Molecular Mechanisms of Outflow Segmentation and Intraocular Pressure Homeostasis

流出分段和眼压稳态的分子机制

• 批准号: 10229419
• 负责人: TED S ACOTT
• 金额: $ 33.61万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10229419
• 关键词: Affect; Anabolism; Anterior; Behavior; Binding; Cells; Characteristics; Data; Disease; Endothelium; Extracellular Matrix; Extracellular Matrix Proteins; Eye; Funding; Glaucoma; Homeostasis; Human; Knowledge; Mechanics; Messenger RNA; Molecular; Organ Culture Techniques; Outcome Study; Pathway interactions; Peptides; Perfusion; Physiologic Intraocular Pressure; Process; Protein Biosynthesis; Protein Overexpression; Proteomics; RNA Interference; Regulation; Resistance; Risk Factors; Role; Stretching; Structure of sinus venosus of sclera; Testing; Therapeutic; Tissues; Trabecular meshwork structure; aqueous; functional restoration; inhibitor/antagonist; knock-down; laser capture microdissection; mRNA Expression; molecular subtypes; novel; pressure; protein expression; protein function; response

Project Summary Glaucoma is a major blinding disease. The primary risk factor and only current treatment target for all types of glaucoma is elevated intraocular pressure (IOP). We have identified a robust IOP homeostatic mechanism in which sustained pressure deviations are sensed as mechanical stretching/distortion by cells within the juxtacanalicular (JCT) region of the outflow pathway and corrective adjustments are made to the outflow resistance which restore IOP to appropriate levels. This appears to be a key reason that most people do not develop glaucoma. We recently showed that glaucomatous anterior segments cannot execute a normal IOP homeostatic response. Outflow is segmental around the circumference of the eye with regions of high flow (HF) intermediate flow (IF) and low flow (LF). We recently showed that glaucomatous eyes have more LF regions than normal eyes. This proposal is directed at understanding these two phenomena, IOP homeostasis and outflow segmentation, and exploiting this understanding to correct the glaucomatous deficiencies in them. To begin understanding the IOP homeostatic process and outflow segmentation, we evaluated molecular distribution differences between HF and LF regions of human anterior segments that had been perfused at 1x (normal) or 2x (homeostatic response) pressures. We selected a subset of the molecular differences that seemed most relevant to these processes; they were mostly extracellular matrix (ECM) proteins that function in ECM organization and remodeling. We will refine their distributions, evaluate their regional biosynthesis/dynamics rates, use RNAi silencing to knockdown their levels, interfere directly with their binding interactions, and conduct a few select protein overexpression studies. Primary readouts will be outflow segmentation changes and outflow facility changes in perfused human anterior segment organ culture. Next we will obtain the same molecular distribution data for glaucomatous eyes and using the most effective RNAi silencing and binding interaction perturbations from normal and apply them to glaucomatous eyes. The point will be to modify outflow segmentation and IOP homeostatic responsiveness in diseased tissue to restore function.

项目摘要 青光眼是一种主要的盲目疾病。所有类型的主要危险因素和唯一的当前治疗目标 青光眼是升高的眼内压（IOP）。我们已经确定了一种强大的IOP稳态机制 持续的压力偏差将其视为通过细胞内的机械拉伸/失真感。 流出路径的近距离（JCT）区域和对流出进行纠正调整 阻力将IOP恢复到适当的水平。这似乎是大多数人没有的关键原因 发展青光眼。我们最近表明，青光眼前部无法执行正常IOP 稳态反应。流出围绕眼周的圆周，高流量区域（HF）处于节段 中间流（如果）和低流量（LF）。我们最近表明青光眼的眼睛有更多的LF区域 比普通的眼睛。该建议旨在了解这两种现象，IOP稳态和 流出分割，并利用此理解以纠正其中的青光眼缺陷。 为了开始理解IOP稳态过程和流出分段，我们评估了分子 人类前部的HF和LF区域之间的分布差异在1x处灌注 （正常）或2倍（稳态响应）压力。我们选择了似乎有分子差异的子集 与这些过程最相关；它们主要是在ECM中起作用的细胞外基质（ECM）蛋白 组织和改建。我们将完善它们的分布，评估其区域生物合成/动力学 速率，使用RNAi沉默来敲定其水平，直接干扰其结合相互作用并进行 一些精选的蛋白质过表达研究。主要读数将是流出分割的更改和流出 设施变化的灌注人体前部器官培养物的变化。接下来，我们将获得相同的分子 青光眼的分布数据，并使用最有效的RNAi沉默和结合相互作用 从正常的扰动并将其应用于青光眼的眼睛。关键是要修改流出 分割和IOP稳态反应性在患病组织中恢复功能。