Trabecular Meshwork Proteins in Glaucoma

青光眼中的小梁网蛋白

• 批准号: 8235226
• 负责人: Sanjoy K Bhattacharya
• 金额: $ 37.3万
• 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/8235226
• 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. PUBLIC HEALTH RELEVANCE: The proposed research focuses on the mechanisms by which trabecular meshwork (TM) cells in the eye sense the fluid flow fluctuations in the extracellular matrix (ECM) and how they transduce the sensation to respond against fluid shear changes. The outcomes of this research will expand our understanding of the mechanisms of regulation of fluid flow in the TM, and thus of the pressure in the eye, and will eventually enable the developing of effective therapies for glaucoma progression.

描述（由申请人提供）：长期目标是了解通过小梁网（TM）的细胞外基质（ECM）调节流体流动的机制，并最终使用此知识来开发有效的疗法，以防止主要开放式疗法角度青光眼（POAG）进展。 该竞争更新项目的直接目标是测试有关TM细胞在ECM中感知流体流动波动的分子机制的假设，并通过将感觉传递到改变细胞形状和运动性，从而增加或减少TM孔径，从而改变TM孔径的大小调节流体通过TM的传递。特别是，我们专注于Cochlin，这是一种分泌的ECM蛋白，因为质谱分析已在人青光眼TM中仅确定Cochlin，但在正常TM中却没有。我们已经在体外表明，当受到流体剪切波动的影响时，Cochlin会经历聚集体的形成和多聚化，这表明Cochlin能够进行机械效率。我们的组织假设是，在青光眼TM中，Cochlin机械感应与跨膜蛋白通信以调节TM细胞形状和运动性，从而导致ECM中流体流动的失调。 因此，科克林在眼内压（IOP）抬高中起关键作用。 目的1是检验以下假设：IOP失调发作时发生异常的Cochlin过表达。 我们将确定实时的Cochlin和Trek-1水平以及IOP（IOP的早期和连续异常上升）的失调，在活的青光眼DBA/2J小鼠中，使用新开发的试剂型小鼠对照DBA/2J-GPNMB+/SJJ小鼠进行比较基于基于磁光（SD）和磁电磁（MM）光学相干断层扫描（OCT）。 AIM 2是测试通过与跨膜蛋白（例如Trek-1）相互作用的Cochlin机械传感信号的假设，导致细胞骨架变化，从而调节跨TM滤波器的流体流量。 AIM 3是检验以下假设：Cochlin的慢性异常表达受一组转录因子（BARX2，NRF2和BRN3A）的调节。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的相对水平（对压力/拉伸循环的响应），其水平调节与Cochlin过表达伴随。 Cochlin是第一个与TM ECM中流体剪切变化机械连接的机械连接的分子。确定该蛋白质在异常水流流出调节中的功能对于理解IOP调节，POAG发病机理和潜在干预策略具有重要意义。 公共卫生相关性：拟议的研究重点是眼睛意义上的小梁网络（TM）细胞的机制，细胞外基质（ECM）的流体流动波动以及它们如何转导感觉以响应液体剪切变化。这项研究的结果将扩大我们对TM中流体流动调节机制的理解，从而扩大了眼睛压力的调节机制，并最终将能够开发有效的青光眼进展疗法。