BDNF在ALS转基因小鼠活化星形胶质细胞中表达升高

Expression of BDNF is increased in activated astrocytes of ALS transgenic mice

目的探索脑源性神经营养因子(BDNF)在肌萎缩侧索硬化症(ALS)转基因小鼠神经元及星形胶质细胞(AS)表达及定位,进一步明确ALS发病机制。方法以同窝野生型(WT)小鼠为对照;免疫荧光法检测BDNF在95、108和122 d ALS转基因小鼠脊髓组织神经元及星形胶质细胞中的表达;以神经元样杂交细胞系NSC34(具有运动神经元特征)细胞为模型,建立野生型及SOD1-G93A突变型NSC34细胞模型;取同窝新生转基因小鼠,进行原代星形胶质细胞培养,免疫印迹检测BDNF在NSC34模型细胞及原代星形胶质细胞中的表达水平。结果与WT小鼠相比,在95、108和122 d ALS转基因小鼠脊髓组织中,BDNF在神经元内表达降低(P<0.05),而BDNF/GFAP(神经胶质纤维酸性蛋白)双阳性细胞明显增多;BDNF在SOD1-G93A突变型NSC34模型细胞中表达下降(P<0.05),在活化星形胶质细胞中表达增加(P<0.05)。结论BDNF在ALS转基因小鼠神经元及活化星形胶质细胞的表达变化及定位,提示神经元自主机制与星形胶质细胞介导的非自主机制在ALS的发病中起到重要作用。

Objective To explore the expression and localization of brain derived neurotrophic factor(BDNF)in neurons and astrocytes(AS)of transgenic mice with amyotrophic lateral sclerosis(ALS),and to further clarify the pathogenesis of ALS.Methods Immunofluorescence assay was used to detect the expression of BDNF in spinal cord neurons and astrocytes of 95,108 and 122 days old ALS transgenic mice.The wild type(WT)mice were used as controls group.Neuron cell line NSC34 was used as a cell model to establish wild type and SOD1-G93A mutant NSC34 cell strains,the transgenic mice from the same litter were selected to culture the primary astrocytes.The protein expression of BDNF in NSC34 cell model and primary astrocytes was detected by Western blot.ResultsCompared with WT mice,the expression of BDNF in neurons was decreased in spinal cord tissues of 95,108 and 122 days old ALS transgenic mice(P<0.05),while the expression of BDNF/GFAP double positive cells was significantly increased.In the cell model,BDNF expression decreased in SOD1-G93A mutant NSC34 cells(P<0.05)and increased in activated astrocytes(P<0.05).Conclusions The expression and localization of BDNF in neurons and activated astrocytes of transgenic mice with ALS suggest that the autonomic mechanism of neurons and the non-autonomic mechanism mediated by astrocytes play an important role in the pathogenesis of ALS.