ABSTRACT
miR-146a is an immunoregulatory microRNA closely associated with viral infection. This study investigated the expression changes of miR-146a in peripheral blood monocytes of HCV-infected patients and the mechanism by which the THP-1 cells were stimulated with HCV core protein in vitro. It was found that in the peripheral blood monocytes of HCV-infected patients, miR-146a expression was upregulated. After treated by interferon/ribavirin, miR-146a expression was decreased when HCV RNA became undetectable. HCV core could directly stimulate THP-1 cells to produce miR-146a. Silencing TLR2 and MyD88 could significantly inhibit the expression of miR-146a. It was concluded that the expression of miR-146a in peripheral blood monocytes of HCV-infected patients was abnormally increased. The TLR2-MyD88 signaling pathway may take part in the overexpression of miR-146a in monocytes stimulated with HCV core protein.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Young Adult , Base Sequence , Cell Line , DNA Primers , Hepatitis C, Chronic , Blood , MicroRNAs , Blood , Monocytes , Metabolism , Myeloid Differentiation Factor 88 , Physiology , Reverse Transcriptase Polymerase Chain Reaction , Toll-Like Receptor 2 , PhysiologyABSTRACT
miR-146a is an immunoregulatory microRNA closely associated with viral infection. This study investigated the expression changes of miR-146a in peripheral blood monocytes of HCV-infected patients and the mechanism by which the THP-1 cells were stimulated with HCV core protein in vitro. It was found that in the peripheral blood monocytes of HCV-infected patients, miR-146a expression was upregulated. After treated by interferon/ribavirin, miR-146a expression was decreased when HCV RNA became undetectable. HCV core could directly stimulate THP-1 cells to produce miR-146a. Silencing TLR2 and MyD88 could significantly inhibit the expression of miR-146a. It was concluded that the expression of miR-146a in peripheral blood monocytes of HCV-infected patients was abnormally increased. The TLR2-MyD88 signaling pathway may take part in the overexpression of miR-146a in monocytes stimulated with HCV core protein.
ABSTRACT
The activation of hepatic stellate cells (HSCs) and their transformation to myofibroblasts are the key steps in the pathological progress of liver fibrosis. The transforming growth factor-β (TGFβ)/Smad pathway is involved in the proliferation and collagen synthesis of HSCs. This study aimed to examine the effect of the protease inhibitor MG132 on the signaling pathway of TGFβ/Smad in HSC-T6 cells and seek a novel therapeutic approach for liver fibrosis. The HSC-T6 cells were treated with MG132 at different concentrations (0-10 μmol/L). Cell proliferation was detected by MTT method. The mRNA and protein expression levels of TGFβ1, Smad3 and Smad7 were determined in HSC-T6 cells by real-time PCR and Western blotting, respectively, after treatment with MG132 at different concentrations (1, 2, 3 μmol/L) or RPMI1640 alone (serving as control). The results showed that MG132 could inhibit the proliferation of HSC-T6 cells in a dose-dependent manner, and the IC50 of MG132 was 6.84 μmol/L. After treatment with MG132 at 1, 2 or 3 μmol/L for 24 h, the mRNA expression levels of TGF-β1 and Smad3 were significantly decreased (P0.05). There was also a significant decrease in the protein expression level of TGF-β1 and Smad3 (P<0.05). However, the expression of Smad7 protein was substantially increased when compared with the control group (P<0.05). It was concluded that the inhibition of TGFβ/Smad pathway in HSC-T6 cells by MG132 can reduce the production of profibrosis factors (TGFβ1, Smad3) and promote the expression of anti-fibrosis factor (Smad7), suggesting that MG132 may become a potential therapeutic alternative for liver fibrosis.
ABSTRACT
The activation of hepatic stellate cells (HSCs) and their transformation to myofibroblasts are the key steps in the pathological progress of liver fibrosis. The transforming growth factor-β (TGFβ)/Smad pathway is involved in the proliferation and collagen synthesis of HSCs. This study aimed to examine the effect of the protease inhibitor MG132 on the signaling pathway of TGFβ/Smad in HSC-T6 cells and seek a novel therapeutic approach for liver fibrosis. The HSC-T6 cells were treated with MG132 at different concentrations (0-10 μmol/L). Cell proliferation was detected by MTT method. The mRNA and protein expression levels of TGFβ1, Smad3 and Smad7 were determined in HSC-T6 cells by real-time PCR and Western blotting, respectively, after treatment with MG132 at different concentrations (1, 2, 3 μmol/L) or RPMI1640 alone (serving as control). The results showed that MG132 could inhibit the proliferation of HSC-T6 cells in a dose-dependent manner, and the IC(50) of MG132 was 6.84 μmol/L. After treatment with MG132 at 1, 2 or 3 μmol/L for 24 h, the mRNA expression levels of TGF-β1 and Smad3 were significantly decreased (P<0.05), but the Smad7 mRNA expression had no significant change (P>0.05). There was also a significant decrease in the protein expression level of TGF-β1 and Smad3 (P<0.05). However, the expression of Smad7 protein was substantially increased when compared with the control group (P<0.05). It was concluded that the inhibition of TGFβ/Smad pathway in HSC-T6 cells by MG132 can reduce the production of profibrosis factors (TGFβ1, Smad3) and promote the expression of anti-fibrosis factor (Smad7), suggesting that MG132 may become a potential therapeutic alternative for liver fibrosis.