Takahashi H, Noda S, Mashima Y, Kubota R, Ohtake Y, Tanino T, Kudoh J, Minoshima S, Oguchi Y, Shimizu N
Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
Curr Eye Res. 2000 Feb;20(2):81-4.
We previously reported a novel cytoskeletal protein with a myosin-like domain which is localized in the ciliary rootlet and basal body of connecting cilium of photoreceptor and hence we named it 'myocilin'. It was soon realized that myocilin is identical to a protein called TIGR (trabecular meshwork inducible glucocorticoid response protein) which was found to be responsible for the pathogenesis of juvenile open angle glaucoma. In this study, we employed in situ RNA hybridization to examine the myocilin (MYOC)/ TIGR gene expression in the trabecular meshworks of glaucomatous and nonglaucomatous eyes.
The glaucomatous specimens were obtained by trabeculectomy from the patients with primary open angle glaucoma (POAG), chronic angle closure glaucoma (CACG) and steroid glaucoma, respectively, and the nonglaucomatous specimens were obtained from a victim of traffic accident at autopsy and from a patient with maxillary sinus carcinoma at enucleation for the operation. The in situ RNA hybridization was carried out with digoxigenin-labeled sense and antisense RNA probes.
In all cases, hybridization signals were detected primarily in the trabecular meshwork cells and secondarily in the fibroblast-like cells of corneoscleral wall.
Myocilin gene is expressed clearly in the trabecular meshwork cells of both glaucomatous and nonglaucomatous eyes.
我们之前报道了一种具有肌球蛋白样结构域的新型细胞骨架蛋白，其定位于光感受器连接纤毛的纤毛小根和基体，因此我们将其命名为“肌纤蛋白”。很快人们就意识到肌纤蛋白与一种名为TIGR（小梁网诱导性糖皮质激素反应蛋白）的蛋白质相同，该蛋白被发现与青少年开角型青光眼的发病机制有关。在本研究中，我们采用原位RNA杂交技术检测青光眼和非青光眼眼中小梁网中肌纤蛋白（MYOC）/TIGR基因的表达。
青光眼标本分别取自原发性开角型青光眼（POAG）、慢性闭角型青光眼（CACG）和类固醇性青光眼患者的小梁切除术，非青光眼标本取自交通事故受害者的尸检以及上颌窦癌患者手术摘除眼球时。采用地高辛标记的正义和反义RNA探针进行原位RNA杂交。
在所有病例中，杂交信号主要在小梁网细胞中检测到，其次在角膜巩膜壁的成纤维细胞样细胞中检测到。
肌纤蛋白基因在青光眼和非青光眼的小梁网细胞中均有明显表达。
