KALLIKREIN AND VASCULAR DISEASE RISK IN DIABETES

描述(由申请人提供)：导致糖尿病血管疾病发展的危险因素尚未完全定义。这项建议侧重于确定血浆前激肽释放酶(PK)在1型糖尿病血管病变的发生和发展中的作用，并描述促进糖尿病血管并发症发展的血浆PK的分子决定因素。从临床、动物和基础研究对血浆PK的新机制和功能的研究中，PI产生了令人兴奋的新信息。基于1型糖尿病患者DCCT/EDIC队列产生的横断面数据的初步研究表明，血浆PK与微量白蛋白尿、高血压和血脂升高之间存在独立的关联。多变量回归分析首次提供了血浆PK水平与颈总动脉和颈内动脉内膜中层厚度之间独立且正相关的证据。在血浆PK基因编码区发现了一种新的SNP。生存分析表明，与没有SNP相比，有SNP的糖尿病受试者发生微量白蛋白尿的速度更快。最后，我们发现了血管平滑肌细胞(VSMC)激活血浆PK的新机制。一旦激活，血浆激肽释放酶通过反式激活表皮生长因子受体来刺激MAPK的磷酸化，并诱导VSMC的凋亡。我们假设，血浆PK水平的升高是糖尿病状态的结果，并在糖尿病血管疾病的发生和发展中发挥关键作用。为了验证这一假设，我们提出了以下具体目标：1)确定发生肾脏和血管病变的1型糖尿病患者与没有发生肾脏和血管病变的1型糖尿病患者相比，是否先行血浆PK水平升高。2)探讨血浆前激肽释放酶在载脂蛋白E(ApoE-/-)缺失型糖尿病小鼠动脉粥样硬化和肾病发生发展中的作用。3)阐明血浆前激肽释放酶刺激下血管重塑的细胞和分子机制。拟议的研究应将血浆PK确立为血管疾病的重要病理危险因素。从机理上讲，拟议的研究应该会对糖尿病患者血浆PK信号转导和血管疾病调控的新方面产生重要的见解。糖尿病中血管疾病和血管疾病风险对健康的重要性怎么强调都不为过。它是美国发病率和死亡率的主要原因。这项建议的目的是阐明糖尿病血管疾病的危险标记和机制，并阐明糖尿病血管并发症的潜在分子、细胞和遗传决定因素。

DESCRIPTION (provided by applicant): The risk factors that contribute to the development of vascular disease in diabetes are not fully defined. This proposal focuses on defining the role of plasma prekallikrein (PK) in the initiation and progression of vascular disease in type 1 diabetes, and on describing the molecular determinants of plasma PK that foster the development of diabetic vascular complications. Exciting new information has been generated by the PI from clinical, animal and basic studies on novel mechanisms and functions of plasma PK. Preliminary studies based on cross-sectional data generated from the DCCT/EDIC-cohort of type 1 diabetic patients, demonstrated an independent association between plasma PK and microalbuminuria, hypertension and elevated lipids. Multivariable regression analysis provided the first evidence of an independent and positive association between plasma PK levels and common and internal carotid intima medial thickness. A novel polymorphism (SNP) in the coding region of the plasma PK gene was identified. Survival analyses demonstrated that the onset of microalbuminuria occurs at a more rapid rate in diabetic subjects with the SNP than without the SNP. Finally, we discovered a novel mechanism of plasma PK activation by vascular smooth muscle cells (VSMC). Once activated, plasma kallikrein stimulates MAPK phosphorylation via transactivation of the epidermal growth factor receptor and induces apoptosis of VSMC. We hypothesize that, increased levels of plasma PK are a result of the diabetic state and play a pivotal role in the initiation and progression of diabetic vascular disease. To test this hypothesis, we propose the following specific aims: 1) To determine whether type 1 diabetic patients who develop renal and vascular disease have antecedent increases in the levels of plasma PK compared with type 1 diabetic patients who do not develop renal and vascular disease. 2) To determine the role of plasma prekallikrein in the initiation and progression of atherosclerosis and nephropathy in diabetic Apolipoprotein E (ApoE-/-) null mice. 3) To elucidate the cellular and molecular mechanisms underlying vascular remodeling in response to plasma prekallikrein stimulation. The proposed studies should establish plasma PK as a pathologically-important risk factor for vascular disease. Mechanistically, the proposed studies should generate significant insights into novel aspects of plasma PK signal transduction and regulation of vascular disease in diabetes. The health related significance of vascular disease and vascular disease risk in diabetes cannot be overstated. It is the leading cause of morbidity and mortality in the United States. The goals of this proposal are to elucidate risk markers and mechanisms of vascular disease that are operative in diabetes and to elucidate underlying molecular, cellular and genetic determinants of vascular complications of diabetes.