The spreading and accumulation of α-synuclein and dopaminergic neurodegeneration, two hallmarks of Parkinson's disease (PD), have been faithfully reproduced in rodent brains by chronic, oral administration of β-sitosterol β-D-glucoside (BSSG). We investigated whether a single injection of BSSG (6 μg BSSG/μL DMSO) in the left substantia nigra of Wistar rats causes the same effects. Mock DMSO injections and untreated rats formed control groups. We performed immunostainings against the pathological α-synuclein, the dopaminergic marker tyrosine hydroxylase (TH), the neuroskeleton marker β-III tubulin, the neurotensin receptor type 1 (NTSR1) as non-dopaminergic phenotype marker and Fluro-Jade C (F-J C) label for neurodegeneration. Using β-galactosidase (β-Gal) assay and active caspase-3 immunostaining, we assessed cell death mechanisms. Golgi-Cox staining was used to measure the density and types of dendritic spines of striatal medium spiny neurons. Motor and non-motor alterations were also evaluated. The study period comprised 15 to 120 days after the lesion. In the injured substantia nigra, BSSG caused a progressive α-synuclein aggregation and dopaminergic neurodegeneration caused by senescence and apoptosis. The α-synuclein immunoreactivity was also present within microglia cells. Decreased density of dopaminergic fibers and dendritic spines also occurred in the striatum. Remarkably, all the histopathological changes also appeared on the contralateral nigrostriatal system, and α-synuclein aggregates were present in other brain regions. Motor and non-motor behavioral alterations were progressive. Our data show that the stereotaxic BSSG administration reproduces PD α-synucleinopathy phenotype in the rat. This approach will aid in identifying the spread mechanism of α-synuclein pathology and validate anti-synucleinopathy therapies.

中文翻译：

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β-谷甾醇β-D-葡萄糖苷的单侧鼻内给药触发了大鼠的病理性α-突触核蛋白扩散和双侧黑质纹状体多巴胺能神经变性。

通过长期口服β-谷甾醇β-D-葡萄糖苷（BSSG），在啮齿类动物的大脑中忠实地再现了帕金森氏病（PD）的两个标志-α-突触核蛋白和多巴胺能神经变性的扩散和积累。我们调查了在Wistar大鼠的左黑质中单次注射BSSG（6μgBSSG /μLDMSO）是否引起相同的作用。模拟DMSO注射和未治疗的大鼠组成对照组。我们针对病理性α-突触核蛋白，多巴胺能标记酪氨酸羟化酶（TH），神经骨架标记β-III微管蛋白，神经紧张素受体1型（NTSR1）作为非多巴胺能表型标记和Fluro-Jade C（FJ C）进行了免疫染色神经变性的标签。我们使用β-半乳糖苷酶（β-Gal）检测和活性caspase-3免疫染色，评估了细胞死亡机制。Golgi-Cox染色用于测量纹状体中棘神经元的树突棘的密度和类型。还评估了运动和非运动改变。研究期为病变后15至120天。在受损的黑质中，BSSG引起了由衰老和凋亡引起的进行性α-突触核蛋白聚集和多巴胺能神经变性。小胶质细胞中也存在α-突触核蛋白的免疫反应性。纹状体中也发生多巴胺能纤维和树突棘的密度降低。值得注意的是，所有组织病理学变化也出现在对侧黑纹状体系统上，其他脑区也存在α-突触核蛋白聚集体。运动和非运动行为改变是进行性的。我们的数据表明，立体定向BSSG给药可在大鼠中复制PDα-突触核蛋白病表型。这种方法将有助于确定α-突触核蛋白病理学的传播机制，并验证抗突触核蛋白病疗法。