Depolarization Induces NR2A Tyrosine Phosphorylation and Neuronal Apoptosis

作者：Liu, Yong; Yan, Jing-Zhi; Gu, Ying-Hui; Wang, Wei; Zong, Yan-Yan; Hou, Xiao-Yu; Zhang, Guang-Yi^*

来源：Canadian Journal of Neurological Sciences, 2011, 38(6): 880-886.

DOI：10.1017/S0317167100012476

• TRANSIENT BRAIN ISCHEMIA
• GATED CALCIUM-CHANNELS
• NMDA-RECEPTORS
• SYNAPTIC-TRANSMISSION
• CA2+ CHANNELS
• SRC KINASE
• ACTIVATION
• PSD-95
• DEPRESSION
• ALPHA(1C)

Background: Cytosol Ca2+ overload plays a vital role in ischemic neuronal damage, which is largely contributed by the Ca2+ influx through L-type voltage-gated calcium channels (L-VGCCs) and N-methyl-D-aspartate (NMDA) type glutamate receptors. In this article, L-VGCCs were activated by depolarization to investigate the cross-talk between NMDA receptors and L-VGCCs. Methods: Depolarization was induced by 20 minutes incubation of 75 mM KCl in cultured rat cortical neuron. Apoptosis-like neuronal death was detected by DAPI staining. Tyrosine phosphorylation of NMDA receptor subunit 2A (NR2A), interactions of Src and NR2A were detected by immunoblot and immunoprecipitation. Results: Depolarization induced cortical neuron apoptosis-like cell death after 24 hours of restoration. The apoptosis was partially inhibited by 5 mM EGTA, 100 mu M Cd2+, 10 mu M nimodipine, 100 mu M genistein, 20 mu M MK-801, 2 mu M PP2 and combined treatment of nimodipine and MK-801. NR2A tyrosine phosphorylation increased after depolarization, and the increase was inhibited by the drugs listed above. Moreover, non-receptor tyrosine kinase Src bound with NR2A after depolarization and restoration. The binding was also inhibited by the drugs listed above. Conclusions: The results indicated that depolarization-induced neuronal death might be due to extracellular Ca2+ influx through L-VGCCs and subsequently Src activation-mediated NR2A tyrosine phosphorylation.

• 出版日期2011-11
• 单位徐州医科大学