Basic research of the process of degradation of rhodopsin by the retinal pigment epithelium and the clinical application.

视网膜色素上皮(RPE)在生理上降解视紫红质，视紫红质是在视觉细胞中合成的，在视杆细胞外节的形成中起主要作用的蛋白质。本项目的目的是通过体外和体内研究来阐明视蛋白的降解规律。我们从牛RPE中分离纯化出具有裂解视蛋白活性的组织蛋白酶D。以小鼠骨髓瘤P6为材料，制备抗组织蛋白酶D的单抗。我们将在日本眼科学会的下一次会议上展示免疫细胞化学和电子免疫细胞化学数据。我们还研究了视蛋白在病理条件下的含量和分布。用酶联免疫吸附试验检测，视蛋白免疫反应随着视网膜脱离时间的延长而减少。视网膜下液中的视蛋白裂解酶可降解视蛋白。C3H小鼠，视网膜变性小鼠，在视蛋白的定位方面具有异常的极性。视蛋白的正常合成、运输和降解受到干扰。前型持续性增生性原发玻璃体视网膜表现为视网膜发育不良。视蛋白免疫细胞化学也显示视蛋白在视觉细胞中异常堆积。1例部分5q三体和7q单体合并Leber‘s先天性黑猩猩。7号染色体在视觉细胞器官发生中可能起重要作用。

The retinal pigment epithelium (RPE) physiologically degrades rhodopsin which is synthesized in visual cells and plays a major part of protein in the formation of rod outer segments. The purpose of this project is to clarify the regulation of degradation of opsin by in vitro and in vivo studies. We purified cathepsin D from bovine RPE, having opsin-cleaving activity. Monoclonal antibody to cathepsin D was made using mouce myeloma P6. We will show the immunocytochemical and electron immunocytochemical data at the next meeting of Society of Japanese Ophthalmology. We studied also the content and the distribution of opsin in pathological conditions. Immunoreactive opsin decreased with the duration of the retinal detachment, assayed by ELISA. Opsin cleaving enzyme in subretinal fluid may degrade opsin. C3H mice, retinal degeneration mice, was shown to have abnormal polarity in regard to the localization of opsin. Normal synthesis, transport and degradation of opsin were disturbed. The retina of the case of anterior type of persistent hyperplastic primary vitreous showed retinal dysplasia. Immunocytochemistry of opsin also revealed abnormal accumulation of opsin in visual cells. A case of partial 5q trisomy and 7q monosomy had Leber's congenital amaurosis. Chromosome 7 might play an important role in organogenesis of visual cells.