# Multi-omics mapping identifies CYBA-mediated mitochondrial dysfunction driving macrophage polarization and ferroptosis via Nrf2 pathway in atherosclerosis

## TL;DR

This study shows that CYBA promotes mitochondrial dysfunction and inflammation in macrophages during atherosclerosis by suppressing the Nrf2 antioxidant pathway.

## Contribution

The novel contribution is identifying CYBA as a mitochondrial checkpoint linking oxidative stress to macrophage polarization and ferroptosis in atherosclerosis.

## Key findings

- CYBA knockdown in mice reduced atherosclerotic plaque formation and rescued mitochondrial damage.
- CYBA silencing inhibited oxidative stress and pro-inflammatory polarization in macrophages.
- CYBA deficiency activated Nrf2 and its antioxidant targets, which were reversed by Nrf2 inhibition.

## Abstract

Atherosclerosis (AS), a chronic inflammatory process driven largely by macrophage-mediated plaque formation, remains poorly understood in mitochondrial–macrophage crosstalk. While CYBA polymorphisms correlate with cardiovascular risk, the functional role of CYBA in connecting mitochondrial dysfunction to macrophage phenotypic alteration and functional modulation remains largely unknown. In this study, we integrated multi-omics profiling of AS immune microenvironments with mitochondrial-associated gene sets. Machine learning and single-cell RNA sequencing identified CYBA as a key oxidative stress regulator. CYBA expression was significantly upregulated both in oxidized low-density lipoprotein (ox-LDL)-stimulated THP-1 macrophages and in atherosclerotic lesions, with immunofluorescence confirming macrophage enrichment. In vivo, ApoE−/− mice fed a high-fat/high-cholesterol diet and adeno-associated virus-mediated CYBA knockdown attenuated atherosclerotic plaque formation and lipid deposition and rescued mitochondrial damage. In vitro, CYBA silencing attenuated ox-LDL-induced mitochondrial dysfunction and oxidative stress, concurrently inhibiting pro-inflammatory polarization and ferroptosis. Mechanistically, CYBA deficiency facilitated Nrf2 nuclear translocation and downstream activation of heme oxygenase 1 and NAD(P)H quinone dehydrogenase 1, whereas pharmacological Nrf2 inhibition reversed these protective effects. Our findings unveil CYBA as a mitochondrial checkpoint that constrains Nrf2-mediated antioxidant responses, thereby promoting inflammatory polarization and ferroptosis in macrophages during AS. Targeting the CYBA offers a promising therapeutic strategy to attenuate plaque progression.