ENDOTHELIAL DYSFUNCTION IN HUMAN DIABETIC NEUROPATHY

人类糖尿病神经病的内皮功能障碍

基本信息

批准号：
6524532
负责人：
CHARLENE E HAFER-MACKO
金额：
$ 22.28万
依托单位：
UNIVERSITY OF MARYLAND BALTIMORE
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-09-30 至 2005-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6524532
关键词：
biopsy clinical research diabetic neuropathy glycation human subject immunocytochemistry in situ hybridization microcirculation pathologic process peripheral nervous system plasminogen activator plasminogen activator inhibitors thrombomodulin vascular endothelium

项目摘要

DESCRIPTION (Applicant's abstract): Diabetes mellitus remains a leading cause of neurological morbidity (1). In particular, neuropathy affects 60-70% of diabetics and has no effective treatment options. Though the precise mechanisms underlying human diabetic neuropathy are not established, significant research indicates nerve ischemia as a final common pathway. Numerous clinical and experimental studies show impaired vascular endothelial fibrinolysis and antithrombotic regulatory mechanisms, factors inked to diabetes, are important predictors for increased risk of vascular events and ischemic stroke. Furthermore, in vitro studies suggest that key regulatory proteins for both native endothelial fibrinolysis and antithrombotic function may be reduced by metabolic and inflammatory consequences of advanced glycosylation end stage product deposition (AGE's) in blood vessels. Yet, no prior studies have examined whether these same thrombosis regulatory mechanisms are important in the pathogenesis of diabetic neuropathy. Our preliminary data shows that tissue plasminogen activator (tPA) is absent from a substantial proportion of endoneurial vessels in diabetic nerves, but not controls. We also found that thrombomodulin (TM), an endothelial membrane receptor that deactivates thrombin and accelerates activated protein C formation (APC, anti-thrombotic enzyme), is essentially absent in diabetic nerve microvessels, but present in all controls. This biopsy based case-control study tests the hypothesis that key vascular endothelial proteins that regulate fibrinolysis and the TM-Protein C mechanisms are deficient in diabetic nerve microvasculature, constituting a distinct prothrombotic profile compared to non-diabetic control nerves, and that these deficiencies are related to neuropathy severity and the deposition of advanced glycation endproducts; (AGES) in the microvessel wall. Specific aims are to determine (a) whether tPA and TM expression are reduced and plasminogen activator inhibitor-1 (PAI-1) increased, by immunohistochemistry and in situ hybridization, on epi-, peri-, and endoneurial vessels in the microcirculation of diabetic peripheral nerve compared to age-sex matched non-diabetic controls, (b) whether alterations of tPA, PAI-1 or TM expression in nerve microvessels or plasma are greater in individuals with more severe clinical, electrophysiological and neuropathological rating scores, and or (c) related to AGE deposition on nerve microvasculature. Results of this proposal will establish the requisite mechanistic relationships between AGE-mediated endothelial based prothrombotic changes and clinical diabetic neuropathy severity to better understand hyperglycemia induced nerve injury and develop pharmacological and genetic strategies to reduce morbidity associated with this common disorder.

描述（申请人摘要）：糖尿病仍然是一个主要原因神经系统发病率 (1).特别是，神经病影响 60-70% 糖尿病患者，并且没有有效的治疗方案。尽管有精确的机制潜在的人类糖尿病神经病变尚未确定，重要研究表明神经缺血是最终的共同途径。众多临床和实验研究表明血管内皮纤维蛋白溶解受损抗血栓调节机制是糖尿病的重要因素血管事件和缺血性中风风险增加的预测因素。此外，体外研究表明，两者的关键调节蛋白天然内皮纤维蛋白溶解和抗血栓功能可能会降低晚期糖基化末期的代谢和炎症后果血管中的产物沉积（AGE's）。然而，之前的研究还没有研究了这些相同的血栓形成调节机制是否重要糖尿病神经病变的发病机制。我们的初步数据表明，组织相当大比例的纤维蛋白溶酶原激活剂（tPA）不存在糖尿病神经中的神经内血管，但不是对照。我们还发现血栓调节蛋白 (TM)，一种使凝血酶失活的内皮膜受体并加速活化蛋白 C 的形成（APC，抗血栓酶），糖尿病神经微血管中基本上不存在，但在所有对照中都存在。这项基于活检的病例对照研究检验了以下假设：关键血管调节纤维蛋白溶解的内皮蛋白和 TM-Protein C 机制糖尿病神经微脉管系统存在缺陷，构成了独特的与非糖尿病控制神经相比，血栓形成特征，并且这些缺陷与神经病变的严重程度和晚期沉积有关糖化终产物； (AGES) 存在于微血管壁中。具体目标是确定 (a) tPA 和 TM 表达是否减少以及纤溶酶原是否减少通过免疫组织化学和原位检测，激活剂抑制剂 1 (PAI-1) 增加微循环中的表层、周围和神经内血管杂交与年龄性别匹配的非糖尿病对照相比，糖尿病周围神经的变化， (b) 神经微血管中 tPA、PAI-1 或 TM 表达的改变是否临床症状更严重的个体血浆含量更高，电生理学和神经病理学评分，和/或 (c) 与神经微血管上的 AGE 沉积。该提案的结果将建立 AGE 介导之间必要的机制关系基于内皮的血栓前变化和临床糖尿病神经病变严重程度，以更好地了解高血糖引起的神经损伤并发展降低与此相关的发病率的药理学和遗传策略常见疾病。