Identifying bio-markers for putative epidermal stem cells in mouse skin.

描述（由申请人提供）：组织内细胞的不频繁分裂或所谓的“慢循环”性质与包括小鼠皮肤在内的几种成体组织中的干性有关。被定义为H2 B-GFP或DNA标记保留细胞（LRC）的慢循环细胞被认为作为干细胞存在于谱系层级的顶部，从而产生活跃的循环细胞（非LRC），其可以作为转运扩增（TA）短寿命祖细胞起作用。尽管表皮对于基本身体功能和皮肤再生治疗至关重要，但尚未实现毛囊间表皮基底层内的干细胞和TA细胞的分子表征。因此，我们缺乏特异性标记物来准确定义该组织内的动态干细胞行为，并了解维持干细胞性的调节因素。在我们的初步研究中，我们已经从表皮基底层分离出LRC和非LRC，并通过微阵列分析了这些细胞的分子特征。在这里，我们提出了表征几个假定的表皮干细胞和TA细胞标记物在我们的微阵列，包括一个新的基底层LRC细胞表面标记物的表达模式。我们将通过三种功能测定来分析基底层细胞亚群的谱系潜力：集落形成活性、细胞移植中的再生潜力和谱系追踪。这些数据将揭示长期干细胞的潜力和谱系层次的表皮基底细胞亚群在体外和体内，并将提供新的工具，研究干细胞调节表皮。从我们提出的实验中获得的数据将对基于干细胞的人类皮肤损伤或皮肤替代疗法具有全球相关性，其中慢循环细胞被认为发挥核心作用。

DESCRIPTION (provided by applicant): The infrequently dividing or so-called "slow-cycling" nature of cells within tissues has been linked to stemness in several adult tissues including mouse skin. Slow-cycling cells defined as H2B-GFP or DNA label retaining cells (LRCs) are thought to reside at the top of the lineage hierarchy, as stem cells, giving rise to actively-cyclig cells (non-LRCs), which may function as transit-amplifying (TA) short-lived progenitor cells. Despite the crucial importance of the epidermis for essential body functions and for skin regeneration therapy, molecular characterization of stem and TA cells within the basal layer of the inter-follicular epidermis has not been achieved. Consequently, we lack the specific markers to accurately define the dynamic stem cell behavior within this tissue and to understand the regulatory factors maintaining stemness. In our preliminary study, we have isolated LRCs and non-LRCs from the basal layer of the epidermis and analyzed the molecular signature of these cells by microarray. Here we propose to characterize the expression pattern of several putative epidermal stem and TA cell markers identified in our microarray, including one novel cell surface marker for basal layer LRCs. We will analyze the lineage potential of subpopulations of basal layer cells by three functional assays: colony formation activity, regeneration potential in cell transplantation, and lineage tracing. These data will reveal long-term stem cell potential and lineage hierarchy of epidermal basal cell subpopulations in vitro and in vivo and will provide new tools for studying stem cell regulation in the epidermis. Data obtained from our proposed experiments will have global relevance for stem cell-based therapy of human skin injury or skin replacement, where slow-cycling cells are thought to play central roles.