Mochizuki Nobuyuki, Takagi Norio, Kurokawa Koji, Kawai Takayuki, Besshoh Shintaro, Tanonaka Kouichi, Takeo Satoshi
Department of Molecular and Cellular Pharmacology, Tokyo University of Pharmacy & Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
Neurosci Lett. 2007 May 1;417(2):143-8. doi: 10.1016/j.neulet.2007.02.066. Epub 2007 Mar 2.
The N-methyl-D-aspartate (NMDA) receptor, a subtype of ionotropic glutamate receptors, plays an important role in the regulation of neuronal development, learning and memory, and neurodegenerative diseases. NMDA receptor blockade enhances neurogenesis in the hippocampal dentate gyrus in vivo. The effect of NMDA receptor antagonist on proliferation of neural progenitor cells, however, remains to be determined. We investigated changes in the diameter and number of neurospheres derived from the embryonic rat brain after NMDA receptor blockade. Cortical progenitor cells were isolated from gestational day 18 fetal rats according to the Percoll density gradient method. Cultured spheres expressed neural progenitor markers, musashi-1 and nestin. Immunohistochemical analysis demonstrated that cells in Dulbecco's modified Eagle medium/F12 containing 1% fetal bovine serum on day 8 differentiated to MAP-2-positive neurons and GFAP-positive astrocytes. The expression of NR1 and NR2B subunits of the NMDA receptor in neurospheres was detected. Neither brief nor sustained exposure to NMDA altered the diameter and number of neurospheres. Brief exposure to 30 microM MK-801, an NMDA receptor antagonist, decreased the diameter of neurospheres. Sustained exposure to 30 microM MK-801 decreased the diameter and number of neurospheres. Our results provide evidence that MK-801 directly decreased proliferation of neural progenitor cells.
N-甲基-D-天冬氨酸（NMDA）受体是离子型谷氨酸受体的一种亚型，在神经元发育、学习和记忆以及神经退行性疾病的调节中发挥着重要作用。在体内，NMDA受体阻断可增强海马齿状回中的神经发生。然而，NMDA受体拮抗剂对神经祖细胞增殖的影响仍有待确定。我们研究了NMDA受体阻断后源自胚胎大鼠脑的神经球直径和数量的变化。根据Percoll密度梯度法从妊娠第18天的胎鼠中分离出皮质祖细胞。培养的神经球表达神经祖细胞标志物musashi-1和巢蛋白。免疫组织化学分析表明，在第8天含有1%胎牛血清的杜氏改良 Eagle培养基/F12中的细胞分化为MAP-2阳性神经元和GFAP阳性星形胶质细胞。检测了神经球中NMDA受体NR1和NR2B亚基的表达。短暂或持续暴露于NMDA均未改变神经球的直径和数量。短暂暴露于30 microM的NMDA受体拮抗剂MK-801可减小神经球的直径。持续暴露于30 microM的MK-801可减小神经球的直径和数量。我们的结果提供了证据表明MK-801直接降低了神经祖细胞的增殖。
