Molecular Mechanisms of Outflow Segmentation and Intraocular Pressure Homeostasis

项目摘要 青光眼是一种主要的致盲疾病。主要的危险因素和目前所有类型的治疗目标 青光眼是眼压升高。我们已经确定了一种强大的眼压稳态机制 这些持续的压力偏差是由细胞内的机械拉伸/变形感知的 流出通道的邻近(JCT)区域，并对流出进行纠正调整 将眼压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 患上青光眼。我们最近发现，青光眼眼前段不能执行正常眼压。 动态平衡反应。流出眼周呈节段性，有高流量区(HF)。 中流(IF)和低流(LF)。我们最近发现，青光眼有更多的LF区 而不是普通眼睛。这一建议旨在理解这两个现象，眼压动态平衡和 流出部分，并利用这一认识来纠正其中的青光眼缺陷。 为了开始了解眼压的稳态过程和流出部分，我们评估了分子 1X灌流的人眼前段高频区和低频区的分布差异 (正常)或2倍(动态平衡反应)压力。我们选择了分子差异的一个子集，看起来 与这些过程最相关；它们主要是在细胞外基质(ECM)中发挥作用的蛋白质 组织和重塑。我们将细化它们的分布，评估它们的区域生物合成/动力学 速率，使用RNAi沉默来降低它们的水平，直接干扰它们的结合相互作用，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 灌流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 青光眼的分布数据和使用最有效的RNAi沉默和结合相互作用 并将其应用于青光眼。重点将是修改流出 病变组织的节段性和眼压动态平衡反应以恢复功能。

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.