Objective To explore the impact of silencing neuron-derived neurotrophic factor(NDNF)on pulmonary inflammation,oxidative stress and epithelial-mesenchymal transition(EMT)in mice with bleomycin-induced pulmonary fibrosis.Methods A mouse model of pulmonary fibrosis was established by tracheal injection of bleomycin(5 mg/kg,fibrosis group),and NDNF knockdown pulmonary fibrosis group was established by tail vein injection of siRNA-NDNF adenovirus vector(siRNA-NDNF group),with concurrent establishment of empty vector group and healthy group.At 2 weeks after successful modeling,HE and Masson staining were used to observe the pathological changes in mouse lung tissues(alveolar inflammation score)and the degree of pulmonary fibrosis(fibrosis ratio).ELISA was used to detect the levels of inflammatory factors[tumor necrosis factor-alpha(TNF-α),transforming growth factor-beta1(TGF-β1),interleukin(IL)-4,and IL-6],oxidative stress factors[malondialdehyde(MDA),reactive oxygen species(ROS),and superoxide dismutase(SOD)]and hydroxyproline(HYP)in lung tissues.Western blot was performed to detect the expressions of EMT-related proteins[E-cadherin,α-smooth muscle actin(α-SMA),Snail1,and Collagen Ⅰ]in mouse lung tissues in each group.Results Pulmonary fibrosis group exhibited severe damage in alveolar structure,severe alveolar damage,remarkable inflammatory infiltration and extensive deposition of collagen fibers.Pulmonary coefficient,fibrosis ratio,alveolar inflammation score and HYP level in pulmonary tissues were all higher in pulmonary fibrosis group than those of healthy group(P＜0.05).The damage in alveolar structure,inflammatory infiltration,and blue areas of collagen fibers in mouse lung tissues were reduced in siRNA-NDNF group when compared to empty vector group(P＜0.05).The pulmonary coefficient,fibrosis ratio,alveolar inflammation score and HYP level in pulmonary tissues were lower in siRNA-NDNF group than those in empty vector group(P＜0.05).The levels of TNF-α,TGF-β1,IL-6,IL-4,MDA,and ROS as well as the protein expressions of α-SMA,Snail1,and Collagen Ⅰ in pulmonary tissues in fibrosis group were higher than those in healthy group(P＜0.05),while SOD level and E-cadherin protein expression were lower than those in healthy group(P＜0.05).The levels of TNF-α,TGF-β1,IL-6,IL-4,MDA,and ROS as well as the protein expressions of α-SMA,Snail1 and Collagen Ⅰ in pulmonary tissues in siRNA-NDNF group were lower than those in empty vector group(P＜0.05),while SOD level and E-cadherin protein expression were higher than those in empty vector group(P＜0.05).Conclusion Downregulating NDNF expression may ameliorate mouse pulmonary fibrosis damage,which may be related to alleviating inflammation and oxidative stress responses and regulating the expression of EMT-related proteins in the lungs.
维普
万方数据
