Zhou L, Li Y, Yue B Y
Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago College of Medicine, Chicago, IL 60612, USA.
Int J Mol Med. 1998 Feb;1(2):339-46.
The trabecular meshwork (TM) is a specialized eye tissue essential for regulation of the aqueous humor outflow and control of the intraocular pressure. Disturbances of TM cells may lead to elevated intraocular pressure and glaucoma. This study assessed the dexamethasone effects on levels of extracellular matrix proteins and their integrin receptors in bovine TM cells. Instillation of glucocorticoids such as dexamethasone is known to result in ocular hypertension. The histologic changes induced resemble those seen in glaucoma. Examination of the effects of glucocorticoid therefore may provide insights into the pathogenesis of glaucoma. TM cells in either tissue culture or organ cultures were treated with 0 (control), 0.1, or 1 microM of dexamethasone for 72 h. Immunostaining, Western, Northern and dot blot analyses showed that dexamethasone caused an increase in levels of fibronectin and collagen type IV in tissue-cultured TM cells. Increased focal contacts were also observed but the levels of laminin and collagen type I were unaffected. The dexamethasone effect was similarly demonstrated in organ cultures, with the exception that collagen type I also was enhanced. These results suggest that dexamethasone modulates extracellular matrices in the TM. Glucocorticoid may exert its effect through such a modulation in the development of steroid glaucoma.
小梁网（TM）是一种特殊的眼部组织，对于调节房水流出和控制眼压至关重要。TM细胞功能紊乱可能导致眼压升高和青光眼。本研究评估了地塞米松对牛TM细胞中细胞外基质蛋白及其整合素受体水平的影响。已知滴注地塞米松等糖皮质激素会导致高眼压。所诱导的组织学变化与青光眼所见相似。因此，研究糖皮质激素的作用可能有助于深入了解青光眼的发病机制。将组织培养或器官培养中的TM细胞用0（对照）、0.1或1微摩尔的地塞米松处理72小时。免疫染色、蛋白质印迹、Northern印迹和斑点印迹分析表明，地塞米松导致组织培养的TM细胞中纤连蛋白和IV型胶原水平升高。还观察到粘着斑增加，但层粘连蛋白和I型胶原水平未受影响。地塞米松在器官培养中也有类似作用，只是I型胶原也有所增加。这些结果表明，地塞米松可调节TM中的细胞外基质。糖皮质激素可能通过这种调节作用在类固醇性青光眼的发生发展中发挥作用。
