Bestrophin gene mutations cause canine multifocal retinopathy: A novel animal model for best disease
Bestrophin gene mutations cause canine multifocal retinopathy: A novel animal model for best disease
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DOI：
10.1167/iovs.06-1374
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发表时间：
2007-05-01
影响因子：
4.4
通讯作者：
Aguirre, Gustavo D.
中科院分区：
文献类型：
--
作者：
Guziewicz, Karina E.;Zangerl, Barbara;Aguirre, Gustavo D.
目的.犬多灶性视网膜病变是一种多品种犬的非染色体隐性遗传疾病。该疾病与Best黄斑营养不良（BMD）有许多临床和病理相似之处，并且cmr被提议作为Best疾病的新的大型动物模型。cmr的特点是检眼镜和组织病理学，并与BMD影响的患者进行比较。在犬中评价BEST 1（别名VMD 2），即与BMD有因果关系的雌激素基因。克隆犬直向同源物cDNA序列，并使用RPE/脉络膜5 '-和3'-RACE进行验证。通过北方和Western印迹和免疫细胞化学分析犬基因转录本和蛋白质的表达。所有外显子和侧翼剪接点通过直接测序进行筛选。cmr的临床表型和病理学与BMD病变非常相似。犬VMD 2跨越CFA 18上的13.7 kb基因组DNA，在真核生物中显示出高水平的保守性。该转录物主要在RPE/脉络膜中表达，并编码66 kDa的580个氨基酸的蛋白质--雌激素。正常犬视网膜的免疫细胞化学显示蛋白质特异性定位于RPE基底侧质膜。在犬VMD 2基因中发现了两个疾病特异性序列改变：cmr 1的C73 T终止突变和cmr 2的G（482）A错义突变。作者提出，犬VMD 2基因的这两个自发突变导致CMR，作为第一个自然发生的BMD动物模型。cmr模型的进一步发展将有助于阐明这些视网膜病变的复杂分子机制和开发潜在的治疗方法。
PURPOSE. Canine multifocal retinopathy (cmr) is an amosomal recessive disorder of multiple dog breeds. The disease shares a number of clinical and pathologic similarities with Best macular dystrophy (BMD), and cmr is proposed as a new large animal model for Best disease.METHODS. cmr was characterized by ophthalmoscopy and histopathology and compared with BMD-affected patients. BEST1 (alias VMD2), the bestrophin gene causally associated with BMD, was evaluated in the dog. Canine ortholog cDNA sequence was cloned and verified using RPE/choroid 5'- and 3'-RACE. Expression of the canine gene transcripts and protein was analyzed by Northern and Western blotting and immunocytochemistry. All exons and the flanking splice junctions were screened by direct sequencing.RESULTS. The clinical phenotype and pathology of cmr closely resemble lesions of BMD. Canine VMD2 spans 13.7 kb of genomic DNA on CFA18 and shows a high level of conservation among eukaryotes. The transcript is predominantly expressed in RPE/choroid and encodes bestrophin, a 580-amino acid protein of 66 kDa. Immunocytochemistry of normal canine retina demonstrated specific localization of protein to the RPE basolateral plasma membranes. Two disease-specific sequence alterations were identified in the canine VMD2 gene: a C73T stop mutation in cmr1 and a G(482)A missense mutation in cmr2.CONCLUSIONS. The authors propose these two spontaneous mutations in the canine VMD2 gene, which cause cmr, as the first naturally occurring animal model of BMD. Further development of the cmr models will permit elucidation of the complex molecular mechanism of these retinopathies and the development of potential therapies.