Methyltransferase-like 14 promotes ferroptosis in sepsis-induced acute kidney injury via increasing the m6A methylation modification of LPCAT3.

Acute kidney injury (AKI) is one of the most serious and common complications in the course of sepsis, known for its poor prognosis and high mortality rate. Recently, ferroptosis, as a newly discovered regulatory cell death, might be closely associated with the progression of AKI. METTL14 is a writer of RNA m6A, an abundant epigenetic modification in transcriptome with broad function. Hence, the purpose of our study is to explore the potential function and mechanism of METTL14 on the ferroptosis in sepsis-induced AKI. In this paper, TCMK-1 cells and mice treated with LPS were used to constructe AKI model in vitro and in vivo. Pathological changes of renal tissue were observed by HE staining. The fluorescent probe C11-BODIPY and 4HNE kits were used to measure the lipid peroxidation. The ferroptosis index was evaluated by MDA, GSH and Fe²⁺ kits. The total m6A levels were analyzed by EpiQuik M6A RNA methylation kit, and the m6A levels of LPCAT3 were examined by Me-RIP assay. Finally, the interaction between LPCAT3 and METTL14 was clarified using RIP and dual-luciferase reporter gene assays. Our works revealed that the m6A level and ferroptosis was markedly ascended in LPS-induced TCMK-1 cells. The silence of METTL14 lowered the cell viability, the levels of MDA, Fe²⁺ and lipid peroxidation in the LPS-stimulated AKI model in vitro and in vivo, but increase GSH levels. Moreover, the up-regulation of ferroptosis-related proteins by LPS was notably inhibited by the knockdown of METTL14. In addition, silencing METTL14 reduced the m6A and mRNA levels of LPCAT3. Furthermore, the efficacy of METTL14 downregulation on the ferroptosis in the LPS-induced TCMK-1 cells were antagonized by LPCAT3 overexpression. Taken together, our findings revealed that METTL14 knockdown resisted ferroptosis in sepsis-induced AKI through lessening the level of LPCAT3 mediated by m6A modification.