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

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(1 μl/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 G0-G1 phase cell decreased and the proportion of S phase cell increased(P0.01)in PDGF-BB group,meanwhile the expression of CDK2 increased and the expression of p27 decreased(P0.01).Compared with PDGF-BB group,the proportion of G0-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(P0.01).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.