Regionalized Human Motor Neuron Therapies

干细胞替代疗法是一种有前途的，治愈性的长期管理替代方案。 与创伤或神经变性引起的运动缺陷相关的方法。虽然Cell 脊髓再生的治疗是有希望的，迄今为止的研究遭受了不良的神经元损伤。 整合和/或可变的功能结果。其中一个原因可能是区域表型不匹配。 大脑研究强调了人类多能干细胞区域特异性的重要性 （hPSC）衍生的神经祖细胞减轻啮齿动物中的帕金森氏症、亨廷顿氏症和癫痫症症状 模型脊髓中的可比研究受到控制区域神经元的有限能力的阻碍。 hPSC衍生的脊柱群体的表型。这一提议的基本假设是， hPSC衍生的神经元移植到离散的脊髓区域的遗传特异性显著增加， 影响植入效果和随后患者的功能恢复。 这项工作的重点是运动神经元（MN），这是专门针对在一些 神经退行性疾病，并且在脊髓损伤后受损。在神经管发育过程中， 共线HOX表达导致神经元表型沿着脊髓背角R/C轴的空间模式化。 线. Ashton实验室已经建立了在hPSC中概括这种Hox进展的方案，产生神经细胞。 具有离散Hox特征的干细胞。当与形态发生剂结合用于腹侧图案形成时，该方案 能够推导出祖MN（pMN）和MN的完整吻尾光谱， 特定区域的人群进行移植。目标1侧重于这些的生成和表征 代表高颈、中颈、肱、胸、腰和骶的区域化MN培养 解剖节段除了通过分子和功能测定进行表征外，单细胞RNA-seq 将进行，以确定区域化MN人群中的柱状和机动车库身份， 移植目的2和3检验区域化hPSC衍生的pMN差异整合的假设 并选择性地增强体内功能恢复。目的2检查pMN是否 优先移植到他们的区域匹配的脊髓节段，并选择性地将轴突投射到 协调肌肉组织在发育小鸡模型。目标3旨在确定区域化pMN是否 有助于移植到已被选择性消融的成年大鼠后的功能恢复。 膈神经预期的是，行为增益减轻移植沉默。所有这些 目的是建立临床相关的MN移植人群，促进对 人MN多样化，并建立区域特异性对神经元整合到中枢的作用。 神经系统这些发现可以指导未来的临床干预，并可转化为其他脊髓细胞， 包括中间神经元和神经胶质。

Stem cell replacement therapies are a promising, curative alternative to the long-term management approaches associated with locomotor deficits from trauma or neurodegeneration. However, while cell therapies for spinal cord regeneration are promising, studies to date have suffered from poor neuronal integration and/or variable functional outcomes. One reason for this may be regional phenotype mismatch. Studies in the brain have highlighted the importance of regional specification of human pluripotent stem cell (hPSC)-derived neural progenitors to alleviate Parkinson's, Huntington's, and Epilepsy" symptoms in rodent models. Comparable studies in the spinal cord have been hindered by a limited capacity to control the regional phenotype of hPSC-derived spinal populations. The fundamental hypothesis of this proposal is that genetic specification of hPSC-derived neuronal transplants to discrete spinal cord regions significantly affects engraftment efficacy and subsequently patients' functional recovery. This work focuses on motor neurons (MNs), which are specifically targeted in a number of neurodegenerative diseases and are damaged following spinal cord injury. During neural tube development, colinear HOX expression results in spatial patterning of neuronal phenotypes along the R/C axis of the spinal cord. The Ashton lab has established protocols recapitulate this Hox progression in hPSCs, generating neural stem cells with discrete Hox profiles. When combined with morphogens for ventral patterning, this protocol enables the derivation of a full rostrocaudal spectrum of progenitor MNs (pMNs) and MNs that can serve as region-specific populations for transplantation. Aim 1 focuses on the generation and characterization of these regionalized MN cultures representative of high cervical, mid cervical, brachial, thoracic, lumbar, and sacral anatomical segments. In addition to characterization by molecular and functional assays, single cell RNA-seq will be performed to determine columnar and motor pool identities within regionalized MN populations prior to transplantation. Aims 2 and 3 test the hypothesis that regionalized hPSC-derived pMNs differentially integrate into host circuits and selectively enhance functional recovery in vivo. Aim 2 examines whether pMNs preferentially engraft into their region-matched spinal cord segment and selectively project axons onto coordinate musculature in a developmental chick model. Aim 3 seeks to determine whether regionalized pMNs contribute to functional recovery following transplantation into an adult rat that has been selectively ablated of phrenic MNs. The expectation is that behavioral gains are mitigated upon transplant silencing. Together, these aims establish clinically relevant MN populations for transplantation, advance a mechanistic understanding of human MN diversification and establish the role of regional specificity on neuronal integration into the central nervous system. The findings can guide future clinical interventions and are translatable to other spinal cells, including interneurons and glia.