Jin Jing, Peng Chao, Wu Su-zhen, Chen Hong-min, Zhang Bai-fang
Department of Biochemistry, Wuhan University School of Basic Medical Sciences, Wuhan 430071, China.
1] Department of Biochemistry, Wuhan University School of Basic Medical Sciences, Wuhan 430071, China [2] Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071, China.
Acta Pharmacol Sin. 2015 Jul;36(7):831-40. doi: 10.1038/aps.2015.23. Epub 2015 May 4.
RhoA/ROCK signaling plays an important role in diabetic nephropathy, and ROCK inhibitor fasudil exerts nephroprotection in experimental diabetic nephropathy. In this study we investigated the molecular mechanisms underlying the protective actions of fasudil in a rat model of diabetic nephropathy.
Streptozotocin (STZ)-induced diabetic rats, to which fasudil or a positive control drug enalapril were orally administered for 8 months. Metabolic parameters and blood pressure were assessed during the treatments. After the rats were euthanized, kidney samples were collected for histological and molecular biological studies. VEGF, VEGFR1, VEGFR2 and fibronectin expression, and Src and caveolin-1 phosphorylation in the kidneys were assessed using RT-PCR, Western blot and immunohistochemistry assays. The association between VEGFR2 and caveolin-1 was analyzed with immunoprecipitation.
Chronic administration of fasudil (30 and 100 mg·kg(-1)·d(-1)) or enalapril (10 mg/kg, bid) significantly attenuated the glomerular sclerosis and albuminuria in the diabetic rats. Furthermore, fasudil treatment prevented the upregulation of VEGF, VEGFR1, VEGFR2 and fibronectin, and the increased association between VEGFR2 and caveolin-1 in the renal cortices, and partially blocked Src activation and caveolin-1 phosphorylation on tyrosine 14 in the kidneys, whereas enalapril treatment had no effects on the VEGFR2/Src/caveolin-1 signaling pathway.
Fasudil exerts protective actions in STZ-induced diabetic nephropathy by blocking the VEGFR2/Src/caveolin-1 signaling pathway and fibronectin upregulation. Thus, VEGFR2 may be a potential therapeutic target for the treatment of diabetic nephropathy.
RhoA/ROCK信号通路在糖尿病肾病中起重要作用，ROCK抑制剂法舒地尔在实验性糖尿病肾病中发挥肾保护作用。本研究旨在探讨法舒地尔在糖尿病肾病大鼠模型中发挥保护作用的分子机制。
用链脲佐菌素（STZ）诱导糖尿病大鼠，分别口服法舒地尔或阳性对照药物依那普利8个月。治疗期间评估代谢参数和血压。大鼠处死后，收集肾脏样本进行组织学和分子生物学研究。采用逆转录-聚合酶链反应（RT-PCR）、蛋白质免疫印迹法（Western blot）和免疫组织化学分析评估肾脏中血管内皮生长因子（VEGF）、血管内皮生长因子受体1（VEGFR1）、血管内皮生长因子受体2（VEGFR2）和纤连蛋白的表达，以及Src和小窝蛋白-1（caveolin-1）的磷酸化情况。用免疫沉淀法分析VEGFR2与caveolin-1之间的关联。
长期给予法舒地尔（30和100mg·kg-1·d-1）或依那普利（10mg/kg，每日两次）可显著减轻糖尿病大鼠的肾小球硬化和蛋白尿。此外，法舒地尔治疗可防止糖尿病大鼠肾皮质中VEGF、VEGFR1、VEGFR2和纤连蛋白的上调，以及VEGFR2与caveolin-1之间关联的增加，并部分阻断肾脏中Src的激活和caveolin-1酪氨酸14位点的磷酸化，而依那普利治疗对VEGFR2/Src/caveolin-1信号通路无影响。
法舒地尔通过阻断VEGFR2/Src/caveolin-1信号通路和纤连蛋白上调，对STZ诱导的糖尿病肾病发挥保护作用。因此，VEGFR2可能是治疗糖尿病肾病的潜在治疗靶点。
