Targeting endothelial migration to prevent neovascularization

 描述(申请人提供)：在美国，大多数严重的视力丧失是由于与眼部疾病患者的视网膜新生血管相关的并发症所致，包括糖尿病视网膜病变(DR)和老年性黄斑变性(AMD)。这些疾病的特点是血管过度生成，导致血管渗漏，导致水肿、出血和视网膜脱离，损害视力。迄今为止，过度血管生成的治疗在很大程度上依赖于抑制血管内皮细胞生长这一单一因素。 因子(血管内皮生长因子)，有一定的治疗成功。临床试验表明，抗血管内皮生长因子治疗减少了AMD和DR患者的血管生成，表明抗血管生成治疗是一种可行的治疗选择。然而，治疗需要频繁的眼内注射，部分患者的视力没有改善。因此，开发能够增强对抗血管内皮生长因子药物的反应并改善眼部新生血管疾病患者生活的治疗方法具有巨大的治疗意义。我们在此确认，除血管内皮生长因子外，导向分子Slit2也是促进血管生成的必需因子。通过暂时诱导Slit2基因的缺失以及在内皮细胞中联合缺失其Robo1和Robo2受体来破坏Slit2的功能，可以有效地抑制视网膜新生血管。这些数据使我们检验了一种假设，即通过Robo1和2阻断Slit2信号代表了另一种阻断过度血管生成的途径，该途径可能与抗血管内皮生长因子治疗一起作为AMD的治疗靶点。在机制上，我们将验证阻断Slit2-Robo1/2信号通路通过选择性地靶向EC迁移来提高抗血管内皮生长因子治疗效果的假设，并定义调控这一过程的信号通路。我们的研究将首次对Sit-Robo1/2介导的眼球新生血管形成进行全面的研究，确定其生物学意义，并确定Sit通过Robo1/2信号转导的分子和细胞基础。了解这些机制将有助于深入了解新生血管形成过程中极化内皮细胞迁移所需的信号事件，这是血管生物学中一个基本但知之甚少的事件。我们建议的最终目标是开发新的治疗方法来预防眼内血管疾病。

 DESCRIPTION (provided by applicant): 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.