冠状动脉支架术后再狭窄中血管平滑肌细胞表型转换的研究

目的：通过制作猪冠状动脉支架术后再狭窄模型,研究冠状动脉支架内再狭窄时平滑肌细胞表型的变化. 方法：将12只家猪随机分为正常对照组和支架组,每组各6只.正常对照组进行假手术,不做其他处理.支架组家猪于冠状动脉前降支和回旋支各置入裸支架1枚（微创Firebird）.取30 d后经冠状动脉造影确定发生再狭窄的血管段,HE染色观察组织形态;取中层平滑肌细胞培养,电镜观察细胞形态与结构;Western blot测定缝隙连接蛋白（connexin,Cx）43、Cx40、a-平滑肌肌动蛋白（α-SMA）、S100钙结合蛋白A4 （S100A4）的表达. 结果：支架组血管内膜显著增厚,中层平滑肌细胞以长菱形平滑肌细胞（R-SMC）为主,而对照组以纺锤形平滑肌细胞（S-SMC）为主;支架组Cx43、S100A4表达较对照组增强,Cx40、α-SMA表达较对照组降低（P＜0.01）.结论：经皮冠状动脉介入术后S-SMC向R-SMC的转换可能参与了再狭窄过程.

Phenotypic change of smooth muscle cells in restenosis after percutaneous coronary intervention

Objective：To investigate phenotypic transition of smooth muscle cells （SMCs） in a porcine coronary restenosis model.Methods：A total of 12 experimental domestic pigs were randomly divided into two groups：control group （n =6） and restenosis group （n =6）.Pigs in control group received sham operation,and the other 6 pigs were implanted 1 stent in the left anterior descending coronary artery and circumflex coronary artery respectively.Histomorphology was observed by HE staining.Cell morphology and structure was examined by electron microscopy.The expression of connexin （Cx）43,Cx40,α-smooth muscle actin（a-SMA）,S100 calcium binding protein A4（S100A4） in SMCs of coronary artery were examined by western blot.Results：Spindle-SMCs （S-SMCs） were predominant in control group,whereas rhomboid-SMCs （R-SMCs） were in higher proportion in restenosis group.Cx40 and a SMA were highly expressed in control group（P＜0.01）.In contrast,Cx43 and S100A4 were markedly upregulated in restenosis group（P＜0.01）.Conclusion：The switch from S-SMC to R SMC phenotype may be involved in restenosis after percutaneous coronary intervention.