Multiple System Atrophy (MSA) is a progressive neurodegenerative disease characterized by chronic neuroinflammation and widespread α-synuclein (α-syn) cytoplasmic inclusions. Neuroinflammation associated with microglial cells is typically located in brain regions with α-syn deposits. The potential link between microglial cell migration and the transport of pathological α-syn protein in MSA was investigated. Qualitative analysis via immunofluorescence of MSA cases (n = 4) revealed microglial cells bearing α-syn inclusions distal from oligodendrocytes bearing α-syn cytoplasmic inclusions, as well as close interactions between microglia and oligodendrocytes bearing α-syn, suggestive of a potential transfer mechanism between microglia and α-syn bearing cells in MSA and the possibility of microglia acting as a mobile vehicle to spread α-syn between anatomically connected brain regions. Further In vitro experiments using microglial-like differentiated THP-1 cells were conducted to investigate if microglial cells could act as potential transporters of α-syn. Monomeric or aggregated α-syn was immobilized at the centre of glass coverslips and treated with either cell free medium, undifferentiated THP-1 cells or microglial-like phorbol-12-myristate-13-acetate differentiated THP-1 cells (48 h; n = 3). A significant difference in residual immobilized α-syn density was observed between cell free controls and differentiated (p = 0.016) as well as undifferentiated and differentiated THP-1 cells (p = 0.032) when analysed by quantitative immunofluorescence. Furthermore, a significantly greater proportion of differentiated cells were observed bearing α-syn aggregates distal from the immobilized protein than their non-differentiated counterparts (p = 0.025). Similar results were observed with Highly Aggressive Proliferating Immortalised (HAPI) microglial cells, with cells exposed to aggregated α-syn yielding lower residual immobilized α-syn (p = 0.004) and a higher proportion of α-syn positive distal cells (p = 0.001) than cells exposed to monomeric α-syn. Co-treatment of THP-1 groups with the tubulin depolymerisation inhibitor, Epothilone D (EpoD; 10 nM), was conducted to investigate if inhibition of microtubule activity had an effect on cell migration and residual immobilized α-syn density. There was a significant increase in both residual immobilized α-syn between EpoD treated and non-treated differentiated cells exposed to monomeric (p = 0.037) and aggregated (p = 0.018) α-syn, but not with undifferentiated cells. Differentiated THP-1 cells exposed to immobilized aggregated α-syn showed a significant difference in the proportion of distal aggregate bearing cells between EpoD treated and untreated (p = 0.027). The results suggest microglia could play a role in α-syn transport in MSA, a role which could potentially be inhibited therapeutically by EpoD.

中文翻译：

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埃博霉素D抑制小胶质细胞介导的α-突触核蛋白聚集体的扩散。

多系统萎缩症（MSA）是一种进行性神经退行性疾病，其特征在于慢性神经炎症和广泛的α-突触核蛋白（α-syn）细胞质内含物。与小胶质细胞相关的神经炎症通常位于具有α-syn沉积物的大脑区域。研究了小胶质细胞迁移与病理性α-syn蛋白在MSA中的运输之间的潜在联系。MSA病例（n = 4）的免疫荧光定性分析显示，小胶质细胞的α-syn内含物远离带有α-syn胞质内含物的少突胶质细胞，以及小胶质细胞与荷有α-syn的少突胶质细胞之间的紧密相互作用，这提示了MSA中小胶质细胞和带有α-syn的细胞之间的潜在转移机制，以及小胶质细胞作为移动载体在解剖学上相连的大脑区域之间传播α-syn的可能性。进一步的体外实验使用小胶质细胞样的THP-1细胞进行了研究，以研究小胶质细胞是否可以作为α-syn的潜在转运蛋白。将单体或聚集的α-syn固定在玻璃盖玻片的中心，并用无细胞培养基，未分化的THP-1细胞或小胶质状佛波12-肉豆蔻酸13-乙酸酯分化的THP-1细胞处理（48小时； n = 3）。在无细胞对照和分化（p = 0.016）以及未分化和分化的THP-1细胞（p = 0）之间观察到残留固定的α-syn密度存在显着差异。032）通过定量免疫荧光分析。此外，与未分化的对应物相比，观察到比例更大的分化细胞带有固定化蛋白远端的α-syn聚集体（p = 0.025）。在高度侵袭性永生化（HAPI）小胶质细胞中观察到了相似的结果，暴露于聚集的α-syn的细胞产生的残余固定化α-syn较低（p = 0.004），而α-syn阳性远端细胞的比例更高（p = 0.001） ）比暴露于单体α-syn的细胞多。将THP-1基团与微管蛋白解聚抑制剂Epothilone D（EpoD; 10 nM）进行了共处理，以研究抑制微管活性是否对细胞迁移和残留的固定化α-syn密度有影响。在暴露于单体（p = 0.037）和聚集（p = 0.018）α-syn的EpoD处理的和未处理的分化细胞之间，残留固定的α-syn都有显着增加，而未分化的细胞则没有。暴露于固定化聚集的α-syn的分化型THP-1细胞在EpoD处理和未处理之间显示出远端聚集骨细胞的比例有显着差异（p = 0.027）。结果表明，小胶质细胞可能在MSA中的α-syn转运中起作用，这一作用可能被EpoD治疗性抑制。暴露于固定化聚集的α-syn的分化型THP-1细胞在EpoD处理和未处理之间显示出远端聚集骨细胞的比例有显着差异（p = 0.027）。结果表明，小胶质细胞可能在MSA中的α-syn转运中起作用，这一作用可能被EpoD治疗性抑制。暴露于固定化聚集的α-syn的分化型THP-1细胞在EpoD处理和未处理之间显示出远端聚集骨细胞的比例有显着差异（p = 0.027）。结果表明，小胶质细胞可能在MSA中的α-syn转运中起作用，这一作用可能被EpoD治疗性抑制。