School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Forester Hill, Aberdeen, AB25 2ZD, UK.
Institute of Pharmacology, Charité-Universitätsmedizin Berlin, Hessische Str. 3-4, 10115, Berlin, Germany.
Sci Rep. 2024 Mar 14;14(1):6239. doi: 10.1038/s41598-024-56735-6.
The accumulation of α-synuclein (α-Syn) into Lewy bodies is a hallmark of synucleinopathies, a group of neurological disorders that include Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Small oligomers as well as larger fibrils of α-Syn have been suggested to induce cell toxicity leading to a degenerative loss of neurones. A richer understanding of α-Syn aggregation in disease, however, requires the identification of the different α-Syn species and the characterisation of their biochemical properties. We here aimed at a more in-depth characterisation of the α-Syn transgenic mice, Line 62 (L62), and examined the deposition pattern and solubility of human and murine α-Syn in these mice using immunohistochemical and biochemical methods. Application of multiple antibodies confirmed mAb syn204 as the most discriminatory antibody for human α-Syn in L62. Syn204 revealed an intense and widespread immunohistochemical α-Syn labelling in parietal cortex and hippocampus, and to a lower level in basal forebrain and hindbrain regions. The labelled α-Syn represented somatic inclusions as well as processes and synaptic endings. Biochemical analysis revealed a Triton-resistant human α-Syn pool of large oligomers, a second pool of small oligomers that was not resistant to solubilization with urea/Triton. A third SDS-soluble pool of intermediate sized aggregates containing a mixture of both, human and mouse α-Syn was also present. These data suggest that several pools of α-Syn can exist in neurones, most likely in different cellular compartments. Information about these different pools is important for the development of novel disease modifying therapies aimed at α-Syn.
α-突触核蛋白（α-Syn）的积累形成路易体是突触核蛋白病的一个标志，这类疾病包括帕金森病（PD）和路易体痴呆（DLB）。小寡聚体以及较大的α-Syn 纤维被认为会诱导细胞毒性，导致神经元退行性丧失。然而，为了更深入地了解疾病中 α-Syn 的聚集，需要识别不同的 α-Syn 物种，并对其生化特性进行特征描述。在这里，我们旨在更深入地研究 Line 62（L62）转基因小鼠，并使用免疫组织化学和生化方法检查这些小鼠中人类和鼠源 α-Syn 的沉积模式和可溶性。应用多种抗体证实 mAb syn204 是 L62 中用于检测人类 α-Syn 的最具鉴别力的抗体。Syn204 揭示了在顶叶皮层和海马区中强烈而广泛的 α-Syn 免疫组织化学标记，在基底前脑和后脑区标记水平较低。标记的 α-Syn 代表了体部包涵体以及突起和突触末梢。生化分析显示，Triton 抗性的人类 α-Syn 有一个大寡聚物池，第二个小寡聚物池不易用尿素/Triton 溶解。还存在第三个 SDS 可溶性中间大小的聚集物池，其中包含混合的人类和鼠源 α-Syn。这些数据表明，神经元中可能存在几个 α-Syn 池，很可能存在于不同的细胞隔室中。这些不同池的信息对于开发旨在靶向 α-Syn 的新型疾病修饰疗法非常重要。
