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.

项目概要 青光眼是一种主要致盲疾病。所有类型的主要危险因素和当前唯一的治疗目标 青光眼是指眼内压（IOP）升高。我们已经确定了一种强大的 IOP 稳态机制 持续的压力偏差被内部细胞感知为机械拉伸/扭曲 流出通路的近小管 (JCT) 区域并对流出进行校正调整 使 IOP 恢复到适当水平的阻力。这似乎是大多数人不这样做的一个关键原因 发展为青光眼。我们最近发现青光眼眼前节无法执行正常的眼压 稳态反应。流出物围绕眼睛周围呈分段状，具有高流量 (HF) 区域 中流量（IF）和低流量（LF）。我们最近发现青光眼眼睛有更多的 LF 区域 比正常的眼睛。该提案旨在理解这两种现象：眼压稳态和 流出分割，并利用这种理解来纠正其中的青光眼缺陷。 为了开始了解 IOP 稳态过程和流出分段，我们评估了分子 1x 灌注的人类眼前节 HF 和 LF 区域之间的分布差异 （正常）或 2x（稳态反应）压力。我们选择了分子差异的一个子集 与这些过程最相关；它们主要是在 ECM 中发挥作用的细胞外基质 (ECM) 蛋白 组织和重塑。我们将完善它们的分布，评估它们的区域生物合成/动态 率，使用 RNAi 沉默来降低其水平，直接干扰其结合相互作用，并进行 一些精选的蛋白质过度表达研究。主要读数将是流出分段变化和流出 灌注人类眼前段器官培养的设施变化。接下来我们将获得相同的分子 青光眼眼的分布数据并使用最有效的 RNAi 沉默和结合相互作用 正常的扰动并将其应用于青光眼眼睛。重点是修改流出 病变组织的分割和眼压稳态反应以恢复功能。