KALLIKREINS-KININS AND DIABETIC VASCULAR COMPLICATIONS

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确定。我们在这个应用程序的目的是确定钾likrein-kinin系统（KKS）在血管并发症发病机制中的独特作用，并阐明在这一过程中涉及的潜在机制。我们的假设基于1型糖尿病患者的DCCT/ edic队列的初步数据，首次证明血浆预钾likrein水平与大血管疾病的替代标志物（内颈动脉和颈总动脉内膜-内壁厚度）之间存在关联。此外，我们的数据还表明KKS成分与血管疾病危险因素（如高血压、血脂升高、微量白蛋白尿、纤维蛋白原和PAI1）之间存在关联。此外，我们的数据还表明，KKS成分与结缔组织生长因子（cTGF）的循环水平呈正相关。我们还发现循环中cTGF水平与白蛋白排泄率有很强的相关性。最后，我们最近在细胞水平上的数据表明，激肽通过其受体刺激几种促进血管细胞增殖和/或硬化的关键信号通路，参与糖尿病血管损伤的发展。在这方面，缓激素（BK）刺激血管平滑肌细胞（VSMC）中胶原- 1、cTGF和转化生长因子- β (tgf - β)的水平。BK介导的胶原蛋白1的增加是通过tgf - β的自分泌激活介导的。此外，BK通过激活MAPK通路介导了VSMC中tgf - β的诱导。因此，我们假设糖尿病状态下KKS组分的激活在糖尿病血管疾病的发生和发展中起着关键作用。为了验证我们的假设，我们提出以下具体目标。确定发生血管疾病的糖尿病患者与未发生血管疾病的患者相比，是否有KKS活性改变的标志物。在这些研究中，我们将定义KKS成分的生物标志物（血浆前钾激肽、激肽原、因子XII）与1型和2型糖尿病患者大血管疾病指标的关系。我们还将发现糖尿病患者血管和肾功能障碍标志物的新多态性。确定KKS在调节血管和肾损伤生物标志物产生中的作用和贡献。在这些研究中，我们将测量1型和2型糖尿病患者的循环tgf - β和cTGF水平。我们将明确KKS与tgf - β和cTGF之间的相互关系，并确定tgf - β和cTGF是否能预测糖尿病血管并发症的发生。我们将研究过氧化物酶体增殖体激活受体γ (ppar - γ)激活剂对BK信号的影响，从而促进VSMC硬化。3. 研究高血糖是否会调节内皮细胞表面KKS的组装和激活。这些研究将为KKS对糖尿病血管疾病的贡献提供全面和关键的评估，并将增强我们对糖尿病血管疾病多因素机制的理解。

DESCRIPTION (provided by applicant): The risk factors that contribute to the development of vascular disease in diabetes are not fully defined. Our objective in this application is to define the unique role of the kallikrein-kinin system (KKS) in the pathogenesis of vascular complications and to elucidate the underlying mechanisms involved in this process. Our hypothesis which is based on preliminary data generated from the DCCT/EDIC-cohort of type 1 diabetic patients, demonstrate, for the first time, an association between plasma prekallikrein levels and surrogate markers of macrovascular disease (internal and common carotid intima-medial wall thickness). IN addition, our data also demonstrates an association between KKS components and established vascular disease risk factors such as, hypertension, elevated lipids, microalbuminuria, fibrinogen and PAI1. Further, our data also demonstrates that KKS components positively correlate with the circulating levels of the prosclerotic factor connective tissue growth factor (cTGF). We have also discovered that there is a strong correlation between the circulating levels of cTGF and the excretion rate of albumin. Finally, our recent data at a cellular level indicates that kinins participate in the development of diabetic vascular injury by acting through their receptors to stimulate several key-signaling pathways that promote proliferation and/or sclerosis of vascular cells. In this regard, bradykinin (BK) stimulates the levels of collagen 1, cTGF and transforming growth factor-beta (TGF-beta) in vascular smooth muscle cells (VSMC). This increase in collagen 1 by BK was mediated via autocrine activation of TGF-beta. Moreover, the induction of TGF-beta by BK in VSMC was mediated via activation of the MAPK pathways. Therefore, we hypothesize that activation of the KKS components by the diabetic state plays a pivotal role in the initiation and progression of diabetic vascular disease. To test our hypothesis, we propose the following specific aims.1. Determine whether diabetic patients who develop vascular disease have markers of altered KKS activity, compared with patients who do not develop vascular disease. For these studies we will define the relationships of biomarkers of KKS components (plasma prekallikrein, kininogen, Factor XII) to indices of macrovascular disease in type 1 and type 2 diabetic patients. We will also identify novel polymorphisms to markers of vascular and renal dysfunction in diabetic patients.2. Determine the role and contribution of the KKS to modulate production of biomarkers of vascular and renal injury. For these studies, we will measure the circulating levels of TGF-beta and cTGF in type 1 and type 2 diabetic patients. We will define interrelationships between KKS and TGF-beta and cTGF, and determine whether TGF-beta and cTGF will predict the development of diabetic vascular complications. The effect of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) activators on BK signaling to promote VSMC sclerosis will be examined. 3. Investigate if hyperglycemia will modulate the assembly and activation of KKS on endothelial cell surfaces. These studies will provide a comprehensive and critical assessment of the contribution of the KKS to diabetic vascular disease and will enhance our understanding of the multi-factorial mechanisms underlying vascular disease in diabetics.