Objective To investigate the expression of AMPA receptor subunit-GluR2 (AMPA-GluR2) in oligodendrocyte precursor cells (OPCs) before and after spinal cord injury (SCI) for revealing the role of AMPA-GluR2 in the apoptosis of OPCs. Methods OPCs were isolated and cultured from neonatal SD rats by trypsin digestion method. The injured spinal cord was obtained from the established SCI model of SD rats. OPCs were divided into normal spinal cord (control group) , SCI group, glutamate receptor antagonist 2, 3-dihydroxy-6-nitro-7-sulfamoyl-benzo (f) quinoxaline-2, 3-dione (NBQX) group and spider toxin (JSTX) group. In the control group, OPCs were cultured with normal spinal cord tissue for 48 h, while in the other groups, OPCs were cultured with injured spinal cord tissue for 48 h. In NBQX group and JSTX group, OPCs were treated with NBQX (100 μmol/L) or JSTX (1 μmol/L) for 10 min before adding the injured spinal cord, and then the normal medium was used. The expression of AMPA-GluR2 was detected by Western-blotting and immunohistochemistry technique in control and SCI group. The apoptosis rate of each group was detected by flow cytometry. Results AMPA-GluR2 was expressed in the membrane and cytoplasm of OPC. The expression of AMPA-GluR2 in OPC of SCI group was significantly lower than that of control group, and the difference was statistically significant (P < 0.05) . The expression of AMPA-GluR2 in NBQX group and JSTX group was similar to that in control group, which was significantly higher than that in SCI group, and the difference was statistically significant (P < 0.05) . Compared with the control group, the apoptosis rate of OPCs in SCI group was higher;compared with SCI group, the apoptosis rates of OPCs in NBQX group and JSTX group were lower;the differences were all statistically significant (P < 0.05) . Conclusion The apoptosis of OPCs caused by SCI may be related to the down regulation of AMPA-GluR2.%目的 观察AMPA受体亚基Glu R2 (AMPA-Glu R2) 在脊髓损伤 (SCI) 前后少突胶质前体细胞 (OPC) 中的表达, 明确AMPA-Glu R2在OPC凋亡中的作用.方法 采用胰酶消化法分离并培养原代新生大鼠OPC, 建立SD大鼠SCI模型并获取受损脊髓组织.实验分为对照组、SCI组及谷氨酸受体拮抗剂2, 3-二羟基6-硝基7-氨磺基苯基喹恶啉 (NBQX) 组和蜘蛛毒素 (JSTX) 组.对照组将OPC与正常脊髓组织共培养48 h, 其余组将OPC与受损脊髓组织共培养48 h.NBQX组和JSTX组在加入受损脊髓前分别用NBQX (100μmol/L) 、JSTX (1μmol/L) 处理OPC 10 min后更换正常培养基培养.采用免疫细胞化学染色法和蛋白质印迹分析法检测对照组和SCI组AMPA-Glu R2表达量, 采用流式细胞术检测各组OPC凋亡情况.结果 AMPA-GluR2在OPC细胞膜和细胞质均有表达.SCI组OPC中AMPA-GluR2的表达量较对照组明显降低, 差异有统计学意义 (P <0.05) ;NBQX组及JSTX组AMPA-GluR2的表达量与对照组相当, 均明显高于SCI组, 差异有统计学意义 (P <0.05) .与对照组相比, SCI组OPC凋亡率升高;与SCI组相比, NBQX组和JSTX组OPC凋亡率下降;差异均有统计学意义 (P <0.05) .结论 SCI诱发的OPC凋亡与AMPAR-GluR2的表达下降有关.
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