USP11 exacerbates intestinal I/R injury by driving NCOA4-mediated ferritinophagy and ferroptosis via Beclin-1 deubiquitination.

Abstract

Intestinal ischemia/reperfusion (I/R) injury is a life-threatening clinical condition associated with high mortality and limited therapeutic options. Ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation, has emerged as a critical contributor to intestinal I/R injury. Nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy promotes ferroptosis by increasing intracellular iron availability; however, the upstream mechanisms governing this process remain poorly understood. Beclin-1 is a key initiator of autophagy, whereas ubiquitin-specific protease 11 (USP11) regulates protein stability through deubiquitination. Whether USP11 modulates NCOA4-mediated ferritinophagy via Beclin-1 during intestinal I/R injury remains unknown. Here, we investigated the role of the USP11/Beclin-1/NCOA4 signaling axis using a murine intestinal I/R model and an oxygen-glucose deprivation/reoxygenation (OGD/R)-induced IEC-6 cell injury model. Bioinformatic analysis, co-immunoprecipitation (CO-IP), gene knockdown, and rescue experiments were performed to characterize ferritinophagy and ferroptosis. Intestinal I/R injury and OGD/R treatment markedly induced NCOA4-mediated ferritinophagy, accompanied by enhanced lipid peroxidation and characteristic mitochondrial damage, whereas these alterations were reversed by the autophagy inhibitor 3-methyladenine (3-MA) and ferroptosis-specific inhibitor Ferrostatin-1 (Fer-1). Beclin-1 was identified as a critical interacting partner of NCOA4, and its knockdown suppressed ferritinophagy, ferroptosis, and intestinal injury. Mechanistically, USP11 expression was significantly upregulated following intestinal I/R injury and stabilized Beclin-1 through deubiquitination. Conversely, USP11 knockdown enhanced Beclin-1 ubiquitination, reduced its stability, and consequently inhibited NCOA4-mediated ferritinophagy and ferroptosis. Consistently, inhibition of USP11 markedly alleviated intestinal injury both in vivo and in vitro. Collectively, our findings reveal a previously unrecognized USP11/Beclin-1/NCOA4 signaling axis that drives ferritinophagy-dependent ferroptosis during intestinal I/R injury. By promoting Beclin-1 deubiquitination and stabilization, USP11 facilitates NCOA4-mediated ferritinophagy and subsequent ferroptotic cell death, highlighting USP11 as a promising therapeutic target for intestinal I/R injury.