Background: Hypoxia and consequent production of vascular endothelial growth factor A (VEGFA) promote blood vessel leakiness and edema in ocular diseases.Anti-VEGFA therapeutics may aggravate hypoxia; therefore, therapy development is needed.Methods: Oxygen-induced retinopathy was used as a model to test the role of nitric oxide (NO) in pathological neovascularization and vessel permeability.Suppression of NO formation was achieved chemically using L-NMMA, or genetically, in depileve easy clean endothelial NO synthase serine to alanine (S1176A) mutant mice.
Results: Suppression of NO formation resulted in reduced retinal neoangiogenesis.Remaining vascular tufts exhibited reduced vascular leakage through stabilized endothelial adherens junctions, manifested as reduced phosphorylation of vascular endothelial (VE)-cadherin Y685 in a c-Src-dependent manner.Treatment with a single dose of L-NMMA in established retinopathy restored the vascular barrier and prevented leakage.Conclusions: We conclude that NO destabilizes adheren junctions, resulting in vascular hyperpermeability, by converging with the VEGFA/VEGFR2/c-Src/VE-cadherin pathway.
Funding: This study was cybst.us supported by the Swedish Cancer foundation (19 0119 Pj ), the Swedish Research Council (2020-01349), the Knut and Alice Wallenberg foundation (KAW 2020.0057) and a Fondation Leducq Transatlantic Network of Excellence Grant in Neurovascular Disease (17 CVD 03).KAW also supported LCW with a Wallenberg Scholar grant (2015.0275).
WCS was supported by Grants R35 HL139945, P01 HL1070205, AHA MERIT Award.DV was supported by grants from the Deutsche Forschungsgemeinschaft, SFB1450, B03, and CRU342, P2.