Genes, environment & neural stem cell transplantation in the gut

描述（由申请人提供）：功能性肠神经元的丧失导致临床疾病，例如贲门失弛缓症、胃轻瘫、假性梗阻的神经病形式、肠神经元发育不良、结肠惯性和先天性巨结肠。尽管在这些条件下缺乏显着的神经发生在体内，有越来越多的证据表明，在肠道中存在大量的多能神经前体细胞（NPC）。包括我们在内的一些研究人员已经表明，这些细胞具有一些典型的神经胶质细胞表型标记，能够在体外进行强大的神经发生。我们现在已经表明，肠神经节在纵肌肌间神经丛（LMMP）的制剂显示神经发生，这是在完全分离的NPC制剂在文化中更显着。我们已经确定了肠神经前体在体内和体外，我们的初步研究牵连磷酸酶和张力蛋白同源物（PTEN）在这些细胞中的主要“刹车”在体内神经发生。当加入到LMMP制剂中时，进一步的胶原IV可以对神经发生具有深刻的抑制作用。因此，它是合乎逻辑的假设，体内和离体情况之间的差异可以解释的微环境中的因素，调节PTEN。因此，在本提案中，我们打算通过以下具体目的来检查IV型胶原和下游途径（包括可能驱动PTEN活性的整合素、FAK和RhoA/ROCK）的作用，检查体内肠神经发生：（胶原）和内在（PTEN）对健康和疾病中神经发生的制动为了检查对抗内在和外在制动对健康和疾病中体内肠神经发生的影响，具体目标3：为了检查操纵这些途径的选定关键组分对同种异体肠NSC（ENSC）移植物的存活和功能的影响，术语目的是开发神经元移植作为人类肠神经系统疾病的治疗以及刺激这些疾病中的神经再生。通过建立PTEN和相关通路的作用，拟议的研究将为新的治疗干预提供关键的基础。

DESCRIPTION (provided by applicant): Loss of functional enteric neurons results in clinical disorders such as achalasia, gastroparesis, neuropathic forms of pseudoobstruction, enteric neuronal dysplasia, colonic inertia and Hirschsprung's disease. Despite the lack of significant neurogenesis in vivo in these conditions, there is growing evidence to suggest the existence of multipotent neural precursor cells (NPCs) in abundant numbers in the gut. Several investigators including ourselves have shown that these cells, which have some phenotypical markers typical of glia, are capable of robust neurogenesis in vitro. We have now shown that enteric ganglia in longitudinal muscle myenteric plexus (LMMP) preparations display neurogenesis and this is even more pronounced in completely dissociated NPC preparations in culture. We have identified enteric neural precursors in vivo and in vitro and our preliminary studies implicate phosphatase and tensin homolog (PTEN) in these cells as the major "brake" on neurogenesis in vivo. Further collagen IV when added to LMMP preparations can have a profound inhibitory effect on neurogenesis. Thus it is logical to hypothesize that the discrepancy between the in vivo and ex vivo situation can be explained by factors in the microenvironment that regulate PTEN. In this proposal we therefore intend to examine the effects of collagen IV and downstream pathways including integrin, FAK and RhoA/ROCK which may drive PTEN activity, checking enteric neurogenesis in vivo, via the following specific aims: Specific Aim 1: To determine the interactions between extrinsic (collagen) and intrinsic (PTEN) brakes on neurogenesis in health and disease Specific Aim 2: To examine the effects of countering intrinsic and extrinsic brakes on enteric neurogenesis in vivo in health and disease Specific Aim 3: To examine the effects of manipulating selected key components of these pathways on survival and function of allogeneic enteric NSC (ENSC) transplants Our long-term objective is to develop neuronal transplantation as a treatment for human diseases of the enteric nervous system as well as stimulate neural regeneration in these disorders. By establishing a role for PTEN and related pathways the proposed studies will provide the critical groundwork for novel therapeutic interventions.