Mechanisms of hydrogen sulfide that attenuate high glucose-induced injury in endothelial cells

Objective To observe the production of hydrogen sulfide in endothelial cells exposed to high glucose as well as the effects of hydrogen sulfide on high glucose-induced injury of endothelial cells,and to explore the possible mechanisms.Methods Human umbilical vein endothelial cells were divided into 4 groups: A 5.5 mmol/l glucose,B 25 mmol/L glucose,C 25 mmol/L glucose + 50 μmol/L NaHS,and D 5.5 mmol/L glucose+ 50 μmol/L NaHS.After treatment for 48 h,the production of H2S was measured,cell viability was detected by MTT,and the expressions of apoptosis-related proteins,such as Bax,Bcl-2 and cleaved caspase-3,were examined by Western Blot analysis.Results ① Compared with that of group A,the production of H2S distinctly decreased in group B(P0.05),however,the production of H2S distinctly increased in group C when compared with that of group B(P0.05).② Compared with that of group A,the percentage of cell viability obviously decreased in group B(P0.05),but NaHS could reverse the viability of HUVECs which was induced by high glucose in group C(P0.05).③ High glucose significantly increased Bax protein expression(P0.05) and decreased the Bcl-2 protein expression(P0.05),and the level of cleaved Caspase-3,the activated form of Caspase-3,was higher in group B compared with that of group A(P0.05).Compared with that of group B,decrease in Bax(P0.05) and cleaved Caspase-3 expressions(P0.05) and increase in Bcl-2 expression(P0.05) were observed in group C.There was no significant difference between group A and group D in cell viability,Bax,Bcl-2,cleaved Caspase-3 expressions and the production of H2S.Conclusions High glucose can inhibit the production of H2S in endothelial cells.Supplementation of extrinsic H2S can protect against high glucose-induced injury in human umbilical vein endothelial cells possibly through the inhibition of cell apoptosis.