The role of Rho/Rho kinase pathway in the metabolic syndrome-associated renal insufficiency

我们研究了小G偶联蛋白Rho及其下游靶分子Rho激酶在代谢综合征相关肾功能不全发病机制中的作用。2006年4月起，我们开始了以C57 BL/6 J小鼠为研究对象的研究。将6周龄的C57 BL/6 J小鼠随机分为三个实验组：低脂肪饮食喂养的小鼠（L组）、高脂肪饮食喂养的小鼠（H组）和用Rho激酶抑制剂法舒地尔处理的高脂肪饮食喂养的小鼠（F组）。每组均饲养12周。已证实法舒地尔改善高脂饮食喂养小鼠的尿蛋白排泄。我们探索了其机制，发现法舒地尔抑制高脂饮食喂养的云母肾脏中MCP-1和PDGF的表达增加。从2007年4月起，我们进一步研究了Rho/Rho激酶通路在脂肪组织和脂肪细胞中的作用，因为这些组织在代谢综合征的发病机制中起着核心作用。在体外实验中，我们利用TIS ...更多信息 使用分化成脂肪细胞3 T3-L1成纤维细胞的细胞培养系统。研究表明，成熟脂肪细胞向肥大脂肪细胞转化后，Rho激酶活性增强，MCP-1和TNF-α表达增加。Rho激酶抑制剂可阻断Rho激酶的激活，同时下调MCP-1和TNF-α的表达。在体内实验中，我们使用相同的饮食诱导的肥胖模型。证明Rho激酶抑制剂法舒地尔抑制高脂肪饮食喂养的小鼠的体重增加。与H组相比，F组小鼠脂肪组织重量减轻，脂肪细胞体积缩小，脂肪细胞因子表达水平降低。提示Rho/Rho激酶通路在代谢综合征的发病机制中起重要作用。下一步，我们构建了以脂肪组织特异性方式表达组成型活性Rho和显性阴性Rho的基因工程小鼠。本研究分析了这些小鼠的表型变化以及脂肪组织和肾组织的病理变化。这些数据将比迄今为止进行的实验更具体地描述Rho/Rho激酶的作用。少

We investigated the role of a small G-coupled protein Rho and its downstream target molecule, Rho kinase in the pathogenesis of metabolic syndrome-associated renal insufficiency. From April, 2006, we started the research by using C57BL/6J mice. 6-week-old C57BL/6J mice were randomly divided into three experimental groups; mice fed with low fat diet (group L), mice fed with high-fat diet (group H), and high fat-fed mice treated with Rho kinase inhibitor, Fasudil (group F). Each group was kept for 12 weeks. It has been demonstrated that Fasudil ameliorated urinary protein excretion in high-fat diet-fed mice. We explored its mechanism and found out that Fasudil inhibited the increased expression of MCP-1 and PDGF in the kidney of high fat diet-fed mica From April, 2007, we further examined the role of Rho/Rho kinase pathway in the adipose tissue and adipocytes since these tissues play a central role in the pathogenesis of metabolic syndrome. In the in vitro experiment, we utilized the tis … More sue culture system using 3T3-L1 fibroblasts differentiated into adipocytes. It has been demonstrated that, after mature adipocytes becomes hypertrophic adipocytes, Rho kinase activity was enhanced and the expression of MCP-1 and TNF-a in the adipocytes were increased. Rho kinase inhibitor blocked the activation of Rho kinase concommitently with the downregulation of MCP-1 and TNF-a. In in vivo experiments, we utilized the same diet-induced obesity model. It was demonstrated that Rho-kinase inhibitor, Fasudil inhibited the increase in body weight of high fat diet-fed mice. The weights of adipose tissues were also decreased in group F mice as compared with that in group H mice The sizes of adipocytes were also decreased and the expression levels of adipocytokines were also deceased in group F mice as compared with those in group H mice. These data suggested that Rho/Rho kinase pathway played important roles in the pathogenesis of metabolic syndrome. In the next step, we constructed gene-engineered mice which expressed constitutive active Rho and dominant negative Rho in an adipose-tissue specific manner. In the present we are analyzing the phenotypic changes of these mice and the pathological changes in the adipose tissues and renal tissues. These data would delineate the role of Rho/Rho kinase more specifically than the experiments hitherto performed. Less