Trabecular Meshwork Proteins in Glaucoma

青光眼中的小梁网蛋白

• 批准号: 8585850
• 负责人: Sanjoy K Bhattacharya
• 金额: $ 37.49万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2016-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8585850
• 关键词: Age; Anatomy; Bioinformatics; Cadaver; Cartoons; Cell Shape; Cells; Chronic; Custom; Cytoskeleton; Development; Esthesia; Extracellular Matrix; Extracellular Matrix Proteins; Eye; Glaucoma; Goals; Human; Imaging Techniques; Immunoprecipitation; In Vitro; Integral Membrane Protein; Intervention; Knowledge; Lead; Life; Link; Liquid substance; Magnetic Resonance Imaging; Mass Spectrum Analysis; Methods; Microscope; Molecular; Mus; Optical Coherence Tomography; Outcomes Research; Pathogenesis; Physiologic Intraocular Pressure; Play; Primary Open Angle Glaucoma; Proteins; Reagent; Regulation; Relative (related person); Research; Signal Transduction; Stretching; System; Testing; Time; Tissues; Trabecular meshwork structure; Yeasts; aqueous; base; cell motility; effective therapy; fluid flow; overexpression; potassium channel protein TREK-1; pressure; prevent; protein function; response; shear stress; transcription factor; yeast two hybrid system

DESCRIPTION (provided by applicant): The long-term goals are to understand the mechanisms of regulation of fluid flow through the extracellular matrix (ECM) of the trabecular meshwork (TM) and to eventually use this knowledge to develop effective therapies for preventing primary open angle glaucoma (POAG) progression. The immediate goal of this competing renewal project is to test hypotheses about the molecular mechanisms by which TM cells sense the fluid flow fluctuations in the ECM and by which the sensation is transduced to change cell shape and motility to increase or decrease TM pore size, thus regulating the passing of fluid through TM. In particular, we focus on cochlin, a secreted ECM protein, because mass spectrometric analyses have identified cochlin exclusively in human glaucomatous TM but not in normal TM. We have shown in vitro that cochlin undergoes aggregate formation and multimerization when subjected to fluid shear fluctuations indicating that cochlin is capable of mechanosensing. Our organizing hypothesis is that cochlin mechanosensing, in glaucomatous TM, communicates with transmembrane proteins to modulate TM cell shape and motility leading to dysregulation of fluid flow in ECM. Thus, cochlin plays a key role in intraocular pressure (IOP) elevation. Aim 1 is to test the hypothesis that aberrant cochlin over-expression occurs at the onset of IOP dysregulation. We will determine real time cochlin and TREK-1 levels and dysregulation of IOP (early and continuous abnormal rise in IOP) across different ages in live glaucomatous DBA/2J mice and compare with control DBA/2J-Gpnmb+/SjJ mice using newly developed reagent-based spectral (SD) and magnetomotive (MM) optical coherence tomography (OCT). Aim 2 is to test the hypothesis that the cochlin mechanosensing signal is transduced via interaction with transmembrane proteins (such as TREK-1), leading to the cytoskeleton changes that modulates fluid flow across the TM filter. Aim 3 is to test the hypothesis that chronic aberrant expression of cochlin is regulated by a set of transcription factors (Barx2, Nrf2 and Brn3a). We will use primary TM cells, cadaver TM tissues and DBA/2J mice to determine the relative levels of transcription factors (that are responsive to pressure/stretch cycles) whose level modulation is accompanied with cochlin overexpression. Cochlin is the first molecule mechanistically linked to mechanosensing of fluid shear change in the ECM of TM. Establishing this protein's function in aberrant aqueous outflow regulation has great significance for understanding IOP regulation, POAG pathogenesis, and potential intervention strategies.

描述（由申请人提供）：长期目标是了解流经小梁网（TM）细胞外基质（ECM）的液体流动调节机制，并最终利用这些知识开发有效的疗法来预防原发性开角型青光眼（POAG）进展。 这个竞争性更新项目的直接目标是测试有关分子机制的假设，TM细胞通过该分子机制感知ECM中的流体流动波动，并通过这种感觉转导来改变细胞形状和运动性，从而增加或减小TM孔径，从而调节流体通过TM。我们特别关注耳蜗蛋白（一种分泌性 ECM 蛋白），因为质谱分析已在人类青光眼 TM 中鉴定出耳蜗蛋白，而在正常 TM 中则没有。我们已经在体外证明，当受到流体剪切波动时，耳蜗蛋白会发生聚集体形成和多聚化，这表明耳蜗蛋白能够进行机械传感。我们的组织假设是，青光眼 TM 中的耳蜗蛋白机械传感与跨膜蛋白进行通讯，调节 TM 细胞的形状和运动性，导致 ECM 中的液体流动失调。 因此，耳蜗蛋白在眼压（IOP）升高中起着关键作用。 目标 1 是检验以下假设：异常的 cochlin 过度表达发生在 IOP 失调开始时。 我们将测定不同年龄活青光眼 DBA/2J 小鼠的实时 cochlin 和 TREK-1 水平以及 IOP 失调（IOP 的早期和持续异常升高），并使用新开发的基于试剂的光谱 (SD) 和磁动 (MM) 光学相干断层扫描 (OCT) 与对照 DBA/2J-Gpnmb+/SjJ 小鼠进行比较。目标 2 是检验以下假设：耳蜗蛋白机械传感信号通过与跨膜蛋白（例如 TREK-1）相互作用进行转导，从而导致细胞骨架发生变化，从而调节穿过 TM 过滤器的流体流动。 目标 3 是检验耳蜗蛋白的慢性异常表达受一组转录因子（Barx2、Nrf2 和 Brn3a）调节的假设。我们将使用原代 TM 细胞、尸体 TM 组织和 DBA/2J 小鼠来确定转录因子（对压力/拉伸周期有反应）的相对水平，其水平调节伴随着 cochlin 过度表达。 Cochlin 是第一个与 TM ECM 中流体剪切变化的机械传感机制相关的分子。建立该蛋白在异常房水流出调节中的功能对于理解 IOP 调节、POAG 发病机制和潜在的干预策略具有重要意义。