Transplantation of Induced Pluripotent Stem Cell-Derived Neural Stem Cells Mediate Functional Recovery Following Thoracic Spinal Cord Injury Through Remyelination of Axons
Transplantation of Induced Pluripotent Stem Cell-Derived Neural Stem Cells Mediate Functional Recovery Following Thoracic Spinal Cord Injury Through Remyelination of Axons
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DOI：
10.5966/sctm.2014-0236
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发表时间：
2015-07-01
影响因子：
6
通讯作者：
Fehlings, Michael G.
中科院分区：
文献类型：
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作者：
Salewski, Ryan P.;Mitchell, Robert A.;Fehlings, Michael G.
胚胎或胎儿/成人组织来源的神经干细胞（NSCs）在创伤性脊髓损伤（SCI）的再生策略中显示出相当大的前景。然而，它们的使用存在与可用性、免疫原性和所涉及机制的不确定性有关的局限性。为了解决这些问题，研究人员使用非病毒的piggyBac转座子方法从诱导多能干细胞（iPS）细胞中获得了最终的NSCs。承诺的NSCs是由iPS细胞生成的，使用我们实验室先前描述的自由浮动神经球方法。为了描述其作用机制，特别是外源性髓鞘形成的作用，我们在胸椎脊髓损伤合并亚急性椎管内移植后使用了野生型（wt）和非髓鞘性Shiverer (shi) iPS细胞系衍生的NSCs。对行为、组织学和电生理结果进行分析，以评估这种治疗的有效性。wt-和ship - ips - nscs经过验证，除了髓鞘形成能力外，它们是相同的。两种iPS-NSC细胞系都成功地整合到受损脊髓中，并主要分化为少突胶质细胞，但只有wt-iPS-NSC治疗产生了功能上的益处。与非髓鞘iPS-dNSCs和无细胞对照相比，显示出髓鞘再生能力的wt-iPS-dNSCs显著改善了神经行为功能（Basso小鼠量表和CatWalk）、组织学结果和轴突功能的电生理测量（蔗糖间隙分析）。总之，我们证明了iPS细胞可以产生翻译相关的NSCs用于SCI。尽管NSCs在损伤脊髓中具有多种功能，但髓鞘再生是胸段脊髓损伤后恢复的主要机制。
Neural stem cells (NSCs) from embryonic or fetal/adult tissue sources have shown considerable promise in regenerative strategies for traumatic spinal cord injury (SCI). However, there are limitations with their use related to the availability, immunogenicity, and uncertainty of the mechanisms involved. To address these issues, definitive NSCs derived from induced pluripotent stem (iPS) cells generated using a nonviral, piggyBac transposon approach, were investigated. Committed NSCs were generated from iPS cells using a free-floating neurosphere methodology previously described by our laboratory. To delineate the mechanism of action, specifically the role of exogenous myelination, NSCs derived from wildtype (wt) and nonmyelinating Shiverer (shi) iPS cell lines were used following thoracic SCI with subacute intraspinal transplantation. Behavioral, histological, and electrophysiological outcomes were analyzed to assess the effectiveness of this treatment. The wt- and shi-iPS-NSCs were validated and shown to be equivalent except in myelination capacity. Both iPS-NSC lines successfully integrated into the injured spinal cord and predominantly differentiated to oligodendrocytes, but only the wt-iPS-NSC treatment resulted in a functional benefit. The wt-iPS-dNSCs, which exhibited the capacity for remyelination, significantly improved neurobehavioral function (Basso Mouse Scale and CatWalk), histological outcomes, and electrophysiological measures of axonal function (sucrose gap analysis) compared with the nonmyelinating iPS-dNSCs and cell-free controls. In summary, we demonstrated that iPS cells can generate translationally relevant NSCs for applications in SCI. Although NSCs have a diverse range of functions in the injured spinal cord, remyelination is the predominant mechanism of recovery following thoracic SCI.