Decorin Accumulation Contributes to the Stromal Opacities Found in Congenital Stromal Corneal Dystrophy
Decorin Accumulation Contributes to the Stromal Opacities Found in Congenital Stromal Corneal Dystrophy
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DOI：
10.1167/iovs.09-4933
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发表时间：
2010-11-01
影响因子：
4.4
通讯作者：
Rodahl, Eyvind
中科院分区：
文献类型：
--
作者：
Bredrup, Cecilie;Stang, Espen;Rodahl, Eyvind
目的。先天性间质角膜营养不良（CSCD）的特征是间质混浊，形态学上表现为带小细丝的无定形物质的层间层，其性质迄今尚不清楚。CSCD与decorin基因（DCN）的截断突变有关。为了了解角膜混浊的分子基础，我们从形态学和分子水平分析了decorin在角膜混浊中的表达。角膜标本经cuprolinic蓝增强和免疫电镜检查。用免疫印迹法研究了O和n去糖基化前后角膜组织和角质细胞培养中的Decorin蛋白。采用Q-RT-PCR检测DCN mRNA的相对表达水平，并对cDNA进行测序。用凝胶过滤和免疫印迹法分析重组野生型和截断型decorin在HEK293细胞中的瞬时表达。层间丝区用铜丙蓝染色。使用decorin抗体的免疫电子显微镜显示这些区域有强烈的标记。野生型和截断型的decorin蛋白均在患者的角膜组织和角膜细胞中表达。凝胶过滤检测HEK293细胞中decorin的表达，截断的decorin被洗脱为高分子量的聚集体。在无定形物质的层间区域发现了装饰素的积累。截短的decorin存在于CSCD角膜中，并且有证据表明它可能在体外聚集。因此，decorin的积累似乎导致了间质混浊，这是CSCD的特征。（Invest Ophthalmol Vis Sci. 2010;51:5578-5582） DOI: 10.1167/iovs.09-4933
PURPOSE. Congenital stromal corneal dystrophy (CSCD) is characterized by stromal opacities that morphologically are seen as interlamellar layers of amorphous substance with small filaments, the nature of which has hitherto been unknown. CSCD is associated with truncating mutations in the decorin gene (DCN). To understand the molecular basis for the corneal opacities we analyzed the expression of decorin in this disease, both at the morphologic and the molecular level.METHODS. Corneal specimens were examined after contrast enhancement with cuprolinic blue and by immunoelectron microscopy. Decorin protein from corneal tissue and keratocyte culture was studied by immunoblot analysis before and after O- and N-deglycosylation. The relative level of DCN mRNA expression was examined using Q-RT-PCR, and cDNA was sequenced. Recombinant wild-type and truncated decorin transiently expressed in HEK293 cells were analyzed by gel filtration and immunoblotting.RESULTS. The areas of interlamellar filaments were stained by cuprolinic blue. Immunoelectron microscopy using decorin antibodies revealed intense labeling of these areas. Both wildtype and truncated decorin protein was expressed in corneal tissue and keratocytes of affected persons. When decorin expressed in HEK293 cells was examined by gel filtration, the truncated decorin eluted as high molecular weight aggregates.CONCLUSIONS. Accumulation of decorin was found in the interlamellar areas of amorphous substance. The truncated decorin is present in CSCD corneas, and there is evidence it may aggregate in vitro. Thus, decorin accumulation appears to contribute to the stromal opacities that are characteristic of CSCD. (Invest Ophthalmol Vis Sci. 2010;51:5578-5582) DOI: 10.1167/iovs.09-4933