Abstract: Objective To investigate the regulatory role of α-1,6-fucosyltransferase (FUT8) in TGF-β1-induced proliferation, migration and fibrosis of human embryonic lung fibroblasts (MRC-5 cells) and explore the underlying molecular mechanism. Methods C57/BL6 mice were randomized into 4 groups for treatment with saline (control group), bleomycin, bleomycin+sh-NC or bleomycin + sh-FUT8, and pulmonary fibrosis was observed using Masson staining. MRC-5 cells were transfected with si-NC, FUT8 siRNA (si-FUT8), or both si-FUT8 and a galectin-3 (Gal-3) overexpression plasmid (pcDNA3.1-Gal) prior to TGF-β1 treatment, and the changes in cell proliferation and migration were assessed using CCK-8 assay, BrdU assay, and wound healing assay; the changes in the expression levels of α-SMA, collagen I (COLIA1) and extracellular matrix fibronectin (FN) were detected with real-time quantitative PCR (RT-qPCR) and Western blotting. The interaction of FUT8 and Gal-3 was tested using coimmunoprecipitation (Co-IP) assay, and the effect of FUT8 silencing on Gal-3 and FAK/Akt signaling pathways was analyzed. Results FUT8 knockdown significantly reduced bleomycin-induced extracellular collagen deposition in the lung tissues of the mice. Silencing FUT8 obviously inhibited cell proliferation (P<0.05) and migration mediated by TGF-β1. FUT8 knockdown down-regulated the mRNA and protein levels of α-SMA, COLIA1 and FN (P<0.05) in the cells. Coimmunoprecipitation analysis showed that FUT8 interacted with Gal-3. Silencing FUT8 significantly down-regulated Gal-3 expression and inhibited the activation of the FAK/Akt signaling pathway (P<0.05). Overexpression of Gal-3 obviously reversed the effects of FUT8 silencing on cell proliferation, migration and fibrosis (P<0.05). Conclusion FUT8 regulates TGF-β1-induced proliferation, migration and fibrosis of MRC-5 cells by modulating Gal-3 expression, in which the FAK/Akt pathway may play a role.

Key words: FUT8; galectin-3; proliferation; migration; fibrosis