ABSTRACT
Objective To establish high level expression system of exogenous hepatocyte growth factor(HGF) protein in mouse livers by in vivo gene transfection and to observe the inhibition effect of exogenous HGF on hepatocyte apoptosis in mice. Methods Mice were divided into four groups, with 10 mice in each arm, which were injected with control solution, empty pcDNA3 plasmids, pCMV-HGF plasmid or 0.9% sodium chloride solution by tail vein. Enzyme-linked immunosorbent assay(ELISA) was used to determine the peak level and the expression duration of HGF protein in the peripheral blood and liver tissue. Western blotting was performed to measure the Caspase-3, tBid, Bax and Cytochrom C in the hepatocyte homogenatea and mitochondrion. Results HGF protein was detected in the mice blood as early as 4 hours after single injection of pCMV-HGF plasmid. The peak level of HGF protein in liver and plasma was respectively achieved by 8 hours and 12 hours after first injection while HGF protein was still detectable in the blood 6 days after the initial injection. D-Galactosamine/lipopolysaeeharide (LPS) led to obvious hepatocyte apoptnsis and induced an increased concentration of tBid, Bax, Caspase-3 and Cytochrom C in the hepatocyte homogenates and mitochondrion. Compared to sodium chloride control group and empty pcDNA3 protected group, the expression of tBid, Bax, Caspase-3 and Cytochrom C decreased in pCMV-HGF plasmid protecting group. Conclusions Hepatocyte apoptosis can be inhibited by exogenous HGF protein expression in mouse livers, which is induced by in vivo gene transfection. Moreover, it may inhibit the activation of downstream apoptotic proteins by blocking the expression of tBid.