Regulation of vascular remodeling & angiogenesis by Nogo

描述（由申请人提供）：我们的实验室发现RTN-4 B（称为Nogo-B）是一种在内皮细胞（EC）和血管平滑肌（VSM）细胞中高度丰富的蛋白质，缺乏Nogo-B的小鼠在血管损伤后具有加速的新生内膜，伤口愈合不良和缺血后血流恢复受损。在令人兴奋的初步数据中，我们表明内皮中的Nogo-B在体外和体内调节急性炎症反应和中性粒细胞迁移。从机制上讲，Nogo的缺失抑制了ICAM-1介导的信号传导和EC中VE钙粘蛋白的磷酸化，这有助于减少缺乏Nogo-B的小鼠的炎症。在检查NgBR的细胞内功能的一系列单独的实验中，我们发现除了结合Nogo-B之外，NgBR通过稳定尼曼匹克C2蛋白（NPC 2）来调节细胞内胆固醇代谢是至关重要的，这提高了Nogo-B/NgBR信号传导在胆固醇稳态的基本方面发挥基本作用的可能性。为了了解NgBR的综合作用，我们已经产生了条件性敲除小鼠，并将检查其在Nogo-A/B KO小鼠中受损的几种实验血管范例中的作用。因此，我们假设Nogo-B和NgBR作为一种新的内源性调节系统发挥作用，该系统协调对血管损伤或组织缺血的反应，并通过稳定NPC 2调节内质网（ER）功能，如胆固醇代谢。在本提案中，我们将：1。定义Nogo-B如何调节白细胞跨内皮迁移和血管炎症; 2.检查Nogo-B对NgBR介导的NPC 2稳定和细胞胆固醇代谢的调节;以及3.表征条件性NgBR敲除小鼠。总的来说，这项提案的中心目标是广泛了解Nogo-B作为原型reticulon家族成员的功能，并检查其作为血管稳态调节剂的功能。 公共卫生相关性：这项研究与公共卫生相关，因为炎症是大多数心血管疾病的常见表现。我们的研究发现了一种新的动脉粥样硬化或高血压期间血管功能和重塑的调节剂。这项资助支持的研究可能有助于确定减少心脏病和改善心血管疾病患者生活质量的新药。

DESCRIPTION (provided by applicant): Our lab discovered RTN-4B (called Nogo-B) as a protein highly abundant in endothelial cells (EC) and vascular smooth muscle (VSM) cells and mice deficient in Nogo-B have accelerated neointima after vascular injury, defective wound healing and impaired blood flow recovery post-ischemia. In exciting, preliminary data, we show that Nogo-B in the endothelium regulates the acute inflammatory response and neutrophil transmigration in vitro and in vivo. Mechanistically, the loss of Nogo suppresses ICAM-1 mediated signaling and the phosphorylation of VE cadherin in EC, which contributes to reduced inflammation in mice lacking Nogo-B. In a separate series of experiments examining the intracellular function of NgBR, we have discovered that in addition to binding Nogo-B, NgBR is critical for regulating intracellular cholesterol metabolism by stabilizing the Niemann Pick C2 protein (NPC2), raising the possibility that Nogo-B/NgBR signaling exerts a fundamental role in basic aspects of cholesterol homeostasis. In order to understand the integrated role of NgBR, we have generated conditional knockout mice and will examine its role in several experimental vascular paradigms that are impaired in Nogo-A/B KO mice. Thus, we hypothesize that Nogo-B and NgBR function as a novel endogenous regulatory system that coordinates the response to vascular injury or tissue ischemia and regulates endoplasmic reticulum (ER) functions such as cholesterol metabolism via stabilization of NPC2. In this proposal we will: 1. Define how Nogo-B regulates leukocyte transendothelial migration and vascular inflammation; 2. Examine Nogo-B regulation of NgBR mediated stabilization of NPC2 and cellular cholesterol metabolism; and 3. Characterize conditional NgBR knockout mice. Overall, the central goal of this proposal is to broadly understand the functions of Nogo-B as a prototypical reticulon family member and to examine its functions as a regulator of vascular homeostasis. PUBLIC HEALTH RELEVANCE: This research is relevant to public health since inflammation is a common manifestation of most cardiovascular diseases. Our research has discovered a new modulator of blood vessel function and remodeling during atherosclerosis or hypertension. Research supported by this grant may help identify new drugs that reduce heart disease and improve the quality of life of people suffering with cardiovascular disease.