Mechanism of Neuropilin and TM inhibitor peptides in AD/angiogenesis

描述（由申请人提供）：视网膜相关性黄斑变性（AMD）是负责约。世界上9%的失明，影响了美国的200万人。病理性新生血管是视网膜中央视区变性的主要原因之一。血管内皮生长因子及其受体，血管内皮生长因子受体和共同受体神经纤毛蛋白（Nrp）与丛蛋白一起，指导这种血管的形成，但受体也调节细胞的生长。 生存和增殖。在过去的十年中，抗VEGF疗法已成为AMD的主要治疗模式。抗VEGF-A的几种抗体，兰尼单抗和贝伐单抗的标签外使用，在90%的患者中有效减缓视力丧失。然而，它们对血管生成的长期影响尚不清楚，并且对VEGFR阻断样治疗的抗性已经成为一个问题。因此，需要在分子水平上更深入地了解Neuropilin/VEGFR/丛蛋白信号传导，以设计更特异的药物。此外，这两种药物都需要每月直接注射到眼睛中，使得开发可以至少静脉内（如果不是口服的话）施用的治疗剂是非常可取的。该项目的重点是神经纤毛蛋白信号在分子和机制水平。到目前为止，还没有详细的跨膜（TM）段的结构信息，为保守的46个残基的细胞外，或为44个残基的胞内区域的Nrp 1。我们假设TM和膜近端区域之间的关系构成了跨膜信号传导机制的关键部分;特别是这些区域可能以分层的方式参与调控事件。对应于Nrp 1 TM区域的肽可以抑制受体功能和血管生成。然而，需要在分子水平上的见解，以便理解这种机制，并优化肽抑制剂，利用膜周围区域的背景，用于抗血管生成治疗。我们的结构研究将与几个实验室正在进行的Nrp 1功能研究协同作用。R21项目有两个探索性目标：目标1将采取步骤，通过溶液NMR光谱法确定神经纤毛蛋白-1（Nrp 1）跨膜（TM）二聚体结构，并表征TM抑制肽相互作用，以及细胞内和部分细胞外区域的背景。目的2检测细胞内44个残基区域及其与Nrp 1共受体丛蛋白-D1的新发现的相互作用。

DESCRIPTION (provided by applicant): Age-related macular degeneration (AMD) is responsible for approx. 9% of the world's blindness, affecting 2 million people in the United States. Pathological neovasculation is one of the main causes of degeneration of the central vision region of the retina. VEGF and its receptors, VEGFR and co-receptor Neuropilin (Nrp) together with plexins, direct this formation of blood vessels, but the receptors also regulate cell survival and proliferation. Over the last decade, anti-VEGF therapy has become a principal mode of treatment for AMD. Several antibodies against VEGF-A, Ranibizumab and off-label use of Bevacizumab, are effective in slowing visual loss in 90% of patients. However, their long term effects on angiogenesis are not yet known and resistance against VEGFR blockade-like treatments has already become a problem. Thus a deeper understanding of Neuropilin/VEGFR/Plexin signaling is needed at the molecular level for the design of more specific agents. Furthermore, both drugs need to be injected directly into the eye every month, making the development of therapeutics that can be administered at least intravenously, if not orally, highly desirable. The proposed project focuses on Neuropilin signaling at the molecular and mechanistic level. As yet there is no detailed structural information for the transmembrane (TM) segment, for the well conserved 46 residues just outside the cell, or for the 44 residue intracellular region of Nrp1. We hypothesize that the relationship between the TM and membrane proximal regions constitutes key parts of the mechanism for transmembrane signaling; specifically the regions are likely to participate in regulatory events in a hierarchica manner. Peptides corresponding to the Nrp1 TM region can inhibit receptor function and angiogenesis. However, insights are needed at the molecular level in order to understand this mechanism and to optimize the peptide inhibitors, utilizing the context of the membrane surrounding regions, for anti- angiogenesis therapy. Our structural studies will synergize with functional studies of Nrp1 that are ongoing in several laboratories. The R21 project has two exploratory aims: Aim 1 will take steps towards the determination of the neuropilin- 1 (Nrp1) transmembrane (TM) dimer structure by solution NMR spectroscopy and characterization of TM inhibitory peptide interactions, also the context of the intracellular and a portion of the extracellular region. Aim 2 examines the intracellular 44 residue region and its newly discovered interaction with the Nrp1 co- receptor plexin-D1.