HBV induces liver fibrosis through regulating TGF-β1/Nur77 pathway / 医学研究生学报

ABSTRACT

ObjectiveTo investigate the role of TGF-β1/Nur 77 in HBV-induced liver fibrosis.MethodsHE, Masson's and immunohistochemistry (IHC) staining were used to detect Nur 77 expression in liver tissue. NTCP-Huh7.5.1 was constructed by transfecting pCMV6-NTCP into Huh 7.5.1 cells to explore effects of HBV replication and TGF-β1 expression. LX-2 cells was incubated with TGF-β1 in the presence of Nur 77 gRNA. QPCR was used to observe the effect of TGF-β1/Nur 77 on LX-2 activation and liver fibrosis. Our study engaged a co-culture system in the presence of Nur 77 gRNA to observe the relationship between HBV replication andα-SMA, TIMP-1 and CoL1A1 expression.ResultsIHC showed a higher Nur 77 level in severe fibrosis liver (≥S2) than in mild fibrosis liver (≤S1). Western blot showed that pCMV6-NTCP could express in Huh 7.5.1 cells. At 3 days after infection, HBV DNA level in supernatant of NTCP-Huh 7.5.1 cells was 5.39±0.96×103 copies/ml (P<0.01), HBV infection enhanced TGF-β1 mRNA expression in NTCP-Huh 7.5.1 cells (1.94 vs 1.00，P<0.01). At 72 h after TGF-β1 incubation, mRNA expression of Nur 77, α-SMA, TIMP-1 and CoL1A1 expression was up-regulated significantly compared to control group (P<0.05), which can be inhibited by Nur 77 gRNA (P<0.05). Co-cultured with HBV infected NTCP-Huh 7.5.1 cells for 72 h, mRNA expression of Nur 77, α-SMA, TIMP-1 and CoL1A1 expression in LX-2 cells was up-regulated significantly compared to control group (P<0.05), which can be inhibited by Nur 77 gRNA (P <0.05).ConclusionHBV contributes to liver fibrosis through up-regulating TGF-β1/Nur 77 signaling pathway. Our study provides a new target for the treatment of HBV induced liver fibrosis.