ATXN1:扩大ALS中多聚谷氨酰胺重复序列的范围ATXN1: expanding the spectrum of polyglutamine repeats in ALS |
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课程网址: | http://videolectures.net/encals2017_tazelaar_polyglutamine_repeat... |
主讲教师: | Gijs Tazelaar |
开课单位: | 荷兰乌得勒支大学 |
开课时间: | 2017-07-21 |
课程语种: | 英语 |
中文简介: | 目的:多聚谷氨酰胺蛋白在长程扩张时可引起广泛的神经退行性疾病,如亨廷顿病和脊髓小脑共济失调(SCA)。ATXN2基因中编码CAG/CAA三核苷酸重复序列的多聚谷氨酰胺的中间长度被证明是肌萎缩侧索硬化症(ALS)的危险因素。尽管在发现ALS和SCA1疾病同时发生的家系后,在一个小型意大利队列中发现ATXN1与中间长度相关,但其他CAG重复基因的参与仅被适度调查或报告。在确定了一个类似的家系后,我们开始调查一个大型ALS患者和对照国际队列中ATXN1中间扩增的频率。方法:我们通过PCR在来自4个不同国家(比利时、法国、爱尔兰和荷兰)的2742名ALS患者和2374名对照者的DNA中筛选ATXN1 CAG/CAT三核苷酸重复序列长度。在一个子集(N=850)的数据中使用Sanger测序进一步验证PCR片段重复大小。通过控制分布确定中间截止值,发现其在33 CAG/CAT重复和更高水平。结果:我们在对照组中发现242例(11.4%)中间扩张携带者,在ALS患者中发现333例(13.8%)。对4个不同队列的频率进行的荟萃分析显示,与对照组相比,ALS患者的ATXN1重复次数显著增加(p=0.006,单侧),优势比为1.25(95%可信区间:1.05-1.50)。解释:与ATXN2类似,ATXN1和ALS中CAG(/CAT)三核苷酸重复序列长度增加与此相关。有趣的是,与ATXN2相比,我们发现在ALS(ATXN2为1-2%,ATXN1为6-7%)和对照个体(ATXN2为0.3-0.4%,ATXN1为5-6%)中,ATXN1的中间扩增频率相对较高。这符合这样的假设,即中间多聚谷氨酰胺扩张可能不是病因,但会增加ALS的发病风险。然而,与ATXN2中的中间载体相比,ATXN1中的总体风险似乎更小(或ATXN2中的3.06或ATXN1中的1.25)。未来的实验将集中于ATXN1和ATXN2之间的相似性,如TDP-43结合能力,以及差异性,如ATXN1中的CAT中断,以进一步阐明多聚谷氨酰胺扩增在ALS中的作用。 |
课程简介: | Objective: Polyglutamine proteins can cause a wide range of neurodegenerative disorders upon long-range expansions such as Huntington’s disease and spinocerebellar ataxia (SCA). Intermediate length of the polyglutamine coding CAG/CAA trinucleotide repeat in the ATXN2 gene was shown to be a risk factor for amyotrophic lateral sclerosis (ALS). Involvement of other CAG-repeat genes has only been moderately investigated or reported, although an association was found with intermediate length in the ATXN1 in a small Italian cohort after discovery of a pedigree with co-occurrence of ALS and SCA1 disease. After identification of a similar pedigree, we set out to investigate the frequency of ATXN1 intermediate expansions in a large international cohort of ALS patients and controls. Methods: We screened the ATXN1 CAG/CAT trinucleotide repeat length via PCR in DNA of 2,742 ALS patients and 2,374 controls from 4 different countries (Belgium, France, Ireland and The Netherlands). PCR-fragment repeat size was additionally validated using Sanger sequencing in a subset (N=850) of the data. An intermediate cut-off was determined via control distribution and was found to be at 33 CAG/CAT repeats and higher. Results: We found 242 (11.4%) intermediate expansion carriers in control individuals and 333 (13.8%) in ALS patients. Meta-analysis of the frequencies in the 4 different cohorts showed significantly more expanded repeats in ATXN1 in ALS patients compared to controls (p = 0.006, one sided) with an odds ratio of 1.25 (95% CI: 1.05- 1.50). Interpretation: Similar to ATXN2, there is an association with an increased length of CAG(/CAT) trinucleotide repeats in ATXN1 and ALS. Interestingly, in contrast to ATXN2, we found a relative high frequency of intermediate expansions in ATXN1 in both ALS (1-2% in ATXN2 vs 6-7% in ATXN1) and control individuals (0.3-0.4% in ATXN2 vs 5-6% in ATXN1). This fits with the hypothesis that intermediate polyglutamine expansions might not be causative but pose an increased risk for developing ALS. However, this overall risk in ATXN1 seems to be smaller compared to intermediate carriers in ATXN2 (OR 3.06 in ATXN2 vs OR 1.25 in ATXN1). Future experiments will focus on both the similarities between ATXN1 and ATXN2, such as TDP-43 binding capacity, as well as the differences, such as the CAT-interruptions in ATXN1, to further elucidate the role of polyglutamine expansions in ALS. |
关 键 词: | 多聚谷氨酰胺蛋白; 神经退行性疾病; ALS |
课程来源: | 视频讲座网 |
数据采集: | 2021-12-10:zkj |
最后编审: | 2021-12-10:zkj |
阅读次数: | 91 |