METTL3-mediated m6A modification of TIFA mRNA promotes tubular cell pyroptosis in acute kidney injury.

Abstract

Tubular cell death is a hallmark of acute kidney injury (AKI), yet its mechanisms remain unclear. This study elucidates the role of N6-adenosine-methyltransferase-like 3 (METTL3) in renal tubular pyroptosis. METTL3 was upregulated in ischemic AKI models and in hypoxia/reoxygenation (H/R)-treated tubular epithelial cells (TECs). Its silencing alleviated pyroptosis, while overexpression exacerbated it. Conditional METTL3 knockout in mouse TECs attenuated ischemia/reperfusion (I/R)-induced renal injury. Through m6A methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing, we identified TRAF-interacting protein with a forkhead-associated domain (TIFA) as a key target. METTL3 mediates m6A modification of TIFA mRNA, which is recognized by IGF2BP2 to enhance mRNA stability. TIFA promotes NLRP3 transcription via NF-κB signaling, activating the NLRP3 inflammasome and Caspase-1, thereby driving pyroptosis. Targeting METTL3 with tetrahedral framework nucleic acid-delivered siRNA reduced TIFA expression, mitigated renal dysfunction, and suppressed pyroptosis, highlighting the METTL3/TIFA/NLRP3 axis as a potential therapeutic target for AKI.