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致盲性疾病。所有类型的主要风险因素和唯一的当前治疗目标 青光眼是眼内压（IOP）升高。我们已经确定了一个强大的IOP稳态机制， 所述持续的压力偏差被感测为细胞内的机械拉伸/变形 流出道的前小管（JCT）区域，并对流出道进行校正调整 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关键原因。 患上青光眼。我们最近发现，青光眼的眼前节不能执行正常的眼压， 稳态反应外流是围绕眼周的节段性高流量（HF）区域 中间流量（IF）和低流量（LF）。我们最近发现，青光眼的眼睛有更多的LF区域， 比正常的眼睛。该建议旨在理解这两种现象，IOP稳态和IOP内分泌。 流出分割，并利用这种理解，以纠正他们的昏迷缺陷。 为了开始了解IOP稳态过程和流出道分割，我们评估了分子水平的 人眼前节HF和LF区域之间的分布差异，已在1x （正常）或2倍（稳态反应）压力。我们选择了一部分分子差异， 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 速率，使用RNAi沉默来敲低它们的水平，直接干扰它们的结合相互作用， 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 灌注的人眼前节器官培养中的设施变化。接下来我们将获得相同的分子 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，并将其应用到昏迷的眼睛。关键是要改变外流 分割和IOP稳态响应以恢复功能。