ApoE调节谷氨酸及其受体表达对视神经脊髓炎体外模型的作用研究

The role of Apolipoprptein E in regulating glutamate NAD and its receptors in euromyelitis model in vitro

目的研究谷氨酸(Glu)及其受体N-甲基-D-天冬氨酸受体(NMDAR)、载脂蛋白E(Apo E)在视神经脊髓炎(NMO)发病中的作用。方法取7～14 d大小的C57BL/6野生型(WT)小鼠及Apo E基因敲除(ApoE-/-)小鼠脊髓切片及视神经体外培养。用NMO-IgG及补体(HC)干预脊髓切片及视神经制成NMO体外模型实验组,设无干预的对照组。分别检测各组水通道蛋白4(AQP4)、胶质纤维酸性蛋白(GFAP)的表达、培养液中谷氨酸浓度、各组NMDAR1、NMDAR2B蛋白表达。结果 (1)实验组脊髓和视神经组织的GFAP、AQP4表达显著少于对照组(P <0. 05),且Apo E-/-实验组比WT实验组GFAP、AQP4缺失更显著(P <0. 05);(2)实验组脊髓和视神经组织的NMDAR1、NMDAR2B表达水平明显高于对照组(P <0. 05),实验组间对比Apo E-/-组NMDAR2B表达显著高于WT组(P <0. 05);(3)各组间培养液谷氨酸浓度无显著差异性(P> 0. 05)。结论 (1) NMDAR可能参与NMO致病,特别NMDAR2B可能通过诱导兴奋毒性作用参与NMO发病;(2) Apo E可能通过影响NMDAR活性间接对抗谷氨酸的神经毒性作用。

Objective To study the role of glutamate(Glu)and its receptors N-methyl-D-aspartate receptor(NMDAR)and apolipoprotein E(ApoE)in the pathogenesis of optic neuromyelitis(NMO).Methods Spinal cord sections and optic nerves of C57BL/6 wild-type mice and ApoE-/-A-mice(7~14 d in size)were cultured in vitro.The spinal cord slices and optic nerve were treated with purified NMO-IgG and complement(HC)to make NMO in vitro model experimental group,and no intervention control group was set up.The expression of aquaporin 4(AQP4),glial fibrillary acidic protein(GFAP),glutamic acid concentration in culture medium,and NMDAR1 and NMDAR2B protein expression in each group were detected.Colorimetric method was used to detect glutamate concentration in culture medium.Group NMDAR1,NMDAR2B protein expression.Results The expression of GFAP and AQP4 in the spinal cord and optic nerve tissue of the experimental group was significantly lower than that of the control group(P<0.05).The ApoE-/-experimental group was more significant than the WT experimental group(P<0.05).The expression levels of NMDAR1 and NMDAR2B in the spinal cord and optic nerve tissues of the experimental group were significantly higher than those in the control group(P<0.05).The expression of NMDAR2B in the ApoE-/-group was significantly higher than that in the WT group(P<0.05).There was no significant difference in the concentration of glutamate in the culture medium between the groups(P>0.05).Conclusion NMDAR may be involved in the pathogenesis of NMO.In particular,NMDAR2B may participate in the pathogenesis of NMO by inducing excitotoxicity.ApoE may indirectly counteract the neurotoxic effect of glutamate by affecting NMDAR activity.