ABSTRACT
AIM:To investigate the effects of xeroderma pigmentosum group D ( XPD) gene on the prolifera-tion of human umbilical arterial smooth muscle cells ( HUASMCs) induced by oxidized low-density lipoprotein ( Ox-LDL) . METHODS:The recombinant plasmid pEGFP-N2/XPD was transfected into HUASMCs by liposome .The cells were di-vided into blank control group , pEGFP-N2 group, pEGFP-N2/XPD group, Ox-LDL group, Ox-LDL+pEGFP-N2 group and Ox-LDL+pEGFP-N2/XPD group.The proliferation rate of the cells was detected by MTT and EdU assays .The apop-totic rate and cell cycle distribution were analyzed by flow cytometry .The protein levels of XPD, caspase-3, Bcl-2 and Bax were determined by Western blot .RESULTS:Compared with blank control group , the expression of XPD was increased in pEGFP-N2/XPD group (P<0.05).According to the results of MTT and EdU assays , the cell proliferation in pEGFP-N2/XPD group was reduced compared with blank control group (P<0.05).Compared with Ox-LDL group, the cell prolifera-tion in Ox-LDL+pEGFP-N2/XPD group was significantly inhibited (P<0.05).According to the results of flow cytome-try, the cell proportion of S phase decreased and the G 0/G1-phase cell proportion increased significantly in pEGFP-N2/XPD group and Ox-LDL+pEGFP-N2/XPD group compared with blank control group and Ox-LDL group, repectively (P<0.05).Compared with blank control group and Ox-LDL group, the protein level of Bcl-2 decreased and the protein levels of Bax and cleaved caspase-3 increased in pEGFP-N2/XPD group and Ox-LDL +pEGFP-N2/XPD group, respectively (P<0.05).CONCLUSION:XPD inhibits the proliferation of HUASMCs and promotes their apoptosis , and reduces the promoting effect of Ox-LDL on the proliferation of HUVSMCs .XPD may be the target for treatment of atherosclerosis .