Renal tubular Nfe2l1 protect cisplatin-induced acute kidney injury via suppressing ACSL4-dependent ferroptosis

INTRODUCTION: Nfe2l1 is a transcription factor that is highly conserved and is encoded by the Nuclear Factor Erythroid 2 Like 1 (Nfe2l1) gene, which responds to oxidative stress, proteotoxic stress, and endoplasmic reticulum stress in cells; However, its specific role in the context of acute kidney injury (AKI) is not fully understood. OBJECTIVES: We were aim to explore the protective effect and mechanism of Nfe2l1 on ferroptosis in cisplatin-induced AKI (CI-AKI), as well as the protective effect of RUN-47, a Nfe2l1 activator, on CI-AKI in vivo and in vitro. METHODS: We established models of cisplatin-induced nephrotoxicity in vitro and in vivo. RESULTS: We observed that Nfe2l1, highly expressed in renal tubular cells, was significantly downregulated following cisplatin treatment. Proximal tubule-specific Nfe2l1 knockout aggravated CI-AKI, whereas Nfe2l1 overexpression attenuated it. RNA sequencing analysis revealed that Nfe2l1 overexpression decreased the number of transcripts involved in ferroptosis, after cisplatin treatment. Furthermore, ferroptosis responses, characterized by increased lipid peroxidation and iron content, along with decreased ferroportin (FPN), XCT, and glutathione peroxidase 4 (GPX4) levels, were mitigated in Nfe2l1-overexpressing HK-2 cells but exacerbated in Nfe2l1-knockout mice and Nfe2l1-knockdown HK-2 cells. Moreover, lipidomic and RNA sequencing indicated that Nfe2l1 regulated polyunsaturated fatty acids (PUFAs) levels and inhibited ACSL4 expression. Additionally, Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter gene assay experiments demonstrated direct binding of Nfe2l1 to the ACSL4 promoter, thereby inhibiting its transcription. Significantly, ACSL4 inhibitors reduced the sensitivity of HK-2 cells to ferroptosis induced by Nfe2l1 knockdown. Finally, RUN-47, a novel Nfe2l1 activator, significantly alleviated CI-AKI in vivo and in vitro . CONCLUSION: These findings identify Nfe2l1 as a novel suppressor of renal tubular ferroptosis by transcriptionally inhibiting ACSL4 expression and thereby reducing PUFA levels. RUN-47 can serve as a potential therapeutic agent for CI-AKI.