Role of bone marrow mesenchymal stem cells in the development of PQ-induced pulmonary fibrosis

Paraquat (PQ) poisoning-induced pulmonary fibrosis is one of the primary causes of mortality in patients with PQ poisoning. The potential mechanism of PQ-induced pulmonary fibrosis was thought to be mediated by inflammation. Recently, bone marrow-derived mesenchymal stem cells (BMSCs) have been considered as a potential strategy for the treatment of fibrotic disease due to their anti-inflammatory and immunosuppressive effects. In the present study, an increased accumulation of BMSCs in a mouse model of PQ-induced pulmonary fibrosis following their transplantation, markedly improving the survival rate of mice with PQ poisoning. In addition, the results indicated that BMSC transplantation may inhibit the production of pro-inflammatory cytokines, including tumor necrosis factor- interleukin (IL)-1, IL-6 and IL-10 in the lung tissues of PQ-poisoned mice, and ultimately attenuate the pulmonary fibrosis. In vitro, BMSCs may suppress PQ-induced epithelial-to-mesenchymal transition and protect pulmonary epithelial cells from PQ-induced apoptosis. These findings suggest that BMSC transplantation may be a promising treatment for pulmonary fibrosis induced by PQ poisoning.