Studies of optineurin, a glaucoma gene - Golgi fragmentation and cell death from overexpression of wild-type and mutant optineurin in two ocular cell types
Studies of optineurin, a glaucoma gene - Golgi fragmentation and cell death from overexpression of wild-type and mutant optineurin in two ocular cell types
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DOI：
10.2353/ajpath.2006.060400
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发表时间：
2006-12-01
影响因子：
6
通讯作者：
Yue, Beatrice Y. J. T.
中科院分区：
文献类型：
--
作者：
Park, Bum-Chan;Shen, Xiang;Yue, Beatrice Y. J. T.
最近，人们发现视神经蛋白（OPTN）与青光眼有关，青光眼是全世界失明的主要原因。据报道，在患者中，特别是常压青光眼患者中存在Glu(50)-> Lys （E50K）等oprN突变。在这里，我们发现内源性OPTN在两种眼细胞类型，人小梁网和视网膜色素上皮细胞中不分泌。它以弥漫性模式定位于细胞质中，与高尔基体没有明显的联系。然而，当过表达时，野生型om -绿色荧光蛋白（GFP）形成病灶，特别是在高尔基体周围，与两种细胞类型中共同的内吞途径标志物转铁蛋白受体部分共定位。还观察到高尔基体的碎裂。在诺可达唑处理下，OPTN灶分散到细胞质中。与野生型相比，突变体OPTNE50K-GFP过表达导致病灶数量和大小增加（P < 0.0055），高尔基改变增强。与野生型OPTN-GFP相比，OPTNE50K-GFP在表达OPTN-GFP的培养物中观察到的细胞损失更为明显（P < 0.01）。这项研究强调了OPTN在囊泡运输和高尔基体完整性中的可能作用。它还提供了E50K为何会表现出青光眼发展倾向的可能机制的见解。
Optineurin (OPTN) has recently been linked to glaucoma, a major cause of blindness worldwide. Mutations in oprN such as Glu(50)-> Lys (E50K) have been reported in patients, particularly those with normal pressure glaucoma. Here, we show that the endogenous OPTN was not secreted in two ocular cell types, human trabecular meshwork and retinal pigment epithelial cells. it localized instead in the cytoplasm in a diffuse pattern without a distinct association with the Golgi apparatus. When overexpressed, however, wild-type OM-green fluorescent protein (GFP) formed foci especially around the Golgi, colocalizing partially with the common endocytic pathway marker transferrin receptor in both cell types. Fragmentation of the Golgi was also observed. On nocodazole treatment, the OPTN foci were dispersed into the cytoplasm. Overexpression of mutant OPTNE50K-GFP resulted in a greater number (P < 0.0055) and size of the foci, compared with the wild type, and the Golgi alteration was potentiated. Cell loss observed in OPTN-expressing cultures was also more pronounced in OPTNE50K-GFP compared with that of wild-type OPTN-GFP counterparts (P < 0.01). This study highlights a possible role of OPTN in vesicle trafficking and Golgi integrity. it also provides insights into the possible mechanisms why E50K would exhibit a propensity toward the development of glaucoma.