Immunolocalization of ubiquitin and related enzymes in human retina and retinal pigment epithelium
Immunolocalization of ubiquitin and related enzymes in human retina and retinal pigment epithelium
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DOI：
10.1007/bf00941767
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发表时间：
1997-04-01
影响因子：
2.7
通讯作者：
Mangini, NJ
中科院分区：
文献类型：
--
作者：
Loeffler, KU;Mangini, NJ
目的：检查泛素 (Ub) 和相关酶在人视网膜中的定位，重点关注视网膜色素上皮 (RPE)-布鲁赫膜复合物。方法：对因各种疾病过程而被摘除的 30 只人眼进行检查。使用针对 Ub、Ub 结合酶 (E2)、Ub 羧基末端水解酶 (PGP 9.5) 的抗体以及用于比较的抑制蛋白 (Arr) 对石蜡切片进行免疫组织化学分析。使用亲和素-生物素方法测试免疫反应性 (IR)。结果：Ub 存在于整个视网膜中，但在神经节细胞和 RPE 中尤其突出。最有趣的是 Ub IR 存在于与年龄相关的亚 RPE 沉积物中，例如玻璃疣和基底层沉积物 (BLD)。 RPE 免疫标记在较老的组织中更为强烈，但除此之外，没有任何 Ub IR 模式与特定疾病相关。 E2 IR 与 Ub 共定位，但有一个例外； E2 IR 在玻璃疣或 BLD 中未发现。 PGP 9.5 IR 在神经纤维、神经节细胞、内核层和丛状层中强烈。 RPE 染色微弱且不均匀；子 RPE 沉积物未贴上标签。 Arr IR 存在于光感受器中，但不在 RPE 细胞内或下方。结论：泛素化过程在人类视网膜，特别是神经节细胞中很重要。 Ub 相关过程在 RPE 中也很活跃，并且可能参与这些细胞中蛋白质的降解和处理。亚 RPE 沉积物中 Ub 的存在（没有相关的 Ub 加工酶）增加了某些蛋白质在 RPE 内泛素化的可能性，但 Ub 蛋白复合物不会发生进一步降解。
Purpose: To examine the localization of ubiquitin (Ub) and related enzymes in human retina with emphasis on the retinal pigment epithelium (RPE)-Bruch's membrane complex. Methods: Thirty human eyes enucleated for various disease precesses were examined. Immunohistochemistry was performed on paraffin sections using antibodies against Ub, Ub-conjugating enzyme (E2), Ub carboxylterminal hydrolase (PGP 9.5), and, for comparison, arrestin (Arr). Immunoreactivity (IR) was tested using the avidin-biotin method.Results: Ub was present throughout retina but was particularly prominent in ganglion cells and RPE. Most intriguing was the presence of Ub IR in age-related, sub-RPE deposits such as drusen and basal laminar deposits (BLD). RPE immunolabeling was more intense in older tissue, but otherwise no pattern of Ub IR could be linked to specific diseases. E2 IR colocalized with Ub, with one exception; E2 IR was not found in drusen or BLD. PGP 9.5 IR was intense in nerve fibers, ganglion cells, and the inner nuclear and plexiform layers. RPE staining was faint and patchy; sub-RPE deposits were not labeled. Arr IR was present in photoreceptors but not within or beneath RPE cells. Conclusion: The ubiquitination process is important in human retina and particularly in ganglion cells. Ub-related processes are also active in RPE and may be involved in the degradation and disposal of proteins from these cells. The presence of Ub in sub-RPE deposits - without related Ub-processing enzymes - raises the possibility that certain proteins become ubiquitinated within RPE but that further degradation of the Ub-protein complexes does not occur.