Molecular analysis of a new type of spinocerebellar degeneration with GFAP mutations

具有 GFAP 突变的新型脊髓小脑变性的分子分析

基本信息

批准号：
15590902
负责人：
NAKAGAWA Masanori
金额：
$ 2.24万
依托单位：
Kyoto Prefectural University of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15590902/
关键词：
GFAP Alexander disease Genotype phenotype correlation Juvenile onset Adult onset mitochondrial DNA Spinal cord atrophy Ataxia ragged-red fibers

项目摘要

Glial fibrillary acidic protein (GFAP) is an intermediate filament protein expressed in astrocyte. Recently heterozygous point mutations in the GFAP have been reported in patients with various forms of Alexander disease (ALX). ALX is classified into infantile, juvenile and adult forms by age of disease onset. Infantile form is characterized by progressive psychomotor deterioration, seizure, hydrocephalus, and dies in infancy. Juvenile form is characterized by psychomotor deterioration, bulbar signs, and weakness and spasticity of lower limbs, but mental retardation and progression are less severe than those of the infantile form. Adult form is characterized by ataxia, palatal myoclonus and spastic paraparesis, but the symptoms are extremely variable from severe neurological defects to asymptomatic state.We reported familial cases of palatal myoclonus and spinal cord atrophy with V87G GFAP mutation. We also reported a new case of palatal myoclonus, pyramidal tract signs, cerebellar sign … More s, and marked atrophy of the medulla oblongata and spinal cord, and heterozygous R416W mutation which was also found in both of infantile and juvenile forms. To clarify the correlation of the clinical phenotypes and GFAP mutations, we analyzed nine patients in four Japanese families and reviewed 65 reported patients on the point of GFAP mutations. In addition, we produced the mutant GFAP expression vectors and investigated the expression pattern of the mutant GFAP in the culture cells.In the 74 patients, 42, 13 and 19 patients were infantile, juvenile and adult forms, respectively. In the 19 patients with adult form, two of them had no subjective symptoms and six of seven families had family history of the disease. The juvenile and adult forms coexisted in the same family members. Palatal myoclonus was recognized only four patients with the adult form. Regarding MRI findings, frontal dominant white matter lesion was detected in the infantile form, but spinal cord atrophy was prominent in the adult form. The sites of GFAP mutation mainly localized at exon 1, 4 and 8. R416W mutation was detected all forms of ALX and no clear correlation between the clinical forms and nature of the mutations. Mitochondrial abnormalities, ragged-red fibers, mtDNA A8291G substitution and 9bp deletion, were detected in one patient with the juvenile form. No nestin mutation was detected in the adult form.We produced four different GFAP mutations (T235C, T274G, C276T, C1260T) by site specific mutagenesis. These mutants were transfected into cloned human glioma cells. We investigated the expressions properties of the GFAP protein through immunohistochemical staining using anti-GFAP antibody. Over expression of GFAP was found in the cells with GFAP mutations in comparison with those of wild type GFAP.In conclusion, we confirmed the phenotypic and genetic features of adult form ALX with GFAP mutations. The phenotypic difference between each form of ALX is due not only to the different site and nature of mutations in GFAP, but also to other modifying factor(s) like other intermediate filaments and mitochondrial functions. Comparison of the expression patterns of each mutation in transgenic mice and culture system may clarify the phenotypic and genetic correlation in ALX with GFAP mutations. Less

神经胶质原纤维酸性蛋白（GFAP）是在星形胶质细胞中表达的中间细丝蛋白。最近，在患有各种形式的亚历山大病（ALX）的患者中，GFAP中的杂合点突变已报道。 ALX按疾病发作年龄分类为婴儿，少年和成人形式。婴儿形式的特征在于，婴儿期进行性心理运动定义，癫痫发作，脑积水和死亡。少年形式的特征是下肢的精神运动定义，鳞茎迹象以及弱点和痉挛，但智力低下和进展不如基础设施形式的严重。成人形式的特征是共济失调，pal骨肌阵挛和痉挛性瘫痪，但是症状从严重的神经系统缺陷到渐近状态极大。我们还报道了一种新的一例新病例肌阵挛，锥体痕迹，小脑迹象……更多S，并标记了髓质长肌和脊髓的萎缩以及杂合R416W突变，在婴儿和幼年形式中也发现了杂合R416W突变。为了阐明临床表型和GFAP突变的相关性，我们分析了四个日本家庭中的9例患者，并在GFAP突变点审查了65例报告患者。此外，我们产生了突变的GFAP表达载体，并研究了培养细胞中突变GFAP的表达模式。在74例患者中，42、13和19例患者分别是婴儿，少年和成人形式。在19例成人形式的患者中，其中两个没有主题符号，七个家庭中有6个患有该疾病的家族史。少年和成人形式共存在同一家庭成员中。帕拉塔尔·肌阵挛仅被公认为四名成人形式的患者。关于MRI的发现，基础设施形式检测到前显性白质病变，但脊髓萎缩在成人形式中很明显。 GFAP突变的位点主要位于外显子1、4和8。R416W突变被检测到所有形式的ALX，并且在突变的临床形式和性质之间没有明显的相关性。在一名患有少年形式的患者中检测到线粒体异常，破烂的红色纤维，mtDNA A8291G取代和9BP缺失。在成人形式中未检测到Nestin突变。我们通过位点特异性诱变产生了四个不同的GFAP突变（T235C，T274G，C276T，C276T，C1260T）。这些突变体被翻译成克隆的人神经胶质瘤细胞。我们使用抗GFAP抗体通过免疫组织化学染色研究了GFAP蛋白的表达特性。与野生型GFAP相比，在具有GFAP突变的细胞中发现了GFAP的过度表达。总而言之，我们确认了具有GFAP突变的成年成年ALX的表型和遗传特征。每种ALX形式之间的表型差异不仅归因于GFAP中突变的不同位点和性质，还归因于其他修饰因子（S），例如其他中间丝和线粒体功能。比较转基因小鼠和培养系统中每个突变的表达模式可以阐明与GFAP突变的ALX中的表型和遗传相关性。较少的