Involvement of REV-ERBα dysregulation and ferroptosis in aristolochic acid I-induced renal injury

The molecular events underlying aristolochic acid (AA) nephropathy are poorly understood, and specific ther-apies for treatment of AA nephropathy are still lacking. Here we aimed to investigate a potential role of REV-ERB alpha and ferroptosis in renal injury induced by aristolochic acid I (AAI), a typical AA. The regulatory effects of REV-ERB alpha on AAI-induced renal injury were determined using kidney-specific Rev-erb alpha knockout mice. Fer-roptosis was assessed based on measurements of iron, GSH, and GPX4. Targeted antagonism of REV-ERB alpha to alleviate AAI-induced renal injury and ferroptosis was assessed using the small molecule antagonist SR8278. mRNAs and proteins were quantified by qPCR and Western blotting, respectively. We first showed that REV-ERB alpha was upregulated and its target BMAL1 was downregulated in the kidney of mice with AAI nephropathy. Upregulation of REV-ERB alpha protein was confirmed in aristolactam I (ALI, a nephrotoxic metabolite of AAI)-treated mRTECs. We also observed enhanced ferroptosis (known to be regulated by REV-ERB alpha) in mice with AAI nephropathy and in ALI-treated mRTECs. Kidney-specific knockout of Rev-erb alpha reduced the sensitivity of mice to AAI-induced ferroptosis and renal injury. Furthermore, knockdown of Rev-erb alpha by siRNA or SR8278 (a REV-ERB alpha antagonist) treatment attenuated ALI-induced ferroptosis in mRTECs. Moreover, REV-ERB alpha antago-nism by SR8278 alleviated ferroptosis and renal injury caused by AAI in mice. In conclusion, we identify REV-ERB alpha as a regulator of AAI-induced renal injury via promoting ferroptosis. Targeting REV-ERB alpha may represent a promising approach for management of AAI nephropathy.

Automated summary

The molecular events underlying aristolochic acid nephropathy are poorly understood, and lack of specific therapies remains a challenge. This study reveals REV-ERB alpha as a regulator of AAI-induced renal injury by promoting ferroptosis, suggesting that targeting REV-ERB alpha may be a promising approach for managing AAI nephropathy.