HIF dysregulation as a novel genetic model to study retinal neovascular disease.

描述（由申请人提供）：本提案的总体目标是为首席研究员（PI）提供必要的经验和技能，使其成为研究视网膜新生血管疾病基本机制的独立研究人员。这项建议的科学重点是更好地了解眼睛中的病理性血管生成，这是全世界不可逆转失明的主要原因。新出现的证据表明，眼部新生血管的共同病因是局部缺氧导致缺氧诱导因子（hif）的上调。hif是一个转录因子家族，它刺激几种“缺氧诱导”基因的产生，包括血管生成生长因子（如血管内皮生长因子或VEGF），而血管生成生长因子反过来又促进（渗漏）血管的生长。有趣的是，我们对hif在病理性血管生成中的调节的理解取得了重大进展，这是由于最近研究了von Hippel-Lindau （VHL）病患者中hif的失调。视网膜血管母细胞瘤是新生血管肿瘤，是VHL患者最常见的临床表现，通常表现为大量水肿，并导致严重的视力丧失。VHL蛋白（pVHL）针对hif进行降解。因此，VHL患者pVHL的缺失导致hif的失调和缺氧诱导基因的过度表达，模拟病理性血管生成。该提议的基本假设是，VHL视网膜血管母细胞瘤是病理性血管生成的模型，并提供了一个理想的遗传模型来研究hif及其靶点在血液-视网膜屏障（iBRB）破坏中的作用，iBRB是视网膜新生血管疾病的一个鲜为人知但关键的早期事件。为了解决这一假设，提出了三个具体目标：目标1：检查hif在iBRB分解中的必要性。目的2：确定HIF失调是否足以促进iBRB的分解。目的3：确定hif依赖性生长因子在iBRB分解中的相对贡献。在拟议的研究和选定的教学活动中，PI将在研究视网膜新生血管疾病的分子发病机制方面获得宝贵的培训经验和指导。这种专业知识被认为是必要的PI谁渴望开发一个独立的研究计划，研究视网膜病理性血管生成的基本机制。

DESCRIPTION (provided by applicant): The overall goal of this proposal is to provide the principal investigator (PI) with the experience and skills necessary to become an independent researcher studying basic mechanisms of retinal neovascular disease. The scientific focus of this proposal is to gain a better understanding of pathological angiogenesis in the eye, a principal cause of irreversible blindness worldwide. Emerging evidence suggests a shared etiology for neovascularization in the eye in which local hypoxia leads to upregulation of the hypoxia inducible factor (HIFs). HIFs are a family of transcription factors which stimulate production of several "hypoxia inducible" genes, including angiogenic growth factors (e.g. vascular endothelial growth factor or VEGF), which, in turn, promote the growth of (leaky) blood vessels. Of interest, significant progress in our understanding of the regulation of HIFs in pathological angiogenesis has come from recent work examining the dysregulation of HIFs in patients with von Hippel-Lindau (VHL) disease. Retinal hemangioblastomas are neovascular tumors that remain the most common clinical manifestation in patients with VHL disease, often manifesting with profuse edema and resulting in profound loss of vision. The VHL protein (pVHL) targets HIFs for degradation. Therefore, loss of pVHL in patients with VHL disease results in dysregulation of HIFs and over expression of hypoxia-inducible genes, mimicking pathological angiogenesis. The underlying hypothesis of this proposal is that VHL retinal hemangioblastomas are a model for pathological angiogenesis and provide an ideal genetic model to examine the role(s) of HIFs and their targets in the breakdown of the inner blood- retinal barrier (iBRB), a poorly understood, but critical early event in retinal neovascular disease. To address this hypothesis, three specific aims are proposed: Aim 1: To examine the necessity for HIFs in the breakdown of the iBRB. Aim 2: To determine if HIF dysregulation is sufficient to promote breakdown of the iBRB. Aim 3: To determine the relative contribution of HIF-dependent growth factors in breakdown of the iBRB. In the course of the proposed research and selected didactic activities, the PI will gain invaluable training experience and mentoring in studying the molecular pathogenesis of retinal neovascular disease. This expertise is deemed essential for the PI who aspires to develop an independent research program studying basic mechanisms of retinal pathological angiogenesis.