Autophagy of OTUD5 Destabilizes GPX4 to Confer Ferroptosis-Dependent Kidney Injury
Ferroptosis is an iron-dependent programmed cell death associated with severe kidney diseases, linked to decreased glutathione peroxidase 4 (GPX4). However, the spatial distribution of renal GPX4-mediated ferroptosis and the molecular events causing GPX4 reduction during ischemia-reperfusion (I/R) remain largely unknown. Using spatial transcriptomics, we identify that GPX4 is situated at the interface of the inner cortex and outer medulla, a hyperactive ferroptosis site post-I/R injury. We show that OTU deubiquitinase 5 (OTUD5) is a GPX4-binding protein that confers ferroptosis resistance by stabilizing GPX4. During I/R, ferroptosis is induced by mTORC1-mediated autophagy, causing OTUD5 degradation and subsequent GPX4 decay. Functionally, OTUD5 deletion intensifies renal tubular cell ferroptosis and exacerbates acute kidney injury, while AAV-mediated OTUD5 delivery mitigates ferroptosis and promotes renal function recovery from I/R injury. In this work, our study highlights a new autophagy-dependent ferroptosis module: hypoxia/ischemia-induced OTUD5 autophagy triggers GPX4 degradation, offering a potential therapeutic avenue for I/R-related kidney diseases. Overall design: To elucidate the comprehensive molecular alterations in kidneys exposed to ischemia-reperfusion (I/R), we generated a mouse model of bilateral I/R-induced acute kidney injury (AKI). Subsequently, we performed single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (stRNA-seq) on the mouse kidneys of sham and I/R-treated ones.