Dual Regulation of ACSL3 by TRIM33-Mediated Ubiquitination and NBR1-Dependent Autophagy: A Therapeutic Target for Cerebral Ischemia-Reperfusion Injury.

BACKGROUND

Cerebral ischemia-reperfusion injury (CIRI) is a key contributor to stroke-related neurological damage, but the functional interplay between autophagy and ferroptosis-two critical pathological processes-remains poorly understood.

METHODS

Using oxygen-glucose deprivation/reperfusion in PC12 cells and middle cerebral artery occlusion (MCAO) in rats, we combined molecular, pharmacological, and imaging approaches to investigate how autophagy regulates the ferroptosis suppressor acyl-CoA synthetase long-chain family member 3 (ACSL3).

RESULTS

Ischemia-reperfusion triggered hyperactivated autophagy, which promoted ferroptosis by selectively targeting ACSL3 for degradation via the autophagy receptor neighbor of BRCA1 gene 1 protein (NBR1). We further identified that tripartite motif-containing protein 33 (TRIM33), an E3 ubiquitin ligase induced after ischemia, directly ubiquitinates ACSL3 and facilitates its proteasomal degradation. This ubiquitin-mediated pathway acted synergistically with autophagy to control ACSL3 stability. Pharmacological inhibition of autophagy with curcumin derivative 5g (CUR5g) restored ACSL3 protein levels and suppressed ferroptosis. In MCAO rats, CUR5g-administered alone or in combination with the ferroptosis inhibitor Ferfluor-1-significantly improved functional recovery and reduced brain injury.

CONCLUSION

Our study reveals a novel autophagy-NBR1/TRIM33-ACSL3 regulatory axis that drives ferroptosis in CIRI, highlighting a promising therapeutic strategy for ischemic stroke through cotargeting autophagy and ferroptosis. Antioxid. Redox Signal. 45, 676-692.