DRG Progenitor: Role of extrinsic and intrinsic cues

描述(申请人提供)：周围神经系统(PNS)是生命所必需的。我们自主地对氧气水平、二氧化碳、血压的变化做出反应的能力，以及检测可能对机体有害的有害刺激的能力，都是由三叉神经节介导的关键功能。当这些系统的发育出错时，会导致感觉和/或自主神经疾病，包括隐性遗传病，家族性自主神经异常(FD)，在这种疾病中，感觉和自主神经系统都不能正常发育。大多数三叉神经节来自于一群堂吉诃德式的干细胞，也就是神经脊。这些细胞从神经管中剥离，沿着定型的轨迹在整个胚胎中迁移，最终形成三叉神经核内的大多数衍生物。尽管在过去的10年里，许多调节感觉神经元发育的分子机制已经被发现，但我们对NCC在产生特定衍生物时协调其行为的细胞机制的了解很少。然而，随着活体成像技术和荧光蛋白变体试剂的革命，再加上在鸟类胚胎中进行体内得失函数扰动的简便性，现在可以在进行分子扰动的同时实时成像神经脊细胞的迁移和分化。我们将在这项提案中结合这些强大的技术来研究不同的神经脊细胞亚群是否会在背根神经节中产生亚型特定类型的感觉神经元。为此，我们将使用可光激活的GFP变体、基因特异的报告构建体和逆转录病毒来跟踪从神经管的空间离散区域迁移的神经脊细胞，跨越三个不同的时间迁移波，并在它们产生祖细胞和感觉神经元亚型时追踪它们的谱系。此外，我们将扩展我们从研究正常感觉神经元发育中学到的知识，通过分析导致FD疾病的基因缺失(小鼠)或击倒(小鸡)的小鼠和小鸡的感觉神经元发育，来研究导致FD的潜在分子和细胞机制。 与公共健康相关：我们的工作重点是了解痛觉神经元是如何出生和成熟的。这些神经元对生命是必不可少的，因为它们可以保护身体免受有害刺激的伤害。我们建议的目标的实现将确定可用于治疗发育性和退行性周围神经疾病的细胞和分子机制，包括家族性自主神经功能障碍和糖尿病周围神经病变。

DESCRIPTION (provided by applicant): The peripheral nervous system (PNS) is essential for life. Our ability to autonomously respond to alterations in oxygen levels, CO2, blood pressure, and detection of noxious stimuli that could harm the organism, are all critical functions mediated by the PNS. When the development of these systems go awry, sensory and/or autonomic neuropathies result including the recessive genetic disease, Familial Dysautonomia (FD), in which neither the sensory nor the autonomic nervous systems develop correctly. Most of the PNS derives from a quixotic population of stem-like cells, the neural crest. These cells delaminate from the neural tube, and migrate along stereotyped trajectories throughout the embryo to ultimately give rise to the majority of derivatives within the PNS. Although over the past 10 years, many of the molecular mechanisms that mediate sensory neuron development have been identified our understanding of the cellular mechanisms that orchestrate the behaviors of NCCs as they give rise to specific derivatives is sparse. However, with the revolution in live imaging technologies and fluorescent protein variant reagents, combined with the ease of conducting in vivo gain and loss function perturbations in the avian embryo, it is now possible to image in real time the migration and differentiation of neural crest cells while simultaneously conducting molecular perturbations. We will combine these powerful technologies in this proposal to investigate whether distinct subpopulations of neural crest cells give rise to subtype-specific classes of sensory neurons in the dorsal root ganglia. To this end, we will use photoactivatable GFP variants, gene-specific reporter constructs, and retroviruses to track neural crest cells that emigrate from spatially discrete regions of the neural tube, over the three temporally distinct waves of emigration, and trace their lineage as they give rise to subtypes of progenitor cells and sensory neurons. Furthermore we will extend what we learn from studying normal sensory neuron development to investigate the underlying molecular and cellular mechanisms that go awry to result in FD by analyzing sensory neuron development in both mice and chick in which the gene responsible for the FD disease is deleted (mouse) or knocked-down (chick). PUBLIC HEALTH RELEVANCE: Our work is focused on understanding how pain-sensing neurons are born and mature. These neurons are essential for life as protection against noxious stimuli that could harm the organism. Achievement of the aims of our proposal will identify cellular and molecular mechanisms that can be applied to the treatment of both developmental and degenerative peripheral neuropathies including Familial dysautonomia and diabetic peripheral neuropathy.