The Regulation Mechanism Of MPTP On Apoptosis In E.Tenalla Host Cells

In order to investigate the regulation mechanism of MPTP on apoptosis in E.tenella host cells, we used ELISA activity assay, primary chick embryo cecum epithelial cell culture technique, flow cytometry, laser scanning confocal microscopy and spectrophotometer technology to detect the apoptosis and the membrane potential changes, the opening of MPTP and the dynamic changes of Bcl-2, Bcl-xl, Bax, Bak, Bid, Bad, HK-Ⅱ and ATP in E.tenella host cells that were treated or untreated with the MPTP inhibitor (cyclosporin A), ATP or the bax-inhibiting peptide, the results show that:(1) At4h to120h after infection with E.tenella sporozoites, the membrane potentials in the untreated groups were extremely significantly (P<0.01) lower or significantly lower (P<0.05) than the control group, while the degrees of MPTP openness were significantly higher (P<0.01) than the control group. All the results indicate that infection with E.tenella can result in a decline of membrane potential and increase the openness of MPTP in the host cells.(2) After infection with E.tenella sporozoites, the membrane potentials in the treated groups with cyclosporin A were extremely significantly (P<0.01) higher or significantly higher (P<0.05) than the untreated groups, whilst the degrees of MPTP openness significantly were lower (P<0.01) than the untreated groups, so do the rates of apoptosis. We demonstrate that the openness of MPTP is the regulating key in the mitochondrial apoptotic pathway of E.tenella host cells.(3) At4h after infection with E.tenella sporozoites, the level of Bcl-2, ATP, Bax and Bad of the untreated were extremely significantly (P<0.01) lower or significantly lower (P<0.05) than the control group; At24h to120h after infection, the level of Bcl-2, Bcl-xl, Bax, Bak, Bid, Bad and HK-Ⅱ are higher than control group; in contrast, the level of ATP were extremely significantly (P<0.01) lower than control group. It indicates that infection with E.tenella can cause a huge change of regulatory factors of MPTP in the host cells.(4) The degree of MPTP openness in the groups after ATP and bax-inhibiting peptide treatment were extremely significant (P<0.01) lower or significantly lower(P<0.05) than the untreated groups, while the rates of early apoptosis and the rates of late apoptosis and necrosis were extremely significant (P<0.01) lower or significantly lower(P<0.05) than the untreated groups, which indicates that ATP and Bax are the key factors in the regulation of the MPTP opening in E.tenella host cells.