Length-dependent axonal degeneration is the pathologic hallmark of several neurodegenerative disorders, including inherited peripheral neuropathies (Charcot-Marie-Tooth (CMT) disease). CMT is currently an untreatable disorder. This is partially due to lack of translational models suitable for drug discovery. In vitro models of CMT have been hindered by the 2D configuration of neuronal cultures, which limits visualization and orientation of axons. To overcome these limitations, we cultured induced pluripotent stem cell (iPSC)-derived spinal motor neurons as 3D spheroids, which grow axons in a centrifugal fashion when plated. Using these iPSC-derived spinal spheroids, we demonstrate neurofilament deposits in motor neuron axons of three patients with CMT2E, caused by mutations in the NEFL gene. This phenotype is partially reversed by two kinase inhibitors. In summary, we developed a human tridimensional in vitro system that models length-dependent axonopathies, recapitulates key pathophysiologic features of CMT2E, and should facilitate the identification of new therapeutic compounds for CMT.

中文翻译：

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人类三维神经元文化中遗传性周围神经病的表型药物筛选。

长度依赖性轴突变性是几种神经退行性疾病的病理标志，包括遗传性周围神经病（夏科-玛丽-牙（CMT）疾病）。CMT目前是一种无法治愈的疾病。部分原因是缺乏适用于药物发现的翻译模型。CMT的体外模型已被神经元文化的2D配置所阻碍，这限制了轴突的可视化和方向。为了克服这些局限性，我们将诱导多能干细胞（iPSC）衍生的脊髓运动神经元培养为3D球体，在接种时会以离心的方式生长轴突。使用这些iPSC衍生的脊髓球体，我们证明了NEFL基因突变引起的3例CMT2E患者的运动神经元轴突中的神经丝沉积。该表型被两种激酶抑制剂部分逆转。总而言之，我们开发了一种人类三维体外系统，该系统可模拟长度依赖性轴突病，概括CMT2E的关键病理生理特征，并应有助于鉴定CMT的新治疗化合物。