Fluorofenidone attenuates interleukin-1β production by interacting with NLRP3 inflammasome in unilateral ureteral obstruction.

Abstract

We explored whether Fluorofenidone reduced interleukin-1β (IL-1β) production by interacting with NLRP3 inflammasome in unilateral ureteral obstruction (UUO). Ureteral obstruction rats were treated with Fluorofenidone (500mg/kg per day) for 3, 7days. Morphologic analysis and leukocytes infiltration were assessed in ligated kidneys. Furthermore, plasmids of NLRP3, ASC, pro-Caspase-1, pro-IL-1β were co-transfected into 293T cells, and then treated with Fluorofenidone (2mM). The expression of NLRP3, ASC, pro-caspase-1, cleavage caspase-1, pro-IL-1β and cleavage IL-1β were measured by Western blot or real-time PCR in vivo and in vitro. Moreover the interaction of NLRP3 inflammasome-assembly was detected by co-immunoprecipitation and confocal immunofluorescence. Fluorofenidone treatment significantly attenuated renal fibrosis and leukocytes infiltration in UUO model. Fluorofenidone had no effect on the expression of pro-IL-1β. Interestingly, Fluorofenidone inhibited the activation of NLRP3 inflammasome, downregulated Caspase-1 levels and thereby decreased the cleavage of pro-IL-1β into IL-1β in vivo and in vitro. Fluorofenidone treatment distinctively weakened the interaction between NLRP3 and ASC, as well as ASC and pro-Caspase-1 in vivo. However, Fluorofenidone treatment only significantly weakened the interaction between ASC and pro-Caspase-1 in co-transfected 293T cells. Fluorofenidone serves as a novel anti-inflammatory agent that attenuates IL-1β production in UUO model by interacting with NLRP3 inflammasome.