PROGRAMMED CELL-DEATH IN TERMINALLY DIFFERENTIATING KERATINOCYTES - ROLE OF ENDOGENOUS ENDONUCLEASE
PROGRAMMED CELL-DEATH IN TERMINALLY DIFFERENTIATING KERATINOCYTES - ROLE OF ENDOGENOUS ENDONUCLEASE
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DOI：
10.1111/1523-1747.ep12478519
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发表时间：
1991-07-01
影响因子：
6.5
通讯作者：
COHEN, JJ
中科院分区：
文献类型：
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作者：
MCCALL, CA;COHEN, JJ
哺乳动物上皮是一种具有非常高更新率的组织。 它由快速增殖的隔室组成，所述隔室包括基底和基底上角质形成细胞，细胞从基底和基底上角质形成细胞向上移动，同时分化成颗粒角质形成细胞。 最终产物脱落为去核角质细胞，其具有机械刚性、耐化学性交联角质包膜。 细胞核的丢失特别发生在颗粒状角质形成细胞层中;在这里，可以观察到具有典型的细胞凋亡形态的聚集和边集的浓缩染色质。 这种形态是其他系统中“程序性”细胞死亡的特征，其中淋巴细胞已被最广泛地研究，并与核DNA裂解成核小体大小的片段有关。 在本研究中，我们将新生小鼠皮肤分为基底和颗粒角质形成细胞部分，并检查了每个部分中DNA的状态。 我们的研究结果表明，基底层的细胞，虽然它们的DNA是完全完整的，但正在准备死亡。 DNA片段化起始于颗粒状角质形成细胞层，其模式与程序性细胞死亡的其他实例中所见的模式相同。
Mammalian epithelium is a tissue with a very high turnover rate. It consists of a rapidly proliferating compartment comprising basal and suprabasal keratinocytes, from which cells move upwards while differentiating into granular keratinocytes. The end product is shed as an enucleate corneocyte, which has a mechanically rigid, chemically resistant cross-linked keratinous envelope. The loss of the nucleus occurs specifically in the granular keratinocyte layer; here, cells with the classical apoptotic morphology of clumped and marginated condensed chromatin may be observed. This morphology is characteristic of "programmed" cell death in other systems, of which the lymphocyte has been most extensively studied, and is associated with the cleavage of nuclear DNA into nucleosome-sized fragments. In the present investigation we separated newborn mouse skin into basal and granular keratinocyte fractions and examined the state of the DNA in each fraction. Our results indicate that cells in the basal layer, while their DNA is perfectly intact, are preparing to die. DNA fragmentation is initiated in the granular keratinocyte layer and is identical in pattern to that seen in other examples of programmed cell death.