Regulation of vascular leakage in age related macular degeneration

年龄相关性黄斑变性中血管渗漏的调节

基本信息

批准号：
8534134
负责人：
MEREDITH GREGORY-KSANDER
金额：
$ 21.67万
依托单位：
SCHEPENS EYE RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-01 至 2014-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8534134
关键词：
Address Age related macular degeneration Age-Years Agonist American Angiogenic Factor Animal Model Apoptosis Apoptotic Atrophic Binding Binding Proteins Blindness Blood Blood Vessels Cell surface Cells Choroidal Neovascularization Cleaved cell Data Development Doxycycline Endothelial Cells Extravasation Eye Failure Fluorescein Angiography Gene Targeting Goals Growth Immune Induction of Apoptosis Inflammatory Inflammatory Infiltrate Integral Membrane Protein Interleukin-1 Isolectin Knock-in Mouse Laboratories Lasers Lead Lesion Liquid substance Maintenance Mediating Membrane Metalloproteases Modeling Mouse Strains Mus Mutate Optical Coherence Tomography Pathogenesis Pathway interactions Patients Phenotype Play Population Protein Isoforms Proteins Recombinants Regulation Reporting Retina Retinal Role Site Staining method Stains Structure of retinal pigment epithelium System TNF gene Therapeutic Time Tissues Transgenic Mice Tumor Necrosis Factor Ligand Superfamily Member 6 Vascular Endothelial Cell Vascular Endothelial Growth Factors Vision Wild Type Mouse Work bevacizumab cell type cytokine cytotoxic extracellular in vivo intravitreal injection macrophage mouse model neovascular new growth new therapeutic target novel overexpression photoreceptor degeneration prevent protein function success

项目摘要

DESCRIPTION (provided by applicant): Age-related macular degeneration (AMD) is a leading cause of blindness in Americans 60 years of age and older. There are two forms of AMD: Dry or atrophic and Wet or exudative. However, the Wet form of AMD, which is characterized by choroidal neovascularization (CNV), is associated with more severe vision loss caused primarily by the leakage of fluid and blood from the abnormal vessels. Anti-VEGF therapy has emerged as the treatment of choice for patients with wet AMD. However, some patients never respond to anti-VEGF therapy, while still others stop responding after initial success, highlighting the fact that the pathobiology of wet AMD development and progression is still unknown. FasL is an important protein in maintaining immune privilege in the eye, where it is thought to induce apoptosis of infiltrating inflammatory cells. In fact, several reports indicate that FasL expressed on retinal pigment epithelial cells inhibits choroidal neovascularization by triggering apoptosis o vascular endothelial cells. However, FasL exists as both a membrane bound and soluble protein with potentially opposing functions and it is unclear how the different forms of FasL contribute to the development of CNV. We recently developed a unique knock-in mouse strain in which the FasL metalloproteinase cleavage sites were mutated to prevent cleavage of the membrane-bound protein. In these ¿CS mice, FasL is expressed by the physiologically relevant cell types, but these cells are unable to cleave FasL and therefore, can only express mFasL (termed ¿CS mice). For the first time, these mice have allowed us to study the in vivo function of membrane FasL in the absence of soluble FasL. To better understand the function of the different FasL isoforms in the development of choroidal neovascularization, we used a laser-induced murine model of CNV. Our preliminary data indicate that, in ¿CS mice, either the increased expression of mFasL (or the loss of sFasL) prevents vascular leakage following laser induced-CNV. Spectral domain optical coherence tomography (SD-OCT) and Isolectin-B staining demonstrated no difference in the size of the neovascular lesion between ¿CS mice and wild-type mice. However, fluorescein angiography revealed a significant decrease in vascular leakage in ¿CS mice as compared to wild-type mice. These results indicate that membrane FasL does not prevent the ingrowth of choroidal vessels, as previously documented, but rather plays a critical function in preventing vascular leakage, the primary cause of vision loss in patients with wet AMD. We hypothesize that membrane FasL inhibits vascular leakage in laser-induced CNV through Fas mediated pathways triggered in infiltrating macrophages and/or RPE cells. The goals of this proposal are as follows: (Aim 1) Determine whether the decreased vascular leakage in ¿CS mice is due to increased mFasL and/or a lack of sFasL and whether the decreased leakage coincides with a shift in the M1/M2 phenotype of infiltrating macrophages (Aim 2) Establish whether infiltrating macrophages and/or RPE are the critical Fas+ targets through which mFasL mediates inhibition of vascular leakage.

描述（由申请人提供）：年龄相关性黄斑变性 (AMD) 是 60 岁及以上美国人失明的主要原因。AMD 有两种形式：干性或萎缩性和湿性或渗出性。 AMD 的特征是脉络膜新生血管 (CNV)，与更严重的视力丧失有关，主要是由于抗 VEGF 治疗导致液体和血液渗漏。然而，一些患者对抗 VEGF 治疗始终没有反应，而还有一些患者在初步成功后停止反应，这凸显了湿性 AMD 发生和进展的病理学仍然未知的事实。 FasL 是维持眼睛免疫特权的重要蛋白质，被认为可诱导浸润性炎症细胞凋亡。事实上，一些报告表明 FasL 表达。视网膜色素上皮细胞上的 FasL 通过触发血管内皮细胞凋亡来抑制脉络膜新生血管形成。然而，FasL 以膜结合蛋白和可溶性蛋白的形式存在，具有潜在的相反功能，目前尚不清楚不同形式的 FasL 如何促进血管内皮细胞的形成。我们最近开发了一种独特的敲入小鼠品系，其中 FasL 金属蛋白酶切割位点发生突变，以防止膜结合蛋白的切割。 CS小鼠中，FasL由生理相关细胞类型表达，但这些细胞无法裂解FasL，因此只能表达mFasL（称为¿CS小鼠），这些小鼠首次使我们能够在体内研究FasL。缺乏可溶性 FasL 时膜 FasL 的功能为了更好地了解不同 FasL 亚型在脉络膜新生血管形成中的功能，我们使用了激光诱导的小鼠模型。我们的初步数据表明，在 ¿ CS 小鼠中，mFasL 表达增加（或 sFasL 缺失）可防止激光诱导 CNV 后的血管渗漏。谱域光学相干断层扫描 (SD-OCT) 和异凝集素-B 染色显示新生血管病变的大小没有差异。之间 CS 小鼠和野生型小鼠然而，荧光素血管造影显示 ¿与野生型小鼠相比，CS 小鼠的结果表明，如先前所述，膜 FasL 并不阻止脉络膜血管的向内生长，而是在防止血管渗漏方面发挥着关键作用，而血管渗漏是湿性患者视力丧失的主要原因。 AMD。我们研究膜 FasL 通过在浸润巨噬细胞和/或 RPE 细胞中触发的 Fas 介导途径抑制激光诱导的 CNV 中的血管渗漏。该提案的目标如下：（目标 1）确定血管渗漏是否减少 ¿ CS 小鼠的原因是 mFasL 增加和/或 sFasL 缺乏，以及渗漏减少是否与浸润巨噬细胞 M1/M2 表型的转变一致（目标 2）通过以下方式确定浸润巨噬细胞和/或 RPE 是否是关键的 Fas+ 靶标mFasL 介导血管渗漏的抑制。