Acrolein-Triggered Ferroptosis and Protection by Intermittent Fasting via the AMPK/NRF2-CLOCK/BMAL1 Pathway

Environmental pollution significantly exacerbates various diseases, particularly those affecting the cardiovascular and respiratory systems. Our previous studies have shown that acrolein, an environmental pollutant, promotes atherosclerosis by downregulating the circadian clock genes (CLOCK/BMAL1) and disrupting circadian rhythm. We have also found that intermittent fasting (IF), closely linked to the circadian clock, may mitigate atherosclerosis induced by acrolein. Ferroptosis, a newly identified form of regulated cell death, is associated with the acceleration of atherosclerotic development, but its relationship with the circadian clock is not well understood. In this study, we explored the potential of IF to alleviate ferroptosis by modulating the circadian clock. Our in vivo experiments revealed that IF reversed ferroptosis and upregulated CLOCK/BMAL1 in APOE-/- mice. In human umbilical vein endothelial cells (HUVECs), we discovered that acrolein-induced ferroptosis leads to cell death, while short-term starvation (STS, IF cell model) reversed this effect. Acrolein also suppressed the expression of AMP-activated protein kinase (AMPK), nuclear factor erythroid 2-related factor 2 (NRF2), and CLOCK/BMAL1, which were restored by subsequent STS treatments. Additionally, the overexpression of CLOCK/BMAL1 mitigated ferroptosis, consistent with findings from CLOCK gene knockout experiments. Notably, CLOCK/BMAL1 and AMPK/NRF2 were found to be mutually regulated. Concurrently, the AMPK and NRF2 signaling pathways may be interdependent and act in concert. In conclusion, our findings suggest that IF modulates the CLOCK/BMAL1-AMPK/NRF2 pathway to alleviate acrolein-induced ferroptosis, offering a potential strategy to address health issues related to environmental pollution.