Autophagy inhibition and ferroptosis activation during atherosclerosis: Hypoxia-inducible factor 1α inhibitor PX-478 alleviates atherosclerosis by inducing autophagy and suppressing ferroptosis in macrophages

Objective: To elucidate the key regulator responsible for autophagy and ferroptosis, and if specific pharmacological inhibitor of upregulated gene exerted the pro-autophagic and anti-ferroptotic effect on macrophage to alleviate the atherosclerosis. Methods: Autophagy and ferroptosis were evaluated in atherosclerotic lesions and THP-1 macrophages exposed to ox-LDL. Autophagy/ferroptosis-related differentially expressed genes (DEGs) in atherosclerosis were identified by bioinformatic analysis of GSE97210 dataset, and were validated in atherosclerotic cells and tissues. The efficacy and mechanism of pharmacological inhibition of the validated DEGs on alleviating atherosclerosis were explored in vivo and in vitro. Results: Atherosclerotic lesions were characterized by autophagy inhibition and ferroptosis activation in macrophages. The crosslink between autophagy and ferroptosis were demonstrated. Ox-LDL induced THP-1 macrophage foam cell formation, autophagy dysfunction, and ferroptosis occurrence. Rapamycin ameliorated and, conversely, erastin deteriorated the effect of ox-LDL on THP-1 macrophages. Eleven autophagy/ferroptosisrelated DEGs were identified in atherosclerosis vs. normal. The up-regulated expression of HIF-1 alpha was verified in atherosclerotic lesions and THP-1 macrophages induced by ox-LDL. HIF-1 alpha inhibitor PX-478 restored autophagy function, depressed ferroptosis, and reduced lipid accumulation in ox-LDL induced THP-1 macrophage. Autophagy inhibitor 3-MA obviously abrogated the pro-autophagic, anti-ferroptotic, and anti-atherosclerotic effects of PX-478. PX-478 treatment down-regulated HIF-1 alpha expression and reduced atherosclerotic plaques in the mice model. Conclusions: Autophagy is inhibited, ferroptosis is activated, and crosslink occurs between autophagy and ferroptosis during atherosclerosis. HIF-1 alpha, an upregulated DEG between atherosclerosis and normal, co-regulates autophagy and ferroptosis. HIF-1 alpha inhibitor PX-478 attenuates foam cell formation and lessens atherosclerosis by enhancing autophagy and depressing ferroptosis in macrophages.

Automated summary

This study aims to investigate the key regulator responsible for autophagy and ferroptosis, and the effects of specific pharmacological inhibitor on macrophages to alleviate atherosclerosis. Autophagy is inhibited and ferroptosis is activated in atherosclerotic lesions. The upregulated expression of HIF-1 alpha is involved in the regulation of autophagy and ferroptosis. The HIF-1 alpha inhibitor PX-478 can attenuate foam cell formation and lessen atherosclerosis by enhancing autophagy and depressing ferroptosis in macrophages.