Over-expression of uPA increases risk of liver injury in pAAV-HBV transfected mice

AIM:To investigate the relationship between overexpression of urokinase plasminogen activator(uPA) and hepatitis B virus(HBV) related liver diseases in a transgenic mouse model.METHODS:Albumin-tetracycline reverse transcriptional activator and tetO-uPA transgenic mice were generated respectively through pronuclear injection and crossed to produce the double transgenic in-alb-uPA mice,for which doxycycline(Dox)-inducible and liver-specific over-expression of uPA can be achieved.Hydrodynamic transfection of plasmid adeno-associated virus(AAV)1.3HBV was performed through the tail veins of the Dox-induced in-alb-uPA mice.Expression of uPA and HBV antigens were analyzed through double-staining immunohistochemical assay.Cytokine production was detected by enzyme linked immunosorbent assay and α-fetoprotein(AFP) mRNA level was evaluated through real-time quantitative polymerase chain reaction.RESULTS:Plasmid AAV-1.3HBV hydrodynamic transfection in Dox-induced transgenic mice not only resulted in severe liver injury with hepatocarcinoma-like histological changes and hepatic AFP production,but also showed an increased serum level of HBV antigens and cytokines like interleukin-6 and tumor necrosis factor-α,compared with the control group.CONCLUSION:Over-expression of uPA plays a synergistic role in the development of liver injury,inflammation and regeneration during acute HBV infection.