Wren D, Wolswijk G, Noble M
Department of Clinical Neurology, Institute of Neurology, Queen Square, London, England.
J Cell Biol. 1992 Jan;116(1):167-76. doi: 10.1083/jcb.116.1.167.
We have been studying the differing characteristics of oligodendrocyte-type-2 astrocyte (O-2A) progenitors isolated from optic nerves of perinatal and adult rats. These two cell types display striking differences in their in vitro phenotypes. In addition, the O-2Aperinatal progenitor population appears to have a limited life-span in vivo, while O-2Aadult progenitors appear to be maintained throughout life. O-2Aperinatal progenitors seem to have largely disappeared from the optic nerve by 1 mo after birth, and are not detectable in cultures derived from optic nerves of adult rats. In contrast, O-2Aadult progenitors can first be isolated from optic nerves of 7-d-old rats and are still present in optic nerves of 1-yr-old rats. These observations raise two questions: (a) From what source do O-2Aadult progenitors originate; and (b) how is the O-2Aadult progenitor population maintained in the nerve throughout life? We now provide in vitro evidence indicating that O-2Aadult progenitors are derived directly from a subpopulation of O-2Aperinatal progenitors. We also provide evidence indicating that O-2Aadult progenitors are capable of prolonged self renewal in vitro. In addition, our data suggests that the in vitro generation of oligodendrocytes from O-2Aadult progenitors occurs primarily through asymmetric division and differentiation, in contrast with the self-extinguishing pattern of symmetric division and differentiation displayed by O-2Aperinatal progenitors in vitro. We suggest that O-2Aadult progenitors express at least some properties of stem cells and thus may be able to support the generation of both differentiated progeny cells as well as their own continued replenishment throughout adult life.
我们一直在研究从围产期和成年大鼠视神经中分离出的少突胶质细胞-2型星形胶质细胞（O-2A）祖细胞的不同特性。这两种细胞类型在体外表型上表现出显著差异。此外，围产期O-2A祖细胞群体在体内似乎具有有限的寿命，而成年O-2A祖细胞似乎能终生维持。围产期O-2A祖细胞在出生后1个月时似乎已从视神经中大量消失，在成年大鼠视神经来源的培养物中也检测不到。相比之下，成年O-2A祖细胞最早可从7日龄大鼠的视神经中分离出来，并且在1岁大鼠的视神经中仍然存在。这些观察结果提出了两个问题：（a）成年O-2A祖细胞起源于何种来源；（b）成年O-2A祖细胞群体在神经中是如何终生维持的？我们现在提供体外证据表明成年O-2A祖细胞直接来源于围产期O-2A祖细胞的一个亚群。我们还提供证据表明成年O-2A祖细胞在体外能够进行长时间的自我更新。此外，我们的数据表明，与围产期O-2A祖细胞在体外表现出的对称分裂和分化的自我消亡模式相反，成年O-2A祖细胞在体外产生少突胶质细胞主要是通过不对称分裂和分化。我们认为成年O-2A祖细胞至少表达了干细胞的一些特性，因此可能能够支持分化后代细胞的产生以及它们在成年期的持续自我补充。
