Atorvastatin suppresses NLRP3 inflammasome activation via TLR4/MyD88/NF-κB signaling in PMA-stimulated THP-1 monocytes.

AIMS: Increasing evidence shows that NLRP3 inflammasome is closely associated with the progression of atherosclerosis. The purpose of the present study was to evaluate the effects of atorvastatin on NLRP3 inflammasome in PMA-stimulated THP-1 cells and explore its underlying mechanism.

METHODS: Human monocytic THP-1 cells were pretreated with atorvastatin for 1h and then induced by PMA for 48h. Total protein was collected for real-time PCR and Western blot analysis. Cytokine IL-1β release was detected by ELISA assay. And the NF-κB p65 translocation was detected by cellular NF-κB translocation kit.

RESULTS: It was shown that atorvastatin significantly reduced the expression of NLRP3, the cleavage of caspase-1 and IL-1β in PMA-induced THP-1 cells. Moreover, Bay (a NF-κB inhibitor) treatment greatly suppressed the expression of NLRP3, the cleavage of caspase-1 and IL-1β in PMA-induced THP-1 cells, suggesting that the activation of NF-κB pathway takes part in regulating the expression of NLRP3 inflammasome. In addition, atorvastatin markedly inhibited the up-regulation of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and the activation of nuclear factor kappa b (NF-κB) in PMA-stimulated THP-1 cells.

CONCLUSIONS: Atorvastatin exerts an anti-inflammatory effect by inhibiting NLRP3 inflammasome through suppressing TLR4/MyD88/NF-κB pathway in PMA-induced THP-1 monocytes.