关键词: 细胞色素C , 线粒体, Bax基因, Bak基因

Abstract: Abstract:Objective To study the function of Bak in mitochondrial signaling pathway and interaction between Bax and Bak during apoptosis.Methods Bax/Bak double knock out (Bax^-/- and Bak^-/-)MEF cells from mouse embryo fibroblasts (MEF) and Hela cells were divided into four groups according the cell different genotypes(wild type,Bax^-/-,Bak^-/- and double knock out) and treated with different chemical reagents after co-transfection with Bax,Bak,Mito-Red and empty pEGFP vector.Apoptosis,mitochondrial morphology and cytochrome C release were detected with confocal microscope,immunofluoresence and Western blotting techniques.Results There were correlations between the percentage of Hela cell apoptosis and mitochondrial fission(%) as well as cytochrome C(%) (P<0.01).When Bak gene deletion,the apoptotic rate of MEF cells(17.9%) induced by chemical reagent was lower than that of wild type MEF cells(71.3%)(P<0.01); When gene double knock out MEF cells were transfected with GFP-Bak,mitochondrial fission incresed from 43.7% to 76.4%,the apopotic rate in pEGFP-Bak group was significantly higher than that in GFP-Bax group(P<0.05) and the same result was gotten when treated with different chemical reagents. Bcl-2 can not inhibit the apoptosis induced with Bak.Conclusion Bak can induce cell mitochondria fission and cytochrome C release and result in apoptosis.Bak can induce more cell apoptosis than Bax and the effect stands alone besides Bax action.

Key words: cytochrome C, mitochondria, Bax gene, Bak gene