The Role Of The Mitochondrial Apoptotic Pathway In The Host Cell Apoptosis Of E.Tenella

In order to explore the role of the mitochondrial apoptotic pathway in the host cell apoptosis of E.tenella, we use the primary chick embryo cecum epithelial cell culture technique, in situ terminal transferase enzyme marker technology, electron microscopy, ELISA activity assay and flow cytometry to detect the apoptosis and ultrastructural changes, the development of the parasite, the activity of caspase-9and caspase-3of the host cell of E.tenella that treated or untreated with the Caspases inhibitor (Z-LEHD-FMK), the mitochondrial protective agent (diazoxide) or the inhibitor of MPTP (cyclosporine A), the results show that:(1) The parasites infection rate of E.tenella had no significant difference (P>0.05) between the treated (treat with Z-LEHD-FMK, diazoxide or cyclosporine A) and untreated group at4h after inoculating sporozoits; In the subsequent24to120h, the infection rate of E.tenella in the treated groups are extremely significant (P<0.01) higher than the untreated group.It shows that inhibiting the apoptosis of the host cell is beneficial to the development of E.tenella.(2) The activity of caspase-9and caspase-3of the host cell had no significant difference (P>0.05) between the untreated and the treated groups, but they were extremely significant (P<0.01) lower than the control group at4h after inoculating sporozoits; Then the activity of caspase-9and caspase-3of the host cell in the untreated group were extremely significant (P<0.01) higher than that of the control and treated groups at24h-120h after inoculating sporozoits and increased with the passage of time by the parasite infection. It shows that activating the caspase-9and caspase-3is one of the key links in the mitochondrial apoptotic pathway of the E.tenella host cell.(3) The early apoptosis rate, the late apoptosis and necrosis, the apoptosis rate of the infected and uninfected cells in the untreated group were extremely significant (P<0.01) or significant (P<0.05) lower than that of the control group at4h after inoculating sporozoits, the apoptosis rate of the infected cells were extremely significant (P<0.01) lower than the uninfected cells at the same time; The early apoptosis rate, the late apoptosis and necrosis, the apoptosis rate of the infected and uninfected cells in the untreated group were extremely significant (P<0.01) higher than that of the control group at48h-120h after inoculating sporozoits and and increased with the passage of time by the parasite infection. Indicating that the early development stage (within24h) of E.tenella inhibited the apoptosis of the host cell, and then promoted the apoptosis of the host cell in the late (24h-120h), it affects both the infected and uninfected cells, which the affection of infected cells was significantly greater than uninfected cells.(4) The early apoptosis rate, the late apoptosis and necrosis, the apoptosis rate of the apoptosis rate of the infected and uninfected cells in the treated groups (treat with Z-LEHD-FMK, diazoxide or cyclosporine A) were extremely significant (P<0.01) or significant (P<0.05) lower than that of the untreated group at24h-120h after inoculating sporozoits. It shows that the mitochondrial apoptotic pathway is one of the main ways which the apoptosis of the host cell induced by E.tenella.