MiR-181a Down-regulates NLRP1 Inflammasome Expression In THP-1 Macrophages And Reduces Intracellular Lipid Storage

Objective As an important member of the miRNA family,miR-181 a plays an important role in cell proliferation and differentiation.In recent years,some studies have found that miR-181 a plays an important role in the occurrence and development of As.NLRP1 inflammasome is a complex composed of a variety of proteins.After activation,it can mediate the maturation of inflammatory factors such as IL-1?,IL-18,and TNF-?.Analysis by starbase website found that there are multiple binding sites for NLRP1 3 'UTR and miR-181 a,and it is predicted that the free energy required to bind NLRP1 to miR-181 a is low,so we speculate that miR-181 a targets NLRP1 3 'UTR by targeting binds,thereby inhibiting NLRP1 inflammasome expression in THP-1 macrophages.The purpose of this study was to confirm that miR-181 a can inhibit the expression of NLRP1 inflammasomes,down regulate the expression of inflammatory factors,and reduce intracellular lipid storage in THP-1 macrophages.Methods THP-1 cells were induced to differentiate into macrophages by phorbol(PMA),and THP-1 macrophages were incubated with 100 ?g/ml oxidized low density lipoprotein(ox LDL)to transform them into foam cells.The treated cells were divided into five groups: blank control group,miR-181 a mimics group,miR-181 a mimics control group,miR-181 a inhibitor group,and miR-181 a inhibitor control group.After the cells of each group were cultured for 72 hours,oil red "O" staining was used to observe the intracellular lipid accumulation.RT-qPCR was used to detect NLRP1,ASC,Caspase1 mRNA levels,and Western blot was used to detect NLRP1,ASC,Caspase1,IL-1?,and IL-18 protein levels.Results Oil red "O" observed a significant decrease in lipid accumulation in the miR-181 a mimics group compared with the blank control group,and a significant increase in lipid accumulation in the miR-181 a inhibitor group compared with the blank control group.RT-qPCR showed that the expression of NLRP 1,ASC,Caspase 1 mRNA in miR-181 a mimics group decreased,while the expression of miR-181 a inhibitor group increased,blank control group,miR-181 a mimics control group and there was no significant difference in miR-181 a inhibitor control group comparison.Western blot analysis showed that the expression of NLRP 1,ASC,Caspase 1,IL-1?,and IL-18 proteins in the miR-181 a mimics group decreased,while the expression of miR-181 a inhibitor group increased.There was no significant difference in comparison expression between the control group and miR-181 a inhibitor control group.Conclusion miR181 a can down-regulate THP 1 macrophage NLRP1 inflammasome expression,reduce the secretion of inflammatory factors IL-1? and IL-18,and reduce intracellular lipid accumulation.