Cellular Dysfunction in Exfoliation Glaucoma

项目概要/摘要：剥脱性青光眼的细胞功能障碍剥脱综合征 (XFS)是一种与年龄有关的疾病，涉及聚集的纤维状物质（XFM）沉积在 细胞外基质它的主要发病率是在眼睛，其中XFM形成在表面上， 眼前节组织XFM导致剥脱性青光眼（XFG），一种快速进展的疾病 与全球约1/3的开角型青光眼（POAG）病例相关。XFG 与许多与年龄有关的疾病相似， 聚集性疾病L0 XL 1，一种基质交联酶，其催化 弹性蛋白原是合成弹性纤维的主要成分，也是XFM的主要成分，已与XFG联系在一起 然而，目前还不清楚LOXL 1蛋白如何与其他蛋白结合。 有助于疾病病理学。在理解XFS/G的细胞基础方面的进展已经 由于缺乏实验模型而变得缓慢。使用原代人Tenon成纤维细胞（TF） 来源于XFG患者和对照组（年龄匹配的POAG患者和No. 我们最近发现，XFG-TF显示出许多功能特征 在其他与年龄相关的聚集性疾病如帕金森氏症、阿尔茨海默氏症和 AMD包括溶酶体定位、自噬、微管组织和功能的缺陷， 和线粒体健康状况。将LOXL 1与XFG的开发联系起来，我们发现， XFG-TF a）通过旨在中和错误折叠的机制显示增加的LOXL 1输出 新生多肽; B）通过自噬处理LOXL 1，表明存在 该蛋白质的错误折叠或变性单位; c）积累细胞内蛋白质聚集体， 更高的内源性表达;和d）过表达聚集体响应性伴侣蛋白中的簇- 比如蛋白质。最后，对LOXL 1二级结构的计算机检测表明，LOXL 1 蛋白质在N-末端内具有元素结构，预测其赋予增加的 聚集倾向此外，LOXL 1全蛋白或缺失的实验显示， LOXL 1确实具有高聚集倾向，并且这种倾向的位点位于 在N端的特定区域因此，我们试图回答基本的问题。 关于XFG病理基础因素的问题。我们建议，SpA 1）研究分子 导致微管功能缺陷的机制; SpA 2）以研究细胞应激 反应，以及LOXL 1输出和错误折叠蛋白质机器之间的联系，以及SpA 3） 为了鉴定LOXL 1序列的最小氨基酸序列和结构特征， 介导其聚集倾向。

Project Summary/Abstract: Cellular Dysfunction in Exfoliation Glaucoma Exfoliation syndrome (XFS) is an age-related disease involving the deposition of aggregated fibrillar material (XFM) in extracellular matrices. Its main morbidity is in the eye, where XFM forms on the surface of anterior segment tissues. XFM causes exfoliation glaucoma (XFG), a rapidly progressing disease associated with approximately 1/3 of open-angle glaucoma (POAG) cases worldwide. XFG demonstrates a sharp age-dependence in similarity to the many age-related diseases qualified as aggregopathies. LOXL1, a matrix cross-linking enzyme that catalyzes the crosslinking of tropoelastin for the synthesis of elastic fibers and a major component of XFM, has been linked to XFG by Genomics Wide Association Studies, however, it is still unclear how LOXL1 protein contributes to disease pathology.Progress in understanding the cellular basis for XFS/G has been slowed by a lack of experimental models. Working with primary human tenon fibroblasts (TF) derived from trabeculectomies of XFG patients and controls (age-matched POAG patients and No- Glaucoma patients), we recently found that, XFG-TFs display many of the functional features observed in cells from other age-related aggregopathies such as Parkinson's, Alzheimer's, and AMD including defects in lysosomal positioning, autophagy, microtubule organization and function, and mitochondrial health status. Linking LOXL1 to the development of XFG, we have found that XFG-TF a) display increased LOXL1 export by a mechanism aimed at neutralizing misfolded nascent polypeptides; b) process LOXL1 through autophagy indicating the presence of misfolded or denatured units of this protein; c) accumulate intracellular protein aggregates with higher endogenous expression; and d) overexpress clusterin an aggregate-responsive chaperone- like protein. Finally, an in silico examination of LOXL1 secondary structure indicated that LOXL1 protein has elemental structures within the N-terminus that are predicted to confer an increased aggregation propensity. Furthermore, experiments of LOXL1 whole protein or with deletions shows that indeed LOXL1 has high aggregation propensity and that the loci of this propensity reside within specific stretches of the N-terminus. Accordingly, we seek to answer fundamental questions on the factors that underpin XFG pathology. We propose, SpA1) to study the molecular machinery leading to the defects in microtubule function; SpA2) to investigate cellular stress responses, and the connection between LOXL1 export and misfolded protein machinery, and SpA3) to identify the minimal amino acid sequences and structural features of the LOXL1 sequence that mediate its aggregation propensity.