Prevent Vasculopathy and Nephropathy in Metabolic Syndro

描述（由申请人提供）：糖尿病和代谢综合征患者的心血管系统加速动脉粥样硬化和早衰已成为流行病。我们之前对内皮细胞在模拟糖尿病环境的微环境下的研究揭示了细胞衰老的加速发展。我们观察到，在过早衰老的细胞中，硝基酪氨酸修饰蛋白的表达增强，而完整细胞经过过氧亚硝酸盐处理后会导致过早衰老，因此，我们用一种真正的过氧亚硝酸盐清除剂/抗氧化剂ebselen处理内皮细胞。这种治疗与预防和逆转过早衰老有关。这些发现促使我们在代谢综合征- Zucker糖尿病大鼠模型中研究细胞过早衰老的分子机制，埃布selen对内皮细胞过早衰老的影响，并检查这些动物血管病变的发展。我们假设氧化应激/过氧亚硝酸盐诱导的溶酶体功能障碍启动内皮细胞衰老和神经节苷的积累，从衰老到凋亡的分子转换-支持血管病变进展的事件。体外和体内研究采用图像分析和荧光活体显微镜，生化技术检测溶酶体和线粒体蛋白的渗漏以及神经节苷脂的积累，定量分析细胞周期标志物，旨在探讨过早衰老和凋亡的分子和细胞机制。用依布硒治疗的Zucker糖尿病脂肪大鼠将进行体内研究，以研究预防和逆转该综合征大血管和微血管病变（肾病）的可能性。这些研究可能揭示内皮细胞过早衰老的机制，过氧亚硝酸盐在启动衰老中的作用，以及过氧亚硝酸盐清除在改善血管病变中的潜在治疗效果。

DESCRIPTION (provided by applicant): Accelerated atherosclerosis and premature aging of the cardiovascular system in patients with diabetes mellitus and metabolic syndrome have acquired epidemic proportions. Our previous studies of endothelial cells subjected to a microenvironment emulating the diabetic milieu revealed accelerated development of cell senescence. Based on the observations that the expression of nitrotyrosine-modified proteins was enhanced in the prematurely senescent cells and peroxynitrite treatment of intact cells led to premature senescence, we treated endothelial cells with a bona fide peroxynitrite scavenger/antioxidant ebselen. Such a treatment was associated with the prevention and reversal of premature senescence. These findings prompted us to investigate the molecular mechanism(s) of premature cell senescence, effects of ebselen on premature endothelial cell senescence in a model of metabolic syndrome - Zucker diabetic rats, and examine the development of vasculopathy in these animals. We hypothesize that oxidative stress/peroxynitrite-induced lysosomal dysfunction initiates endothelial cell senescence and accumulation of gangliosides, a molecular switch from senescence to apoptosis - events underpinning the progression of vasculopathy. In vitro and in vivo studies employing image analysis and fluorescence intravital microscopy, biochemical techniques to detect leakage of lysosomal and mitochondrial proteins as well as accumulation of gangliosides, and quantitative analysis of the markers of cell cycle are designed to investigate molecular and cellular mechanisms of premature senescence and apoptosis. In vivo studies of the Zucker diabetic fat rat treated with ebselen will be conducted to examine the possibility of preventing and reversing macro- and micro-vasculopathy (nephropathy) in this syndrome. The investigations may shed light on mechanisms of premature senescence of endothelial cells, role of peroxynitrite in initiating it, and potential therapeutic efficacy of peroxynitrite scavenging in amelioration of vasculopathy.