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

AimWe explored whether Fluorofenidone reduced interleukin-1 (IL-1) production by interacting with NLRP3 inflammasome in unilateral ureteral obstruction (UUO). MethodsUreteral 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-1 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-1 and cleavage IL-1 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. ResultsFluorofenidone treatment significantly attenuated renal fibrosis and leukocytes infiltration in UUO model. Fluorofenidone had no effect on the expression of pro-IL-1. Interestingly, Fluorofenidone inhibited the activation of NLRP3 inflammasome, downregulated Caspase-1 levels and thereby decreased the cleavage of pro-IL-1 into IL-1 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. ConclusionFluorofenidone serves as a novel anti-inflammatory agent that attenuates IL-1 production in UUO model by interacting with NLRP3 inflammasome. Summary at a Glance An interesting manuscript which investigates whether fluorofenidone (one of the pyridine agents) could ameliorate kidney fibrosis process in UUO model by regulating the interaction of NLRP3 inflammasome-assembly and the inhibition of IL-1B production.