Effects And Mechanisms Of Extracorporeal Cardiac Shock Wave On Endothelial Progenitor Cells Function Through PI3K/AKT And MEK/ERK Signaling Pathway

Objectives:Extracorporeal cardiac shock wave(ECSW)is an safe,effective and non-invasive vascular regeneration therapeutic strategy for coronary artery disease because of its ability to promote angiogenesis in ischemic myocardium.Endothelial progenitor cells(EPCs)play an important role during the process of vascular repair and vasculogenesis,by migrating to ischemic myocardium,,where they differentiate into mature endothelial cells.However,it remains unclear whether ECSW can activate EPCs function,to eventually promote angiogenesis.Therefore,This study aimed to investigate the effect of ECSW on EPCs function and to explore its underlying mechanism.Methods:EPCs derived from mouse bone marrow were obtained by the method of density gradient centrifugation,then were treated with ECSW(500 shots at 0.09mJ/mm2).Cell proliferation,apoptosis rate,migration,tube formation of EPCs were assayed by MTT,flow cytometry,Transwell chamber,Matrigel.The expression of AKT,p-AKT,ERK,p-ERK,eNOS,p-eNOS,Bcl-2,Bax and Caspase3 in the cells were assessed by Western blotting.In addition,in order to study the involvement of PI3K/AKT and MEK/ERK signaling pathway in the transduction of the function of EPCs,the same target parameters were detected after adding related inhibitors of LY294002 and PD98059,including cell proliferation,antiapoptosis,migration,tube formation and the expression of AKT,p-AKT,ERK,p-ERK,eNOS,p-eNOS,Bcl-2,Bax and Caspase3.Results:ECSW markedly promoted proliferation,migration,tube formation(p<0.05),and decreased the apoptosis rate(p<0.05).Western blot showed that ECSW markedly up-regulated the expression of p-AKT,p-ERK and downstream signal molecule p-eNOS and Bcl-2,down-regulated the expression of Bax and Caspase3(all p<0.05).However,the effects of ECSW on EPCs were inhibited by PI3K/AKT inhibitor LY294002 and MEK/ERK inhibitor PD98059(all p<0.05).Conclusions:ECSW promotes proliferation,migration,tube formation,and inhibits the apoptosis by up-regulating the expression of downstream signal molecule p-eNOS and anti-apoptotic protein of Bcl-2,down-regulating the expression of pro-apoptotic protein of Bax and Caspase3 in EPCs through PI3K/AKT and MEK/ERK signaling pathway.