Sja-Let-7 Attenuates Carbon Tetrachloride-Induced Liver Fibrosis in a Mouse Model via Col1α2.

Liver fibrosis (LF) is a chronic progressive disease with no definitive treatment. The aim of this study was to assess helminth-derived molecules as potential therapeutic targets to prevent or reverse LF. A mouse model of carbon tetrachloride (CCL4)-induced LF was established and sja-let-7 was overexpressed by treatment with a miRNA agomir once per week. After four weeks, serum biochemistry, hepatic hydroxyproline content measurements, liver histology, mRNA expression profiling of fibrotic markers, the dual-luciferase reporter assay, and fluorescence in situ hybridization (FISH) were performed. Administration of the sja-let-7 agomir markedly ameliorated hepatosplenomegaly and reduced the liver hydroxyproline content. Liver histological analysis showed significant reductions in collagen deposition in the sja-let-7 agomir-treated mice. Additionally, the mRNA levels of both pro-fibrotic markers and pro-inflammatory cytokines were diminished after treatment. Furthermore, the dual-luciferase reporter assay and FISH identified the α2 chain of collagen type 1 (Col1α2) as the direct target of sja-let-7. Accordingly, the progression of LF was attenuated by targeting Col1α2 and the TGF-β/Smad signaling pathway.