Src在氧化型低密度脂蛋白诱导平滑肌细胞表型转化中的作用

The role of Src in oxidized low-density lipoprotein induced phenotypic switching of vascular smooth muscle cells

目的:探究Src对氧化型低密度脂蛋白(oxLDL)诱导血管平滑肌细胞表型转化的调控作用。方法:体外培养小鼠原代平滑肌细胞,以不同浓度的oxLDL刺激血管原代平滑肌细胞,检测平滑肌细胞表型分子平滑肌细胞表型肌球蛋白重链11(MYH11)、巨噬细胞表型CD68的表达变化,以及Src的激活情况。通过小干扰RNA(siRNA)抑制Src蛋白表达,Src特异性抑制剂PP2抑制Src激活,观察Src对oxLDL诱导的平滑肌细胞表型转化的影响。结果:分别以0、12.5、25.0、50.0μg/mL oxLDL刺激血管平滑肌细胞后发现MYH11的mRNA及蛋白表达逐渐下降(P<0.05),CD68的mRNA及蛋白表达逐渐升高(P<0.05)。以不同浓度(12.5、25.0、50.0μg/mL)、不同时间(15、30、60 min)的oxLDL刺激平滑肌细胞后,发现Src活性逐渐升高(P<0.05)。敲减Src siRNA或以PP2抑制Src蛋白活性后,oxLDL诱导的平滑肌细胞向巨噬细胞转化的分子表型的表达水平受到抑制。结论:oxLDL可以通过提高Src活性,进而诱导平滑肌细胞表型改变。

Objective:To investigate whether Src can regulate oxidized low-density lipoprotein(oxLDL)induced phenotypic transformation of vascular smooth muscle cells(SMCs).Methods:The primary mouse SMCs were cultured in vitro.And then we stimulated SMCs with different doses of oxLDL to detect the protein expression of phenotype molecules including Myosin Heavy Chain 11(MYH11)and CD68,as well as the activation of Src.Inhibiting Src expression with small interfering RNA(siRNA)and Src activation with specific inhibitor PP2 to observe the impact of Src on phenotypic transformation of SMCs.Results:The expression level of MYH11 mRNA and protein were down-regulated gradually,while the expression of CD68 mRNA and protein level were up-regulated gradually when vascular SMCs were stimulated with 0,12.5,25.0 and 50.0μg/mL oxLDL(P<0.05).The activity of Src was up-regulated gradually(P<0.05)when vascular SMCs were stimulated with different dose of oxLDL(12.5,25.0,50.0μg/mL)for different time(15,30,60 minutes)(P<0.05).Src siRNA knock-out and PP2 could inhibite the expression of phenotype molecules which indicated the transformation from SMCs to macrophage.Conclusions:OxLDL can induce phenotype transformation in SMCs by enhancing Src activity.