Cellular Physiology of the Aqueous Outflow Pathway

房水流出途径的细胞生理学

• 批准号: 9383966
• 负责人: HAIYAN GONG
• 金额: $ 41.15万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-30 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9383966
• 关键词: Address; Age; Aqueous Humor; Area; Blindness; Bypass; Cell Wall; Cell physiology; Cells; Clinical; Connective Tissue; Cytoskeleton; Data; Development; Devices; Disease; Disease Progression; Distal; Electron Microscopy; Endothelium; Eye; Filtration; Fluorescein Angiography; Funding; Gene-Modified; Goals; Human; Image; Imaging Techniques; Knowledge; Liquid substance; Location; Measures; Methods; Morphology; Pathway interactions; Pattern; Permeability; Physiologic Intraocular Pressure; Postoperative Period; Primary Open Angle Glaucoma; Regimen; Regulation; Resistance; Rho-associated kinase; Risk Factors; Role; Stents; Structure; Structure of sinus venosus of sclera; Techniques; Testing; Time; Trabecular meshwork structure; Tracer; Vacuole; Veins; aqueous; base; clinical practice; clinically relevant; drug development; glaucoma surgery; improved; innovation; kinase inhibitor; minimally invasive; novel; three dimensional cell culture

Primary open-angle glaucoma (POAG) is a leading cause of blindness worldwide. A primary risk factor for the development and progression of POAG is elevation of intraocular pressure (IOP), caused by an increase in aqueous outflow resistance. Most of this resistance is believed to be generated in the juxtacanalicular connective tissue (JCT) and modulated by the inner wall endothelium of Schlemm’s canal (SC), and its giant vacuoles and pores. However, the exact mechanisms that regulate outflow resistance remain unclear. Our long-term goal is to understand the mechanisms that regulate aqueous outflow resistance in normal eyes and how this resistance is increased in POAG. In our last funding period, we developed global imaging, a technique that can visualize the outflow pattern around the circumference of the eye and distinguish areas of high, low, or non-flow in the trabecular meshwork (TM), SC, and the distal episcleral veins. In these three parts, we found aqueous outflow to be segmental. We defined the area with active flow as the effective filtration area (EFA). We found inverse relationships between EFA and both IOP and outflow resistance. We also found that EFA and outflow facility increased in eyes treated with methods of lowering IOP: Rho-kinase inhibitors, gene modification, and minimally invasive glaucoma surgery (MIGS) using TM bypass devices. Based on these results, our goal of this project is to determine what mechanisms contribute to the regulation of EFA. We will distinguish morphological features of high, low, and non-flow areas, and determine whether we can increase EFA to lower IOP by converting non/low-flow areas to high-flow areas. To achieve our objectives, we developed a 3D electron microscopy method to reliably provide volumetric and geometric quantitation of giant vacuoles, pores, and cellular connections between the SC inner wall and its underlying JCT. We will test our hypothesis that cellular connections in the inner wall endothelium modulate giant vacuole and pore formation, thereby regulating EFA. We will also pioneer a novel 3D cell culture device with real-time imaging to scrutinize changes in cytoskeletal structure and giant vacuole formation after Rho-kinase inhibitor treatment. Importantly, we have enhanced the global imaging technique by combining it with fluorescein angiography to distinguish flow patterns before and after an IOP-reducing treatment. This offers the opportunity to identify newly converted high-flow areas arising from use of Rho-kinase inhibitors. These innovative methods allow us to address the clinical debate as to whether MIGS devices should be placed in high or non-flow areas to optimize post-operative IOP reduction. Our Specific Aims are: 1. To differentiate structural changes along inner wall of SC in high-flow areas compared to low/non- flow areas of normal and POAG eyes; 2. To determine effect of Rho-kinase inhibitors on giant vacuoles and pore formation; 3. To determine the best location (high, low adjacent to high, or non-flow area) to place a TM bypass stent to effectively increase EFA. The results of this study will advance our understanding of how EFA and outflow resistance are regulated, and potentially improve current clinical methods of IOP reduction in POAG.

原发性开角型青光眼 (POAG) 是全世界失明的主要原因。的一个主要危险因素 POAG 的发生和进展是眼内压 (IOP) 升高，这是由 水流出阻力。大多数阻力被认为是在近小管结缔组织中产生的 组织（JCT）并受到施累姆管（SC）内壁内皮及其巨大液泡和 毛孔。然而，调节流出阻力的确切机制仍不清楚。我们的长期目标是 了解调节正常眼睛房水流出阻力的机制以及这种阻力如何 POAG 增加。在我们上一个资助期间，我们开发了全局成像，这是一种可以可视化的技术 眼睛周围的流出模式，并区分高、低或无流动的区域 小梁网 (TM)、SC 和远端巩膜外静脉。在这三个部位，我们发现有水流出 是分段的。我们将具有活跃流量的区域定义为有效过滤面积（EFA）。我们发现逆 EFA 与 IOP 和流出阻力之间的关系。我们还发现全民教育和流出设施 使用降低 IOP 的方法治疗的眼睛增加：Rho 激酶抑制剂、基因修饰和最低限度 使用 TM 旁路装置进行侵入性青光眼手术 (MIGS)。根据这些结果，我们该项目的目标是 确定哪些机制有助于全民教育的监管。我们将区分形态特征 的高、低和非流动区域，并确定我们是否可以通过转换来增加EFA以降低IOP 无/低流量区域到高流量区域。为了实现我们的目标，我们开发了 3D 电子显微镜 可靠地提供巨液泡、孔和细胞的体积和几何定量的方法 SC 内壁与其下方 JCT 之间的连接。我们将检验我们的假设，即细胞 内壁内皮细胞的连接调节巨液泡和孔的形成，从而调节 EFA。 我们还将开创一种新型 3D 细胞培养装置，具有实时成像功能，可仔细检查细胞骨架的变化 Rho激酶抑制剂处理后的结构和巨型液泡形成。重要的是，我们增强了 整体成像技术，将其与荧光素血管造影相结合，以区分前后的血流模式 降低眼压治疗后。这提供了识别新转变的高流量区域的机会 使用 Rho 激酶抑制剂。这些创新方法使我们能够解决以下问题的临床争论： MIGS 装置应放置在高流量或无流量区域，以优化术后 IOP 降低效果。我们的具体 目的是： 1. 与低/非流动区域相比，区分高流动区域中 SC 内壁的结构变化 正常眼和 POAG 眼的血流面积； 2. 确定Rho激酶抑制剂对巨空泡和孔的影响 形成； 3. 确定放置 TM 旁路的最佳位置（高处、高处附近的低处或非流动区域） 支架有效增加EFA。这项研究的结果将加深我们对全民教育和 流出阻力得到调节，并有可能改善当前 POAG 降低 IOP 的临床方法。