黄芩苷抑制血小板源性生长因子诱导的血管平滑肌细胞增殖机制

Baicalin Inhibits the Proliferation of Vascular Smooth Muscle Cells Induced by Platelet-derived Growth Factor

用黄芩苷处理体外培养的血管平滑肌细胞(VSMC),采用流式细胞分析、免疫细胞化学染色、Western印迹及免疫共沉淀等方法,探讨不同浓度的黄芩苷对血小板源性生长因子(PDGF)诱导的VSMC增殖的影响及其作用机制。结果表明,与单独PDGF刺激组比较,黄芩苷预处理可明显抑制PDGF诱导的细胞增殖和迁移活性,同时伴有增殖和迁移相关蛋白PCNA、VCAM-1、ICAM-1、cyclinE、CDK2的表达减少;细胞周期分析显示,黄芩苷处理可明显减少处于细胞周期S时相的细胞数,而G_0/G_1期细胞增加,黄芩苷抑制增殖和迁移、阻滞细胞周期进程的作用具有浓度依赖性。免疫共沉淀分析证实,黄芩苷可抑制cyclinE-CDK2复合物的形成,上调p27蛋白水平,二者变化程度具有反相关关系。结果提示,黄芩苷是一种具有抗VSMC增殖和迁移活性的天然单体,其作用机制可能与抑制cyclinE-CDK2复合物的形成和上调p27水平有关。

To investigate the effects of baicalin on the proliferation in vascular smooth muscle cells （VSMCs） treated with platelet-derived growth factor （PDGF） and the action mechanism of baicalin. Flow cytometry, immunocytochemistry, Western blotting and co-immunoprecipitation assays were performed, respectively. The results showed that proliferation and migration of VSMCs induced by PDGF were significantly inhibited by baicalin in a concentration-dependent manner. The expression of proliferation- and migration-related proteins - PCNA, VCAM-1, ICAM-1, cyclinE, and CDK2 decreased markedly in baicalin-treated VSMCs. Baicalin treatment resulted in an increased cell population in the G0/G1-phase and a decreased distribution in S phase. Co-immunoprecipitation assay showed that the formation of cyclinE-CDK2 complex was reduced, and p27 level was elevated in the baicalintreated VSMCs. Taken together, our results demonstrated that baicalin is a natural active compound which inhibits the proliferation and migration of VSMCs, and arrests cell cycle progression via inhibiting the cyclinE-CDK2 complex formation and up-regulating p27 expression.