[miR-21 promotes expression of NF-κB and NLRP3 in mouse RAW264.7 cells by inhibiting A20].

Objective To investigate the effect of miR-21 on the expression of NF-κB and NLR family pyrin domain containing 3 (NLRP3) in RAW264.7 cells stimulated by lipopolysaccharide (LPS) and its possible mechanism. Methods Real-time fluorescent quantitative PCR was used to detect the expression of miR-21 after RAW264.7 cells were stimulated with 100 ng/mL LPS for 24 hours. miR-21 inhibitors or mimics were transfected to regulate the expression of miR-21 in RAW264.7 cells. After miR-21 inhibitors or mimics were stimulated by LPS, real-time quantitative PCR was used to detect its effect on the mRNA expression of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and IL-1β, and Western blotting was used to detect the effects on the expression of NF-κB, NLRP3 and A20 proteins. Results The expression of miR-21 significantly increased when RAW264.7 cells were stimulated by LPS. The expression of IL-6, TNF-α, IL-1β, NF-κB and NLRP3 was raised when the expression of miR-21 was up-regulated. The expression of IL-6, TNF-α, IL-1β, NF-κB and NLRP3 was reduced when the expression of miR-21 was down-regulated. miR-21 targeted the inhibition of A20 expression. Conclusion miR-21 can promote the expression of NF-κB and NLRP3 in RAW264.7 cells and its mechanism may be related to the targeted inhibition of A20.