连接蛋白 Cx43参与冠状动脉平滑肌细胞的异质性促进冠脉再狭窄

目的：研究猪冠状动脉平滑肌细胞异质性与连接蛋白 Cx43关系，进一步阐明连接蛋白 Cx43在冠状动脉再狭窄发生中的作用。方法分别培养正常及支架术后猪原代冠状动脉平滑肌细胞，正常组应用血小板源生长因子（PDGF-BB）进行诱导，两组细胞分别进行电子显微镜观察细胞形态及结构变化，采用 Western Blotting 方法及实时荧光定量 PCR 测定 Cx43、Cx40、α-SMA、S100A4蛋白和 mRNA 表达；然后诱导组应用 Cx43阻断剂进行干预，再次检测上述指标变化。结果正常冠状动脉平滑肌细胞可见：纺锤型（spindle-shaped，S-SMC）和长菱形（rhomboid，R-SMC）两类，以 S-SMC 为主，其内 Cx40、α-SMA 有较高的蛋白和 mRNA 表达，而 Cx43表达较少；正常组经 PDGF-BB 诱导后细胞由 S-SMC 向 R-SMC 转变，同时伴随 Cx43表达上调，而 Cx40表达明显下降；通过反义 RNA 降低 Cx43表达，这种变化受抑制，并且 S-SMC 细胞保持原有形态，同时表达 a-肌动蛋白，支架组平滑肌细胞以 R-SMC 为主，Cx43、S100A4有较高的蛋白和 mRNA 表达。结论冠状动脉平滑肌细胞表型变化与连接蛋白 Cx43表达密切相关，连接蛋白 Cx43可能参与冠脉再狭窄的过程。

The role of connexin43 in coronary artery smooth muscle cells heterogeneity and coronary restenosis

Objective To investigate the correlation of connexin43 （Cx43）and coronary artery smooth muscle cells （SMC）heterogeneity,and the role in coronary restenosis.Methods SMCs from normal porcine coronary artery media and stent-induced intimalthickening cultured in vitro were induced by PDGF-BB and then intervened by Cx43 inhibitor. The cell morphology was observed by electron microscopy.The expression of Cx43、Cx40、α-SMA、S100A4 in SMCs of coronary artery were examined by Western Blotting and real time RT-PCR.Results The normal SMCs isolated from the porine coronary artery exhibit distinct phenotypes in vitro：spindle-shaped （S-SMC）and rhomboid （R-SMC）.S-SMCs were predominant in the normal media in which Cx40 andα-SMA was highly expressed ,whereas Cx43 was bare-ly detectable.PDGF-BB increased the level of Cx43,and promoted the transition of S-SMCs to R-SMCs.However,in-hibiting the expression of Cx43 decreased the level of Cx43,promoted the transition of R-SMCs to S-SMCs and ex-pressedα-SMA.R-SMCs were predominant in the stent-induced intimal thickening and that this modulation was accom-panied by the expression of Cx43 and S100A4.Conclusion The phenotype of coronary artery SMCs is closely related to the changes of the expression of Cx43 which may participate in the restenotic process.