Regionalized Human Motor Neuron Therapies

干细胞替代疗法是长期治疗的一种有前景的、有效的替代疗法。 与创伤或神经变性导致的运动障碍相关的入路。然而，当细胞 脊髓再生的治疗方法很有希望，到目前为止，研究发现神经元细胞很差。 整合和/或可变的功能结果。其中一个原因可能是地区表型不匹配。 对大脑的研究强调了对人类多能干细胞进行区域性规范的重要性。 (HPSC)来源的神经前体细胞可缓解啮齿动物的帕金森氏症、亨廷顿氏症和癫痫症状 模特们。在脊髓中的可比研究由于控制区域的能力有限而受到阻碍。 HPSC来源的脊髓细胞群体的表型。这项提议的基本假设是 HPSC来源的神经元移植到离散脊髓区域的遗传学规范 影响植入效果，进而影响患者的功能恢复。 这项工作的重点是运动神经元(MN)，它是许多 神经退行性疾病，并在脊髓损伤后受损。在神经管发育过程中， 共线HOX表达导致神经元表型沿脊髓R/C轴的空间构型 电源线。阿什顿实验室已经建立了协议，在hPSCs中重述这种HOX进程，产生神经 具有离散HOX特征的干细胞。当与形态促进剂结合用于腹侧模式时，该方案 能够派生出祖细胞MN(PMN)和MN的全吻尾谱，其可用作 用于移植的区域特定人群。目标1侧重于这些基因的产生和表征 代表高颈、中颈、臂、胸、腰椎和骶骨的区域性MN培养 解剖节段。除了通过分子和功能分析进行表征外，单细胞RNA-seq 将在以下时间之前执行，以确定区域化MN人口中的柱状和机动车池身份 移植。AIMS 2和3检验区域化的hPSC来源的pMN差异整合的假设 进入宿主电路并选择性地增强体内的功能恢复。AIM 2检查pMN是否 优先植入与其区域匹配的脊髓节段，并选择性地将轴突投射到 在发育雏鸟模型中协调肌肉结构。目标3试图确定区域化的pMN 移植到选择性切除的成年大鼠体内后有助于功能恢复 隔膜型MNS。人们的预期是，移植沉默后，行为方面的进步会有所减轻。加在一起，这些 目的建立临床相关的MN移植人群，促进对MN的机制的理解 人类MN多样化并确立区域特异性对神经元向中枢整合的作用 神经系统。这一发现可以指导未来的临床干预，并可移植到其他脊髓细胞， 包括中间神经元和神经胶质细胞。

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.