Tiers of clonal organization in the epidermis: the epidermal proliferation unit revisited.
Tiers of clonal organization in the epidermis: the epidermal proliferation unit revisited.
复制标题
表皮中的克隆组织层：重新审视表皮增殖单位。
DOI：
10.1007/s12015-008-9020-6
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Ghadially,Ruby
中科院分区：
文献类型：
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作者：
Strachan,LaurenR;Ghadially,Ruby
作为成年哺乳动物中最具增殖性的组织之一，表皮是干细胞自我更新和分化之间所需的精确调节的一个很好的例子。表皮来源于外胚层祖细胞，并且含有三种不同类型的细胞：表皮干细胞，其能够进行无限轮的细胞分裂;其直接后代，瞬时扩增细胞，其能够进行许多但有限轮的细胞分裂;以及最后，非分裂的分化细胞（Aberdam in Cell and Tissue Research 331：103-107，2008）。在表皮发育和体内平衡期间，这种增殖层次必须在时间和空间上受到严格调节，以防止不受控制的生长导致过度增殖状态和/或肿瘤发生。历史上，表皮增殖的最基本单位被描述为表皮增殖单位（EPU）。EPU最初由Christophers、Potten和麦肯齐表征，是由大约10个基底细胞组成的增殖单位，其中克隆形成细胞位于中心，并被基底上和角质细胞后代覆盖（综述于Potten，C. S.（1974年）。表皮增殖单位：中央基底细胞的可能作用。Cell and Tissue Kinetics，7（1），77-88）。许多研究人员已经在各种哺乳动物皮肤来源中鉴定出这种经典的EPU结构，由大约20个细胞组成。然而，最近，谱系分析提供了证据，更大的克隆表皮单位组成的数百至数千个细胞。此外，皮肤镶嵌现象以及各种皮肤病理学表明，克隆区延伸到哺乳动物皮肤的许多厘米宽的整个补丁。在这篇综述中，我们回顾了四十年的实验证据，并提出了一个模型的克隆单位来自多个类别的表皮祖细胞，从最大和最原始的单位，克隆外胚层单位，表皮干细胞单位，最后，最基本的结构单位，EPU。
As one of the most proliferative tissues in adult mammals, the epidermis is a good example of the precise regulation necessary between stem cell self-renewal and differentiation. The epidermis is derived from ectodermal progenitor cells and contains three distinct classes of cells: epidermal stem cells which are capable of infinite rounds of cell division; their immediate descendants, transient amplifying cells, which are capable of numerous but finite rounds of cell division; and finally, non-dividing, differentiating cells (Aberdam in Cell and Tissue Research 331:103–107, 2008). This proliferative hierarchy must be tightly regulated both temporally and spatially during epidermal development and homeostasis in order to prevent uncontrolled growth leading to hyperproliferative states and/or tumorigenesis. Historically, the most basic unit of epidermal proliferation has been described as the epidermal proliferation unit (EPU). The EPU, as originally characterized by Christophers, Potten and Mackenzie, is a proliferation unit consisting of approximately 10 basal cells with a clonogenic cell in the center and overlaid by the suprabasal and corneocyte progeny (reviewed in Potten, C. S. (1974). The epidermal proliferative unit: the possible role of the central basal cell. Cell and Tissue Kinetics, 7(1), 77–88). Numerous researchers have identified this classical EPU structure, consisting of approximately 20 cells, in a variety of mammalian skin sources. Recently however, lineage analyses have provided evidence for much larger clonal epidermal units consisting of hundreds to thousands of cells. Furthermore, cutaneous mosaicism as well as a variety of cutaneous pathologies indicate that clonal areas extend to whole patches of mammalian skin many centimeters across. In this review we revisit four decades of experimental evidence and put forward a model of clonal units derived from multiple classes of epidermal progenitors ranging from the largest and most primitive units, clonal ectodermal units, to epidermal stem cell units, and finally, to the most basic structural unit, the EPU.