Amelioration of paraquat-induced pulmonary fibrosis in mice byregulating miR-140-5p expression with the fibrogenic inhibitorXuebijing

摘要

Intravenous Xuebijing (XBJ) therapy suppresses paraquat (PQ)-induced pulmonaryfibrosis. However, the mechanism underlying this suppression remains unknown.This work aimed to analyze the miR-140-5p-induced effects of XBJ injection onPQ-induced pulmonary fibrosis in mice. The mice were arbitrarily assigned tofour groups. The model group was administered with PQ only. The PQ treatmentgroup was administered with PQ and XBJ. The control group was administered withsaline only. The control treatment group was administered with XBJ only. ThemiR-140-5p and miR-140-5p knockout animal models were overexpressed. The geneexpression levels of miR-140-5p, transglutaminase-2 (TG2), β-catenin, Wnt-1,connective tissue growth factor (CTGF), mothers against decapentaplegic homolog(Smad), and transforming growth factor-β1 (TGF-β1) in the lungs were assayedwith quantitative reverse transcription polymerase chain reaction (qRT-PCR) andWestern blot analysis. The levels of TGF-β1, CTGF, and matrixmetalloproteinase-9 (MMP-9) in the bronchoalveolar lavage fluid were assessed byenzyme-linked immunosorbent assay (ELISA). Hydroxyproline (Hyp) levels andpulmonary fibrosis were also scored. After 14 days of PQ induction of pulmonaryfibrosis, AdCMV-miR-140-5p, and XBJ upregulated miR-140-5p expression; blockedthe expressions of TG2, Wnt-1, and β-catenin; and decreased p-Smad2, p-Smad3,CTGF, MMP-9, and TGF-β1 expressions. In addition, Hyp and pulmonary fibrosisscores in XBJ-treated mice decreased. Histological results confirmed thatPQ-induced pulmonary fibrosis in XBJ-treated lungs was attenuated. TG2expression and the Wnt-1/β-catenin signaling pathway were suppressed by theelevated levels of miR-140-5p expression. This inhibition was pivotal in theprotective effect of XBJ against PQ-induced pulmonary fibrosis. Thus, XBJefficiently alleviated PQ-induced pulmonary fibrosis in mice.