PKC Activation and Cardiovascular Disease in Diabetes

描述(由申请人提供)： 1型糖尿病(T1 DM)患者心血管疾病(CVD)的危险因素包括高血糖、高脂血症、肾功能障碍、氧化剂、糖化脂质和蛋白质以及其他代谢异常。T1 DM患者CVD的发病机制与非糖尿病患者相似，提示T1 DM患者也存在加速CVD的危险因素。单核细胞、血管内皮细胞(EC)和平滑肌细胞(SMC)的激活在T1 DM和非糖尿病患者动脉粥样硬化的发生发展中起重要作用。蛋白激酶C(PKC)的激活对于促进这些细胞进入促动脉粥样硬化状态具有重要意义。上述许多危险因素都会激活单核细胞和血管细胞中的PKC。因此，我们认为，胰岛素缺乏引起的糖脂代谢异常将激活单核细胞、EC和SMC中的PKC，特别是β亚型。这将导致蛋白质的表达和分泌，有利于巨噬细胞/泡沫细胞的形成，内皮功能障碍，以及SMC的迁移和增殖。这些改变将进一步加速T1 DM患者的动脉粥样硬化。为了明确地检验这一假设，我们建议：L)表征蛋白激酶Cα、β和德尔塔亚型在葡萄糖诱导的单核细胞、动脉内皮细胞和平滑肌细胞激活中的作用。2)为了探讨PKCβ亚型激活在apoE-KO小鼠动脉粥样硬化形成中的作用，方法：a)应用或不使用PKCβ抑制剂的糖尿病或非糖尿病apoE-KO小鼠；b)血管特异性高表达PKCβ2(PKCβ2 V-TgXapoE-KO)小鼠的后代(PKC beta 2 V-TgXapoE-KO)与apoE-KO小鼠杂交；c)PKCβ缺失小鼠(PKC beta-KO)与apoE-KO小鼠杂交。3)利用单核细胞CD68启动子(PKCβ2 M-TG)建立和鉴定在非糖尿病和糖尿病状态下视网膜、肾脏和心脏异常的单核细胞高表达PKCβ2亚型的小鼠。我们将PKCβ2 M-TG小鼠与apoE KO小鼠杂交，以确定其在动脉粥样硬化发展中的作用。

DESCRIPTION (provided by applicant): Risk factors for cardiovascular disease (CVD) in type 1 diabetic patients (T1DM) include hyperglycemia, hyperlipidemia, renal dysfunction, oxidants, glycated lipids and proteins and other metabolic abnormalities. The pathologies of CVD in T1DM are similar to those of nondiabetic subjects, suggesting the risk factors accelerating CVD also present in T1DM. Activation of monocytes, endothelial cells (EC) and smooth muscle cells (SMC) are shown to be important for the development of atherosclerosis both in T1DM and nondiabetic patients. Protein kinase C (PKC) activation is important for promoting these cells into pro-atherogenic state. Many of the risk factors stated above, will activate PKC in monocytes and vascular cells. Thus, we propose that abnormal metabolites of glucose and lipids due to insulin deficiency will activate PKC, especially the beta isoforms, in monocytes, EC and SMC. This will result in the expression and secretion of proteins in favor of the formation of macrophages/foam cells, endothelial dysfunction, and SMC migration and proliferation. These alterations will further accelerate atherosclerosis in T1DM. To test this hypothesis definitively, we propose: l) to characterize the role of PKC alpha, beta, and delta isoforms in glucose-induced activation of monocytes, arterial EC and SMC. 2) to assess the role of PKC beta isoform activation in the development of atherosclerosis in apoE-KO mice by comparing the atherosclerotic lesions in :a) diabetic or nondiabetic apoE-KO mice with or without PKC beta inhibitor; b) offsprings (PKC beta 2 V-TgXapoE-KO) of mice with vascular-specific overexpression of PKC beta 2 (PKC beta 2 V-Tg) crossbred with apoE KO-mice; c) offsprings of PKC beta null mice (PKC beta-KO) crossbred with apoE-KO mice. 3) to make and characterize mice overexpressing PKC beta 2 isoform in monocytes using a monocyte CD68 promoter (PKC beta 2 M-Tg) with respect to retinal, renal and cardiac abnormalities in nondiabetic and diabetic state. We will crossbreed PKC beta 2 M-Tg mice with apoE KO mice to determine its effect on the development of atherosclerosis.