PRESSURE REGULATION OF HUMAN TRABECULAR MESHWORK GENES

人类小梁网基因的压力调节

• 批准号: 6525160
• 负责人: Teresa Borras
• 金额: $ 3.68万
• 依托单位: DUKE UNIVERSITY
• 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 2002-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6525160
• 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.

人类小梁网络(TM)的细胞不断地暴露在由眼内压/房水流动产生的流体机械力中。暴露在这些力量下可以调节许多涉及房水生理学和病理生理学的基因的表达。眼压升高(IOP)存在于大多数形式的青光眼中，已知会影响TM的结构和功能。在高眼压6h后，我们发现11个基因在人TM中持续上调：白细胞介素6、速激肽前1、分泌型颗粒素II、组织蛋白酶L、基质分解素1、胸腺肽-β4、α-微管蛋白、α-晶体蛋白、甘油醛-3-磷酸脱氢酶、金属硫蛋白和铜/锌超氧化物歧化酶。7d后TIGR/MYOC基因表达上调。我们的一般假设是，眼压的调节在一定程度上是由TM基因的协调表达决定的。具体地说，我们假设，对高眼压的早期反应将诱导参与维持流出调节的动态平衡机制的基因，而持续的眼压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，可能类似于调节血管通透性的机制。为了验证这些假说，我们建议识别人类TM/Schlemm管(SC)基因，这些基因在高压暴露1小时、48小时和7天后差异表达。我们还建议研究在压力升高和所选基因表达过高/过低的条件下，人类外流细胞和器官培养中细胞渗透性的机制。我们的策略包括灌流的人眼前节培养、指数扩增文库、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(压力下降)、遗传同质性(配对眼睛)、具有少量组织的文库和高效的基因传递系统。即使一些被选择的基因或机制似乎与眼压的调节不是主要相关的，在阵列中识别人类TM/SC基因将为机械应力下流出系统的协调基因表达提供重要的新信息。