TURNOVER OF SUBSTANCES IN THE OUTFLOW PATHWAY OF THE EYE

眼睛流出通道中的物质周转

• 批准号: 3263908
• 负责人: ARNOLD L MILLER
• 金额: $ 14.88万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-03-01 至 1991-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3263908
• 关键词: carbohydrate structure; chemical structure function; chromatography; electron microscopy; enzyme biosynthesis; enzyme mechanism; fluoresceins; glaucoma; human tissue; intraocular aqueous flow; intraocular pressure; lysozyme; membrane activity; microscopy; organ culture; phagocytosis; radiotracer; spectrometry; tissue /cell culture; trabecular meshwork

The precise mechanism by which aqueous outflow is regulated is not known but interactions between the cells of the trabecular meshwork, their underlying collagen beams and other extracellular substances (including glycosaminoglycans) may play an important role. These cells, given their phagocytic properties, are capable of removing debris or particles in the anterior chamber that become trapped in the pores of the meshwork, thereby affecting intraocular pressure. A change in the metabolic state of these cells due to the effects of aging, drugs, hormones, environment or other influences may lead to an altered turnover of endogenous and foreign substances and decrease aqueous outflow facility. The goal of the proposed research is to evaluate the role of phagosome/lysosome-mediated events of the trabecular cells in regulating agueous outflow facility. Trabecular cells obtained from human, monkey and bovine eyes will be maintained in culture. The rate of phagocytosis by these cells of various radiolabeled particles including lens material, red blood cells and protein-laden latex spheres will be determined. The trabecular cell surface components involved in particle recognition and ingestin will be identified by cell surface radiolabeling and by radio-iodinated and fluorscein-labeled lectin binding studies. Chemical modification of the trabecular cell surface or the addition of various substances to the trabecular cells prior to or concomitant with phagocytosis may provide insights regarding factors that effect particle recognition and ingestion. The kinetics of particle degradation by the lysosomal enzymes will be examined as well as the effect of phagocytosis on the synthesis and release of these enzymes from the cells. The lysosomal enzymes may also play an important role in the turnover of material endogenous to the trabecular meshwork and thus contribute to the regulation of intraocular pressure. Enzyme activities and biochemical properties of lysosomal enzymes from human trabecular tissue excised from normal and glaucomatous eyes will be compared. In addition, studies are proposed to investigate the biochemical properties of lysosomal enzymes in trabecular cells and to determine factors that influence their cellular and extracellular localization. The mechanism by which these enzymes are targeted to lysosomes and extracellular fluids will be investigated by determining the types of carbohydrate structure on the lysosomal enzymes from trabecular cells. The localization and biochemical properties of lysosomal enzymes in cultured trabecular cells will also be evaluated after treatment with experimental agents that are known to affect intraocular pressure.

调节房水流出的精确机制是 未知，但小梁细胞之间的相互作用 网状结构，其底层胶原蛋白束和其他 细胞外物质（包括糖胺聚糖）可能发挥作用 一个重要的角色。 这些细胞由于其吞噬特性， 能够清除前部的碎片或颗粒 被困在网孔中的腔室， 从而影响眼压。 新陈代谢的变化 由于衰老、药物、激素的影响，这些细胞的状态 环境或其他影响可能会导致营业额发生变化 内源性和外来物质并减少水 流出设施。 拟议研究的目标是评估 吞噬体/溶酶体介导的事件的作用 小梁细胞调节水流出设施。 从人、猴和牛眼中获得的小梁细胞 将在文化中得以保留。 这些物质的吞噬率 各种放射性标记颗粒的细胞，包括晶状体材料，红色 将测定血细胞和富含蛋白质的乳胶球。 参与颗粒的小梁细胞表面成分 识别和摄入将被细胞表面识别 放射性标记以及放射性碘标记和荧光素标记的凝集素 结合研究。 小梁细胞的化学修饰 表面或向小梁添加各种物质 在吞噬作用之前或同时进行的细胞可以提供 关于影响粒子识别的因素的见解 摄入。 溶酶体降解颗粒的动力学 将检查酶以及吞噬作用对 这些酶从细胞中合成和释放。 这 溶酶体酶也可能在其中发挥重要作用 小梁网内源性物质的周转和 从而有助于眼压的调节。 酶 溶酶体酶的活性和生化特性 从正常和青光眼患者中切除的人小梁组织 眼睛会被比较。 此外，建议研究 研究溶酶体酶的生化特性 小梁细胞并确定影响其的因素 细胞和细胞外定位。 其机制 这些酶针对溶酶体和细胞外液 将通过确定碳水化合物的类型进行研究 小梁细胞溶酶体酶的结构。 这 溶酶体酶的定位和生化特性 治疗后还将评估培养的小梁细胞 使用已知影响眼内的实验药物 压力。