NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, Florida 32826, United States.
College of Medicine, University of Central Florida, 6850 Lake Nona Blvd, Orlando, Florida 32827, United States.
ACS Biomater Sci Eng. 2024 Nov 11;10(11):7132-7143. doi: 10.1021/acsbiomaterials.4c01431. Epub 2024 Oct 22.
Myelination and the formation of nodes of Ranvier are essential for the rapid conduction of nerve impulses along axons in the peripheral nervous system (PNS). While many animal-based and serum-containing models of peripheral myelination have been developed, these have limited ability when it comes to studying genetic disorders affecting peripheral myelination. We report a fully induced pluripotent stem cell (iPSC)-derived human model of peripheral myelination using Schwann cells (SCs) and motoneurons, cultured in a serum-free medium on patterned and nonpatterned surfaces. Results demonstrated iPSC-derived SC-expressed early growth response protein 2 (Egr2), a key transcription factor for myelination, and after ∼30 days in coculture, hallmark features of myelination, including myelin segment and node of Ranvier formation, were observed. Myelin segments were stained for the myelin basic protein, which surrounded neurofilament-stained motoneuron axons. Clusters of voltage-gated sodium channels flanked by paranodal protein contactin-associated protein 1, indicating node of Ranvier formation, were also observed. High-resolution confocal microscopy allowed for 3D reconstruction and measurement of myelin g-ratios of myelin segments, with an average g-ratio of 0.67, consistent with reported values in the literature, indicating mature myelin segment formation. This iPSC-based model of peripheral myelination provides a platform to investigate numerous PNS diseases, including Charcot-Marie Tooth disorder, Guillian-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, and antimyelin-associated glycoprotein peripheral neuropathy, with the potential for greater translatability to humans for improving the applicability for drug-screening programs.
髓鞘形成和郎飞结的形成对于外周神经系统（PNS）中轴突的神经冲动快速传导至关重要。虽然已经开发出许多基于动物和含血清的周围髓鞘形成模型，但这些模型在研究影响周围髓鞘形成的遗传疾病方面能力有限。我们报告了一种使用施万细胞（SCs）和运动神经元的完全诱导多能干细胞（iPSC）衍生的人外周髓鞘形成模型，该模型在无血清培养基中在图案化和非图案化表面上培养。结果表明，iPSC 衍生的 SC 表达早期生长反应蛋白 2（Egr2），这是髓鞘形成的关键转录因子，在共培养约 30 天后，观察到髓鞘形成的标志性特征，包括髓鞘节段和郎飞结的形成。髓鞘节段用髓鞘碱性蛋白染色，该蛋白包围神经丝染色的运动神经元轴突。也观察到被连接蛋白相关蛋白 1 包围的电压门控钠通道簇，表明郎飞结的形成。高分辨率共聚焦显微镜允许对髓鞘节段的 3D 重建和测量进行测量，髓鞘节段的平均 g-比值为 0.67，与文献中报道的值一致，表明成熟的髓鞘节段形成。这种基于 iPSC 的周围髓鞘形成模型为研究许多 PNS 疾病提供了一个平台，包括腓骨肌萎缩症、格林-巴利综合征、慢性炎症性脱髓鞘性多发性神经病和抗髓鞘相关糖蛋白周围神经病，具有更大的向人类转化的潜力，以提高药物筛选计划的适用性。
