The Effect of Oxidized LDL on the Expression of Connexin40 Gene in Cultured Human Umbilical Vein Endothelium Cell

Objective To investigate the effect of Oxidized LDL(Ox-LDL) on the expression of Gap junction protein Connexin40 gene in cultured human umbilical vein endothelium cell (HUVEC).Methods HUVEC was intervened with different concentrations of Ox-LDL:HUVEC cultured were divided into control group,and Ox-LDL 50mg/L,100mg/L and 200mg/L intervention groups,24 hours after being given oxidized LDL,the expression of Connexin40 gene mRNA of cultured HUVEC was detected with RT-PCR; For intervention with same concentration of Ox-LDL but different time,HUVEC were divided into 6 groups,they all were intervened with Ox-LDL 50mg/L but intervened for 0 hour(control group),6 hours,12 hours,24 hours,48 hours and 72 hours,respectively; while the expression level of Connexin40 protein was detected with immunocytochemistry method while HUVEC was intervened with Ox-LDL 0mg/L and Ox-LDL 100mg/L.Results Different concentrations(50mg/L,100mg/L,200mg/L) of Ox-LDL can up-regulate mRNA expression level of Connexin40 gene in cultured HUVEC after 24 hours intervention(P0.01).Intervention with Ox-LDL 50mg/L for different times can all up-regulate the mRNA expression level of cultured HUVEC (P0.01),among them the most significant up-regulation effect was in groups of intervention for 6 hours and 12 hours(P0.01).Compared with the control group,the protein expression level of Connexin40 gene of cultured HUVEC in the group intervened with Ox-LDL 100 mg/L for 24 hours was markedly up-regulated (P0.01).Conclusions Ox-LDL may up-regulate the protein and mRNA expression level of Connexin40 gene in cultured HUVEC within short time,indicating that Connexin40 may play an important role in the pro-atherosclerotic effect of Ox-LDL.