IGF-I: A Key Growth Factor that Regulates Neurogenesis and Synaptogenesis from Embryonic to Adult Stages of the Brain.
IGF-I: A Key Growth Factor that Regulates Neurogenesis and Synaptogenesis from Embryonic to Adult Stages of the Brain.
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DOI：
10.3389/fnins.2016.00052
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发表时间：
2016
影响因子：
4.3
通讯作者：
Vicario-Abejón C
中科院分区：
文献类型：
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作者：
Nieto-Estévez V;Defterali Ç;Vicario-Abejón C
成年哺乳动物脑中神经元的产生需要激活静止的神经干细胞（NSC）。这种激活和从NSC形成神经元的连续步骤受到许多刺激物的调节，这些刺激物包括生长因子。胰岛素样生长因子-I（IGF-I）发挥多效性作用，根据其浓度、细胞类型和动物的发育阶段调节多种细胞过程。虽然IGF-I在胚胎脑中的表达相对较高，但其水平在成人脑中急剧下降，除了神经源性区域，即，海马（HP）和脑室下区嗅球（SVZ-OB）。相比之下，IGF-IR的表达在脑中保持相对较高，与动物的年龄无关。有证据表明，IGF-I影响NSC增殖和分化为神经元和神经胶质以及神经元成熟，包括突触形成。此外，最近的研究表明，IGF-I不仅通过调节NSC的数量和分化促进成人神经发生，而且还通过影响神经元的定位和迁移，如SVZ-OB神经发生期间所述。在这篇文章中，我们将修改和讨论的行动报告IGF-I信号在各种体外和体内模型，集中在维护和神经干细胞/祖细胞，神经发生和神经元整合突触电路的增殖。
The generation of neurons in the adult mammalian brain requires the activation of quiescent neural stem cells (NSCs). This activation and the sequential steps of neuron formation from NSCs are regulated by a number of stimuli, which include growth factors. Insulin-like growth factor-I (IGF-I) exert pleiotropic effects, regulating multiple cellular processes depending on their concentration, cell type, and the developmental stage of the animal. Although IGF-I expression is relatively high in the embryonic brain its levels drop sharply in the adult brain except in neurogenic regions, i.e., the hippocampus (HP) and the subventricular zone-olfactory bulb (SVZ-OB). By contrast, the expression of IGF-IR remains relatively high in the brain irrespective of the age of the animal. Evidence indicates that IGF-I influences NSC proliferation and differentiation into neurons and glia as well as neuronal maturation including synapse formation. Furthermore, recent studies have shown that IGF-I not only promote adult neurogenesis by regulating NSC number and differentiation but also by influencing neuronal positioning and migration as described during SVZ-OB neurogenesis. In this article we will revise and discuss the actions reported for IGF-I signaling in a variety of in vitro and in vivo models, focusing on the maintenance and proliferation of NSCs/progenitors, neurogenesis, and neuron integration in synaptic circuits.