Discovery of a Covalent NLRP3 LRR-Domain Probe: Reversing Renal Fibrosis via Immunometabolic Reprogramming in Organoid and Murine Models.

Targeting the NLRP3 inflammasome is critical for treating fibrotic diseases; however, current NACHT domain inhibitors face mutational escape and limited isoform specificity. The autoinhibitory leucine-rich repeat (LRR) domain represents an underexplored pharmacological target. Here, we report QX-31, a novel covalent probe selectively engaging the LRR domain. QX-31 covalently binds to Cysteine 838, stabilizing NLRP3 in an inactive conformation and preventing inflammasome assembly with high selectivity over AIM2 and NLRC4. Furthermore, QX-31 reverses maladaptive immunometabolic reprogramming within the renal microenvironment by blunting the PI3K/AKT/HIF-1α axis, suppressing aberrant glycolysis and glutaminolysis. Evaluated in human kidney organoids and murine models of renal injury (UUO and IRI), QX-31 demonstrated potent antifibrotic efficacy comparable to reference drugs, alongside a favorable safety profile. Collectively, QX-31 serves as a valuable chemical tool, demonstrating that covalent targeting of this conformational regulatory domain is a viable therapeutic strategy for fibrotic diseases.