小窝蛋白-1在膜雌激素受体介导的内皮祖细胞增殖中的作用

目的 探讨微囊结构关键蛋白——小窝蛋白-1( caveolin-1,CAV-1)在膜雌激素受体介导的内皮祖细胞(endothelial progenitor cells,EPC)增殖中的作用.方法 培养的EPC分别用不同浓度( 10-9～10-6 mol/L)雌二醇-牛血清白蛋白复合物(E2-BSA)作用24h或10-8 mol/L E2-BSA作用不同时间,或加雌激素受体阻断剂ICI 182,780、环糊精(MβCD)以及CAV-1 siRNA处理,在DMDM培养基中培养的EPC(不加任何试剂)作为对照,使用3H-脱氧胸苷掺入法检测其对EPC增殖的影响.CAV-1 siRNA干扰的效果利用免疫印迹法检测CAV-1蛋白表达来验证.结果 10-8 mol/L E2-BSA作用24h促进EPC增殖作用最大(比对照组高了约87.5％),ICI 182,780可以抑制其增殖作用,表明膜雌激素受体介导的信号通路参与了雌激素对EPC的增殖作用.用环糊精破坏微囊结构以及使用CAV-1 siRNA下调CAV-1蛋白表达都可抑制EPC的增殖(分别比10-8 mol/L E2-BSA组低了18.6％和41.2％).结论 膜雌激素受体可以通过CAV-1促进EPC的增殖.

Role of caveolin-I on membrane estrogen receptor mediated proliferation of endothelial progenitor cells

Objective To investigate the potential role of caveolin-1 ( CAV-1 ) on membrane estrogen receptor (mER) mediated proliferation of endothelial progenitor cells (EPCs).Methods Bone marrow (BM) -derived EPCs were cultured.The proliferation of EPCs induced by estradiol ( E2 ) -BSA in the absence or presence of ICI 182,780 (a pure ER inhibitor),MβCD and CAV-1 siRNA was determined by 3H]-thymidine incorporation.The expression of CAV-1 was detected by Western blot.Results Proliferation of EPC peaked after 10-8 mol/L E2-BSA culture for 24 h (87.5％ increase vs.control),and this effect could be inhibited by estrogen receptor blocker ICI 182,780,indicating that mER-initiated membrane signaling pathways was involved in the proliferation effect of estrogen on EPC.Both cholesterol depletion and CAV-1 siRNA significantly attenuated E2-BSA induced 3H ]-thymidine incorporation.Western blot result confirmed that cholesterol depletion or CAV-1 siRNA significantly decreased CAV-1 protein expression ( - 18.6％ or -41.2％ vs.10-8 mol/L E2-BSA alone).Conclusion Our results suggested that estradiol promoted EPC proliferation through activating CAV-1 pathway.