Crosstalk between chronic ER stress and mitophagy for the treatment of POAG

慢性 ER 应激与线粒体自噬治疗 POAG 之间的串扰

基本信息

批准号：
10445174
负责人：
Gulab Zode
金额：
$ 37万
依托单位：
UNIVERSITY OF NORTH TEXAS HLTH SCI CTR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-03-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10445174
关键词：
Autophagocytosis Autopsy Biological Assay Blindness Cell Death Cell model Cell physiology Cells Cessation of life Chronic Deposition Disease Endoplasmic Reticulum Enhancers Exhibits Extracellular Matrix Eye Eyedrops Fibrosis Functional disorder Funding Genetic Genus Hippocampus Glaucoma Glucocorticoids Goals Health Homeostasis Human Impairment In Vitro Link Lysosomes Membrane Metformin Mitochondria Molecular Mus Nerve Degeneration Normal tissue morphology Ocular Hypertension Organelles Pathologic Pathology Pathway interactions Pharmacology Physiologic Intraocular Pressure Play Primary Open Angle Glaucoma Proteins Reactive Oxygen Species Reporter Role Stress Time Tissues Trabecular meshwork structure Transmission Electron Microscopy Work endoplasmic reticulum stress improved in vivo in vivo Model insight mitochondrial dysfunction mouse model novel prevent transcription factor treatment strategy

项目摘要

Abstract Primary Open Angle Glaucoma (POAG) is the most common form of glaucoma that leads to irreversible vision loss. Elevated intraocular pressure (IOP) due to dysfunction of trabecular meshwork (TM) tissue is a hallmark of POAG. However, the pathological mechanisms leading to TM dysfunction and IOP elevation are poorly understood. Our recent studies have shown that chronic endoplasmic reticulum (ER) stress is associated with the pathophysiology of glaucomatous TM damage and IOP elevation. However, the exact mechanisms of TM cell dysfunction/loss are not completely understood. The ER and mitochondria communicate constantly via mitochondria-associated ER membranes (MAMs) to regulate vital cellular functions including autophagy. Autophagy degrades long-lived proteins and damaged organelles including mitochondria (known as mitophagy) via lysosomes. Impaired mitophagy is known to cause abnormal accumulation of damaged mitochondria resulting into cell death. In our preliminary studies, primary human TM cells exhibited an abundant mitochondria and MAMs. Interestingly, human primary TM cells and TM tissues from POAG donor eyes demonstrated increased accumulation of mitochondria. Moreover, chronic ER stress-induced transcriptional factors, ATF4 and CHOP led to increased reactive oxygen species and impaired mitophagy in primary human TM cells. Our overall goals are to define the role of MAMs and impaired mitophagy in TM dysfunction and IOP elevation in POAG and to further target these pathways for the treatment of glaucoma. We hypothesize that chronic ER stress induces impaired mitophagy and mitochondrial dysfunction, leading to TM dysfunction/loss and IOP elevation in POAG. We will determine whether impaired mitophagy and mitochondrial dysfunction are associated with TM dysfunction and IOP elevation in human and mouse glaucoma (Aim 1). We will further determine whether chronic ER stress induces impaired mitophagy and mitochondrial dysfunction, leading to TM dysfunction/loss and IOP elevation (Aim 2). Finally, we will perform proof-of-principle studies exploring whether the mitophagy enhancers improve outflow facility and reduce elevated IOP in mouse models of glaucoma (Aim 3). We will utilize human primary TM cells and post-mortem TM tissues from normal and glaucoma donor eyes, mouse models of glaucoma and mitophagy flux reporter mouse model (mito-qc) as well as transmission electron microscopy (TEM) and the Seahorse assays to determine the role of MAMs, mitophagy and mitochondrial dysfunction in TM function and IOP homeostasis. The successful completion of the proposed studies will provide novel crosstalk between ER stress and mitophagy and target the pathological mechanisms for the treatment of general POAG.

抽象的原发性开角型青光眼 (POAG) 是最常见的青光眼形式，可导致视力不可逆损失。由于小梁网 (TM) 组织功能障碍导致的眼内压 (IOP) 升高是波格。然而，导致TM功能障碍和眼压升高的病理机制尚不清楚。明白了。我们最近的研究表明，慢性内质网（ER）应激与青光眼 TM 损伤和 IOP 升高的病理生理学。然而，TM 的确切机制细胞功能障碍/损失尚未完全了解。内质网和线粒体通过以下方式不断沟通线粒体相关内质网膜 (MAM) 调节重要的细胞功能，包括自噬。自噬会降解长寿蛋白质和受损的细胞器，包括线粒体（称为线粒体自噬）通过溶酶体。已知线粒体自噬受损会导致受损线粒体异常积累从而导致细胞死亡。在我们的初步研究中，原代人类 TM 细胞表现出丰富的线粒体和 MAM。有趣的是，来自 POAG 供体眼睛的人类原代 TM 细胞和 TM 组织被证明线粒体积累增加。此外，慢性 ER 应激诱导的转录因子 ATF4 和 CHOP 导致原代人类 TM 细胞中活性氧含量增加并损害线粒体自噬。我们的整体目标是确定 MAM 和受损的线粒体自噬在 TM 功能障碍和 POAG 和 IOP 升高中的作用进一步针对这些途径治疗青光眼。我们假设慢性 ER 应激会导致线粒体自噬受损和线粒体功能障碍，导致 POAG 中 TM 功能障碍/丧失和 IOP 升高。我们将确定受损的线粒体自噬和线粒体功能障碍是否与 TM 有关人类和小鼠青光眼的功能障碍和眼压升高（目标 1）。我们将进一步确定是否为慢性 ER 应激会导致线粒体自噬受损和线粒体功能障碍，导致 TM 功能障碍/丧失和 IOP 海拔（目标 2）。最后，我们将进行原理验证研究，探索线粒体自噬增强剂是否改善青光眼小鼠模型的流出设施并降低眼压升高（目标 3）。我们将利用人力来自正常和青光眼供体眼睛、小鼠模型的原代 TM 细胞和死后 TM 组织青光眼和线粒体自噬通量报告小鼠模型 (mito-qc) 以及透射电子显微镜 (TEM) 和 Seahorse 检测以确定 MAM、线粒体自噬和线粒体功能障碍在 TM 中的作用功能和 IOP 稳态。拟议研究的成功完成将提供新颖的串扰 ER 应激和线粒体自噬之间的关系，并针对一般 POAG 治疗的病理机制。