Genes, Environment & Neural Stem Cell Transplantation in the Gut

神经干细胞(NSC)移植是一种新兴技术，在治疗急性髓细胞白血病方面前景广阔。 外周(PNS)和中枢神经系统(CNS)障碍。最近，我们的实验室已经开始 探讨神经干细胞作为胃肠动力障碍的一种可行治疗策略。使用 神经源性神经干细胞(CNS-NSC)在神经元型一氧化氮基因缺失小鼠体内的移植策略 氧化氮合酶(NNOS)，我们已经证明CNS-NSC可以成功地植入并分化为 神经元型一氧化氮合酶表达的神经元，可以恢复氮能松弛和“拯救”胃功能(排空)。 老鼠。我们还表明，内在的细胞凋亡信号在决定细胞存活率方面更为重要。 移植的NSC比宿主的免疫反应强。这些实验的结果已经产生了 对这一策略作为一种潜在疗法的可行性有相当大的信心。进一步验证这一点 方法将需要更多的知识，负责分化和生存的机制 NSC的肠子里。在这方面，我们最初把重点放在最具特征的负责途径上 为了肠道神经系统的正常发育，胶质源性神经营养因子或GDNF及其 同源受体，RET。我们的初步数据，使用CNS-NSC转染组活性RET 突变体(RET/PTC2)表明该途径的激活导致更大的增殖、存活和 神经干细胞的神经元分化。我们的总体假设是RET的激活足以改善 CNS-NSC肠道移植后的存活和分化 替代肠道神经系统功能的有效治疗策略。为了检验这一假设，我们将 利用从中枢神经系统(CNS-NSC)和肠道(ENS-NSC)分离出来的NSC实现以下具体目标： 具体目标1：使用可诱导的、具有结构性活性的RET/PTC2基因结构来确定持续时间 移植后最佳结果所需的RET激活。 具体目标2：确定RET激活是否可以在CNS或ENS来源的细胞中产生类似的表型 国家安全委员会。 具体目标3：确定RET激活的CNS和ENS来源的NSC是否能有效地恢复肠道功能 先天性巨结肠和炎症性疾病等临床相关疾病模型的神经元功能 神经病。 我们的长期目标是发展神经元移植，作为人类疾病的治疗手段 肠道神经系统。建立干细胞的最佳来源(成体与胚胎；中枢神经系统与 ENS等)目前仍然是一个难以实现的目标，许多实验室还需要几年的工作 在世界各地。通过确立可再生能源技术的许可和必要作用，拟议的研究将提供 治疗使用来自各种来源的神经元前体的关键基础工作。

Neural stem cell (NSC) transplantation is an emerging technique with immense promise for the treatment of disorders of the peripheral (PNS) and central nervous system (CNS). More recently, our laboratory has begun investigating the use of NSC as a viable therapeutic strategy for disorders of gastrointestinal motility. Using a strategy of transplanting CNS-derived NSC (CNS-NSC) in mice with a genetic deletion of the neuronal nitric oxide synthase (nNOS) enzyme, we have shown that CNS-NSC can successfully engraft and differentiate into nNOS expressing neurons, can restore nitrergic relaxation and "rescue" gastric function (emptying) in these mice. We have also shown that intrinsic apoptotic signaling is more important in determining the survival of transplanted NSC than the host immune response. The results of these experiments have generated considerable confidence in the viability of this strategy as a potential therapy. Further validation of this approach will require a greater knowledge of the mechanisms responsible for differentiation and survival of NSC in the gut. In this regard, we have initially focused on the most well characterized pathway responsible for the normal development of the enteric nervous system, glial derived neurotrophic factor or GDNF, and its cognate receptor, RET. Our preliminary data, using CNS-NSC transfected with a constitutively active RET mutant (RET/PTC2) suggest that activation of this pathway results in greater proliferation, survival and neuronal differentiation of NSC. Our overall hypothesis is that activation of RET is sufficient to improve the survival and differentiation of CNS-NSC after transplantation into the gut and that this can be an effective therapeutic strategy to replace enteric nervous system function. To test this hypothesis, we will pursue the following specific aims using NSC isolated from the CNS (CNS-NSC) and the gut (ENS-NSC): Specific Aim 1: To use an inducible, constitutively active RET/PTC2 gene construct to determine the duration of RET activation required for an optimal outcome after transplantation. Specific Aim 2: To determine if RET-activation can produce a similar phenotype in either CNS or ENS derived NSC. Specific Aim 3: To determine if RET-activated CNS and ENS-derived NSC can effectively restore enteric neuronal function in clinically relevant models of disease such as Hirschsprung's disease and inflammatory neuropathies. Our long-term objective is to develop neuronal transplantation as a treatment for human diseases of the enteric nervous system. To establish the optimal source of stem cells (adults versus embryonic; CNS versus ENS etc.) currently remains an elusive goal and will need several more years of work by many laboratories across the world. By establishing a permissive and necessary role of RET, the proposed studies will provide the critical groundwork for the therapeutic use of neuronal precursors from a variety of sources.