| Environmental pollutants,accidental chemical exposure,and ionization and ultraviolet radiation can directly or indirectly increase intracellular reactive oxygen species(ROS)levels.As an important organ of gas exchange,the lungs are often attacked by ROS.ROS can accelerate the fibrosis of the lung and also promote the ability of lung cancer cells to migrate.However,the specific mechanism of ROS involved in pulmonary fibrosis and lung cancer cell migration needs further study.Among them,epithelial-mesenchymal transition(EMT)plays an important role in pulmonary fibrosis.Excessive ROS can cause oxidative damage to DNA.Therefore,it is necessary to study the relationship between DNA damage repair product 8-oxoG and lung EMT.In addition,lung cancer cell migration is the main cause of death in lung cancer patients.The chemokine SDF-1 and its specific receptors CXCR4 and ACKR3 are involved in the migration and invasion of tumor cells to target organs.However,the relationship between ROS and CXCR4 and ACKR3 during lung cancer cell migration is unclear.Therefore,this thesis focuses:(1)the relationship between 8-oxoG and mouse lung bronchial epithelial cells EMT;(2)the effects of ROS on the migration ability of lung adenocarcinoma cells,CXCR4 and ACKR3.On the one hand,the effect of 8-oxoG on the cell morphology of lung bronchial epithelium and the effect of EMT marker genes were detected by immunofluorescence technology and real-time quantitative PCR;subsequently,mice were perfused with GOx or 8-oxoG to observe the effect on lungs.The effect of tissue microstructure;on the other hand,the effect of GOx on the migration ability of A549 cells to SDF-1 was investigated by Transwell experiment,and the effect of GOx on CXCR4 and ACKR3 was detected by real-time quantitative PCR.The main results are as follows:1.8-oxoG transformed HBEC cells from classic cobblestone epithelial cell morphology to mesenchymal cell morphology,increased the expression of α-SMA protein,increased the expression of SNAI1 protein,and decreased the expression of E-cadherin protein.SNAI1 m RNA expression was significantly increased,and changes in these EMT marker proteins collectively indicate that 8-oxoG treatment induces EMT in HBEC cells;although the m RNA expression of E-cadherin is significantly increased,it does not rule out that it will manifest over a longer period Although there is no significant change in the m RNA expression of β-catenin,there is a phenomenon that the cytoplasm enters the nucleus;the m RNA expression of collagen I and FSP1 significantly increases,which is also consistent with EMT.2.A large number of white blood cells appeared in the alveoli of the lung tissue of mice treated with GOx for one week;the fibroblasts of the lung tissue of mice treated with GOx and 8-oxoG for two weeks increased with collagen deposition,indicating that ROS and 8-oxoG can cause pulmonary fibrosis.3.GOx makes A549 cells produce ROS and can significantly increase the sensitivity of A549 cells to SDF-1.At the same time,GOx can significantly increase the m RNA expression of CXCR4 and ACKR3 in A549 cells at 12 h,although at 24 h,the ACKR3 The m RNA was significantly reduced,and the m RNA expression of CXCR4 was still higher than that of the control group.This suggests that the increased sensitivity of A549 to SDF-1 may be caused by the up-regulation of CXCR4 expression.Based on the above results,8-oxoG,the DNA damage repair product of ROS,caused EMT and pulmonary fibrosis in lung bronchial epithelial cells.In addition,ROS increased the expression of SDF-1 receptor CXCR4 and increased the migration capacity of lung adenocarcinoma cells.The completion of this thesis has certain theoretical significance for understanding the mechanism of ROS-induced pulmonary fibrosis and lung adenocarcinoma metastasis. |
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