Tegenge Million Adane, Bicker Gerd
Division of Cell Biology, Institute of Physiology, University of Veterinary Medicine Hannover, Hannover, Germany.
J Neurochem. 2009 Sep;110(6):1828-41. doi: 10.1111/j.1471-4159.2009.06279.x. Epub 2009 Jul 14.
Developmental studies in both vertebrates and invertebrates implicate an involvement of nitric oxide (NO) signaling in cell proliferation, neuronal motility, and synaptic maturation. However, it is unknown whether NO plays a role in the development of the human nervous system. We used a model of human neuronal precursor cells from a well-characterized teratocarcinoma cell line (NT2). The precursor cells proliferate during retinoic acid treatment as spherical aggregate culture that stains for nestin and betaIII-tubulin. Cells migrate out of the aggregates to acquire fully differentiated neuronal phenotypes. The cells express neuronal nitric oxide synthase and soluble guanylyl cyclase (sGC), an enzyme that synthesizes cGMP upon activation by NO. The migration of the neuronal precursor cell is blocked by the use of nNOS, sGC, and protein kinase G (PKG) inhibitors. Inhibition of sGC can be rescued by a membrane permeable analog of cGMP. In gain of function experiments the application of a NO donor and cGMP analog facilitate cell migration. Our results from the differentiating NT2 model neurons point towards a vital role of the NO/cGMP/PKG signaling cascade as positive regulator of cell migration in the developing human brain.
脊椎动物和无脊椎动物的发育研究表明，一氧化氮（NO）信号传导参与细胞增殖、神经元运动和突触成熟。然而，NO是否在人类神经系统发育中发挥作用尚不清楚。我们使用了来自一个特征明确的畸胎瘤细胞系（NT2）的人类神经元前体细胞模型。在前体细胞用视黄酸处理期间，它们作为球形聚集体培养物进行增殖，该聚集体对巢蛋白和βIII微管蛋白呈阳性染色。细胞从聚集体中迁移出来以获得完全分化的神经元表型。这些细胞表达神经元型一氧化氮合酶和可溶性鸟苷酸环化酶（sGC），一种在被NO激活后合成cGMP的酶。神经元前体细胞的迁移被使用nNOS、sGC和蛋白激酶G（PKG）抑制剂所阻断。sGC的抑制作用可以通过一种可透过细胞膜的cGMP类似物来挽救。在功能获得实验中，应用NO供体和cGMP类似物可促进细胞迁移。我们从分化的NT2模型神经元得到的结果表明，NO/cGMP/PKG信号级联作为发育中的人类大脑中细胞迁移的正调节因子起着至关重要的作用。
