Endothelial CYP2J2 overexpression restores the BRB via METTL3‐mediated ANXA1 upregulation

Blood–retinal barrier (BRB) breakdown is responsible for multiple ocular diseases, such as diabetic retinopathy, age‐related macular degeneration, and retinal vascular occlusive diseases. Increased vascular permeability contributes to vasogenic edema and tissue damage, with consequent adverse effects on vision. Herein, we found that endothelial CYP2J2 overexpression maintained BRB integrity after ischemia–reperfusion injury and consequently protected against retinal ganglion cell loss. Oxidative stress repressed endothelial ANXA1 expression in vivo and in vitro. CYP2J2 upregulated methyltransferase‐like 3 (METTL3) expression and hence promoted ANXA1 translation via ANXA1 m6A modification in endothelium under oxidative stress. CYP2J2 maintained the distribution of endothelial tight junctions and adherens junctions in an ANXA1‐dependent manner. Endothelial ANXA1 plays an indispensable role in vascular homeostasis and stabilization during development. Endothelial ANXA1 deletion disrupted retinal vascular perfusion as well as BRB integrity. CYP2J2 metabolites restored BRB integrity in the presence of ANXA1. Our findings identified the CYP2J2–METTL3–ANXA1 pathway as a potential therapeutic target for relieving BRB impairments.