Dynamic changes in the main regulatory genes of mitochondrial permeability transition pore in Eimeria tenella host cells

Abstract

The purpose of the present study was to investigate the dynamic changes in the main regulatory genes of the mitochondrial permeability transition pore in E. tenella host cells. Primary chick embryo cecum epithelial cell culture techniques, spectrophotometer technology, Hoechst-Annexin V-PI apoptosis staining and ELISA were used to detect the apoptosis rate and dynamic changes of Bcl-2, Bcl-xl, Bax, Bak, Bid, Bad, HK-II, and ATP content in E. tenella host cells at 4, 24, 48, 72, 96, and 120 h. The rates of early apoptosis, late apoptosis, and necrosis of group T0 were significantly lower (P < 0.05) or highly significantly lower (P < 0.01) than those of group C at 4 h, but higher (P < 0.05 or P < 0.01) at varying degrees than those of the same group at 24-120 h. Compared to group C, the amount of Bcl-2, ATP, Bax and Bad in group T0 were visibly lower (P < 0.05 or P < 0.01) at 4 h, whereas Bcl-xl/Bax was highly significantly higher (P < 0.01) at 4 h. In addition, group T0 had less ATP at 24-120 h than group C, whereas the amount of Bcl-2, Bcl-xl, Bax, Bak, Bid, Bad and HK-II in group T0 inversely increased in varying degrees at 24-120 h compared with group C. Moreover, Bcl-2/Bax was lower (P < 0.01) at 24, 48, and 96 h, and Bcl-xl/Bax was lower (P < 0.05) at 48 h in group T0 than in group C, respectively. Taken together, these observations indicate that in the early developmental stages of E. tenella, the host-cell apoptosis rate decreased; although the amount of anti- and pro-apoptotic genes in host cells decreased, the ratios of anti-apoptotic to pro-apoptotic bcl-2 gene-family members increased. In the middle and later developmental stages of E. tenella, the host-cell apoptosis rate increased; the amount of anti- and pro-apoptotic genes increased, while the ratios of anti-apoptotic to pro-apoptotic bcl-2 gene-family members decreased. In addition, ATP decreased at all developmental stages of E. tenella.

Keywords: ATP; Apoptosis; Bcl-2 protein family; Eimeria tenella; HK-II; Host cell.