Decimo Ilaria, Fumagalli Guido, Berton Valeria, Krampera Mauro, Bifari Francesco
Department of Public Health and Community Medicine, Section of Pharmacology, University of Verona Italy.
Am J Stem Cells. 2012 May 28;1(2):92-105. Print 2012.
Meninges are a three tissue membrane primarily known as coverings of the brain. More in depth studies on meningeal function and ultrastructure have recently changed the view of meninges as a merely protective membrane. Accurate evaluation of the anatomical distribution in the CNS reveals that meninges largely penetrate inside the neural tissue. Meninges enter the CNS by projecting between structures, in the stroma of choroid plexus and form the perivascular space (Virchow-Robin) of every parenchymal vessel. Thus, meninges may modulate most of the physiological and pathological events of the CNS throughout the life. Meninges are present since the very early embryonic stages of cortical development and appear to be necessary for normal corticogenesis and brain structures formation. In adulthood meninges contribute to neural tissue homeostasis by secreting several trophic factors including FGF2 and SDF-1. Recently, for the first time, we have identified the presence of a stem cell population with neural differentiation potential in meninges. In addition, we and other groups have further described the presence in meninges of injury responsive neural precursors. In this review we will give a comprehensive view of meninges and their multiple roles in the context of a functional network with the neural tissue. We will highlight the current literature on the developmental feature of meninges and their role in cortical development. Moreover, we will elucidate the anatomical distribution of the meninges and their trophic properties in adult CNS. Finally, we will emphasize recent evidences suggesting the potential role of meninges as stem cell niche harbouring endogenous precursors that can be activated by injury and are able to contribute to CNS parenchymal reaction.
脑膜是一种由三层组织构成的膜，主要作为大脑的覆盖物为人所知。最近，对脑膜功能和超微结构的更深入研究改变了人们对脑膜仅仅是一层保护膜的看法。对中枢神经系统中解剖分布的准确评估表明，脑膜在很大程度上深入到神经组织内部。脑膜通过在结构之间突出、在脉络丛基质中进入中枢神经系统，并形成每个实质血管的血管周围间隙（Virchow-Robin间隙）。因此，脑膜可能在整个生命过程中调节中枢神经系统的大多数生理和病理事件。脑膜在皮质发育的早期胚胎阶段就已存在，似乎对正常的皮质发生和脑结构形成是必需的。在成年期，脑膜通过分泌包括FGF2和SDF-1在内的多种营养因子来维持神经组织的稳态。最近，我们首次在脑膜中鉴定出具有神经分化潜能的干细胞群体。此外，我们和其他研究小组进一步描述了脑膜中存在对损伤有反应的神经前体细胞。在这篇综述中，我们将全面介绍脑膜及其在与神经组织的功能网络背景下的多种作用。我们将重点介绍关于脑膜发育特征及其在皮质发育中作用的当前文献。此外，我们将阐明脑膜在成体中枢神经系统中的解剖分布及其营养特性。最后，我们将强调最近的证据，这些证据表明脑膜作为干细胞龛的潜在作用，其中蕴藏着可被损伤激活并能够促进中枢神经系统实质反应的内源性前体细胞。
