GSE158478
Inhibitory effect of a human microRNA, miR-6133-5p, on the fibrotic activity of hepatic stellate cells in culture
Purpose: We recently identified 39 human microRNAs, which effectively suppress hepatitis B virus (HBV) replication in hepatocytes. Because chronic HBV infection often results in active, hepatitis-related liver fibrosis, we assessed whether any of these microRNAs have anti-fibrotic potential and predicted that miR-6133-5p may target several fibrosis-related genes. Methods:  The hepatic stellate cell line LX-2 was transfected with miR-6133-5p mimic and subsequently treated with TGF-ß. mRNA and protein products of COL1A1, encoding collagen, and ACTA2, an activation marker of hepatic stellate cells, were quantified. Results: Expression of COL1A1 and ACTA2 was markedly reduced in LX-2 cells treated with miR-6133-5p. Interestingly, phosphorylation of JNK also was significantly decreased by miR-6133-5p treatment. The expression of several predicted target genes of miR-6133-5p, including TGFBR2 and FGFR1, was also reduced in miR-6133-5p-treated cells. The knockdown of TGFBR2 by the corresponding small interfering RNA greatly suppressed the expression of COL1A1 and ACTA2. Treatment with the JNK inhibitor, SP600125, also suppressed COL1A1 and ACTA2 expression, indicating that TGFBR2 and JNK would mediate the anti-fibrotic effect of miR-6133-5p. Downregulation of FGFR1 may result in a decrease of phosphorylated AKT, ERK, and JNK. Conclusions: miR-6133-5p has a strong anti-fibrotic effect, mediated by inactivation of TGFBR2, AKT and JNK. Overall design: mRNA profiles of  the cells transfected with miR-6133-5p and those transfected with miControl, 24 hours after rhTGF-ß treatment.