Insulin in combination with selenium inhibits HG/Pal-induced cardiomyocyte apoptosis by Cbl-b regulating p38MAPK/CBP/Ku70 pathway.

OBJECTIVE In this study, we investigated whether insulin and selenium in combination (In/Se) suppresses cardiomyocyte apoptosis and whether this protection is mediated by Cbl-b regulating p38MAPK/CBP/Ku70 pathway. MATERIALS AND METHODS Firstly, H9c2 cardiomyocytes were treatment with high glucose (25 mmol/L) and palmitate (600 μmol/L) (HG/Pal). Next, H9c2 cardiomyocytes were treatment with HG/Pal+In/Se (10 nmol/L Insulin in combination with 10 nmol/L selenium). Finally, cells were treated with siRNA against Cbl-b, followed by HG/Pal and HG/Pal+In/Se treatment. Then, Cell apoptosis was observed by flow cytometry (FCM). The levels of Cbl-b, p-p38MAPK, CBP and Bax were examined by Western blotting. The acetylated Ku70 was detected by immunoprecipitation. RESULTS Insulin and selenium in combination reduced cell apoptosis, up-regulated Cbl-b expression, down-regulated p38MAPK, CBP and acetylated Ku70 expressions and prevented Bax translocation, whereas Cbl-b knockdown strongly suppressed In/Se-induced these effects in HG/Pal-treated cardiomyocytes. CONCLUSIONS Insulin and selenium synergistically suppressed cardiomyocyte apoptosis by Cbl-b regulating p38MAPK/CBP/Ku70 pathway.