Development and Characterisation of anin vitroModel of Wallerian Degeneration
Development and Characterisation of anin vitroModel of Wallerian Degeneration
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DOI：
10.3389/fbioe.2020.00784
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发表时间：
2020-07-10
影响因子：
5.7
通讯作者：
Reid, Adam J.
中科院分区：
文献类型：
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作者：
Elsayed, Heba;Faroni, Alessandro;Reid, Adam J.
周围神经损伤后，在远端残端发生一系列称为沃勒变性（WD）的事件，以允许再生轴突向靶器官生长。雪旺细胞（SC）通过启动吸引巨噬细胞和免疫细胞的炎症反应，以及产生对神经再生至关重要的神经营养信号，在其中发挥主导作用。大多数现有的研究都集中在改善再生的工具上，忽略了关键的退化阶段。这也是由于缺乏能概括体内WD特征的体外模型。特别是，为了了解损伤后的初始SC反应，并研究潜在的干预措施，需要将神经与其他全身影响隔离的模型。干细胞干预已被广泛研究作为一种潜在的治疗干预，以增加再生;然而，有关其在WD中的作用的数据是缺乏的。因此，在这项研究中，我们描述了一个体外模型，使用大鼠坐骨神经外植体退化长达14天。除了免疫组织化学分析和电子显微镜检查外，还通过WD关键标志物的基因和蛋白质表达对该模型进行了表征。我们在体内发现了与WD一致的变化：修复程序蛋白CJUN的上调，髓鞘蛋白基因的下调以及随后的髓鞘结构的解体和破坏。作为检测干细胞干预对WD影响的一种手段，我们建立了人脂肪间充质干细胞（AD-MSC）与变性神经外植体的间接共培养。干细胞干预增强了神经营养因子和Cjun的表达。我们的结论是，我们的体外模型的主要特点ofin vivoWD的，我们提供的原则证明其有效性的研究实验方法的神经再生集中在WD期间发生的事件。
Following peripheral nerve injury, a sequence of events termed Wallerian degeneration (WD) takes place at the distal stump in order to allow the regenerating axons to grow back toward the target organs. Schwann cells (SCs) play a lead role in this by initiating the inflammatory response attracting macrophages and immune cells, as well as producing neurotrophic signals that are essential for nerve regeneration. The majority of existing research has focused on tools to improve regeneration, overlooking the critical degeneration phase. This is also due to the lack ofin vitromodels recapitulating the features ofin vivoWD. In particular, to understand the initial SC response following injury, and to investigate potential interventions, a model that isolates the nerve from other systemic influences is required. Stem cell intervention has been extensively studied as a potential therapeutic intervention to augment regeneration; however, data regarding their role in WD is lacking. Thus, in this study we describe anin vitromodel using rat sciatic nerve explants degenerating up to 14 days. Characterisation of this model was performed by gene and protein expression for key markers of WD, in addition to immunohistochemical analysis and electron microscopy. We found changes in keeping with WDin vivo: upregulation of repair program protein CJUN, downregulation of myelin protein genes and subsequent disorganisation and breakdown of myelin structure. As a means of testing the effects of stem cell intervention on WD we established indirect co-cultures of human adipose-derived mesenchymal stem cells (AD-MSC) with the degenerating nerve explants. The stem cell intervention potentiated neurotrophic factors and Cjunexpression. We conclude that ourin vitromodel shares the main features ofin vivoWD, and we provide proof of principle on its effectiveness to study experimental approaches for nerve regeneration focused on the events happening during WD.