The Function And Mechanism Of Circ＿0000638 In Inflammation Of Human Bronchial Epithelial Cells Induced By Neodymium Oxide

Objective To explore the changes of circ＿0000638 in the inflammatory response induced by rare earth neodymium oxide in human bronchial epithelial cells(16HBE),and investigate its function and mechanism of action.Method ELISA and q RT-PCR were used to detect the expression levels of IL-8 and IL-1β in 16 HBE cells that exposed to different doses of neodymium oxide for 48 hours.After 16 HBE cells were stimulated with neodymium oxide at a concentration of 80 μg/ml for 48 hours,the differentially expressed circ RNA was detected by microarray and verified by q RT-PCR.The expression changes of IL-8 and IL-1β were detected by ELISA and q RT-PCR after interference/overexpression of circ＿0000638.The binding of miR-498-5p and circ＿0000638 were verified by dual luciferase reporter gene method.The expression changes of IL-8 and IL-1β were detected by ELISA and q RT-PCR after transfection of miR-498-5p mimic/inhibitor.The expression of NKRF,p-IκB and p-p65 protein was detected by western blot after exposure to neodymium oxide in the 16 HBE cells for 48 hours.After interference/overexpression of circ＿0000638,western blot was used to detect the expression of p-IκB,p-p65 protein and the level of p-p65 protein in the cytoplasm/nucleus of 16 HBE cells after exposure to neodymium oxide.Western blot was used to detect the expression of NKRF,IκB,p-IκB,p65 and p-p65 protein in 16 HBE cells that exposed to neodymium oxide after co-transfection of circ＿0000638 si RNA/oe RNA and miR-498-5p mimic/inhibitor.The expression of IL-8 and IL-1β in 16 HBE cells that exposed to neodymium oxide was detected by ELISA after transfected circ＿0000638si RNA/oe RNA and inhibited NF-κB with BAY11-7082.Results The IL-8 and IL-1βsecretion were increased after 48 hours of cerium oxide exposure compared with the control group(p<0.05).The expression of circ＿0000638 was negatively correlated with the dose of neodymium oxide in 16 HBE cells(r=-0.951,p<0.001).The expression of IL-8 and IL-1β were increased after interference with circ＿0000638 in 16 HBE cells;conversely,the IL-8 and IL-1β expression were decreased,the difference was statistically significant(p<0.001).Dual luciferase reporter gene results show that miR-498-5p can interact with circ＿0000638.The expression of IL-8 and IL-1β were increased after overexpression of miR-498-5p in 16 HBE cells;conversely,the IL-8 and IL-1β expression were decreased,the difference was statistically significant(p<0.05).The expression levels of p-IκB and p-p65 and the expression level of p-p65 in the nucleus were increased after interference with circ＿0000638 in 16 HBE cells;conversely,the expressions of p-IκB and p-p65 were decreased,and the difference were statistically significant(p<0.05).The expression of NKRF was decreased but the expression of p-IκB and p-p65 were increased after interference with circ＿0000638 in 16 HBE cells,and the decreasing trend of NKRF and the increasing trend of p-IκB and p-p65 were weakened after the addition of miR-498-5p inhibitor.The NKRF expression was increased but the expression of p-IκB and p-p65 was decreased after overexpression of circ＿0000638 in 16 HBE cells,and the increasing trend of NKRF and the decreasing trend of p-IκB and p-p65 were attenuated after adding the miR-498-5p mimic.(p<0.05).The expression levels of IL-8and IL-1β in the cells was significantly decreased after the NF-κB was inhibited by BAY11-7082 and there was no significant difference in the expression levels of IL-8 and IL-1β in each BAY11-7082 exposed group.Conclusions circ＿0000638 can inhibit the activation of NF-κB signaling pathway by competitive binding to miR-498-5p,thereby inhibiting the expression of IL-8 and IL-1β in 16 HBE cells induced by neodymium oxide.