Targeted inhibition of Rev-erb-α/β limits ferroptosis to ameliorate folic acid-induced acute kidney injury

Background and purpose: Acute kidney injury (AKI) is a common and critical illness, resulting in severe morbidity and a high mortality. There is a considerable interest in identifying novel molecular targets for management of AKI. We investigated the potential role of the circadian clock components Rev-erb-α/β in regulation of Ferroptosis and AKI.

Experimental approach: AKI model was established by treating mice with folic acid. Regulatory effects of Rev-erb-α/β on AKI and Ferroptosis were determined using single-gene knockout (Rev-erb-α^-/- and Rev-erb-β^-/- ) mice, incomplete double-knockout (icDKO, Rev-erb-α^+/- Rev-erb-β^-/- ) mice and cells with erastin-induced Ferroptosis. Targeted antagonism of Rev-erb-α/β to alleviate AKI and Ferroptosis was assessed using the small-molecule antagonist SR8278. Transcriptional gene regulation was investigated using luciferase reporter, mobility shift and chromatin immunoprecipitation assays.

Key results: Loss of Rev-erb-α or Rev-erb-β reduced the sensitivity of mice to folic acid-induced AKI and eliminated the circadian time dependency in disease severity. This coincided with less extensive Ferroptosis, a main cause of folic acid-induced AKI. Moreover, icDKO mice were more resistant to folic acid-induced AKI and Ferroptosis as compared with single-gene knockout mice. Supporting this, targeting Rev-erb-α/β by SR8278 attenuated Ferroptosis to ameliorate folic acid-induced AKI in mice. Rev-erb-α/β promoted Ferroptosis by repressing the transcription of Slc7a11 and HO1 (two ferroptosis-inhibitory genes) via direct binding to a RORE cis-element.

Conclusion and implications: Targeted inhibition of Rev-erb-α/β limits Ferroptosis to ameliorate folic acid-induced AKI in mice. The findings may have implications for improved understanding of circadian clock-controlled Ferroptosis and for formulating new strategies to treat AKI.