Tan Zhi, Lin Gui-Ping, Wang Ting-Huai
Department of Physiology, College of Basic Medical Sciences, Sun Yat-Sen University, Guangzhou 510089, China.
Sheng Li Xue Bao. 2004 Jun 25;56(3):379-83.
The aim of the present study was to investigate the role of caveolin-1 in the inhibition of endothelin-1 induced proliferation of vascular smooth muscle cells (VSMCs) by 17beta-estradiol. In the cultured rat thoracic aortic VSMCs, proliferation of VSMCs was determined by using [(3)H]-thymidine incorporation and the expression of caveolin-1 protein was measured by immunofluorescence assays and Western blotting. The measurement demonstate VSMCs exposed to various concentrations of endothelin-1 (1-100 nmol/L) for 24 h induced an increase in [(3)H]-thymidine incorporation. Pretreament with various concentrations of 17beta-estradiol (0.1-10 nmol/L) for 24 h inhibited the proliferation effect of endothelin-1. Immunofluorescence assays showed that after 24 h treatment of VSMCs with endothelin-1 (100 nmol/L), the expression of caveolin-1 in VSMCs was significantly increased, whereas pretreament with 17beta-estradiol (10 nmol/L) for 24 h inhibited the effect. Western blotting results further proved that endothelin-1 inhibited and 17beta-estradiol increased the expression of caveolin-1 in VSMCs. These results demonstrate that 17beta-estradiol inhibits the VSMCs proliferation induced by endothelin-1, and that the effect of estradiol is probably mediated by caveolin-1.
本研究的目的是探讨小窝蛋白-1在17β-雌二醇抑制内皮素-1诱导的血管平滑肌细胞（VSMCs）增殖中的作用。在培养的大鼠胸主动脉VSMCs中，通过[³H]-胸腺嘧啶核苷掺入法测定VSMCs的增殖，并通过免疫荧光分析和蛋白质印迹法检测小窝蛋白-1的表达。测量结果表明，VSMCs暴露于不同浓度的内皮素-1（1-100 nmol/L）24小时后，[³H]-胸腺嘧啶核苷掺入增加。用不同浓度的17β-雌二醇（0.1-10 nmol/L）预处理24小时可抑制内皮素-1的增殖作用。免疫荧光分析显示，用内皮素-1（100 nmol/L）处理VSMCs 24小时后，VSMCs中小窝蛋白-1的表达显著增加，而用17β-雌二醇（10 nmol/L）预处理24小时可抑制该作用。蛋白质印迹结果进一步证明，内皮素-1抑制而17β-雌二醇增加VSMCs中小窝蛋白-1的表达。这些结果表明，17β-雌二醇抑制内皮素-1诱导的VSMCs增殖，且雌二醇的作用可能由小窝蛋白-1介导。
