Control of epithelial plasticity and differentiation in hair follicle stem/progenitor cells

 描述（由申请人提供）：在干细胞的刺激下，皮肤上皮细胞在整个成人生活中自我更新。这项研究的长期目标是阐明调节皮肤发育、稳态和再生的遗传和分子机制，并深入了解这种控制机制在特应性皮炎和癌症等皮肤病中是如何出错的。正确的干细胞行为是执行正常再生程序的关键，它们的失调是疾病的基础。基因表达的复杂控制位于干细胞调控的中心，因此我们将注意力集中在转录调控因子上。由R 01 AR 047320支持的实验室过去的研究已经提出Ovol转录因子作为控制皮肤上皮干细胞和祖细胞命运的优秀候选物。资金在上次更新时停止了，但令人兴奋的新数据现在使我们能够探索以前被低估的皮肤干细胞控制领域。令人惊讶的是，毛囊和毛囊间表皮 干细胞/祖细胞使用Ovol因子来抑制它们经历分子和/或形态变化的内在趋势，所述分子和/或形态变化可最终导致在允许条件下转化成间充质细胞类型（上皮-间充质转化或EMT）。我们产生的工具和发现为我们接下来询问毛囊中的发育祖细胞和成体干细胞如何平衡其谱系可塑性与上皮终末分化以实现正常形态发生和再生奠定了坚实的基础。具体地说，我们在本申请中提出以下问题：1）主动抑制EMT样事件对于胚胎毛囊祖细胞的形态发生和分化是必需的吗？2)在生理性毛发再生过程中，成人毛囊干细胞是否也有类似的控制机制？3)皮肤上皮细胞的内在EMT倾向对它们在损伤修复期间获得扩展的谱系潜力是否重要？这种倾向如何保持在检查中以维持上皮分化？我们将结合联合收割机经典的小鼠遗传学（条件性敲除和诱导性过表达）与现代技术，如细胞分选，转录谱，谱系追踪，和离体干细胞培养，研究毛囊干/祖细胞的可塑性和分化的形态发生和再生过程中，在野生型和突变体条件下。

 DESCRIPTION (provided by applicant): Fueled by stem cells, skin epithelia self-renew throughout adult life. The long-term objectives of this research are to elucidate the genetic and molecular mechanisms that regulate skin development, homeostasis and regeneration, and to gain insights into how such control mechanisms go awry in skin diseases such as atopic dermatitis and cancer. Proper stem cell behaviors are key to the execution of normal regenerative programs and their misregulation underlies diseased conditions. Intricate control of gene expression sits at the very center of stem cell regulation, and for this reason we have focused our attention on transcriptional regulators. Past research in the laboratory supported by R01 AR047320 had presented Ovol transcription factors as excellent candidates for controlling the fate of skin epithelial stem and progenitor cells. Funding was discontinued at the last renewal, but exciting new data now poise us to probe into a previously under- appreciated territory of skin stem cell control. Surprisingly, both hair follicle and interfollicular epidermal stem/progenitor cells use Ovol factors to suppress their intrinsic tendency to undergo molecular and/or morphological changes that can ultimately lead to conversion into mesenchymal cell types (epithelial-to- mesenchymal transition or EMT) under permissive conditions. The tools and findings that we generated have laid a strong foundation for us to next ask how developmental progenitor cells and adult stem cells in the hair follicles balance their lineage plasticity with epithelial terminal differentiation to achieve normal morphogenesis and regeneration. Specifically, we ask the following questions in this application: 1) Is active suppression of EMT-like events essential for the morphogenesis and differentiation of embryonic hair follicle progenitor cells? 2) Do similar control mechanisms also operate in adult hair follicle stem cells during physiological hair regeneration? 3) Is the intrinsic EMT tendency of skin epithelial cells important for them to acquire expanded lineage potential during injury repair and how is this tendency kept in check to maintain epithelial differentiation? We will combine classical mouse genetics (conditional knockout and inducible overexpression) with modern techniques such as cell sorting, transcriptional profiling, lineage tracing, and ex vivo stem cell cultures to investiate the plasticity and differentiation of hair follicle stem/progenitor cells during morphogenesis and regeneration, under wild-type and mutant conditions.