Autophagy in embryonic erythroid cells: its role in maturation
Autophagy in embryonic erythroid cells: its role in maturation
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DOI：
10.1078/0171-9335-00096
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发表时间：
2000-10-01
影响因子：
6.6
通讯作者：
Morioka, K
中科院分区：
文献类型：
--
作者：
Takano-Ohmuro, H;Mukaida, M;Morioka, K
卵黄囊来源的胚胎红系细胞在叙利亚仓鼠外周血中同步分化。妊娠第10天的分化阶段相当于成年动物的嗜多染红细胞阶段，第13天相当于成年动物的网织红细胞阶段。胚胎红系细胞在妊娠第12天的细胞质变得稀少，缺乏大部分细胞器。此外，在第13天之前，循环中的非红系细胞非常少。因此，胚胎红系细胞为研究终末分化机制提供了一个纯的、同步的系统。胚胎红系细胞中的线粒体数量在妊娠第10天至第12天期间减少至初始数量的约10%。相比之下，线粒体自噬的频率在同一时期增加了4.6倍。细胞色素c含量随着线粒体的消失而减少。然而，在妊娠第10 - 13天，细胞色素c释放到细胞质中是不可检测的，这表明线粒体在封闭的隔室中被消化。在妊娠第12天和之后，通过电子显微镜在溶酶体中检测到分解的线粒体和铁蛋白颗粒，这也表明在封闭的隔室中消化，线粒体ATP合酶亚基c，这是已知的蛋白酶抗性蛋白，即使在线粒体消失后仍保留在细胞中，表明大部分线粒体没有从细胞中挤出。自溶酶体中的线粒体的消化可以允许细胞通过伴随的线粒体死亡促进因子如细胞色素c的去除而逃离快速的凋亡性细胞死亡。
Yolk sac-derived embryonic erythroid cells differentiate synchronously in the peripheral blood of Syrian hamster. The stage of differentiation on day 10 of gestation is equivalent to polychromatophilic erythroblast stage and that on day 13 is equivalent to the reticulocyte stage in adult animals. The cytoplasm of embryonic erythroid cells became scant and devoid of most organelles on day 12 of gestation. In addition, there were very few non-erythroid cells in circulation before day 13. Thus the embryonic erythroid cells serve a pure and synchronous system to study the mechanisms of terminal differentiation. The number of mitochondria in the embryonic erythroid cells decreased to about 10% of the initial number during the period between day 10 and day 12 of gestation. In contrast, the frequency of autophagy of mitochondria increased 4.6-fold in the same period. The cytochrome c content of the cell decreased as the mitochondria became extinct. However, release of cytochrome c into the cytoplasm was not detectable through day 10 - 13 of gestation, suggesting that the mitochondria were digested within a closed compartment. Decomposed mitochondria and ferritin particles were detected in lysosomes by electron microscopy on and after day 12 of gestation, which also suggested digestion in a closed compartment, Mitochondrial ATP synthase subunit c, which is known to be a protease-refractory protein, was retained in the cells even after the disappearance of mitochondria, indicating that most of the mitochondria were not extruded from the cells. The digestion of mitochondria in autolysosomes may allow the cells to escape from rapid apoptotic cell death through concomitant removal of mitochondrial death-promoting factors such as cytochrome c.