Profiling the transcriptome of globose basal cells of the olfactory epithelium at the single cell level

嗅上皮细胞（OE）补充嗅觉感觉神经元数量的能力， 损伤后上皮的再生取决于干细胞的持续存在和维持功能 在成人的上皮细胞中老年人感觉功能下降伴有病理变化 在OE出现，因为正常活跃的嗅觉干细胞和祖细胞，即球状基底细胞， 细胞（GBC）变得无序并最终耗尽。目前，我们可以构建一个流程图， 旨在涵盖和排序各种类别的GBC，从GBC开始， 多能祖细胞，通过充当转运扩增祖细胞的GBC进展，并达到 GBC直接产生神经元。我们还可以将GBC层次结构中的那些声称的阶段与 各种转录因子的表达。但是，我们对此缺乏全面认识 关键的干/祖细胞群体。这些阶段是离散的，还是更流畅的快照 进展？我们如何解释某些GBC祖细胞能力的可塑性？衰老是如何 打乱了进程本申请提出了两个具体目标，旨在解决关键的 我们对活跃的干细胞和祖细胞群体的知识存在空白。具体目标1将生成 使用转基因小鼠品系， 表达与转录因子基因-Sox 2、Ascl 1和Neurog 1结合的荧光标记物 - 用于定义层次结构中的阶段。具体目标2将侧重于和剖析一个特定的动力学- 定义的GBC子集，其经历延长的有丝分裂静止期，如标记的 组蛋白融合蛋白H2 B/GFP，这是许多干细胞类型共有的特征。在这两种情况下，细胞 将通过FACS分离通过表达荧光标签标记的细胞，捕获为单细胞， 个人简介单细胞表达文库的分析将用于无偏聚类。 细胞和定义基因的表达不同的集群。基因表达模式 将通过Q-PCR和免疫组织化学或原位杂交来验证区分簇的方法。 杂交取决于抗体的可用性。在分析结束时，我们将实现 全面了解GBC人口，并将澄清现有的流程图- 设想了不同的阶段和突然的过渡-是一个准确的代表生物学的这一干， 祖细胞包围群体。这些进展反过来将为我们减轻 嗅觉感觉功能障碍，特别是伴随着衰老。

The capacity of the olfactory epithelium (OE) for replenishing the population of olfactory sensory neurons and for regenerating the epithelium after injury depends on the persistence and maintained function of stem cells within that adult epithelium. Decline in sensory function in the elderly is accompanied by pathological changes in the OE that emerge because the normally active olfactory stem and progenitor cells, namely globose basal cells (GBCs), become disordered and eventually depleted. At present, we can construct a flow diagram designed to encompass and sequence the various categories of GBCs, beginning with GBCs that function as multipotent progenitors, progressing through GBCs that act as transit amplifying progenitors, and reaching GBCs that give rise directly to neurons. We can also align those purported stages in the GBC hierarchy with the expression of various transcription factors. However, we lack a comprehensive understanding of this critical stem/progenitor cell population. Are these stages discrete or are they snapshots of a more fluid progression? How do we explain the plasticity in the progenitor capacity of some GBCs? How might aging disorder the progression? The current application proposes two specific aims designed to address the critical gaps in our knowledge of the active stem and progenitor cell population. Specific Aim 1 will generate transcriptomic profiles of the various functional categories of GBCs using transgenic mouse strains that express a fluorescent marker in conjunction with the transcription factor(s) gene(s) – Sox2, Ascl1, and Neurog1 – used to define the stages in the hierarchy. Specific Aim 2 will focus on and profile a specific kinetically- defined subset of GBCs that experience prolonged mitotic quiescence, as shown by the retention of the tagged histone fusion protein H2B/GFP, which is a feature common to many stem cell types. In both cases, cells labeled by expression of the fluorescent tags will be isolated by FACS, captured as single cells, and individually profiled. Analysis of the single cell expression libraries will be used for unbiased clustering of the cells and defining the genes whose expression differs across the clusters. The patterns of gene expression that differentiate the clusters will be validated by Q-PCR and either immunohistochemistry or in situ hybridization depending on antibody availability. At the conclusion of the analysis we will have achieved a comprehensive understanding of the GBC population and will clarify whether the existing flow diagram – which envisions distinct stages and abrupt transitions – is an accurate representation of the biology of this stem and progenitor cell-encompassing population. These advances, in turn, will inform our attempts to alleviate olfactory sensory dysfunction, particularly that which accompanies aging.