Yangyin Qingfei Yin Protects Rat Lung Tissue From Radiation-induced Apoptosis And Epithelial-mesenchymal Transition Through The ILK-TGFβ-Smad3 Signaling Pathway

Background: Radiation-induced lung injury(RIPI)is a complication of radiation therapy for patients with chest tumors,which limits the outcomes of radiotherapy and seriously affects the quality of life of patients.At present,the treatment of radiation-induced lung injury is limited,and glucocorticoid therapy is still the main treatment.The prevention of radiation-induced lung injury is also a far way to go.Traditional Chinese medicine has shown effectiveness and low toxicity in the prevention and treatment of radiation-induced lung injury,which attacts researcher’s interest across the world.Objective: This study is to expore the effects and the underlying meachnisms of Yangyin Qingfei Yin,a Chineese fomula,on preventing and treating radiation-induced lung injury.Methods: Rat radiation-induced lung injury models were administered by gavage.The serum and rat lung tissue specimens were collected for pathological test.TGF-β expression level in rat serum was detected using enzyme-linked immunosorbent assay(ELISA),and other protein expression in rat lung tissues were detected by western blotting.Transcriptomics was performed on the lung tissues to screen the altered genes as well as the signaling pathways.For in vitro experiments,the rat alveolar type Ⅱ epithelial cells were stimulated with exogenous TGF-β,and Yangyin Qingfei Yin was co-cultured with related inhibitors to explore the regulation of TGF-β on rat alveolar type Ⅱ epithelial cell apoptosis and EMT,and to verify the protective effects of Yangyin Qingfei Yin on rat alveolar type Ⅱ epithelial cells in vitro.Results: For in vivo results,Yangyin Qingfei Yin significantly reduced lung tissue inflammation,apoptosis and EMT.In addition,Yangyin Qingfei Yin inhibited decreased TGF-β concentration in serum,and reduced TGF-β protein expression in rat lung tissue.Transcriptomics revealed that the altered m RNA expression of ILK,Smad3,Bax and α-SMA was closely related with that of TGF-β,which the altered signaling pathway was similarly observed in western blotting.Regarding in vitro experiments,TGF-β induced apoptosis and inhibited EMT of rat alveolar type Ⅱ epithelial cells;Yangyin Qingfei Yin also decreased the expression of Smad3 protein,and inhibited TGF-β-mediated alveolar epithelial cell apoptosis and EMT.Conclusion: Yangyin Qingfei Yin may alleviate lung inflammation and inhibit lung cell apoptosis and EMT in rats with radiation-induced lung injury by down-regulating ILK-TGFβ-Smad3 pathway.