Inhibition of N6-methyladenosine methylation of ASC by berberine ameliorates pyroptosis of renal tubular epithelial cells in acute kidney injury

Acute kidney injury (AKI) lacks a definitive therapeutic approach beyond supportive care. One significant pathological mechanism involves the regulated death of tubular epithelial cells; however, the regulatory mechanisms underlying this cell death pathway require further investigation. The N6-methyladenosine (m6A) modification, recognized as the most prevalent modification in eukaryotes, plays a critical role in the regulatory processes associated with AKI. Here, this study investigates the association between methyltransferase-like 3 (METTL3) and pyroptosis in mice with folic acid (FA)-induced AKI. Both in vitro and in vivo experiments have confirmed that METTL3 plays a role in AKI progression, correlating with renal epithelial cell pyroptosis and inflammation. Moreover, RNA immunoprecipitation quantitative PCR (RIP-qPCR) analysis demonstrated that METTL3-mediated m6A methylation occurred in the mRNA of Apoptosis-associated speck-like protein containing a CARD (ASC) in H₂O₂-induced renal tubular epithelial (TCMK-1) cells. Notably, METTL3 knockdown resulted in reduced ASC protein expression, decreased release of inflammatory factors, and reduced pyroptosis. In addition, we verified the inhibitory effect of berberine hydrochloride, a monomer used in traditional Chinese medicine, on METTL3 expression. We also demonstrated that berberine ameliorated FA-induced AKI and H₂O₂-induced pyroptosis in TCMK-1 cells by inhibiting METTL3 and modulating the ASC/caspase-1/Gasdermin D axis. These findings provide insights into targeted therapies and drug development for AKI.