KU Leuven - University of Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute, Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.
VIB, Center for Brain & Disease Research, Research Group Molecular Neurobiology, Leuven, Belgium; KU Leuven - University of Leuven, VIB Bio Imaging Core, Leuven, Belgium.
Stem Cell Reports. 2021 Sep 14;16(9):2213-2227. doi: 10.1016/j.stemcr.2021.03.029. Epub 2021 Apr 22.
Neuromuscular junctions (NMJs) ensure communication between motor neurons (MNs) and muscle; however, in MN disorders, such as amyotrophic lateral sclerosis (ALS), NMJs degenerate resulting in muscle atrophy. The aim of this study was to establish a versatile and reproducible in vitro model of a human motor unit to investigate the effects of ALS-causing mutations. Therefore, we generated a co-culture of human induced pluripotent stem cell (iPSC)-derived MNs and human primary mesoangioblast-derived myotubes in microfluidic devices. A chemotactic and volumetric gradient facilitated the growth of MN neurites through microgrooves resulting in the interaction with myotubes and the formation of NMJs. We observed that ALS-causing FUS mutations resulted in reduced neurite outgrowth as well as an impaired neurite regrowth upon axotomy. NMJ numbers were likewise reduced in the FUS-ALS model. Interestingly, the selective HDAC6 inhibitor, Tubastatin A, improved the neurite outgrowth, regrowth, and NMJ morphology, prompting HDAC6 inhibition as a potential therapeutic strategy for ALS.
神经肌肉接头 (NMJ) 确保运动神经元 (MNs) 和肌肉之间的通讯；然而，在 MN 疾病（如肌萎缩侧索硬化症）中，NMJ 退化导致肌肉萎缩。本研究的目的是建立一种多功能且可重现的体外人运动单位模型，以研究导致 ALS 的突变的影响。因此，我们在微流控设备中生成了人诱导多能干细胞 (iPSC) 衍生的 MN 和人原代中胚层衍生的肌管的共培养物。趋化性和体积梯度通过微沟促进 MN 轴突的生长，从而与肌管相互作用并形成 NMJ。我们观察到，导致 ALS 的 FUS 突变导致轴突生长减少以及轴突切断后的轴突再生受损。NMJ 数量在 FUS-ALS 模型中也减少了。有趣的是，选择性 HDAC6 抑制剂 Tubastatin A 改善了轴突的生长、再生和 NMJ 形态，提示 HDAC6 抑制可能是 ALS 的一种潜在治疗策略。
