Bidirectional Regulation of Neurogenesis by Neuronal Nitric Oxide Synthase Derived from Neurons and Neural Stem Cells
Bidirectional Regulation of Neurogenesis by Neuronal Nitric Oxide Synthase Derived from Neurons and Neural Stem Cells
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神经元和神经干细胞来源的神经元一氧化氮合酶对神经发生的双向调节
DOI：
10.1002/stem.522
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发表时间：
2010-11-01
期刊：
影响因子：
5.2
通讯作者：
Zhu, Dong-Ya
中科院分区：
文献类型：
--
作者：
Luo, Chun-Xia;Jin, Xing;Zhu, Dong-Ya
神经元型一氧化氮合酶（nNOS）对成人神经发生具有负向调控作用。然而，潜在的细胞和分子机制尚不清楚。在这里，我们发现来自神经干细胞（NSCs）和来自神经元的nNOS在调节神经发生中发挥相反的作用。nNOS抑制剂N-5-（1-亚胺-3-丁烯基）- l -鸟氨酸（L-VNIO）或nNOS基因缺失处理后，NSCs的增殖和神经元分化明显减少，表明NSCs衍生的nNOS对神经发生至关重要。NSCs与神经元共培养后，其增殖能力明显下降，删除神经元中的nNOS基因或清除细胞外一氧化氮（NO）可消除共培养的影响，提示nNOS作为NSCs的外源NO来源，对神经发生具有负向控制作用。事实上，暴露于NO供体DETA/NONOate的NSCs表现出增殖和神经元分化的减少。nNOS对神经发生的双向调节可能与它们不同的亚细胞定位有关，主要是在NSCs的细胞核和神经元的细胞质中。L-VNIO和DETA/NONOate均能抑制野生型（WT） nNOS(-/-) NSCs的端粒酶活性和增殖，但对nNOS-端粒酶无抑制作用，提示nNOS-端粒酶参与神经发生。暴露于DETA/NONOate的NSCs表现出cAMP反应元件结合蛋白（CREB）磷酸化、nNOS表达和增殖的降低。DETA/NONOate的作用可被CREB信号激活剂forskolin逆转。此外，通过H-89或LV-CREB133-GFP破坏CREB磷酸化可以模拟DETA/NONOate的作用，并抑制端粒酶活性。因此，我们得出结论，nNOS通过激活端粒酶刺激神经发生，而神经元来源的nNOS通过提供外源NO来抑制神经发生，而外源NO阻碍CREB的激活，从而减少nNOS在NSCs中的表达。干细胞2010；28:2041 - 2052
It has been demonstrated that neuronal nitric oxide synthase (nNOS) negatively regulates adult neurogenesis. However, the cellular and molecular mechanisms underlying are poorly understood. Here, we show that nNOS from neural stem cells (NSCs) and from neurons play opposite role in regulating neurogenesis. The NSCs treated with nNOS inhibitor N-5-(1-imino-3-butenyl)-L- ornithine (L-VNIO) or nNOS gene deletion exhibited significantly decreased proliferation and neuronal differentiation, indicating that NSCs-derived nNOS is essential for neurogenesis. The NSCs cocultured with neurons displayed a significantly decreased proliferation, and deleting nNOS gene in neurons or scavenging extracellular nitric oxide (NO) abolished the effects of coculture, suggesting that neurons-derived nNOS, a source of exogenous NO for NSCs, exerts a negative control on neurogenesis. Indeed, the NSCs exposed to NO donor DETA/NONOate displayed decreased proliferation and neuronal differentiation. The bidirectional regulation of neurogenesis by NSCs- and neurons-derived nNOS is probably related to their distinct subcellular localizations, mainly in nuclei for NSCs and in cytoplasm for neurons. Both L-VNIO and DETA/NONOate inhibited telomerase activity and proliferation in wild-type (WT) but not in nNOS(-/-) NSCs, suggesting a nNOS-telomerase signaling in neurogenesis. The NSCs exposed to DETA/NONOate exhibited reduced cAMP response element binding protein (CREB) phosphorylation, nNOS expression, and proliferation. The effects of DETA/NONOate were reversed by forskolin, an activator of CREB signaling. Moreover, disrupting CREB phosphorylation by H-89 or LV-CREB133-GFP simulated the effects of DETA/NONOate, and inhibited telomerase activity. Thus, we conclude that NSCs-derived nNOS stimulates neurogenesis via activating telomerase, whereas neurons-derived nNOS represses neurogenesis by supplying exogenous NO that hinders CREB activation, in turn, reduces nNOS expression in NSCs. STEM CELLS 2010;28:2041-2052