超声联合微泡抑制血管平滑肌细胞增殖机制的研究

Mechanism of ultrasound irradiation combined with microbubblesin inhibiting the proliferation of vascular smooth muscle cells

目的观察超声联合微泡对血管平滑肌细胞(VSMCs)周期分布及细胞周期调节蛋白激酶(CDK2)和抑制物p27表达的影响,探讨超声联合微泡抑制VSMCs增殖的作用机制。方法体外培养的VSMCs经血小板衍生生长因子-BB(PDGF-BB)刺激后,以低频连续波超声(频率1MHz、声强为0.3W/cm2)联合脂质微泡(1μl/ml)辐照VSMCs60s。分别用流式细胞仪、免疫细胞化学法检测细胞周期分布和细胞周期调控蛋白CDK2、p27的表达。结果与对照组比较,PDGF-BB刺激组细胞G0～G1期细胞比例下降而S期细胞比例增高(P<0.01),CDK2表达上调而p27表达降低(P<0.01);与PDGF-BB组相比,超声联合微泡组G0～G1期细胞比例增高,S期细胞比例降低(P<0.01),CDK2表达下调而p27表达增高(P<0.01)。结论超声联合微泡下调CDK2蛋白和上调p27蛋白的表达,阻滞细胞周期进程,可能是抑制VSMCs增殖的机制之一。

Objective To investigate the effect of ultrasound irradiation combined with microbubbles on cell cycle, CDK2 expression, p27 expression of vascular smooth muscle cells （VSMCs） and to study the antiproliferative mechanism of it in VSMCs. Methods After treated with platelet derived growth factor- BB （PDGF- BB）, cultured VSMCs were exposed to a low- frequency continuous wave ultrasound （1 MHz, 0.3 W/cm2, 60 s） combined with liposome microbubbles （1μl/ml）. The cell cycle was analyzed by flow cytometry. The expression of CDK2 and p27 were detected by immunocytochemistry techniques. Results Compared with the control group, the proportion of Go - G1 phase cell decreased and the proportion of S phase cell increased （ P 〈 0.01） in PDGF - BB group, meanwhile the expression of CDK2 increased and the expression of p27 decreased （ P 〈 0.01 ）. Compared with PDGF - BB group,the proportion of Go - G1 phase cell increased by ultrasound irradiation combined with microbubbles, the proportion of S phase cell decreased,the expression of CDK2 decreased and the expression of p27 increased （ P 〈 0.01 ）. Conclusion Increase of p27 expression, decrease of CDK2 expression and inhibition of cell cycle progress by ultrasound irradiation combined with microbubbles is one of the mechanisms for antiproliferation of VSMCs.