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风险因素尚未完全确定。 我们的目的是在这个应用程序中定义的独特作用的激肽释放酶-激肽系统（KKS）的血管并发症的发病机制，并阐明在这个过程中涉及的潜在机制。 我们的假设是基于DCCT/EDIC队列1型糖尿病患者的初步数据，首次证明了血浆前激肽释放酶水平与大血管疾病的替代标志物（颈内动脉和颈总动脉内膜-中壁厚度）之间的相关性。 此外，我们的数据还表明KKS成分与已确定的血管疾病风险因素（例如高血压、血脂升高、微量白蛋白尿、纤维蛋白原和PAI 1）之间存在关联。 此外，我们的数据还表明，KKS组分与前胶原因子结缔组织生长因子（cTGF）的循环水平呈正相关。 我们还发现cTGF的循环水平与白蛋白的排泄率之间存在强相关性。 最后，我们最近在细胞水平上的数据表明，激肽参与糖尿病血管损伤的发展，通过其受体刺激几个关键信号通路，促进血管细胞的增殖和/或硬化。 在这方面，缓激肽（BK）刺激血管平滑肌细胞（VSMC）中胶原蛋白1、cTGF和转化生长因子-β（TGF-β）的水平。 BK引起的胶原蛋白1的增加是通过TGF-β的自分泌激活介导的。 此外，BK在VSMC中诱导TGF-β是通过活化MAPK途径介导的。 因此，我们推测糖尿病状态下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，我们提出了以下具体目标。1. 确定与未发生血管疾病的患者相比，发生血管疾病的糖尿病患者是否具有改变的KKS活性标志物。 对于这些研究，我们将确定KKS组分（血浆前激肽释放酶，激肽原，因子XII）的生物标志物与1型和2型糖尿病患者大血管疾病指数的关系。 我们还将确定糖尿病患者血管和肾功能不全标志物的新多态性。 确定KKS调节血管和肾损伤生物标志物产生的作用和贡献。 对于这些研究，我们将测量1型和2型糖尿病患者的TGF-β和cTGF的循环水平。 我们将确定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。 将检查过氧化物酶体增殖物激活受体-γ（PPAR-gamma）激活剂对BK信号传导促进VSMC硬化的作用。 3. 研究高血糖是否会调节内皮细胞表面KKS的组装和活化。 这些研究将对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患者血管疾病的多因素机制的理解。

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.