Geminin在血管平滑肌细胞分化表型转化中的介导作用

Role of Geminin in mediating phenotype transformation of vascular smooth muscle cells in rats

目的通过比较静止状态的血管平滑肌细胞(vascular smooth muscle cells,VSMCs)与血清刺激后的VSMCs在分化表型改变中Geminin的表达变化情况,探讨Geminin对VSMCs表型转化的影响。方法实验设置静止状态(血清饥饿)对照组、血清刺激组,研究不同时相两个组Geminin的分布、活性及表达水平的差异。血清饥饿法可以诱导出VSMCs表型分化及活性差异;免疫荧光染色后激光共聚焦显微镜观察Geminin核内定位;应用PCR检测Geminin基因表达的变化;Western blot检测Geminin蛋白、VSMC合成型标志物骨桥蛋白(osteopontin,OPN)及收缩型标志物平滑肌肌动蛋白相关蛋白(actin-related proteins,ARP)表达的变化。结果①静止状态下(血清饥饿)VSMCs以收缩型为主,血清刺激后以合成型为主;②静止状态Geminin几乎全部存在于细胞质内,而血清刺激后Geminin几乎全部定位于胞核内;③GemininmRNA在血清刺激时明显升高,且在刺激48h时差异表达最明显,与无血清比较差异具有统计学意义(P<0.05);④Geminin蛋白和骨桥蛋白在血清刺激时均明显升高,与无血清比较差异具有统计学意义(P<0.05)。结论 Geminin参与介导了VSMCs由收缩型向合成型的转化。

Objective To investigate the effect of Geminin on phenotype transformation of vascular smooth muscle cells （VSMC） in rats by comparing the expressions of Geminin in resting and serum-simulated VSMC.Methods VSMC were divided into control group （serum starvation group） and serum stimulation group. Differences in distribution,activity,and expression of Geminin were studied between the two groups.Serum starvation was used to induce phenotype differentiation and activity of Geminin. Expression of Geminin was detected by PCR while expression of Geminin protein,synthetic biomarker osteopontin （OPN）,SM-2 actin-related proteins （ARP） was detected by Western blotting.Results The contractible form of VSMC was mainly observed in control group followed by synthetic form after serum stimulation. Almost all kinds of resting Geminin were found in cytoplasm and located in nuclei after serum stimulation. The expression levels of Geminin mRNA and protein as well as OPN were significantly higher after serum stimulation than before serum stimulation,especially 48 h after serum stimulation （P0.05）. Conclusion Geminin participates in transforming VSMC from contractile to synthetic form.