【作者】 杨帆；

【导师】 汪思应； 杨晓明；

【作者基本信息】 安徽医科大学 ， 病理学与病理生理学， 2009， 硕士

【摘要】 多聚谷氨酰胺(polyglutamin,polyQ)疾病是一类由遗传因素导致的神经退行性疾病,该疾病是由于基因编码区域存在的CAG三核苷酸出现重复扩增,导致翻译产物中谷氨酰胺重复数目增加而引发,目前尚有大量类似的致病基因未被揭示。死亡相关蛋白11(thanatos-associated protein-11,THAP11)是我们在研究与白血病发生密切相关的胚胎发育相关基因1(embryonic develop associated gene 1, EDAG-1)发现的与其存在相互作用的蛋白,属于THAP蛋白家族。基因的结构和多态性分析发现,THAP11序列中含有CAG编码片段,其分子中部的谷氨酰胺串联重复排列片段呈现高度的不稳定状态且易发生扩增,我们怀疑其可能为polyQ疾病的候选致病基因之一。为此,我们在前期实验筛查分析了正常人群和神经退行性病变患者的THAP11基因中CAG重复数,发现正常人群中广泛分布THAP11(29Q),而患者中多为THAP11(38Q),高表达THAP11能引起明显的细胞增殖抑制。初步确定THAP11可能为polyQ疾病的候选致病基因。为进一步探讨THAP11的功能,本研究在PC12细胞中建立THAP11的蜕皮激素诱导表达系统,进一步研究THAP11的细胞生物学影响,同时为了后期在模式生物的水平上研究THAP11与polyQ疾病的相关性,我们还构建了一系列THAP11转基因线虫的载体,并制备了部分转基因线虫。结果发现THAP11(29Q)和THAP11(38Q)在PC12细胞中形成聚合物的时间和数目上存在差异。THAP11的表达能够导致PC12细胞产生G0/G1期阻滞,且随着THAP11的表达,PC12细胞的增殖受到抑制。机制探讨发现THAP11(29Q)及THAP11(38Q)均能减低细胞增殖中发挥重要作用的转录因子c-myc表达,但polyQ数目的增加并不能增强这种趋势。成功构建的THAP11转基因线虫表达载体,能够制备出转基因线虫,为后续进一步研究提供模型。更多还原

【Abstract】 Polyglutamine(polyQ) diseases is a kind of neurodegenerative diseases caused by expanded CAG repeats in gene coding region resulting in translation products possessing expanded polyglutamine repeats. At present, a large number of pathogenic genes of polyQ diseases have not been revealed. THAP11 was the interact protein of EDAG1 when we study EDAG1, it belongs to THAP proteins family. The analysis of the construction and polymorphism of THAP11 found that it contains a section of polyglutamine fragment coded by CAG repeats which was very instable and essy to expand. Might THAP11 be a candidate gene for polyglutamine disorders? So, we screen the number of CAG repeats of THAP11 between nomal people and neurodegenerative diseases patients ,we found that THAP11(29Q) was common in the normal, and THAP11(38Q) was too much in the patients. The highly expressing of THAP11 can inhibit cell proliferation. we could primarily confirm THAP11 as a candidate gene for polyglutamine disorders.For futher study of the function of THAP11, we have established the ecdysone-inducible expression system in PC12 cells,and try to research the cytobiology effect of it. In addition,for the reseach of the relationship between THAP11 and polyQ diseases on the level of model organism, we have constructed a series of the THAP11 transgenic Caenorhabditis elegans vectors and created some of the THAP11 transgenic Caenorhabditis elegans. we have found that THAP11(29Q) and THAP11(38Q) was different in the time and nuber of the formation of protein aggregations in the PC12 cells. The expression of THAP11 can cause the arresting of cell cycle in G0/G1, with the expressing of THAP11, the PC12 cell proliferation can be inhibited. Investigating the mechanism of these effects we found that the expression of c-myc,which was important in cell proliferation, was decreased along with the expression of THAP11,but this effect was not associated with the number of polyQs. These THAP11 transgenic Caenorhabditis elegans vectors can be used to create transgenic Caenorhabditis elegans succefully.It can provide the model for the futher study.更多还原