AARS1-mediated lactylation of H3K18 and STAT1 promotes ferroptosis in diabetic nephropathy

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease worldwide. Recent studies have revealed that lactate-mediated histone lactylation, which functions as a novel epigenetic modification, is involved in the occurrence and development of diabetes-related complications. However, little is known about the role of lactyltransferase in DN. Alanyl-tRNA synthetase 1 (AARS1) was identified as a novel lactyltransferase that modulates histone H3-lysine-18 lactylation (H3K18la). In the present study, we determined whether AARS1-mediated H3K18la participates in the pathogenesis of DN. More importantly, we explored the potential mechanism involved. A mouse DN model consisting of both wild-type and alanyl-tRNA synthetase (AARS1) heterozygote (AARS1^+/-) mice was utilized in this study. Transcriptomic and lipidomic analyses, combined with a variety of molecular biological methodologies, were employed to elucidate the potential mechanism by which AARS1 regulates ferroptosis in DN. Our results indicated that the increases in AARS1 and H3K18la expression were involved in kidney dysfunction and renal cell death via the modulation of ferroptosis in the DN model. Moreover, AARS1 induced lipid peroxidation by increasing fatty acid elongase-5 (ELOVL5) transcription, ultimately contributing to ferroptosis induction. Furthermore, AARS1 interacted with signal transducer and activator of transcription 1 (STAT1) to jointly regulate ELOVL5 transcription. Additionally, treatment with the STAT1-specific inhibitor fludarabine delayed DN progression. In addition, we observed that AARS1 modulated the lactylation of both STAT1 and H3K18 to regulate ELOVL5 transcription, thus triggering ferroptosis. Inhibition of AARS1-induced lactylation via β-alanine attenuated ferroptosis in DN model mice and hyperglycaemic cells. The present study showed that AARS1 induced the lactylation of H3K18 and STAT1 to regulate ELOVL5 transcription, thus triggering ferroptosis in a diabetic nephropathy model.