Stem cell defects in ATM-deficient undifferentiated spermatogonia through DNA damage-induced cell-cycle arrest
Stem cell defects in ATM-deficient undifferentiated spermatogonia through DNA damage-induced cell-cycle arrest
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DOI：
10.1016/j.stem.2007.10.023
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发表时间：
2008-02-01
期刊：
影响因子：
23.9
通讯作者：
Suda, Toshio
中科院分区：
文献类型：
--
作者：
Takubo, Keiyo;Ohmura, Masako;Suda, Toshio
哺乳动物的精子发生是由未分化精原细胞亚群内的干细胞能力维持的。在这里，使用表面标记的组合，我们描述了一种纯化未分化精原细胞的方法。流式细胞术分析显示，该群体由plzf阳性细胞组成，表现出安静和侧群体表型，符合一般干细胞标准。然后，我们应用该方法分析了Atm（-/-）小鼠的未分化精原细胞和干细胞活性。Atm（-/-）睾丸显示未分化精原细胞逐渐耗竭并伴有细胞周期阻滞。在体外和体内均观察到Atm（-/-）未分化精原细胞存在自我更新缺陷。在Atm（-/-）未分化精原细胞中观察到DNA损伤的积累和p19(Arf)-p53-p21（Cip1/Waf1）通路的激活。此外，在Atm（-/-）背景下，p21（Cip1/Waf1）的抑制恢复了未分化精原细胞的移植能力，表明Atm通过抑制DNA损伤诱导的细胞周期阻滞，在维持未分化精原细胞及其干细胞能力方面发挥了重要作用。
Mammalian spermatogenesis is maintained by stem cell capacity within undifferentiated spermatogonial subpopulation. Here, using a combination of surface markers, we describe a purification method for undifferentiated spermatogonia. Flow cytometric analysis revealed that this population is composed of Plzf-positive cells and exhibits quiescence and the side population phenotype, fulfilling general stem cell criteria. We then applied this method to analyze undifferentiated spermatogonia and stem cell activity of Atm(-/-) mice. Atm(-/-) testis shows progressive depletion of undifferentiated spermatogonia accompanied by cell-cycle arrest. In Atm(-/-) undifferentiated spermatogonia, a self-renewal defect was observed in vitro and in vivo. Accumulation of DNA damage and activation of the p19(Arf)-p53-p21(Cip1/Waf1) pathway were observed in Atm(-/-) undifferentiated spermatogonia. Moreover, suppression of p21(Cip1/Waf1) in an Atm(-/-) background restored transplantation ability of undifferentiated spermatogonia, indicating that ATM plays an essential role in maintenance of undifferentiated spermatogonia and their stem cell capacity by suppressing DNA damage-induced cell-cycle arrest.