Telomerase activity concentrates in the mitotically active segments of human hair follicles
Telomerase activity concentrates in the mitotically active segments of human hair follicles
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DOI：
10.1111/1523-1747.ep12285654
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发表时间：
1997-01-01
影响因子：
6.5
通讯作者：
Taylor, RS
中科院分区：
文献类型：
--
作者：
Ramirez, RD;Wright, WE;Taylor, RS
端粒酶是一种能够将六核苷酸重复序列添加到线性染色体DNA末端的核糖核蛋白酶，而具有有限复制能力的正常体细胞不能表达端粒酶活性，大多数永生真核细胞表达端粒酶活性。皮肤、肠、血液）需要广泛的增殖能力。这种更新组织中的一些细胞也表达端粒酶活性，最有可能在细胞增殖期间防止其端粒的快速侵蚀。在这项研究中，我们测量了人类毛囊解剖区室中端粒酶活性的水平：毛干，含腺体片段，上部中间片段（在那里它被认为是未分化的干细胞驻留），较低的中间片段，并在球含有片段（具有高有丝分裂活性的区域，包含更分化的角质形成细胞池），在生长期毛囊中，高水平的端粒酶活性几乎仅在卵泡的含球片段中发现，而在隆突区域（中间片段）和含腺片段中发现低水平的端粒酶。相比之下，退化期毛囊在含有球茎的片段以及其他区室中具有低水平的端粒酶活性。这样的观察结果表明，在生长期毛囊中，含有活跃分裂的细胞的片段（例如，瞬时扩增细胞）表达端粒酶活性，而含有具有低有丝分裂活性的细胞（例如静止干细胞）的片段表达低水平的端粒酶活性。
Telomerase is a ribonucleoprotein enzyme capable of adding hexanucleotide repeats onto the ends of linear chromosomal DNA, Whereas normal somatic cells with a Limited replicative capacity fail to express telomerase activity, most immortal eukaryotic cells do, Cells of renewal tissues (e.g., skin, intestine, blood) require an extensive proliferative capacity, Some cells in such renewal tissues also express telomerase activity, most likely to prevent rapid erosion of their telomeres during cell proliferation. In this study, we measured the levels of telomerase activity in dissected compartments of the human hair follicle: hair shaft, gland-containing fragment, upper intermediate fragment (where it is thought undifferentiated stem cells reside), lower intermediate fragment, and in the bulb-containing fragment (an area with high mitotic activity containing a more differentiated pool of keratinocytes), In anagen follicles, high levels of telomerase activity were found almost exclusively in the bulb-containing fragment of the follicles, with low levels of telomerase in the bulge area (intermediate fragments) and gland-containing fragment. In comparison, catagen follicles had low levels of telomerase activity in the bulb-containing fragments as well as in other compartments, Such observations indicate that, in anagen hair follicles, the fragments containing cells actively dividing (e.g., transient amplifying cells) express telomerase activity, whereas fragments containing cells with low mitotic activity, for example, quiescent stem cells, express low levels of telomerase activity.