[Studies on the role of iron death in paraquat-induced mesenchymalization of alveolar epithelial cells].

Objective: To investigate the role of iron death in paraquat (PQ) -induced alveolar epithelial mesangialization (EMT) . Methods: In August 2023, the appropriate PQ staining concentration as well as the intervention concentration of lipoinhibitor-1 (Lip-1) were screened by CCK8 method. The RLE-6TN cells were divided into three groups, which were control group, PQ group and iron death inhibition group, 200 μmol/L PQ solution was given to the PQ group, and PQ 200 μmol/L and 0.1 μmol/L Lip-1 solution was given to the iron death inhibition group, the control group was added the same amount of cell medium. morphological changes and migratory viability of the cells in each group were observed at 12 h, 24 h and 48 h after the poisoning, and the contents of ferrous ions (Fe(2+)), reactive oxygen radicals (ROS), glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) were detected in each group; meanwhile, qRT-PCR and western-blot were used to determine the molecular expression of E-cadherin, α-smooth muscle actin (α-SMA), and Collagen I in the cells in each group. The difference between group was compared by ANOVA, and the further pairwise comparison was conducted by Bonferroni method. Results: Cell viability was detected using CCK8, and the results showed that the cell survival rate of RLE-6TN cells treated with 200 μmol/L PQ+0.1 μmol/L Lip-1 solution was 56.6%. The migration activity of RLE-6TN cells in the iron death inhibition group was weaker than that in the PQ group after 24 and 48 hours of exposure, and the degree of EMT changes in the cells was reduced compared to the PQ group. After 12, 24, and 48 hours of exposure, the Fe(2+) concentration, ROS fluorescence intensity, and MDA content in the iron death inhibition group decreased compared to the corresponding time points in the PQ group (P<0.05/3), while compared with PQ group, the GSH concentration and SOD concentration increased compared to the corresponding time points in the PQ group (P<0.05/3). The results showed that compared with the control group, the expression levels of E-cadherin mRNA and protein in PQ group and iron death inhibition group were both decreased (P<0.05/3), while compared with PQ group, the expression levels of E-cadherin mRNA and protein in iron death inhibition group were increased (P<0.05/3) ; Compared with the control group, the expression levels of α-SMA, Collagen I mRNA and protein in PQ group and iron death inhibition group cells increased (P<0.05/3), while compared with PQ group, the expression levels of α-SMA, Collagen I mRNA and protein in iron death inhibition group cells decreased (P<0.05/3) . Conclusion: Ferroptosis is involved in the EMT process of alveolar epithelial cells induced by PQ. Inhibiting ferroptosis can reduce cellular oxidative damage and alleviate the degree of cellular EMT.