细胞外基质成分对于平滑肌表型及增殖的影响

The effects of extracellular matrix proteins on the phenotypic properties and proliferation of rat aortic smooth muscle cells

目的观察层粘连蛋白 (LN) 、纤维连接蛋白 (LN) 、Ⅳ型胶原蛋白 (collagen Ⅳ, Col Ⅳ) 等细胞外基质成分对于体外培养平滑肌细胞 (VSMC) 表型转化和增殖活性的影响。方法将原代和传代培养的大鼠主动脉 VSMC 分别接种于不同细胞外基质蛋白包被的培养板上,作用24、48、72 h后,以 RT-PCR 和 Westernblot 法检测 VSMC 表型标志平滑肌肌动蛋白 (SMA-α) 、骨桥蛋白 (OPN) mRNA 和蛋白表达水平, MTT 法检测 VSMC 增殖活性。结果与对照组相比, LN 包被组 SMA-α基因及蛋白表达增强,OPN则表达减弱,且可维持48 h以上,于72 h后,与对照组趋于一致,FN包被组OPN基因及蛋白表达增强,SMA-α表达减弱, Col Ⅳ包被组 SMA-α、OPN 与对照组无统计学意义, FN 组增殖活性显著增强,并与作用时间呈正比, LN 包被组与Col Ⅳ包被组对 VSMC 增殖活性无明显影响。结论 LN 可延迟 VSMC 表型转化, FN 则促进 VSMC 表型转化与增殖,细胞外基质成分对于 VSMC 表型转化和增殖具有重要的调节作用。

Objectives To investigate the effects of extracellular matrix （ECM） proteins including Laminin （ LN ） , Fibronectin （ FN ） , collagen （Col Ⅳ）on the phenotypic properties and proliferation of rat aortic smooth muscle cells cultured in vitro. Methods The primarily and passaged cultured rat aortic smooth muscle cells （SMC） were incubated on the plates coated with different matrix proteins LN, FN or Col IV respectively , 24 h, 48 h and 72 h later, the expression of differentiation and de-differentiation marker＇ s mRNA and protein （ α -smooth muscle actin, SMA- α ; osteoponin, OPN） of primarily cultured SMCs were determined by reverse transcription polymerase chain reaction （RT-PCR） analysis and Western blot analysis, MTT assay were employed to detect the proliferation of passaged SMCs. Results The mRNA and protein levels of SMA- α and OPN of SMCs in LN coated group were both greater or weaker respectively than in those of control group for more than 48 h, 72 h later, they tend to be in accordance with the control levels. The mRNA and protein levels of SMA- α and OPN of SMCs in FN coated group were both persistently weaker or greater respectively than in those of control group, while in Col IVcoated group were maintained at control levels. The proliferation activities of SMCs in FN coated group increased significantly with the passage of acting time, but there were no difference among LN coated group, Col Ⅳ coated group and control group. Conclusion LN can retard the dedifferentiation of VSMCs, while FN can promote the phenotypic modulation and proliferation of VSMCs,and the ECM components play an important role in the regulation of the phenotypic modulation and proliferation of VSMCs.