Takubo Keiyo, Ohmura Masako, Azuma Masaki, Nagamatsu Go, Yamada Wakako, Arai Fumio, Hirao Atsushi, Suda Toshio
Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan.
Cell Stem Cell. 2008 Feb 7;2(2):170-82. doi: 10.1016/j.stem.2007.10.023.
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.
哺乳动物的精子发生由未分化精原细胞亚群中的干细胞能力维持。在此，我们结合表面标志物描述了一种未分化精原细胞的纯化方法。流式细胞术分析表明，该群体由Plzf阳性细胞组成，表现出静止和侧群细胞表型，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，并伴有细胞周期停滞。在Atm(-/-)未分化精原细胞中，在体外和体内均观察到自我更新缺陷。在Atm(-/-)未分化精原细胞中观察到DNA损伤的积累以及p19(Arf)-p53-p21(Cip1/Waf1)途径的激活。此外，在Atm(-/-)背景下抑制p21(Cip1/Waf1)可恢复未分化精原细胞的移植能力，这表明ATM通过抑制DNA损伤诱导的细胞周期停滞，在维持未分化精原细胞及其干细胞能力方面发挥着重要作用。
Zotero 插件