Neural Plasticity and Repair Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, BMC A10, 221 84 Lund, Sweden.
Neurobiol Dis. 2013 Aug;56:145-55. doi: 10.1016/j.nbd.2013.04.017. Epub 2013 Apr 30.
Compelling evidence suggests that accumulation and aggregation of alpha-synuclein (α-syn) contribute to the pathogenesis of Parkinson's disease (PD). Here, we describe a novel Bacterial Artificial Chromosome (BAC) transgenic model, in which we have expressed wild-type human α-syn fused to green fluorescent protein (GFP), under control of the mouse α-syn promoter. We observed a widespread and high expression of α-syn-GFP in multiple brain regions, including the dopaminergic neurons of the substantia nigra pars compacta (SNpc) and the ventral tegmental area, the olfactory bulb as well as in neocortical neurons. With increasing age, transgenic mice exhibited reductions in amphetamine-induced locomotor activity in the open field, impaired rotarod performance and a reduced striatal dopamine release, as measured by amperometry. In addition, they progressively developed deficits in an odor discrimination test. Western blot analysis revealed that α-syn-GFP and phospho-α-syn levels increased in multiple brain regions, as the mice grew older. Further, we observed, by immunohistochemical staining for phospho-α-syn and in vivo by two-photon microscopy, the formation of α-syn aggregates as the mice aged. The latter illustrates that the model can be used to track α-syn aggregation in vivo. In summary, this novel BAC α-syn-GFP model mimics a unique set of aspects of PD progression combined with the possibility of tracking α-syn aggregation in neocortex of living mice. Therefore, this α-syn-GFP-mouse model can provide a powerful tool that will facilitate the study of α-syn biology and its involvement in PD pathogenesis.
有强有力的证据表明，α-突触核蛋白（α-syn）的积累和聚集导致帕金森病（PD）的发病机制。在这里，我们描述了一种新型的细菌人工染色体（BAC）转基因模型，在该模型中，我们表达了与人α-syn 融合的绿色荧光蛋白（GFP），受小鼠α-syn 启动子的控制。我们观察到α-syn-GFP 在多个脑区广泛而高度表达，包括黑质致密部（SNpc）和腹侧被盖区的多巴胺能神经元、嗅球以及新皮层神经元。随着年龄的增长，转基因小鼠在旷场中的安非他命诱导的运动活性降低，旋转棒表现受损，并且通过安培法测量纹状体多巴胺释放减少。此外，它们在气味辨别测试中逐渐出现缺陷。Western blot 分析显示，随着小鼠年龄的增长，α-syn-GFP 和磷酸化α-syn 的水平在多个脑区增加。此外，通过对磷酸化α-syn 的免疫组织化学染色和体内双光子显微镜观察，我们观察到随着小鼠年龄的增长，α-syn 聚集体的形成。后者表明该模型可用于在体内跟踪α-syn 聚集。总之，这种新型的 BAC α-syn-GFP 模型模拟了 PD 进展的一系列独特方面，同时具有在活体小鼠新皮层中跟踪 α-syn 聚集的可能性。因此，这种 α-syn-GFP 小鼠模型可以提供一个强大的工具，将有助于研究α-syn 的生物学及其在 PD 发病机制中的作用。
