The decrease of PKC alpha is associated with hepatic apoptosis at early and late phases of polymicrobial sepsis

The present study investigates the relationship between the PKC-alpha and h epatic apoptosis during sepsis. Cecal ligation and puncture- (CLP) induced animal model of polymicrobial sepsis was used, with early and late sepsis r eferring to those animals sacrificed at 9 and 18 h, respectively, after CLP , The expressions of PKC alpha and Bcl-2 family proteins as well as poly(AD P-ribose) polymerase (PARP) cleavage were quantified to evaluate the possib le factors involved in the hepatic cell death during sepsis. The apoptosis of hepatocytes under septic condition or hepatocytes treated with PKC alpha antisense was evaluated by gel electrophoresis and/or flow cytometry after Annexin-V-Fluos and propidium iodide staining. The results indicated that (1) the protein expression of membrane-associated PKC alpha was decreased a t early (P < 0.05) and late (P < 0.01) sepsis; (2) the protein expressions of Bcl-2 and Bcl-xL were decreased, whereas Bax expression was increased at late sepsis; (3) the percentage of PARP cleavage was increased at early (P < 0.05) and late (P < 0.01) sepsis; (4) severe DNA fragmentation was obser ved at late sepsis; (5) the apoptotic cell population was increased at earl y and late sepsis; and (6) the percentage of apoptotic cell population in P KC<alpha> antisense-treated cells was significantly higher than that in unt reated cells. These results suggest that inactivation of PKC alpha may play an important role in modulating hepatic apoptosis during sepsis and the ap optosis is closely associated with the alterations of Bcl-2 family proteins .