Expression of human A53T alpha-synuclein in the rat substantia nigra using a novel AAV1/2 vector produces a rapidly evolving pathology with protein aggregation, dystrophic neurite architecture and nigrostriatal degeneration with potential to model the pathology of Parkinson's disease
Expression of human A53T alpha-synuclein in the rat substantia nigra using a novel AAV1/2 vector produces a rapidly evolving pathology with protein aggregation, dystrophic neurite architecture and nigrostriatal degeneration with potential to model the pathology of Parkinson's disease
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DOI：
10.1186/1750-1326-5-43
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发表时间：
2010-10-28
影响因子：
15.1
通讯作者：
Brotchie, Jonathan M.
中科院分区：
文献类型：
--
作者：
Koprich, James B.;Johnston, Tom H.;Brotchie, Jonathan M.
背景：帕金森病 (PD) 的病理特征包括富含 α-突触核蛋白 (α-syn) 的路易体和神经突的存在以及黑质 (SN) 多巴胺能 (DA) 神经元的丧失。基于病毒载体介导的 α-syn 过度表达的 PD 动物模型已经开发出来，并显示出不同程度的 DA 毒性证据，具体取决于所用病毒的类型、其浓度和所用载体的血清型。迄今为止，这些模型变化多端，难以复制，并且在实现所需表型方面进化缓慢，阻碍了它们作为测试新疗法的模型的使用。为了解决这些问题，我们在这方面采用了一种新型载体，该载体可以高滴度制备，并且具有产生神经元定向表达的能力，并且表达动力学经过优化以提供基因产物表达的快速增加。因此，在本研究中，我们使用高滴度嵌合 AAV1/2 载体来表达人 A53T α-syn、空载体对照 (EV) 或绿色荧光蛋白 (GFP)，后者是为了控制高水平蛋白质本身可能造成损伤的可能性。 结果：我们表明，在向大鼠 SN 中单次注射 2 μl 后，几乎完全覆盖了结构，并且在整个细胞中出现了 A53T α-syn 或 GFP 的结构和表达。纹状体。在 SN 递送各自载体后 3 周内，在 SN DA 神经元中观察到不溶性 α-syn 的聚集。与 EV 对照相比，A53T α-syn 的表达显着减少了 SN 中 DA 神经元的数量 (52%)，而 GFP 的表达则显着减少了 SN 中的 DA 神经元的数量 (24%)（均 P < 0.01）。在纹状体水平，AAV1/2-A53T α-syn 注射产生了营养不良的神经突，并且酪氨酸羟化酶水平显着降低（降低了 53%，P < 0.01），这在 AAV1/2-GFP 条件下没有观察到。结论：在模型的当前实施中，我们概括了 PD 的主要病理特征，尽管 SN 损伤的一部分可能与一般蛋白质超载和 may not be specific for A53T alpha-syn.因此，在充分表征该模型之前，未来的研究需要优化 AAV1/2 的剂量。然而，病理学进化的动态性在提供初始筛选以评估可能阻止/逆转α-syn聚集的新疗法的功效方面比当前模型具有优势。
Background: The pathological hallmarks of Parkinson's disease (PD) include the presence of alpha-synuclein (alpha-syn) rich Lewy bodies and neurites and the loss of dopaminergic (DA) neurons of the substantia nigra (SN). Animal models of PD based on viral vector-mediated over-expression of alpha-syn have been developed and show evidence of DA toxicity to varying degrees depending on the type of virus used, its concentration, and the serotype of vector employed. To date these models have been variable, difficult to reproduce, and slow in their evolution to achieve a desired phenotype, hindering their use as a model for testing novel therapeutics. To address these issues we have taken a novel vector in this context, that can be prepared in high titer and which possesses an ability to produce neuronally-directed expression, with expression dynamics optimised to provide a rapid rise in gene product expression. Thus, in the current study, we have used a high titer chimeric AAV1/2 vector, to express human A53T alpha-syn, an empty vector control (EV), or green fluorescent protein (GFP), the latter to control for the possibility that high levels of protein in themselves might contribute to damage.Results: We show that following a single 2 mu l injection into the rat SN there is near complete coverage of the structure and expression of A53T alpha-syn or GFP appears throughout the striatum. Within 3 weeks of SN delivery of their respective vectors, aggregations of insoluble alpha-syn were observed in SN DA neurons. The numbers of DA neurons in the SN were significantly reduced by expression of A53T alpha-syn (52%), and to a lesser extent by GFP (24%), compared to EV controls (both P < 0.01). At the level of the striatum, AAV1/2-A53T alpha-syn injection produced dystrophic neurites and a significant reduction in tyrosine hydroxylase levels (by 53%, P < 0.01), this was not seen in the AAV1/2-GFP condition.Conclusions: In the current implementation of the model, we recapitulate the primary pathological hallmarks of PD, although a proportion of the SN damage may relate to general protein overload and may not be specific for A53T alpha-syn. Future studies will thus be required to optimise the dose of AAV1/2 employed before fully characterizing this model. The dynamics of the evolution of the pathology however, provide advantages over current models with respect to providing an initial screen to assess efficacy of novel treatments that might prevent/reverse alpha-syn aggregation.