Damm J, Rau T, Maihöfner C, Pahl A, Brune K
Institute for Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nuremberg, Erlangen, Germany.
Exp Eye Res. 2001 Jun;72(6):611-21. doi: 10.1006/exer.2001.0977.
Prostaglandins are involved in the regulation of intraocular pressure and the blood-aqueous barrier of the eye, and are used for the treatment of glaucoma. The decrease of the constitutively expressed PG-synthesizing enzyme cyclooxygenase-2 (COX-2) has been demonstrated in the ciliary non-pigmented epithelial layer of patients with primary open angle glaucoma. Little is known about the distribution of COX-1 and COX-2 in animals. We investigated this in the iris and ciliary body of the normal rabbit eye. The presence of COX-1 and COX-2 in freshly excised iris and ciliary body tissue from adult New Zealand White albino rabbits was demonstrated by real-time RT-PCR, and Western blot analysis. The localization of both isoforms and of the neuron-specific protein gene product 9.5 was determined by indirect immunofluorescence. Both enzymes are expressed in the iris and the ciliary body. Immunofluorescence studies including double staining techniques localized COX-1 and COX-2 to about 50% of cells in the stromal tissue of iris and ciliary body, mainly on the corneal side. They were co-localized in about 75% of these cells. Whereas all stained cells were positive for COX-1, COX-2 showed a gradient-like distribution in the stroma, with some restriction of expression near the epithelial layers, which we clearly showed to be completely negative for both COX-1 and COX-2. Also, neuronal elements did not show COX-1 or COX-2 immunoreactivity. These results establish the presence of COX-1 and COX-2 on the RNA and protein levels in normal, unstimulated rabbit iris and ciliary body. The pattern of distribution suggests a role for both enzymes in maintaining the physiology of the eye. In contrast to our results in man, non-pigmented epithelial cells of the ciliary body did not express immunoreactivity. This could account for differences in the regulation of intraocular pressure and/or blood-aqueous barrier between human and rabbit eyes.
前列腺素参与眼内压和眼血-房水屏障的调节，并用于治疗青光眼。在原发性开角型青光眼患者的睫状体非色素上皮层中，已证实组成型表达的PG合成酶环氧合酶-2（COX-2）减少。关于COX-1和COX-2在动物体内的分布知之甚少。我们在正常兔眼的虹膜和睫状体中对此进行了研究。通过实时RT-PCR和蛋白质印迹分析，证实了成年新西兰白兔新鲜切除的虹膜和睫状体组织中存在COX-1和COX-2。通过间接免疫荧光确定了两种同工型以及神经元特异性蛋白基因产物9.5的定位。两种酶均在虹膜和睫状体中表达。包括双重染色技术在内的免疫荧光研究将COX-1和COX-2定位到虹膜和睫状体基质组织中约50%的细胞上，主要位于角膜侧。它们在约75%的这些细胞中共定位。虽然所有染色细胞COX-1均呈阳性，但COX-2在基质中呈梯度样分布，在上皮层附近表达有所限制，我们明确显示上皮层对COX-1和COX-2均完全呈阴性。此外，神经元成分未显示COX-1或COX-2免疫反应性。这些结果证实了在正常、未受刺激的兔虹膜和睫状体中，COX-1和COX-2在RNA和蛋白质水平上的存在。分布模式表明这两种酶在维持眼睛生理功能中起作用。与我们在人类中的结果相反，睫状体的非色素上皮细胞未表达免疫反应性。这可能解释了人类和兔眼在眼内压和/或血-房水屏障调节方面的差异。
