Eslamboli Andisheh, Romero-Ramos Marina, Burger Corinna, Bjorklund Tomas, Muzyczka Nicholas, Mandel Ronald J, Baker Harry, Ridley Rosalind M, Kirik Deniz
Department of Experimental Psychology, Downing Street, Cambridge, UK.
Brain. 2007 Mar;130(Pt 3):799-815. doi: 10.1093/brain/awl382. Epub 2007 Feb 15.
Overexpression of human alpha-synuclein (alpha-syn) using recombinant adeno-associated viral (rAAV) vectors provides a novel tool to study neurodegenerative processes seen in Parkinson's disease and other synucleinopathies. We used a pseudotyped rAAV2/5 vector to express human wild-type (wt) alpha-syn, A53T mutated alpha-syn, or the green fluorescent protein (GFP) in the primate ventral midbrain. Twenty-four adult common marmosets (Callithrix jacchus) were followed with regular behavioural tests for 1 year after transduction. alpha-Syn overexpression affected motor behaviour such that all animals remained asymptomatic for at least 9 weeks, then motor bias comprising head position bias and full body rotations were seen in wt-alpha-syn expressing animals between 15 and 27 weeks; in the later phase, the animals overexpressing the A53T alpha -syn, in particular, showed a gradual worsening of motor performance, with increased motor coordination errors. Histological analysis from animals overexpressing either the wt or A53T alpha -syn showed prominent degeneration of dopaminergic fibres in the striatum. In the ventral midbrain, however, the dopaminergic neurodegeneration was more prominent in the A53T group than in the WT group suggesting differential toxicity of these two proteins in the primate brain. The surviving cell bodies and their processes in the substantia nigra were stained by antibodies to the pathological form of alpha-syn that is phosphorylated at Ser position 129. Moreover, we found, for the first time, ubiquitin containing aggregates after overexpression of alpha-syn in the primate midbrain. There was also a variable loss of oligodendroglial cells in the cerebral peduncle. These histological and behavioural data suggest that this model provides unique opportunities to study progressive neurodegeneration in the dopaminergic system and deposition of alpha-syn and ubiquitin similar to that seen in Parkinson's disease, and to test novel therapeutic targets for neuroprotective strategies.
使用重组腺相关病毒（rAAV）载体过表达人α-突触核蛋白（α-syn）为研究帕金森病和其他突触核蛋白病中出现的神经退行性过程提供了一种新工具。我们使用假型rAAV2/5载体在灵长类动物腹侧中脑表达人野生型（wt）α-syn、A53T突变型α-syn或绿色荧光蛋白（GFP）。24只成年普通狨猴（Callithrix jacchus）在转导后接受了为期1年的定期行为测试。α-syn过表达影响运动行为，所有动物至少9周无症状，然后在15至27周之间，表达wt-α-syn的动物出现包括头部位置偏差和全身旋转的运动偏差；在后期，特别是过表达A53T α-syn的动物运动性能逐渐恶化，运动协调错误增加。对过表达wt或A53T α-syn的动物进行组织学分析，结果显示纹状体中多巴胺能纤维明显变性。然而，在腹侧中脑，A53T组的多巴胺能神经变性比WT组更明显，表明这两种蛋白在灵长类动物大脑中的毒性不同。黑质中存活的细胞体及其突起被抗在丝氨酸129位磷酸化的α-syn病理形式的抗体染色。此外，我们首次在灵长类动物中脑过表达α-syn后发现了含泛素的聚集体。大脑脚中也存在少突胶质细胞的不同程度缺失。这些组织学和行为学数据表明，该模型为研究多巴胺能系统中的进行性神经变性以及α-syn和泛素的沉积（类似于帕金森病中所见），并测试神经保护策略的新治疗靶点提供了独特的机会。
