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（由申请人提供）：原发性开角型青光眼（POAG）是最常见的青光眼形式，由于升高的小梁网（TM）无法维持正常水平的房水流出，通常伴有眼内压（IOP）我们最近生成了一种新型转基因小鼠模型 (Tg-MYOCY437H)，该模型表达突变型肌纤蛋白（一种已知的人类 POAG 的主要遗传原因），并复制了人类重要的是，我们发现内质网 (ER) 应激与 Tg-MYOCY437H 小鼠青光眼的发病机制相关。错误折叠的肌纤蛋白在 ER 中积累，诱导 ER 应激并激活保护性未折叠蛋白反应 (UPR)。突变肌纤蛋白还会诱导自噬，这是一种已知可降解蛋白质聚集体的溶酶体降解过程，但未能消除。 myocilin 聚集可能是由于 UPR 不足和自噬受损，TM 细胞诱导 ER 应激引发的凋亡转录因子 Chop，这可能进一步恶化 ER 稳态并导致 TM 功能障碍/损失，升高 IOP 并导致 POAG。研究慢性 ER 应激在肌纤蛋白以及非肌纤蛋白相关 POAG 发病机制中的作用。在指导阶段，拟议的研究将确定是否未能激活肌纤蛋白。保护性UPR（Atf-6¿ -/-) 加剧青光眼表型，而干扰 ER 应激诱导的细胞凋亡 (Chop-/-) 可以预防 Tg-MYOCY437H 小鼠的青光眼。此外，我们将研究 ER 应激是否在来自 POAG 供体的死后 TM 组织中被激活。在独立阶段，我们将在地塞米松诱导的高眼压小鼠模型中检查 TM 中 ER 应激的诱导是否与 IOP 升高相关。我们将研究自噬在肌纤蛋白聚集体降解中的作用，并将确定雷帕霉素诱导自噬是否可以挽救 Tg-MYOCY437H 小鼠的青光眼。具体来说，候选人将使用 Atf6 学习并生成新的 ER 应激模型。此外，在指导阶段，我们还对敲除小鼠进行切碎，从 POAG 患者中产生诱导性多能干细胞 (iPSC) 衍生的小梁网样细胞，并在 Val Sheffield 博士的实验室中表征了地塞米松诱导的高眼压小鼠模型。候选人将通过咨询委员会的持续指导继续其专业和科学职业发展。他将参加科学会议，并与 ER 压力专家 Thomas Rutkowski 博士和青光眼合作。临床专家 Lee Alward 博士还将获得教学经验，该项目将促进候选人的持续技术、智力和专业培训，并协助候选人在学术研究机构建立独立的研究实验室。