ABSTRACT
OBJECTIVE: To explore the role of La protein in acute hepatitis B virus (HBV) by establishing a mouse model. METHODS: We constructed an acute hepatitis B virus model by hydrodynamics-based injection of plasmid pAAV/HBV1.2 containing 1.2 times HBV genome. The expression levels of HBV DNA, HBsAg and HBeAg in serum were detected by RT-PCR and ELISA, respectively. HBcAg in liver tissue were assayed by immunohistochemical staining.The level of ALT was detected by bioluminescence. Pathological changes in liver carried by Hematoxylin and eosin (HE) staining. RT-PCR, Western blot and ELISA were used to detect the changes of mRNA level and protein expression level of La protein. RESULTS: The levels of HBV DNA, HBsAg and HBeAg in the serum of mice, and the percentage of HBcAg-positive hepatocytes in liver tissues was up to 3.66% at day 5 showed that the mouse model of acute HBV was successfully constructed. The level of serum ALT and HE results showed that the liver damage was serious after the model was established, and then dropped sharplyand returned to normal. The mRNA level of La protein in the liver of the mice indicates that the level of La protein in the model group was generally higher than that in the control group. However, Western bolt results showed that there was no significant difference in intracellular protein levels, but the level of La protein in serum of mice is generally higher thancontrol group, especially on the 7th day (P<0.000 1). CONCLUSION: The acute HBV model was successfully constructed. The level of La protein in this model is related to HBV expression, suggesting that La protein may be involved in the pathogenesis of HBVandbea new marker in diagnosis of HBV.
ABSTRACT
The human La protein is recently identified as a host factor potentially involved in the post-transcriptional regulation of hepatitis B virus (HBV) RNA. The La binding site is mapped to a predicted stem-loop structure within a region shared by all HBV RNAs, and it is known that human La protein protected HBV RNA against Rnase-mediated degradation. HLa mutants lost the ability of binding and protecting HBV RNA, which make it easy for HBV RNA to degrade and the virus replication to terminate. This review summarizes the latest investigation about the interaction of La protein,HBV RNA and Nuclear RNases, and discusses the possible mechanisms of HBV RNA degradation, the effect of La protein and its mutants on the translation initiation of HBV RNA, and the replication of the virus.
ABSTRACT
Objective:To prove whether La protein could effect the replications of the HBV in cultured cells.Methods:Three specific SiRNAs for human La protein was obtained by transcription in vitro. After transfection with the SiRNAs into HepG2.2.15 cell, the levels of La protein mRNA and HBV DNA were detected by real-time PCR.Results:The HBV DNA secreted by the cell transfected with the SiRNAs was reduced with reduction of the mRNA of the La protein.Conclusion:The La protein can protect the replications of the HBV in cultured cells.