Coronas Valerie
Institut de Physiologie et Biologie Cellulaires, University of Poitiers, CNRS, 40 av. Recteur Pineau, Poitiers Cedex, France.
Cent Nerv Syst Agents Med Chem. 2009 Jun;9(2):110-8. doi: 10.2174/187152409788452081.
Tissue-specific stem cells replenish organs by replacing cells lost due to tears and wears or injury throughout life. Long considered as an exception to this rule, the adult mammalian brain has consistently been found to possess stem cells that ensure neurogenesis. Neural stem cells persist within the subventricular zone bordering the lateral ventricles of the brain. Constitutively, neural stem cells proliferate and produce a continuous supply of new neurons that migrate towards the olfactory bulb where they ensure turnover of interneurons. Owing to their potential clinical use for the treatment of neurodegenerative diseases, the factors that control proliferation, self-renewal and differentiation of neural stem cells have received increasing interest. These studies have unraveled that the cellular dynamic within the subventricular zone is tightly controlled by astrocytes and endothelial cells that neighbor neural stem cells. These neighboring cells produce substrate-bound and soluble factors that make up a specialized microenvironment named the neurogenic niche. The equilibrium between neural stem cells activity and quiescence is adjusted by neurons located in remote brain areas that adapt neuron production to physiological and pathological constraints. Brain injury or neurodegenerative diseases affect neural stem cells proliferation, differentiation and migration suggesting that neural stem cells are involved in brain self-repair. Understanding the endogenous mechanisms that regulate neural stem cells will help to replenish cellular constituents lost by injury and thereby allow an effective development of neural stem cells based therapies of brain diseases.
组织特异性干细胞通过替换因一生中的撕裂、磨损或损伤而丢失的细胞来补充器官。长期以来，成年哺乳动物的大脑一直被认为是这一规则的例外，但人们一直发现它拥有确保神经发生的干细胞。神经干细胞存在于大脑侧脑室附近的脑室下区。神经干细胞持续增殖，并持续产生新的神经元，这些神经元向嗅球迁移，在那里确保中间神经元的更替。由于其在治疗神经退行性疾病方面的潜在临床应用，控制神经干细胞增殖、自我更新和分化的因素受到了越来越多的关注。这些研究表明，脑室下区内的细胞动态受到与神经干细胞相邻的星形胶质细胞和内皮细胞的严格控制。这些相邻细胞产生结合在底物上的和可溶性的因子，构成了一个名为神经发生微环境的特殊微环境。位于大脑远处区域的神经元调节神经干细胞的活动与静止之间的平衡，使神经元的产生适应生理和病理限制。脑损伤或神经退行性疾病会影响神经干细胞的增殖、分化和迁移，这表明神经干细胞参与了大脑的自我修复。了解调节神经干细胞的内源性机制将有助于补充因损伤而丢失的细胞成分，从而有效地开发基于神经干细胞的脑部疾病治疗方法。
