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

• 批准号: 8385057
• 负责人: MEREDITH GREGORY-KSANDER
• 金额: $ 30.02万
• 依托单位: SCHEPENS EYE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 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/8385057
• 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

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. PUBLIC HEALTH RELEVANCE: Age Related Macular Degeneration (AMD) is the primary cause of blindness in patients 60 years of age and older. The growth of abnormal blood vessels into the retina is the main cause of severe vision loss, in part due to vessel leakage of blood and fluid that causes damage to the surrounding retinal tissue. We have identified a novel protein that prevents vascular leakage and the goal of this study is to (i) determine whether the administration of this protein can be used to prevent vascular leakage in a mouse model, and (ii) elucidate the mechanism by which this protein functions.

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。然而，以脉络膜新生血管（CNV）为特征的湿型AMD与更严重的视力丧失相关，主要是由异常血管的液体和血液泄漏引起的。抗vegf治疗已成为湿性AMD患者的治疗选择。然而，一些患者对抗vegf治疗没有反应，而另一些患者在最初成功后停止反应，这突出了湿性AMD发生和进展的病理生物学仍然未知的事实。FasL是维持眼睛免疫特权的重要蛋白，它被认为可以诱导浸润性炎症细胞的凋亡。事实上，一些报告表明FasL表达