Role of ER Stress in the Pathogenesis of Primary Open Angle Glaucoma

内质网应激在原发性开角型青光眼发病机制中的作用

基本信息

批准号：
8534133
负责人：
Gulab Zode
金额：
$ 8.77万
依托单位：
UNIVERSITY OF IOWA
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/8534133
关键词：
Advisory Committees Apoptosis Apoptotic Aqueous Humor Autophagocytosis Autopsy Cell Death Cells Chronic Clinical Data Degradation Pathway Development Dexamethasone Diagnosis Disease Educational process of instructing Endoplasmic Reticulum Eye Failure Functional disorder GRP78 gene GRP94 Genetic Glaucoma Homeostasis Human Individual Knockout Mice Laboratories Laboratory Research Lead Learning Lysosomes Mentors Modeling Molecular Chaperones Mus Mutation Nerve Degeneration Ocular Hypertension Optic Nerve Pathogenesis Pathway interactions Patients Phase Phenotype Phenylbutyrates Phosphorylation Physiologic Intraocular Pressure Play Primary Open Angle Glaucoma Process Proteins Research Institute Resistance Retinal Ganglion Cells Risk Factors Role Sirolimus Sodium phenylbutyrate Steroids Testing Tissues Topical application Trabecular meshwork structure Training Transgenic Mice Transgenic Organisms Western Blotting career development common treatment endoplasmic reticulum stress experience genetic risk assessment improved induced pluripotent stem cell inhibitor/antagonist insight mouse model mutant myocilin novel prevent protein aggregate protein degradation protein misfolding response sensor symposium

项目摘要

DESCRIPTION (provided by applicant): Primary open angle glaucoma (POAG), the most common form of glaucoma, is usually accompanied by elevated intraocular pressure (IOP) due to failure of the trabecular meshwork (TM) to maintain normal levels of aqueous humor outflow. We recently generated a novel transgenic murine model (Tg-MYOCY437H) that expresses mutant myocilin, a known leading genetic cause of POAG in humans and replicates human glaucoma phenotypes. Importantly, we have associated endoplasmic reticulum (ER) stress to the pathogenesis of glaucoma in Tg-MYOCY437H mice. Misfolded myocilin accumulates in the ER, induces ER stress and activates a protective unfolded protein response (UPR). Along with UPR activation, mutant myocilin also induces autophagy, a process of lysosomal degradation known to degrade protein aggregates. However, failure to eliminate myocilin aggregates possibly due to insufficient UPR and impaired autophagy, TM cells induce the ER stress-initiated apoptotic transcriptional factor, Chop, which may further worsen ER homeostasis and cause TM dysfunction/loss, elevating IOP and resulting in POAG. The current proposal will further investigate the role of chronic ER stress in the pathogenesis of myocilin as well as non-myocilin associated POAG. During the mentored phase, the proposed studies will determine whether failure to activate the protective UPR (Atf-6¿-/-) exacerbates glaucoma phenotypes, whereas interference with ER stress-induced apoptosis (Chop-/-) prevents glaucoma in Tg-MYOCY437H mice. In addition, we will investigate whether ER stress is activated in port-mortem TM tissues from POAG donors. During the independent phase, we will examine whether induction of ER stress in the TM is associated with elevation of IOP in a mouse model of dexamethasone-induced ocular hypertension. In addition, we will examine the role of autophagy in degradation of myocilin aggregates and will determine whether inducing autophagy by rapamycin will rescue the glaucoma of Tg-MYOCY437H mice. Specifically, the candidate will learn and generate new models of ER stress using Atf6¿ and Chop knockout mice, generate induced pluripotent stem cells (iPSCs)-derived trabecular meshwork- like cells from POAG patients, and characterize a dexamethasone-induced ocular hypertension mouse model in the laboratory of Dr. Val Sheffield. Additionally, during the mentored phase, the candidate will continue his professional and scientific career development through continual guidance from the advisory committee. He will attend scientific conferences, and collaborate with ER stress expert, Dr. Thomas Rutkowski and glaucoma clinical expert, Dr. Lee Alward. He will also acquire teaching experience. This project will facilitate continued technical, intellectul, and professional training of the candidate, and assist the candidate in the establishment of an independent research laboratory at an academic research institute.

描述（由适用提供）：由于小梁网状（TM）未能维持正常水平的水性幽默出口水平，因此最常见的青光眼形式的初级敞开角度青光眼（POAG）通常伴随着眼内压（IOP）升高。我们最近产生了一种新型的转基因鼠模型（TG-Myocy437h），该模型表达突变体肌动蛋白，这是人类POAG的已知主要遗传原因，并复制了人类青光眼表型。重要的是，我们具有内质网（ER）应激与TG-肌细胞437H小鼠青光眼的发病机理相关联。错误折叠的肌动蛋白积聚在ER中，会影响ER应力并激活保护性展开的蛋白质反应（UPR）。随着UPR激活，突变肌动蛋白还诱导自噬，这是一种已知可降解蛋白质聚集体的溶酶体降解过程。然而，未能消除肌动蛋白聚集的TM细胞会诱导ER应力引起的凋亡转录因子CHOP，这可能会进一步降低ER稳态，并导致TM功能障碍/丢失，升高IOP并导致POAG。当前的提案将进一步研究慢性ER应激在肌动蛋白以及非肌动蛋白相关的POAG中的作用。在修补阶段，提出的研究将确定未能激活受保护的UPR（ATF-6¿-/ - ）加剧青光眼表型，而干扰ER应激诱导的凋亡（CHOP - / - ）会阻止TG-Myocyocy437h小鼠中的青光眼。此外，我们将研究POAG供体的端口验尸TM组织中是否激活ER应力。在独立阶段，我们将检查TM中的ER应力是否与地塞米松诱导的眼部高血压的小鼠模型中的IOP升高有关。此外，我们将研究自噬在肌动蛋白聚集体降解中的作用，并将确定雷帕霉素诱导的自噬是否会挽救TG-Myocy437h小鼠的青光眼。具体而言，候选人将使用ATF6和Chop基因敲除小鼠学习并生成新的ER应力模型，这些小鼠产生了诱导的多能干细胞（IPSC）衍生的小梁网状网络工作，例如POAG患者的细胞，并表征了右甲米松诱导的Ocular Hypertension Hyperensial Model in Val Sheffield博士的实验室。此外，在修补阶段，候选人将通过咨询委员会的持续指导继续其专业和科学的职业发展。他将参加科学会议，并与ER压力专家Thomas Rutkowski博士和青光眼临床专家Lee Alward博士合作。他还将获得教学经验。该项目将促进对候选人的持续技术，intectul和专业培训，并协助候选人在学术研究所建立独立的研究实验室。