抗运动神经元抗体对培养的鼠神经元的杀伤作用

Neurotoxicity of Antibody Against Motoneuron on Cultured Rat Cortical Neurons

目的 研究抗运动神经元抗体在运动神经元病发病机制中的作用。方法应用抗运动神经元抗体作用于体外培养的大鼠神经元。结果 观察到抗运动神经元抗体对体外培养的大鼠神经元具有明显的细胞毒作用。将anti-SMN(1:50)加入培养的细胞中,24h后有31%～41%神经元死亡,48h后有50%～67%神经元死亡,72h后有90%以上神经元死亡。该细胞毒作用不依赖补体参与,强度与抗体浓度呈正相关。AchE组化染色发现anti-SMN对胆碱能神经元有选择性损伤作用,随暴露于抗体时间延长,AchE阳性神经元明显减少。CaBP免疫组化结果显示,CaBP阳性细胞在加入抗体48h达高峰,此后迅速下降,大部分阳性细胞在72h后死亡。结论 antiSMN抗体对胆碱能神经元有选择性细胞毒性作用,其机制可能与神经元内Ca^(2+)浓度的改变有关。

Objective In order to determine the role of antibody against motoneuron in the process of neuronal death. Methods Cultured rat cortical neurons growing in serum-free medium were employed to observe the effects of antibody against motoneuron (anti-SMN) on the survival of these cultured neurons. Results (1) Exposure of the cultures in serum-free medium to anti-SMN with dilution of 1:50 results in death of 31%～41% of neurons for 24 hours incubation, 50%～67% for 48 hours and above 90% after 72 hours. The neurotoxicity induced by anti-SMN was accompanied by concentration-dependent release of lactate dehydrogenase into the culture medium. Cultures exposed to normal rat IgG as controls exhibited no such sign. (2) The cultured neurons exposed to anti-SMN (1:200) expressed markedly higer levels of immunoreactive Calbindin-D_(28k) especially after 48 hours incubation with it. There was a reduction in the number of acetylcholinesterase-positive neurons compared to the normal control. Conclusions The anti-SMN could directly initiate the process of cortical neuronal death and this effect was independent of complement. The alteration of Calbindin-D_(28k) immunoreactivity implied that calcium may be involved in the neurotoxicity induced by antiSMN.