Molecular insights into the pathogenesis of Sorsby Fundus Dystrophy

索斯比眼底营养不良发病机制的分子见解

• 批准号: 8359405
• 负责人: Jian Hua Qi
• 金额: $ 23.55万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8359405
• 关键词: Accounting; Address; Age related macular degeneration; Angiogenesis Inhibitors; Biochemical; Blindness; Blood Vessels; Bruch' s basal membrane structure; Characteristics; Choroid; Choroidal Neovascularization; Coupled; Degenerative Disorder; Deposition; Development; Diabetic Retinopathy; Disease; Employee Strikes; Endothelial Cells; Epithelial; Event; Extracellular Matrix; Eye; Functional disorder; Genes; In Vitro; Induced Mutation; Inherited; Knock-in Mouse; Macular degeneration; Matrix Metalloproteinases; Mediating; Modeling; Molecular; Mutagenesis; Mutation; N-Glycosylation Site; Pathogenesis; Pathway interactions; Patients; Phenotype; Play; Process; Property; Protein Glycosylation; Proteins; Rare Diseases; Research; Resistance; Retinal Degeneration; Retinal Pigments; Role; Sorsby' s fundus dystrophy; Structure; Structure of retinal pigment epithelium; Testing; Therapeutic; Tissue Inhibitor of Metalloproteinase-3; Tissues; Vascular Endothelial Growth Factor Receptor-2; Work; angiogenesis; base; design; dimer; disease phenotype; early onset; glycosylation; in vivo; innovation; insight; mouse model; mutant; neovascularization; novel; novel therapeutic intervention; prevent; therapeutic target

DESCRIPTION (provided by applicant): Tissue Inhibitors of Metalloproteinase-3 (TIMP3) is a regulator of matrix metalloproteinase (MMPs) and a potent angiogenesis inhibitor. Sorsby fundus dystrophy (SFD), a rare, dominantly inherited, early onset macular degenerative disease that is caused by mutations in the TIMP3 gene has marked similarities to age- related macular degeneration (ARMD) disease phenotype including an increased accumulation of TIMP3 in Bruch's membrane (BM) and the development of choroidal neovasculaization (CNV), a major cause of severe vision loss in patients. Our studies using in vitro and in vivo SFD models indicate that SFD-related S156C- TIMP3 promotes CNV via vascular endothelial growth factor receptor-2 (VEGFR-2)- and retinal pigment epithelial (RPE) cell-dependent angiogenic pathways. We also found that increased mutant protein glycosylation is a characteristic of vascular endothelial and RPE cells. Furthermore, we have evidence of increased mutant TIMP3 protein glycosylation with a concomitant increase in mutant TIMP3 levels in RPE- choroid tissue of S156C-TIMP3 knock-in mice. We hypothesize that that S156C-TIMP3 mutation induces N- glycosylation at position184, the only potential N-glycosylation site of TIMP3, resulting in increased accumulation in BM and/or CNV development via VEGFR-2-and/or RPE cell-dependent angiogenic pathways. Using in vitro and in vivo SFD models coupled with pharmacological, mutagenesis, protein over-expression and biochemical characterization approaches our hypothesis will be tested with the following Specific Aims: 1. To determine if inhibition of TIMP-3 glycosylation prevents the increased accumulation of mutant protein in BM and CNV development in S156C-Timp3 knock-in mice. 2. To determine if mutation of Asn184 in S156C-TIMP3 inhibits VEGFR-2- and RPE cell-mediated angiogenesis. The long-term objectives of the proposed research is to identify and dissect the consequences of SFD mutations on TIMP3 structure and functions with particular emphasis on TIMP3 glycosylation as a potential molecular event mediating its accumulation in BM and the subsequent angiogenic or CNV phenotype. Undoubtedly, this would provide novel insights into the pathogenesis of SFD and ARMD that share similar disease phenotype, and thereby establish a potential therapeutic target for these ocular diseases. PUBLIC HEALTH RELEVANCE: Sorsby fundus dystrophy is a rare disease with striking similarities to age-related macular degeneration. Choroidal neovascularization (CNV) occurs in almost all patients with SFD and in about 20% of patients with AMD but accounts for the majority of vision loss in the disease. Thus analyzing CNV in SFD is a useful model to examine the pathophysiology of this phenotype. The molecular and pathological mechanism(s) contributing to CNV are unknown. It is likely that these studies will contribute to our understanding of fundamental principles of neovascularization, as well as provijde insight into the development of new therapeutic approaches for SFD as well as AMD , diabetic retinopathy and other diseases in which angiogenesis play a critical role.

描述（由申请人提供）：金属蛋白酶3（TIMP3）的组织抑制剂是基质金属蛋白酶（MMP）和有效的血管生成抑制剂的调节剂。 Sorsby fundus dystrophy (SFD), a rare, dominantly inherited, early onset macular degenerative disease that is caused by mutations in the TIMP3 gene has marked similarities to age- related macular degeneration (ARMD) disease phenotype including an increased accumulation of TIMP3 in Bruch's membrane (BM) and the development of choroidal neovasculaization (CNV), a major cause of severe vision loss in patients.我们使用体外和体内SFD模型的研究表明，与SFD相关的S156C-TIMP3通过血管内皮生长因子受体-2（VEGFR-2）和视网膜色素上皮（RPE）细胞依赖性血管疾病途径促进CNV。我们还发现，增加的突变蛋白糖基化是血管内皮和RPE细胞的特征。此外，我们有证据表明突变体Timp3蛋白糖基化增加，而S156C-TIMP3敲入小鼠的RPE-horoid组织中突变体Timp3水平的增加。我们假设S156C-TIMP3突变在位置诱导N-糖基化184，这是TIMP3的唯一潜在的N-糖基化位点，从而导致通过VEGFR-2和/或RPE细胞依赖性血管生成途径在BM和/或CNV开发中的积累增加。使用体外和体内SFD模型，再加上药理，诱变，蛋白质过表达和生化特征方法的方法，我们的假设将通过以下具体目的进行检验：1。确定TIMP-3糖基化的抑制是否会阻止BM和CNV中的突变蛋白在BM和CNV中的突变蛋白在S156C的开发中的增加。 2。确定S156C-TIMP3中ASN184的突变是否抑制VEGFR-2-和RPE细胞介导的血管生成。拟议的研究的长期目标是识别和剖析SFD突变对TIMP3结构的后果，并特别强调Timp3糖基化，这是介导其在BM中的积累和随后的血管生成或CNV表型的潜在分子事件。毫无疑问，这将提供有关具有相似疾病表型的SFD和ARMD发病机理的新颖见解，从而为这些眼部疾病建立了潜在的治疗靶标。 公共卫生相关性：Sorsby眼底营养不良是一种罕见的疾病，与与年龄相关的黄斑变性相似。脉络膜新生血管形成（CNV）几乎所有SFD患者以及约20％的AMD患者发生，但占该疾病的大部分视力丧失。因此，分析SFD中的CNV是检查该表型的病理生理学的有用模型。导致CNV的分子和病​​理机制是未知的。这些研究很可能有助于我们对新血管化基本原理的理解，以及对SFD以及AMD，糖尿病性视网膜病和其他血管生成起作用的新型治疗方法发展的开发的洞察力。