Targeting endothelial migration to prevent neovascularization

 描述（由申请人提供）：美国的大多数严重视力丧失是由眼部疾病患者的视网膜新生血管相关并发症引起的，包括糖尿病视网膜病变（DR）和年龄相关性黄斑变性（AMD）。这些疾病的特征在于过度的血管生成，其促进血管渗漏，导致水肿、出血和损害视力的视网膜脱离。迄今为止，过度血管生成的治疗主要依赖于抑制单一因子，即血管内皮生长 因子（VEGF），具有一定的治疗成功。临床试验表明，抗VEGF治疗可减少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，治疗涉及频繁的眼内注射，并且一部分患者没有实现视力改善。因此，开发增强对抗VEGF剂的反应并改善患有眼部新生血管性疾病的患者的生活的治疗具有巨大的治疗兴趣。我们在这里确定的指导分子Slit 2作为一个必要的因素，促进血管生成，除了VEGF。通过Slit 2基因的暂时诱导性缺失以及其Robo 1和Robo 2受体在EC中的组合缺失来破坏Slit 2功能，从而有效地抑制视网膜新生血管形成。这些数据使我们验证了这样一种假设，即通过Robo 1和2阻断Slit 2信号转导代表了阻断过度血管生成的替代途径，该途径可作为AMD抗VEGF治疗的治疗靶点。从机制上讲，我们将检验阻断Slit 2-Robo 1/2信号传导通过选择性靶向EC迁移提高抗VEGF治疗疗效的假设，并定义调节该过程的信号传导途径。我们的研究将提供第一个全面的检查Slit-Robo 1/2介导的血管生成在眼部新生血管，确定其生物学意义，并确定通过Robo 1/2信号Slit信号的分子和细胞基础。了解这些机制将提供深入了解信号事件所需的极化内皮细胞迁移过程中的新血管形成，这是一个基本的，但在血管生物学知之甚少的事件。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.