DIABETIC NEUROPATHY--RECEPTORS AND SIGNALING MECHANISM

糖尿病神经病——受体和信号传导机制

• 批准号: 2143515
• 负责人: LILIANA N BERTI-MATTERA
• 金额: $ 10.96万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-30 至 1997-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2143515
• 关键词: G protein; SDS polyacrylamide gel electrophoresis; Schwann cells; adenylate cyclase; adrenergic receptor; biological signal transduction; bradykinin; cell line; cyclic AMP; diabetic neuropathy; glucose; immunochemistry; laboratory rat; membrane transport proteins; muscarinic receptor; neuropeptide receptor; phospholipase C; potassium; receptor coupling; sodium; sodium potassium exchanging ATPase; stimulant /agonist; tissue /cell culture; western blottings

Diabetic neuropathy, one of the major complications of chronic diabetes is characterized by several biochemical alterations including a reduction in myo-inositol levels, decrease in Na+K+-ATPase activity and abnormalities in phosphoinositide (PPI) metabolism and adenylyl cyclase activity. The current hypothesis regarding the pathophysiology of diabetic neuropathy assign a central role to the decrease in myo-inositol uptake-dependent phosphoinositide turnover and hence availability of second messengers, like diacylglycerol which modulate Na+K+-ATPase activity through activation of protein kinase C. While it is generally accepted that the reduction in Na+K+-ATPase plays a key role in the development of neuropathy, its precise regulation is far from clear. Recent evidence from our and other labs suggests that peripheral nerve possesses muscarinic, bradikynin, purinergic and beta-adrenergic receptors which seem to be linked to stimulation of the breakdown of PPI or adenylyl cyclase. We have recently identified several types of guanine-nucleotide binding (G) proteins, that are known to be involved in other tissues in coupling between the agonist-receptor complexes and the adenylyl cyclase or phospholipase C systems. In nerve and myelin membranes from experimental diabetic animals we demonstrated that some of these signalling pathways are altered. With this evidence, we propose to: 1) characterize the relative levels of G-proteins in total and subcellular fractions of sciatic nerve from diabetic rats by ADP- ribosylation with bacterial toxins and immunoblotting; 2) investigate the receptor-linked signalling pathways that modulate the activity of phospholipase C and adenylyl cyclase and their influence on Na+K+-ATPase activity in sciatic nerve slices or membranes by: a)activation of phospholipase C through muscarinic, purinergic and bradikynin receptors b) modulation of adenylyl cyclase activity through activation of beta- adrenergic and muscarinic receptors: 3) evaluate how the alterations in Na+K+-ATPase in nerves from diabetic animals correlate with changes in the different components of the above mentioned signalling pathway and 4) determine if in cultured Schwann cells the above mentioned agonists are linked to cAMP and phospholipase C and if these pathways are altered under conditions that mimic diabetes like high glucose and myo-inositol free culture conditions.

糖尿病神经病变是慢性糖尿病的主要并发症之一 其特征是多种生化改变，包括减少 肌醇水平、Na+K+-ATP酶活性降低和 磷酸肌醇 (PPI) 代谢和腺苷酸环化酶异常 活动。 目前关于病理生理学的假设 糖尿病神经病变对肌醇减少起重要作用 摄取依赖性磷酸肌醇周转以及因此的可用性 第二信使，如调节 Na+K+-ATP 酶的二酰基甘油 通过激活蛋白激酶 C 来发挥活性。虽然它通常是 公认 Na+K+-ATPase 的减少在 神经病的发生发展，其精确调控还远不清楚。 我们和其他实验室的最新证据表明，周围神经 具有毒蕈碱、缓激宁、嘌呤能和β-肾上腺素能 似乎与刺激 PPI 分解有关的受体 或腺苷酸环化酶。 我们最近确定了几种类型 已知参与的鸟嘌呤核苷酸结合 (G) 蛋白 在其他组织中激动剂-受体复合物之间的耦合 腺苷酸环化酶或磷脂酶 C 系统。 在神经和髓磷脂中 我们利用实验性糖尿病动物的膜，证明了一些 这些信号通路的一部分发生了改变。 有了这些证据，我们建议 目的： 1) 表征总 G 蛋白和 ADP- 糖尿病大鼠坐骨神经的亚细胞部分 细菌毒素核糖基化和免疫印迹； 2）调查 调节活性的受体相关信号通路 磷脂酶C和腺苷酸环化酶及其对Na+K+-ATP酶的影响 坐骨神经切片或神经膜的活动通过：a）激活 磷脂酶 C 通过毒蕈碱、嘌呤能和缓激肽受体 b) 通过激活 β- 来调节腺苷酸环化酶活性 肾上腺素能和毒蕈碱受体：3）评估 糖尿病动物神经中的 Na+K+-ATP 酶与 上述信号通路的不同组成部分和 4) 确定培养的雪旺细胞中是否存在上述激动剂 与 cAMP 和磷脂酶 C 有关，如果这些途径​​发生改变 在模拟糖尿病的条件下，如高血糖和肌醇 自由的培养条件。