Physiological Genomics, Institute of Physiology, Ludwig-Maximilians University, Munich, Germany; Institute for Stem Cell Research, HelmholtzZentrum, Neuherberg, Germany; and Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
Physiol Rev. 2014 Jul;94(3):709-37. doi: 10.1152/physrev.00036.2013.
The diverse functions of glial cells prompt the question to which extent specific subtypes may be devoted to a specific function. We discuss this by reviewing one of the most recently discovered roles of glial cells, their function as neural stem cells (NSCs) and progenitor cells. First we give an overview of glial stem and progenitor cells during development; these are the radial glial cells that act as NSCs and other glial progenitors, highlighting the distinction between the lineage of cells in vivo and their potential when exposed to a different environment, e.g., in vitro. We then proceed to the adult stage and discuss the glial cells that continue to act as NSCs across vertebrates and others that are more lineage-restricted, such as the adult NG2-glia, the most frequent progenitor type in the adult mammalian brain, that remain within the oligodendrocyte lineage. Upon certain injury conditions, a distinct subset of quiescent astrocytes reactivates proliferation and a larger potential, clearly demonstrating the concept of heterogeneity with distinct subtypes of, e.g., astrocytes or NG2-glia performing rather different roles after brain injury. These new insights not only highlight the importance of glial cells for brain repair but also their great potential in various aspects of regeneration.
神经胶质细胞的多种功能促使人们提出这样一个问题，即特定的亚型在多大程度上可能专门用于特定的功能。我们通过回顾神经胶质细胞最近发现的作用之一，即它们作为神经干细胞（NSC）和祖细胞的功能来讨论这个问题。首先，我们概述了发育过程中的神经胶质干细胞和祖细胞；这些是放射状胶质细胞，它们作为 NSC 和其他神经胶质祖细胞发挥作用，突出了体内细胞谱系与其在不同环境（例如体外）中的潜能之间的区别。然后，我们继续讨论成年阶段，并讨论在脊椎动物中继续充当 NSC 的神经胶质细胞，以及其他更具谱系限制的神经胶质细胞，例如成年的 NG2 胶质细胞，这是成年哺乳动物大脑中最常见的祖细胞类型，它们仍保留在少突胶质细胞谱系中。在某些损伤条件下，静止的星形胶质细胞的一个特定亚群重新激活增殖，其潜在能力明显表明存在异质性，例如，星形胶质细胞或 NG2 胶质细胞在脑损伤后可能发挥非常不同的作用。这些新的见解不仅突出了神经胶质细胞在大脑修复中的重要性，还突出了它们在再生的各个方面的巨大潜力。
