PRESSURE REGULATION OF HUMAN TRABECULAR MESHWORK GENES

人小梁网（TM）的细胞不断地暴露于由眼内压/房水流动产生的流体机械力。 暴露于这些力量可以调节参与房水生理学和病理生理学的许多基因的表达。 已知存在于大多数形式的青光眼中的升高的眼内压（IOP）影响TM的结构和功能。 6 h眼压升高后，我们发现11个基因在人TM中持续上调：白细胞介素-6、前速激肽原-1、分泌颗粒蛋白-II、组织蛋白酶-L、基质溶解素-1、胸腺素-β 4、α-微管蛋白、α B-晶状体蛋白、甘油醛-3-磷酸脱氢酶、金属硫蛋白和Cu/Zn超氧化物歧化酶。 7天后编码TIGR/MYOC的基因上调。我们的一般假设是，眼压的调节部分是由TM基因的协调表达。 具体来说，我们假设，早期反应的IOP升高会诱导基因参与维持稳态机制的外流调节，而持续升高的IOP会诱导基因的不良产物将与病理机制。 最后，我们假设，在6小时诱导的基因的产品预测机制调节流出阻力，可能是类似于那些调节血管通透性。为了检验这些假设，我们提出，以确定人类TM/施累姆氏管（SC）基因的差异表达后1小时，48小时和7天暴露于高压侮辱。 我们还建议检查机制的细胞渗透性在人类流出细胞和器官培养物的条件下，压力升高和过/下表达选定的基因。 我们的策略包括人眼前节灌注培养、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（压降）、遗传同质性（双眼）、具有少量组织的文库和有效的基因递送系统。即使一些选定的基因或机制似乎与IOP的调节无关，但阵列中人TM/SC基因的鉴定将提供关于机械应力下流出系统的协调基因表达的重要新信息。

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.