Restoring hair follicle stem cell fate and heterogeneity outside their native niche

项目总结 成体干细胞(SCs)存在于特定的小环境中，依赖微环境线索来指导它们的行为。 毛囊(HF)是研究SC-NICE相互作用的一个很好的模型系统 刻板印象的再生周期。这个自给自足的微型器官利用了高水平的空间组织和 划分以促进沿HF谱系的SC命运决定。然而，当毛囊干 细胞(HfSCs)从它们的利基环境中分离出来，它们失去了身份，并显示出广泛的可塑性， 可以产生皮肤的所有谱系。长期以来，这个多功能国家一直是恢复HFSC身份的障碍 当生态位被扰乱时，尽管有大量关于控制HFSC的信号的信息 行为。为了克服这一挑战，我在我们实验室最近发现的基础上培养了hfSCs 一种伤口状的表观遗传特征，并假设靶向于负责驱动 创伤反应将允许重新获得HFSC的身份。在这里，我在这里介绍一种 恢复hfsc的动态平衡标识的平台，通过我对利基的标识而成为可能 位于组织再生和创伤相关可塑性之间的信号。我的初步数据 展示靶向这些通路的有效性，以解决伤口特征并恢复其敏感性 到支持获取全套差异化HF细胞类型的本地线索。在这份提案中，我将 利用单细胞研究优化生态位信号对HFSC命运异质性的影响 转录学。我正在开发的生物信息学技能将使我能够将这些细胞的命运与它们在体内的命运进行比较 对口单位(目标一)。接下来，我将剖析维甲酸(RA)--一种重要的代谢物--所起的作用 对于HFSC身份和自我更新是必需的。通过关注RA的转录效应，我将从功能上 明确RA的可用性如何影响HF周期和创伤诱导的卵泡新生(AIM II)。最后，我会 将该平台应用于人类患者样本，并从功能上剖析HFSC与其真皮生态位的相互作用 在新设计的皮肤(AIM III)中。总的来说，这项工作将机械地定义最低要求 人肾间充质干细胞自我更新和分化所必需的。如果成功，我的研究有可能 快速模拟和测试与人类心力衰竭相关的假说，加速旨在 实现HF的形态发生，并最终再生完整的体壁系统。

PROJECT SUMMARY Adult stem cells (SCs) reside in defined niches and depend on microenvironmental cues to instruct their behavior. The hair follicle (HF) is an excellent model system to study a rich set of SC-niche interactions as it undergoes stereotypic regenerative cycles. This self-contained mini-organ utilizes high levels of spatial organization and compartmentalization to promote SC fate determination along HF lineages. However, when hair follicle stem cells (HFSCs) become isolated from their niche, they lose their identity and display a wide-ranging plasticity that can produce all lineages of the skin. This multipotent state has long acted as a barrier to restoring HFSC identity when the niche becomes disrupted, despite a wealth of information regarding the signals that control HFSC behavior. To overcome this challenge, I have built upon our lab’s recent discovery that cultured HFSCs exhibit a wound-like epigenetic signature and hypothesized that targeting the pathways responsible for driving the wound response would permit the re-acquisition of HFSC identity. Here, I present here the development of a platform that reinstates the homeostatic identify of HFSCs, made possible through my identification of niche signals that lie at the intersection between tissue regeneration and wound-related plasticity. My preliminary data demonstrate the efficacy of targeting these pathways to resolve the wound signature and restore their sensitivity to local cues that support the acquisition of a full suite of differentiated HF cell types. In this proposal, I will examine the resulting heterogeneity of HFSC fates in response to optimized niche signals using single cell transcriptomics. My developing bioinformatic skillset will allow me to compare these cell fates with their in vivo counterparts (Aim I). Next, I will dissect the mechanistic role played by retinoic acid (RA), an essential metabolite required for HFSC identity and self-renewal. By focusing on the transcriptional effectors of RA, I will functionally define how RA availability impacts HF cycling and wound-induced follicular neogenesis (Aim II). Lastly, I will apply this platform to human patient samples and functionally dissect HFSC interactions with their dermal niche in newly engineered skin (Aim III). In total, this work will mechanistically define the minimal requirements necessary for human HFSC self-renewal and differentiation. If successful, my research has the potential to rapidly model and test hypotheses related to human HF disorders, accelerate therapeutic efforts aimed at achieving HF morphogenesis, and ultimately regenerate the complete integumentary system.