PDF(Pubmed)
Abstract：
In the interfollicular epidermis, keratinocyte stem cells (KSC) generate a short-lived population of transit amplifying (TA) cells that undergo terminal differentiation after several cell divisions. Recently, we isolated and characterized a highly proliferative keratinocyte cell population, named \"early\" TA (ETA) cell, representing the first KSC progenitor with exclusive features. This work aims to evaluate epidermis, with a focus on KSC and ETA cells, during transition from infancy to childhood. Reconstructed human epidermis (RHE) generated from infant keratinocytes is more damaged by UV irradiation, as compared to RHE from young children. Moreover, the expression of several differentiation and barrier genes increases with age, while the expression of genes related to stemness is reduced from infancy to childhood. The proliferation rate of KSC and ETA cells is higher in cells derived from infants\' skin samples than of those derived from young children, as well as the capacity of forming colonies is more pronounced in KSC derived from infants than from young children\'s skin samples. Finally, infants-KSC show the greatest regenerative capacity in skin equivalents, while young children ETA cells express higher levels of differentiation markers, as compared to infants-ETA. KSC and ETA cells undergo substantial changes during transition from infancy to childhood. The study presents a novel insight into pediatric skin, and sheds light on the correlation between age and structural maturation of the skin.
摘要：
在毛囊间表皮，角质形成细胞干细胞（KSC）产生短暂的转运扩增（TA）细胞群，这些细胞在几次细胞分裂后经历终末分化。最近,我们分离并表征了高度增殖的角质形成细胞群，命名为“早期”TA（ETA）单元格，代表第一个具有独特特征的KSC祖细胞。这项工作旨在评估表皮，专注于KSC和ETA细胞，在从婴儿期到童年的过渡期间。从婴儿角质形成细胞产生的重建人表皮（RHE）受到紫外线照射的损害更大，与幼儿的RHE相比。此外，几种分化和屏障基因的表达随着年龄的增长而增加，而与干性相关的基因的表达从婴儿期到儿童期减少。来自婴儿皮肤样本的KSC和ETA细胞的增殖率高于来自幼儿的细胞，以及形成菌落的能力更明显的KSC从婴儿比幼儿的皮肤样本。最后,婴儿-KSC在皮肤等价物中表现出最大的再生能力，而幼儿ETA细胞表达更高水平的分化标记，与婴儿ETA相比。KSC和ETA细胞在从婴儿期到儿童期的过渡过程中经历了实质性的变化。这项研究提出了对儿科皮肤的新见解，并阐明了年龄与皮肤结构成熟之间的相关性。
