Bone Marrow Mesenchymal Stem Cells Alleviated Bleomycin-Induced Pulmonary Fibrosis in Mice

: Objective: The purpose of this study was to investigate the effect of bone marrow mesenchymal stem cells (BMSCs) on bleomycin-induced pulmonary fibrosis in mice. Methods: Pulmonary fibrosis model in mice was established by bleomycin (BLM) induction. This study was divided into 7 groups, bone marrow mesenchymal stem cells (BMSCs) as the treatment measure in 4 groups, the saline and pirfenidone as other 2 groups. The body weight of mice after BLM modeling was measured. The content of hydroxyproline (HYP) and collagen 1 (COL1) in lung tissue were determined by kits. Pathological changes of lung tissue were observed by hematoxylin-eosin (HE) staining. The levels of cytokines in serum and lung tissue of mice were detected by Enzyme-Linked Immunosorbent Assay (ELISA) kits. Immunohistochemistry was used to detect the expression of collagen-1 and α-SMA protein in lung tissue of mice. The levels of TGF-β/smad-3 and NLRP3/NF-κB signal pathway in lung was detected by western blotting. Results: BMSCs significantly decreased the content of HYP and COL1 in lung tissue of mice. BMSCs significantly decreased cytokines in serum and lung tissue. Immunohistochemistry results shown BMSCs significantly decreased the levels of collagen-1 and α-SMA in lung tissue. In addition, BMSCs significantly inhibited TGF-β/smad-3 and NLRP3/NF-κB signal pathway in lung tissue. Conclusions: BMSCs effectively inhibited bleomycin-induced pulmonary fibrosis in mice, and its mechanism may be related to inhibiting the activation of TGF-β/smad-3 and NLRP3/NF-κB signal pathway.