miR-205 Suppresses Pulmonary Fibrosis by Targeting GATA3 Through Inhibition of Endoplasmic Reticulum Stress

OBJECTIVE: To investigate the role of miR-205 and GATA3 in Pulmonary Fibrosis (PF). METHODS: Bleomycin (BLM) was used to induce PF in SD rats and in vitro PF model was established by using TGFβ1-induced RLE-6TN cells. miR-205 mimics were used for the overexpression of miR- 205. The expression of miR-205, GATA3, α-SMA, Collagen I, CHOP and GRP78 were measured using RT-qPCR or western blotting. Dual-luciferase reporter assay was used to confirm binding between GATA3 3'-UTR and miR-205. RESULTS: The expression of miR-205 was significantly down-regulated, while the expression of GATA3 was remarkably up-regulated in the model rats. GATA3 levels were remarkably decreased when miR-205 was overexpressed. When miR-205 was overexpressed, the lung injury by BLM-induced fibrosis was improved. The expression of α-SMA, Collagen I, as well as GRP78 and CHOP, was significantly up-regulated in both in vivo and in vitro PF models, and overexpression of miR-205 remarkably reversed the effects. Dual-luciferase reporter assay showed that miR-205 directly targeted and negatively regulated GATA3. CONCLUSION: miR-205 improved pulmonary fibrosis through inhibiting ER-stress by targeting GATA3.