Effects of xeroderma pigmentosum group D and p53 on replication of HBV

AIM:To investigate the effects of xeroderma pigmentosum D (XPD) and p53 on the replication of hepatitis B virus (HBV). METHODS:Recombinant plasmid pEGFP-N2/XPD and vacant vector plasmid pEGFP-N2 were transfected into HepG2.2.15 cells by liposome. On the next day, these cells were incubated with pifithrin-α, a p53 inhibitor, at a concentration of 20 μmol/L for 24 h. The cells were divided into 5 groups: blank control group, pEGFP-N2 group, pEGFP-N2/XPD group, pEGFP-N2/XPD+pifithrin-α group and pifithrin-α group. The mRNA expression of XPD, hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B virus X protein (HBx) was detected by RT-PCR. The content of HBsAg and HBeAg in the supernatants of culture medium was measured by ELISA. The content of HBV-DNA in the supernatants of culture medium was examined by fluorescence quantitative PCR. Using the method of bDNA, the content of HBV-DNA in the core particles was assessed. RESULTS:The expression of XPD mRNA was elevated by the transfection of recombinant plasmid pEGFP-N2/XPD. The increase in XPD expression significantly down-regulated the mRNA expression of HBsAg, HBeAg and HBx. The content of HBsAg and HBeAg in the supernatants of culture medium was significantly decreased by the increase in XPD expression. The results of fluorescence quantitative PCR showed that the content of HBV-DNA in the supernatants of culture medium was significantly down-regulated by the increase in XPD expression. bDNA results showed that the content of HBV-DNA in the core particles was significantly decreased by the increase in XPD expression.Pifithrin-α abolished the above-mentioned effects of XPD (all P<0.01). CONCLUSION: XPD inhibits the replication of HBV through p53 pathway. Therefore, XPD and p53 may be the targets for antiviral therapy of hepatitis B.