Rapamycin Protects Against Paraquat-induced Pulmonary Epithelial Mesenchymal Transition Through Wnt/β-catenin Pathway

Introduction:Paraquat(PQ)is an effective herbicide which is widely used in developing countries worldwide,and pulmonary fibrosis is one of the most typical features of PQ poisoning and high toxication due to amount of ingestion,then following with multi-organ failure in the following year and finally death because of respiratory failure.The EMT was indicated to be a significant factor in lung fibrosis.However,it has remained elusive whether PQ induces pulmonary fibrosis via EMT.The molecular mechanism of PQ toxicity especially how to treat PQ-induced pulmonary fibrosis is still largely unknown.Objective:To study about Rapamycin protects against paraquat-induced pulmonary epithelial mesenchymal transition through Wnt/β-catenin pathwayMethods:In this study,four groups were divided including negative control group,PQ treated group,Rapamycin treated group and PQ together with Rapamycin treated group.In A549 and MRC-5 cells were cultured in DMEM medium and using SOP of propagation of A549,Human Lung Carcinoma Epithelial Cells and we used western blotting assay,Real-time PCR assay and fluorescent immunostaining assay to analyze the effects of rapamycin on the PQ-induced epithelial mesenchymal transition(EMT).Result:We found that rapamycin down-regulated the mesenchymal cell marker a-SMA and up-regulated the epithelial cell marker E-cadherin both in mRNA and protein levels compared with PQ group.And PQ increased the Wnt1,LRP5,LRP6 and β-catenin in A549 cells,and rapamycin inhibited the these effects of PQ.Activation of Wnt signaling pathway using lithium chloride(LiCl)attenuated the inhibitory effects of rapamycin on the PQ-induced EMT.Conclusion:rapamycin protects against paraquat-induced pulmonary epithelial mesenchymal transition through Wnt/β-catenin pathway.