GPR91 mediates low shear stress-induced endothelial ferroptosis via EGR1-dependent GPX4 repression

Emerging evidence suggests that low shear stress (LSS) contributes to endothelial injury in atherosclerosis, yet the underlying molecular mechanisms remain incompletely understood. Here, we demonstrate that LSS triggers ferroptosis in vascular endothelial cells through a novel GPR91/EGR1/GPX4 signaling axis. By integrating bioinformatics, single-cell RNA sequencing (scRNA-seq), and ChIP-qPCR, we identified a significant correlation between LSS-responsive genes and ferroptosis-related pathways in atherosclerotic plaques. Using parallel-plate flow chamber system, we confirmed that LSS (3 dyne/cm²) induces characteristic ferroptosis markers in human vascular endothelial cells. Mechanistically, LSS upregulated GPR91, enhancing cellular mechanosensitivity, as further validated in HEK293T cells. Pharmacological inhibition of GPR91 attenuated LSS-induced ferroptosis, while its agonists exacerbated ferroptosis. RNA-seq and ChIP-qPCR identified EGR1 as a downstream of GPR91 effector that binds directly to the GPX4 promoter (M2 motif), repressing its transcription under LSS. Our findings establish GPR91 as a mechanosensitive receptor that links LSS to ferroptosis signaling via EGR1- mediated GPX4 repression, providing new therapeutic targets for shear stress-related vascular pathologies.