究 分泌。 我们建议描述这些动物的特征，特别是 将检测葡萄糖、胰岛素、胰高血糖素和生长抑素的水平 确定纯合 SUR1 缺失小鼠是否患有高胰岛素血症 低血糖并表征杂合动物。胰 胰岛将被培养并用于电生理学 KATP 的表征。 这些小鼠将为以下研究提供研究材料 持续性低血糖最常见原因的研究 新生儿，并将深入了解新生儿的生理学和病理学 胰岛素分泌。 我们将通过表达来纠正胰腺缺陷 胰腺中的 SUR1 cDNA 在大鼠胰岛素 II 启动子的控制下。 由此产生的动物将用于研究胰腺外功能 SUR/KIR6.2 ATP 敏感的钾通道，特别是在 神经元。