OBJECTIVETo investigate the inhibitory effect of small interfering RNA (siRNA) targeting Bax-Bak on the apoptosis of human granulosa cells.

METHODSHuman granulosa cells were transfected with Bax-siRNA and Bak-siRNA either alone or in comibnation, and the cell morphological changes were obsered and the cell apoptosis was detected with flow cytometry. Western blotting was performed to examine the changes in Bax and Bak expressions in the transfected cells.

RESULTSWestern blotting demonstrated significantly weakened expressions of Bax and Bak in the transfected cells. The cell morphology of the cells tranfected with Bak siRNA and with both Bak and Bax siRNA remained normal; the cells with exclusive Bax siRNA transfection presented with basically normal cell morphology, but black spots were noted in the cytoplasm. In the positive and negative control groups, the cells became rounded and shrank with expanded intercellular spaces and numerous black spots in the cytoplasm. Flow cytometry showed apoptotic indexes of 3.44% and 3.97% in cells transfected with Bak siRNA and Bax-Bak siRNA, respectively, significantly lower than that in the negative group. Bax siRNA transfection resulted in an apoptotic index of 19.98%, similar to that in the negative group.

CONCLUSIONInterference of the expression of Bak gene inhibits the apoptosis of human granulosa cells, and the inhibitory effect can be enhanced by simultaneous Bax interference, which, when used alone, does not obviosuly inhibit the apoptosis of human granulosa cells.