Induced Neural Cell Integration in the Rat Central Nervous System

描述(申请人提供)：移植是一种被证实的替代或修复受损组织的方法；然而，移植组织的存活和移植的最终成功取决于移植是否被宿主接受。多年来，出现了几种策略来改进自体细胞在中枢神经系统疾病和损伤的移植治疗中的使用：1)体外基因疗法，即通过移植自体细胞来分泌治疗因子；2)移植从各种组织中分离出来的“成人”干细胞；以及3)移植来源于干细胞的中枢神经系统细胞类型，如诱导多能干细胞。这些策略都有缺陷：移植的非中枢神经系统细胞不能在功能上整合和响应体内的中枢神经系统环境，而移植的来源于祖细胞的真实中枢神经系统细胞可能保留一些残留的增殖能力，形成肿瘤。我们已经确定了人和大鼠成纤维细胞的反式激活因子和培养条件的组合，这些条件可以导致细胞具有类似于小鼠“诱导神经细胞”(INCs)的神经元特征。从胚胎或成年大鼠和人类细胞中分离出的INCs在培养中显示了神经元的形态、标志物的表达/分布和电生理特性，但将INC导入活的哺乳动物中枢神经系统后，其功能尚不清楚。本研究的目的是确定移植的自体大鼠和非自体人INCs在新生大鼠和成年大鼠中枢神经系统中的存活、分化和功能整合能力。这项初步研究将确定INCS对CNS的影响以及CNS对INCS的影响--这是两个新的、同样重要的悬而未决的问题。INCs作为可能的神经移植的创新之处在于，它们在理论上结合了当前移植策略的最佳特征，即严格控制生长的细胞的安全性，以及在功能上整合和响应中枢神经系统环境的潜在能力。拟议中的实验旨在确定转分化的神经细胞或跨神经元在其“天然”环境中的潜力。

DESCRIPTION (provided by applicant): Transplantation is a proven method for replacement or repair of damaged tissue; however, the survival of the engrafted tissue and the ultimate success of the transplant rests on whether the transplant is accepted by the host. Several strategies have emerged over the years that would improve the use of autologous cells in transplantation therapy for CNS disease and injury: 1 ) ex vivo gene therapy, where a therapeutic factor is secreted by a transplant of autologous cells, 2) transplantation of "adult" stem cells isolated from various tissues, and 3) transplantation of CNS cell types derived from stem cells such as induced pluripotent stem cells. There are drawbacks to each of these strategies: transplanted non-CNS cells cannot functionally integrate and respond to the in vivo CNS environment, and transplanted bona fide CNS cells derived from progenitors may retain some remnant of their proliferative capability and form a tumor. We have identified a combination of transactivating factors and culture conditions for human and rat fibroblasts that result in cells with neuronal characteristics similar to those described for mouse "induced neural cells" (INCs). INCs generated from fetal or adult rat and human cells display the morphological, marker expression/distribution, and electrophysiological properties of neurons in culture, but nothing is known about INC function when introduced into the living mammalian CNS. The objective of this proposal is to ascertain the survival, differentiation into CNS cell types, and capacity for functional integration of engrafted autologous rat and non-autologous human INCs into the newborn and adult rat CNS. This pilot study will determine the effect of INCs on the CNS and the effect of the CNS on INCs - both new and equally important unanswered questions. The innovation of INCs as possible neural transplants is that they theoretically combine the best features of current transplantation strategies, namely, the safety of cells with stringent growth control combined with the potential capacity to functionally integrate and respond to the CNS environment. The experiments proposed are designed to define the potential of transdifferentiated neural cells or transneurons - in their "native" environment.