Goh Eyleen Lay Keow, Ma Dengke, Ming Guo-Li, Song Hongjun
Institute for Cell Engineering, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
J Hematother Stem Cell Res. 2003 Dec;12(6):671-9. doi: 10.1089/15258160360732696.
Neural stem cells are present not only in the developing nervous systems, but also in the adult central nervous system of mammals, including humans. The mature central nervous system has been traditionally regarded as an unfavorable environment for the regeneration of damaged axons of mature neurons and the generation of new neurons. In the adult central nervous system, however, newly generated neurons from adult neural stem cells in specific regions exhibit a striking ability to migrate, send out long axonal and dendritic projections, integrate into pre-existing neuronal circuits, and contribute to normal brain functions. Adult stem cells with potential neural capacity recently have been isolated from various neural and nonneural sources. Rapid advances in the stem cell biology have raised exciting possibilities of replacing damaged or lost neurons by activation of endogenous neural stem cells and/or transplantation of in vitro-expanded stem cells and/or their neuronal progeny. Before the full potential of adult stem cells can be realized for regenerative medicine, we need to identify the sources of stem cells, to understand mechanisms regulating their proliferation, fate specification, and, most importantly in the case of neuronal lineages, to characterize their functional properties. Equally important, we need to understand the neural development processes in the normal and diseased adult central nervous system environment, which is quite different from the embryonic central nervous system, where neural development has been traditionally investigated. Here we will review some recent progress of adult neural stem cell research that is applicable to developmental neurobiology and also has potential implications in clinical neuroscience.
神经干细胞不仅存在于发育中的神经系统，也存在于包括人类在内的成年哺乳动物的中枢神经系统中。传统上，成熟的中枢神经系统被认为是不利于成熟神经元受损轴突再生和新神经元生成的环境。然而，在成年中枢神经系统中，特定区域成年神经干细胞新生成的神经元表现出显著的迁移能力，能发出长轴突和树突投射，整合到已有的神经元回路中，并对正常脑功能发挥作用。最近，具有潜在神经能力的成体干细胞已从各种神经和非神经来源中分离出来。干细胞生物学的快速发展为通过激活内源性神经干细胞和/或移植体外扩增的干细胞和/或其神经元后代来替代受损或丢失的神经元带来了令人兴奋的可能性。在将成体干细胞的全部潜力用于再生医学之前，我们需要确定干细胞的来源，了解调节其增殖、命运决定的机制，对于神经元谱系而言，最重要的是要表征其功能特性。同样重要的是，我们需要了解正常和患病成年中枢神经系统环境中的神经发育过程，这与传统上研究神经发育的胚胎中枢神经系统有很大不同。在此，我们将综述成年神经干细胞研究的一些最新进展，这些进展适用于发育神经生物学，并且在临床神经科学中也具有潜在意义。
