Regulation of Choroidal Neovascularization in Sorsby's Fundus Dystrophy

项目摘要 Sorsby眼底营养不良（SFD）是一种显性遗传性黄斑变性疾病， 其特征在于作为脉络膜新生血管形成（CNV）的结果的双侧中心视力丧失。 TIMP-3基因中涉及外显子5或内含子4-外显子5边界的特异性突变已被证明， 是causative。今年早些时候，AMD联盟在TIMP 3基因中发现了罕见的编码变体， 分析了16,144名患者和17,832名对照。此外，他们还发现了第一个遗传关联信号， 特异于MMP 9附近的湿性AMD。AMD和SFD之间的临床和组织病理学相似性 并且在AMD中基质金属蛋白酶途径中的变体的鉴定表明，类似的 下游效应物可能在这两种情况下起作用。更好地理解病理生理学 在SFD中促进CNV的机制将提供可能在以下方面有用的信息： AMD.在使用TIMP-3缺陷小鼠、S156 CTIMP-3转基因小鼠和体外培养的比较研究中， 培养实验中，我们已经确定TIMP-3通过阻断TIMP-3与血管内皮细胞的结合而部分抑制血管生成。 VEGR-2的表达。S156 C TIMP-3突变蛋白通过VEGF和bFGF诱导血管生成。我们有 还表明，功能性TIMP-3的缺乏导致透明质酸的积累， 脉络膜脉管系统基于这些结果，我们假设TIMP 3是控制和定位 RPE/脉络膜中的基质降解，以及TIMP 3功能的丧失导致RPE/脉络膜中的异常。 生长因子/血管生成因子，增加HA信号传导和新血管形成。

PROJECT SUMMARY Sorsby fundus dystrophy (SFD) is a dominantly inherited, degenerative disease of the macula that is characterized by bilateral loss of central vision as a consequence of choroidal neovascularization (CNV). Specific mutations in the TIMP-3 gene involving exon 5 or the intron4-exon5 boundary have been shown to be causative. Early this year, the AMD consortium identified rare coding variants in the TIMP3 gene when analyzing 16,144 patients and 17,832 controls. In addition, they identified the first genetic association signal specific to wet AMD near MMP9. The clinical and histopathological similarities between AMD and SFD and the identification of variants in the matrix metalloproteinase pathway in AMD suggest that similar downstream effectors might be in play in both conditions. A better understanding of the pathophysiological mechanisms contributing to the CNV in SFD will provide information that could be potentially useful in AMD. In comparative studies using TIMP-3 deficient mice, S156CTIMP-3 transgenic mice and in vitro culture experiments we have determined that TIMP-3 partially inhibits angiogenesis by blocking the binding of VEGF to VEGR-2. S156C TIMP-3 mutant protein induces angiogenesis via VEGF and bFGF. We have also shown that the absence of functional TIMP-3 results in an accumulation of hyaluronan that regulates choroidal vasculature. Based on these results, we hypothesize that TIMP3 is required to control and localize matrix degradation in the RPE/choroid, and loss of TIMP3 function in this regards leads to an abnormality in growth factor/angiogenesis factor, increased HA signaling and neovascularization.