PRESSURE REGULATION OF HUMAN TRABECULAR MESHWORK GENES

人类小梁网基因的压力调节

• 批准号: 6702361
• 负责人: Teresa Borras
• 金额: $ 22.13万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6702361
• 关键词: extracellular matrix; free radical oxygen; gene expression; gene induction /repression; genetic library; genetic regulation; homeostasis; human tissue; interleukin 6; intraocular aqueous flow; intraocular pressure; microarray technology; nucleic acid hybridization; organ culture; polymerase chain reaction; postmortem; substance P; trabecular meshwork; transfection /expression vector

Cells of the human trabecular meshwork (TM) are constantly exposed to fluid mechanical forces generated by the intraocular pressure/flow of aqueous humor. Exposure to these forces can modulate the expression of many genes involved in aqueous humor physiology and pathophysiology. Elevated intraocular pressure (IOP), present in most forms of glaucoma, is known to affect structure and function of the TM. After 6 h elevated IOP, we found eleven genes to be consistently up-regulated in the human TM: interleukin-6, preprotachykinin-1, secretogranin-II, cathepsin-L, stromelysin-1, thymosin-beta4, alpha-tubulin, alphaB-crystallin, glyceraldehyde-3-phosphate dehydrogenase, metallothionein and Cu/Zn superoxide dismutase. The gene encoding TIGR/MYOC was up-regulated after 7 days. Our general hypothesis is that regulation of IOP is governed in part by the coordinated expression of TM genes. Specifically, we hypothesize that early response to elevated IOP would induce genes involved in maintaining homeostatic mechanisms of outflow regulation whereas sustained elevation of IOP would induce genes whose adverse products would be associated with pathological mechanisms. Finally, we hypothesize that the products of genes induced at 6 h predict mechanisms regulating outflow resistance that might be similar to those regulating vascular permeability. To test these hypotheses we propose to identify human TM/Schlemm's canal (SC) genes that are differentially expressed after 1 h, 48 h and 7 days exposure to an elevated pressure insult. We also propose to examine mechanisms of cellular permeability in human outflow cells and organ cultures under conditions of elevated pressure and over/under expression of selected genes. Our strategy includes perfused human anterior segment cultures, exponential amplification libraries, high- density cDNA arrays and adenoviral technology. This approach provides adequate mechanical stimulus (pressure drop), genetic homogeneity (paired eyes), libraries with small amounts of tissue and efficient gene delivery system. Even if some of the selected genes or mechanisms would appear to be not of primary relevance on the regulation of IOP, the identification of human TM/SC genes in the arrays will provide important new information on the coordinated gene expression of the outflow system under mechanical stress.

人小梁网（TM）的细胞不断暴露于由水中幽默的眼内压/流动产生的流体机械力。 暴露于这些力可以调节与水性幽默生理学和病理生理学有关的许多基因的表达。 众所周知，以大多数青光眼形式存在的眼内压（IOP）会影响TM的结构和功能。 IOP升高6小时后，我们发现在人TM中始终上心上调11个基因：介育6，前旋素金蛋白-1，分泌素-II，Catherepsin-l，Stromelysin-1，胸腺素 - 甲状腺素-beta4，胸腺素 - β4，α-纤维蛋白，α-纤维蛋白，α-甲基乳晶型氢，盖甘油盐和3-3-3-3-3-3-3 Cu/Zn超氧化物歧化酶。 7天后，编码TIGR/MYOC的基因被上调。我们的一般假设是，IOP的调节部分受TM基因的协调表达来控制。 具体而言，我们假设对IOP升高的早期反应将引起与维持流出调节的稳态机制有关的基因，而IOP的持续升高将诱导其不良产物与病理机制相关的基因。 最后，我们假设在6小时诱导的基因产物预测了调节流出阻力的机制，这可能与调节血管渗透性的基因相似。为了检验这些假设，我们建议鉴定人类TM/Schlemm的运河（SC）基因，这些基因在1 h，48 h和7天后差异表达，暴露于升高的压力损害。 我们还建议在压力升高，超过所选基因表达的条件下，检查人流出细胞和器官培养物中细胞渗透性的机制。 我们的策略包括灌注的人类前部培养物，指数扩增库，高密度cDNA阵列和腺病毒技术。 这种方法提供了足够的机械刺激（压降），遗传同质性（配对的眼睛），少量组织和有效基因递送系统的文库。即使某些选定的基因或机制似乎与IOP的调节无关，阵列中人类TM/SC基因的鉴定也将提供有关在机械应力下流出系统协调基因表达的重要新信息。