Role of ATP-sensitive potassium channels-Akt pathway in hydrogen sulfide inhibiting high glucose-induced injury in H9 c2 cardiac cells / 中国药理学通报

ABSTRACT

Aim To investigate the role of ATP-sensi-tive potassium channels-Akt pathway in exogenous hy-drogen sulfide( H2 S) inhibiting the high glucose( HG)-induced injury in H9c2 cardiac cells. Methods The expression level of Akt protein was tested by Western blot assay. The cell viability was measured by cell counter kit-8(CCK-8 assay). The number of apoptotic cells was tested by Hoechst 33258 nuclear staining fol-lowed by photofluorography. The intracellular levels of reactive oxygen species ( ROS ) were detected by DCFH-DA staining followed by photofluorography. Mi-tochondrial membrane potential ( MMP ) was examined by JC-1 staining followed by photofluorography. Results H9c2 cells were treated with 35 mmol·L-1 glucose (high glucose, HG) for 0 ~24 h respectively. After treating for 3 h, the expression level of phosphorated ( p )-Akt protein began to be obviously reduced, the maximum reduced expression level was observed after the cells were exposed to HG for 24 h. Pretreatment of the cells with 50 μmol · L-1 pinacidil ( Pin, a KATP channel opener) or 400 μmol·L-1 NaHS( a donor of H2 S) prior to exposure to HG considerably blocked the down regulation of p-Akt expression level induced by HG. However, pretreatment with 1 mmol · L-1 KATP channel blocker glibenclamide( Gli) obviously attenua-ted the inhibitory effect of NaHS on HG-induced down-regulation of p-Akt expression level. On the other hand, the protective effects of NaHS against the HG-induced cardiomyocyte injury were markedly blocked by 30 μmol·L-1 Ly294002(an inhibitor of Akt), as indicated by the decrease in cell viability and MMP dissipation as well as the increases in the number of apoptotic cells and ROS generation. Conclution KATP channels-Akt pathway mediates the protective effect of H2 S against the HG-induced cardiac injury.