The majority of severe vision loss in the US results from complications associated with retinal neovascularization in patients with ocular diseases, including diabetic retinopathy (DR) and Age- Related Macular Degeneration (AMD). These diseases are characterized by excessive angiogenesis, which promotes vascular leak leading to edema, hemorrhage and retinal detachment compromising vision. To date, the treatment of excessive angiogenesis relies largely on inhibition of a single factor, vascular endothelial growth factor (VEGF), with some therapeutic success. Clinical trials have shown that anti-VEGF treatment reduces angiogenesis in AMD and DR patients, indicating that anti-angiogenic treatment is a viable therapeutic option. However, treatments involve frequent intraocular injections, and a proportion of patients do not achieve vision improvement. Therefore, there is enormous therapeutic interest to develop treatments that enhance response to anti-VEGF agents and improve the lives of patients with ocular neovascular disease. We here identify the guidance molecule Slit2 as a requisite factor that promotes angiogenesis in addition to VEGF. Disruption of Slit2 function by temporally inducible deletion of the Slit2 gene, and combined deletion of its Robo1 and Robo2 receptors in ECs potently inhibits retinal neovascularization. These data lead us to test the hypothesis that blocking Slit2 signaling through Robo1 and 2 represents an alternative pathway to block excessive angiogenesis that may serve as a therapeutic target in conjunction with anti-VEGF treatment of AMD. Mechanistically, we will test the hypothesis that blocking of Slit2-Robo1/2 signaling improves efficacy of anti-VEGF treatment by selectively targeting EC migration and define the signaling pathways regulating this process. Our studies will provide the first comprehensive examination of Slit-Robo1/2-mediated angiogenesis in ocular neovascularization, determine its biological significance and define the molecular and cellular basis of Slit signaling through Robo1/2 signaling. Understanding these mechanisms will provide insight into signaling events required for polarized endothelial cell migration during neovascularization, which is a fundamental, yet poorly understood event in vascular biology. The ultimate goal of our proposal is to develop new therapies to prevent intraocular vascular disease.

Public Health Relevance

The wet form of AMD is characterized by excessive blood vessel formation and is currently treated with therapeutic success by inhibition of vascular endothelial growth factor (VEGF), however, because a proportion of patients do not achieve vision improvement, developing treatments that improve response to anti-VEGF agents is likely to improve the lives of patients with AMD. Our preliminary data show that the guidance factor Slit2 potently and selectively promotes ocular neovascularization in mice by signaling through its cognate receptors Robo1 and 2. Our studies will test the efficacy of Slit-Robo1/2 inhibition in preclinical models of ocular neovascular disease in vivo and define the signaling pathways downstream of Slit2-Robo1/2 mediating this effect.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL125811-04
Application #
9476342
Study Section
Vascular Cell and Molecular Biology Study Section (VCMB)
Program Officer
Gao, Yunling
Project Start
2015-07-01
Project End
2019-04-30
Budget Start
2018-05-01
Budget End
2019-04-30
Support Year
4
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Yale University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
Zhang, Feng; Zarkada, Georgia; Han, Jinah et al. (2018) Lacteal junction zippering protects against diet-induced obesity. Science 361:599-603
Ola, Roxana; Künzel, Sandrine H; Zhang, Feng et al. (2018) SMAD4 Prevents Flow Induced Arteriovenous Malformations by Inhibiting Casein Kinase 2. Circulation 138:2379-2394
Dubrac, Alexandre; Künzel, Steffen E; Künzel, Sandrine H et al. (2018) NCK-dependent pericyte migration promotes pathological neovascularization in ischemic retinopathy. Nat Commun 9:3463
Lee, Heon-Woo; Chong, Diana C; Ola, Roxana et al. (2017) Alk2/ACVR1 and Alk3/BMPR1A Provide Essential Function for Bone Morphogenetic Protein-Induced Retinal Angiogenesis. Arterioscler Thromb Vasc Biol 37:657-663
Ntumba, Kalonji; Akla, Naoufal; Oh, S Paul et al. (2016) BMP9/ALK1 inhibits neovascularization in mouse models of age-related macular degeneration. Oncotarget 7:55957-55969
Ola, Roxana; Dubrac, Alexandre; Han, Jinah et al. (2016) PI3 kinase inhibition improves vascular malformations in mouse models of hereditary haemorrhagic telangiectasia. Nat Commun 7:13650
Baeyens, Nicolas; Larrivée, Bruno; Ola, Roxana et al. (2016) Defective fluid shear stress mechanotransduction mediates hereditary hemorrhagic telangiectasia. J Cell Biol 214:807-16
Zhang, Feng; Prahst, Claudia; Mathivet, Thomas et al. (2016) The Robo4 cytoplasmic domain is dispensable for vascular permeability and neovascularization. Nat Commun 7:13517
Dubrac, Alexandre; Genet, Gael; Ola, Roxana et al. (2016) Targeting NCK-Mediated Endothelial Cell Front-Rear Polarity Inhibits Neovascularization. Circulation 133:409-21
Simons, Michael; Eichmann, Anne (2015) Molecular controls of arterial morphogenesis. Circ Res 116:1712-24

Showing the most recent 10 out of 11 publications