CK-666 protects against ferroptosis and renal ischemia-reperfusion injury through a microfilament-independent mechanism

Ferroptosis is a type of regulated cell death driven by iron-dependent accumulation of lipid peroxidation, exhibiting unique morphological changes. While actin microfilaments are crucial for various cellular processes, including morphogenesis, motility, endocytosis, and cell death, their role in ferroptosis remains unclear. Here, our study reveals that actin microfilaments undergo remodeling and disassembly during ferroptosis. Interestingly, inhibitors that target actin microfilament remodeling do not affect cell sensitivity to ferroptosis, with the exception of CK-666 and its structural analogue CK-636. Mechanistically, CK-666 attenuates ferroptosis independently of its canonical function in inhibiting the Arp2/3 complex. Further investigation revealed that CK-666 modulates the ferroptotic transcriptome, prevents lipid degradation, and diminishes lipid peroxidation. In addition, CK-666 does not impact the labile iron pool within cells, nor does the inhibition of FSP1 impact its anti-ferroptosis activity. Notably, the results of DPPH assay and liposome leakage assay suggest that CK-666 mitigates ferroptosis by directly eliminating lipid peroxidation. Importantly, CK-666 significantly ameliorated renal ischemia-reperfusion injury and ferroptosis in renal tissue, underscoring its potential therapeutic impact.