USP7 Drives Atherosclerosis by Promoting Ferroptosis in Vascular Endothelial Cells via the KIAA1429/NEAT1/CTCF Axis.

Abstract

BACKGROUND: Ferroptosis is an iron-dependent form of necrosis that promotes AS by accelerating endothelial dysfunction in lipid peroxidation. This study aims to investigate the role of deubiquitinase USP7 in ferroptosis of VECs during AS. METHODS: AS models were established using HFD-fed ApoE−/− mice in vivo and ox-LDL-treated HUVECs in vitro. After USP7 inhibition, plaque area and necrotic core in aortas were assessed by Oil-red O and H&E staining. TC, TG, HDL-C, and LDL-C were measured, and iron content, ROS, MDA, and GSH levels in tissues and cells were quantified. USP7, KIAA1429, lncRNA NEAT1, GPX4 and SLC7A11 expression were analyzed by qRT-PCR or Western blot. Cell viability was assessed by CCK-8 assay. Protein interactions between USP7 and KIAA1429 and ubiquitination level of KIAA1429 were detected via Co-IP. Total m6A levels were quantified. M6A enrichment on NEAT1 was measured by MeRIP. Binding between KIAA1429 and NEAT1 was detected. Bindings between YTHDF1 and NEAT1, and between NEAT1 and CTCF were detected by RIP. CTCF binding and H3K27me3 enrichment at the SLC7A11 promoter were analyzed by ChIP. RESULTS: USP7, KIAA1429, and NEAT1 were upregulated in mouse AS models and ox-LDL-treated HUVECs. USP7 inhibition attenuated AS pathology and VECs ferroptosis. USP7 deubiquitinated and stabilized KIAA1429, which facilitated YTHDF1-mediated m6A modification to stabilize NEAT1. NEAT1 recruited CTCF to maintain H3K27me3 modification at the SLC7A11 promoter, repressing SLC7A11 transcription and triggering HUVECs ferroptosis. Overexpression of KIAA1429 or NEAT1 reversed protective effects of USP7 inhibition on ferroptosis. CONCLUSION: USP7 promotes VECs ferroptosis in AS via the KIAA1429/NEAT1/CTCF axis.