Bottai Daniele, Fiocco Roberta, Gelain Fabrizio, Defilippis Lidia, Galli Rossella, Gritti Angela, Vescovi L Angelo
Stem Cell Research Institute, DIBIT, Fondazione Centro San Raffaele del Monte Tabor, 20132 Milan, Italy.
J Hematother Stem Cell Res. 2003 Dec;12(6):655-70. doi: 10.1089/15258160360732687.
The concept of the immutability of the nervous tissue has recently been replaced with the new idea that a continuous neurogenic turnover does occur in some limited areas of the central nervous system (CNS). At least two neurogenic regions of the adult mammalian CNS are involved in this process: the subventricular zone of the forebrain and the dentate gyrus of the hippocampus, which are considered to be a reservoir of new neural cells. Neural stem cells (NSCs) are multipotential progenitors that have self-renewal capability. While in vivo endogenous NSCs seem able to produce almost exclusively neurons, a single NSC in vitro is competent to generate neurons, astrocytes, and oligodendrocytes. NSCs lack a specific morphology and unambiguous surface markers that could allow their identification. For this reason, one of the major difficulties in identifying stem cells is that they are defined in terms of their functional capabilities, the determination of which might alter the cells' nature. The purpose of this review is to describe the characteristics of the NSCs of the adult mammalian CNS, their potentiality in terms of proliferation and differentiation capabilities, as well as their stability in long-term culture, all attributes that make them a good tool for tissue replacement therapies.
神经组织不可改变的概念最近已被新观点所取代，即中枢神经系统（CNS）的某些有限区域确实存在持续的神经发生更替。成年哺乳动物中枢神经系统至少有两个神经发生区域参与这一过程：前脑的脑室下区和海马体的齿状回，它们被认为是新神经细胞的储备库。神经干细胞（NSCs）是具有自我更新能力的多能祖细胞。虽然体内内源性神经干细胞似乎几乎只能产生神经元，但单个神经干细胞在体外能够生成神经元、星形胶质细胞和少突胶质细胞。神经干细胞缺乏能够使其被识别的特定形态和明确的表面标志物。因此，识别干细胞的主要困难之一在于它们是根据其功能能力来定义的，而功能能力的测定可能会改变细胞的性质。本综述的目的是描述成年哺乳动物中枢神经系统神经干细胞的特征、其在增殖和分化能力方面的潜能，以及它们在长期培养中的稳定性，所有这些特性使其成为组织替代疗法中的良好工具。
