Effect of homocysteine on CD40 expression in endothelial cells

AIM:To investigate the effect of homocysteine(Hcy) on the e xpression of CD40 in cultured endothelial cells (ECs). METHODS: E CV304 cells were incubated in vitro, then exposed to Hcy at the concentratio ns of 0、20、50、100 μmol/L for 24h, of which, some cells were pretreated wit h pyrrolidinedithiocarbamate (PDTC) or pravastatin for 24h before the exposure to 100 μmol/L Hcy. Flow cytometry was performed to measure the expression of C D40. Spectrophotometer was used to detect the production of H 2O 2 in the cult ure medium. RESULTS:Flow cytometry showed that Hcy significantly increased CD40 expression in a concentration-dependent manner. Spectrophotometr y showed that Hcy at concentrations of 20, 50 and 100 μmol/L resulted in a 1.7 1±0.04-fold, a 1.76±0.05-fold and a 1.99±0.05-fold increase respectively i n the production of H 2O 2 , as compared with the control group. In the p resence of PDTC or pravastatin, both the expression of CD40 and production of H 2O 2 declined, compared with the 100 μmol/L Hcy group. There was a posit ive correlation between CD40 expression and H 2O 2 production ( r=0.702, P0.01). CONCLUSION:Hcy can increase CD40 expression in ECs, and oxidative stress plays a role during the process. Inflammation activated by a high CD40 expression may be an important atherogenic mechanism of Hcy.