Effect of proprotein convertases on transforming growth factor β1-induced HBV replication inhibition

AIM: To study the effect of proprotein convertases (PCs) on the transforming growth factor (TGF) β1-induced inhibition of HBV replication.METHODS: HepG2.2.15 cells cultured regularly were exposed to recombinant TGFβ1 at concentration of 2 μg/L or 5 μg/L and/or PC inhibitor at concentration of 20 μmol/L for 18 h. The total RNA and HBV core particle DNA were extracted from these cells, and PC mRNA and core-associated HBV DNA were detected by real-time PCR technique. RESULTS: The mRNA expression levels of 7 PCs in HepG2.2.15 cells were observed with various degrees. Recombinant TGFβ1 significantly up-regulated the mRNA expression of all PCs except for the down-regulation of PC5/6, though PC1/3 and PC2 were up-regulated most obviously. Furin and PACE4 were the predominant PCs before and after TGFβ1 exposure when the basic mRNA expression was taken into account. Further study showed that TGFβ1-induced the inhibition of HBV replication was abrogated by PC inhibitor in HepG2.2.15 cells. CONCLUSION: TGFβ1-induced the inhibition of HBV replication is mediated by the up-regulation of PCs, which might be of many implications in efficient interferences of TGFβ1 on HBV replication.