载脂蛋白（a）对血管平滑肌细胞增殖及其信号通路的影响

目的： 探讨载脂蛋白（a）［apo（a）］对血管平滑肌细胞增殖的影响及其机制。方法：原代培养血管平滑肌细胞并给予传代以进行实验，并采用α-actin抗体进行免疫组化细胞鉴定；分别给予apo（a）、apo（a）+整合素αⅤβ3单克隆抗体LM609及单独LM609干预细胞，采用细胞计数和MTT实验观察细胞增殖情况，采用Western blotting分析相关信号蛋白的变化。结果：所用实验细胞经鉴定均为血管平滑肌细胞；apo（a）能促进血管平滑肌细胞增殖，但这一作用能被整合素αⅤβ3单克隆抗体LM609所对抗，单独的LM609干预对细胞生长并无影响；Western blotting显示apo（a）能促进黏附斑激酶（FAK）磷酸化，并使总的转化生长因子β1（TGF-β1）及其磷酸化形式均表达减少，而LM609能对抗apo（a）的这些作用。结论：Apo（a）促进血管平滑肌细胞增殖的作用是通过整合素αⅤβ3介导的， 以致FAK活化，进而TGF-β1表达及磷酸化均减少。

Effects of apolipoprotein (a) on vascular smooth muscle cells proliferation and cell signal transduction pathway

AIM: To investigate the effect and the mechanism of apolipoprotein (a) [apo (a) ] on proliferation of vascular smooth muscle cells ( VSMCs). METHODS: All VSMCs used in experiments were serial subcultured from primary cells and were identified by immunohistochemistry staining of a - actin. Cell growth assay was observed as cell counting and MTT assay. Western blotting was also employed to detect the related mechanism. RESULTS: All cells used in experiments were confirmed as VSMCs. Although apo (a) enhanced VSMCs proliferation, this effect was attenuated by anti -integrin α_vβ_3, LM609.Use these reagents alone had no effect on VSMCs growth. The results of Western blotting demonstrated that focal adhesion kinase (FAK) was activated by apo (a) and the expression of total or phosphorylated transforming growth factor β_1 (TGF -β_1) was also decreased. However, these effects described above were all blocked by LM609.CONCLUSION: Apolipoprotein (a) enhances VSMCs proliferation and this effect is mediated by integrin α_vβ_3, which activates FAK and attenuates TGF - β_1 and phospho -TGF - β_1 expression.