Hou Xiao-Yu, Zhang Guang-Yi, Zong Yan-Yan
Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, PR China.
Neurosci Lett. 2003 Jun 5;343(2):125-8. doi: 10.1016/s0304-3940(03)00365-3.
The effects of suppression of postsynaptic density protein 95 (PSD-95) expression on the increased tyrosine phosphorylation of N-methyl-D-aspartate receptor subunit NR2A and interactions of Src and Fyn with NR2A after brain ischemia were investigated by immunoprecipitation and immunoblotting. Transient (15 min) brain ischemia was induced by the four-vessel occlusion method in Sprague-Dawley rats. Intracerebroventricular infusion of PSD-95 antisense oligonucleotides (every 24 h for 3 days before ischemia), but not missense oligonucleotides or vehicle, not only markedly decreased the protein level of PSD-95 but also attenuated the elevated tyrosine phosphorylation of NR2A and interactions of Src and Fyn with NR2A induced by 6 h of reperfusion following ischemia in the hippocampus. The protein levels of NR2A, Src and Fyn had no differences under the above conditions. These data suggested that PSD-95 is critical for facilitating NR2A tyrosine phosphorylation by Src family kinases in postischemic brain.
通过免疫沉淀和免疫印迹法，研究了抑制突触后致密蛋白95（PSD-95）表达对脑缺血后N-甲基-D-天冬氨酸受体亚基NR2A酪氨酸磷酸化增加以及Src和Fyn与NR2A相互作用的影响。采用四动脉闭塞法在Sprague-Dawley大鼠中诱导短暂性（15分钟）脑缺血。脑室内注入PSD-95反义寡核苷酸（缺血前每24小时一次，共3天），而非错义寡核苷酸或溶剂，不仅显著降低了PSD-95的蛋白水平，还减弱了海马缺血后6小时再灌注诱导的NR2A酪氨酸磷酸化升高以及Src和Fyn与NR2A的相互作用。在上述条件下，NR2A、Src和Fyn的蛋白水平无差异。这些数据表明，PSD-95对于促进缺血后脑中Src家族激酶介导的NR2A酪氨酸磷酸化至关重要。
