ABSTRACT
Acute kidney injury (AKI) presents a daunting challenge with limited therapeutic options. To explore the contribution of N6-methyladenosine (m6A) in AKI development, we have investigated m6A-modified mRNAs within renal tubular cells subjected to injuries induced by diverse stressors. Notably, while the overall level of m6A-modified RNA remains unaltered in renal tubular cells facing stress, a distinct phenomenon emerges-mRNAs bearing m6A methylation exhibit a pronounced tendency to accumulate within stress granules (SGs), structures induced in response to these challenges. Cumulation of m6A-modified mRNA in SGs is orchestrated by YTHDF1, a m6A 'reader' closely associated with SGs. Strikingly, AKI patients and various mouse AKI models showcase elevated levels of renal tubular YTHDF1. Depleting YTHDF1 within renal tubular cells leads to a marked reduction in m6A-modified mRNA accumulation within SGs, accompanied by an escalation in cell apoptosis under stress challenges. The significance of YTHDF1's protective role is further underscored by findings in AKI mouse models triggered by cisplatin or renal ischemia-reperfusion treatments. In particular, renal tubular-specific YTHDF1 knockout mice exhibit heightened AKI severity when contrasted with their wild-type counterparts. Mechanistic insights reveal that YTHDF1 fulfills a crucial function by safeguarding m6A-modified mRNAs that favor cell survival-exemplified by SHPK1-within SGs amid stress-challenged renal tubular cells. Our findings collectively shed light on the pivotal role of YTHDF1 in shielding renal tubules against AKI, through its adeptness in recruiting and preserving m6A-modified mRNAs within stress-induced SGs.
