Loss of Endothelial ZEB1 enhances neovascularisation during choroidal neovascularisation

Background: Choroidal neovascularisation (CNV) is a hallmark of wet/neovascular age-related macular degeneration (wAMD), characterized by aberrant blood vessel growth from the choroid into the retina. Both pathological angiogenesis and inflammation contribute to disease progression. Objective: To investigate the role of endothelial zinc finger E-box-binding homeobox 1 (ZEB1) during CNV. Methods: Single-cell RNA sequencing of experimental CNV lesions revealed upregulation of Zeb1 in angiogenic endothelial cells (ECs). We generated an endothelial-specific Zeb1 knockout (Zeb1iECKO) mouse model to assess its functional role. CNV was induced via laser photocoagulation, and vascular leakage and inflammation were evaluated using fluorescein angiography, immunohistochemistry, and transcriptomic analyses. Results: Zeb1iECKO mice exhibited increased fluorescein leakage and enhanced vascular invasion during CNV, indicating destabilized neovascular structures. However, leukocyte infiltration within CNV lesions was not elevated. In vitro, ZEB1 knockdown in human ECs led to downregulation of inflammatory signalling pathways and reduced expression of adhesion molecules in response to TNF-α stimulation yet retained angiogenic capacity. Conclusion: ZEB1 coordinates angiogenic and inflammatory responses in CNV. Its loss enhances neovascularisation without promoting inflammation, suggesting a potential therapeutic target for modulating pathological angiogenesis in wAMD while minimizing inflammatory damage.