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: 6358711
• 负责人: Joseph Bryan
• 金额: $ 5.23万
• 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 2002-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6358711
• 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Beta细胞夫妇如何 使用SUR1 NULL小鼠对膜活性的代谢。 我们有 重组了Beta细胞ATP敏感的K+通道KATP， 高亲和力磺酸盐受体（SUR1）和一个沉默的成员 小型内整流器家族（KIR6.2）。 KATP是 用于治疗非胰岛素依赖性糖尿病的磺酰尿菌， NIDDM，以及用于治疗超胰岛素主义的K+通道开启器（KCO）。 Sur1是ATP结合盒的成员，有多个 跨膜结构域和两个核苷酸结合褶皱（NBF）。 katp 渠道在调节胰岛素分泌方面起着关键作用。 葡萄糖 代谢改变了Beta细胞中的ATP/ADP比率，尤其是MGADP 刺激KATP开口的水平，这使Beta细胞休息设置 膜电位。 SUR1感应核苷酸水平的变化并降低 K+通量通过KATP，从而使β细胞膜去极化。 去极化激活电压门控的Ca2+通道；由此产生的Ca2+ 瞬态触发胰岛素胞吐作用。 Sur1中的突变 灭活KATP或影响MGADP的调节，导致持续 女性高胰岛素低血糖（PHHI），一种常染色体隐性 尽管严重 低血糖。 我们已经制作了sur1 null小鼠，以表征 PHHI表型和研究KATP通道在胰岛素中的功能 分泌。 我们建议表征这些动物，特别是 将分析葡萄糖，胰岛素，胰高血糖素和生长抑素的水平 确定纯合sur1 null小鼠是否是高胰岛素和 降血糖并表征杂合动物。胰 胰岛将被培养并用于电生理学 katp的特征。 这些老鼠将为 研究最常见的持续性低血糖原因 新生儿，并将提供有关生理和病理学的见解 胰岛素分泌。 我们将通过表达来纠正胰腺缺陷 大鼠胰岛素II启动子控制胰腺中的SUR1 cDNA。 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。