Liu L, Aldskogius H, Svensson M
Department of Neuroscience, Uppsala University, Sweden.
J Neurocytol. 1998 Oct;27(10):737-48. doi: 10.1023/a:1006950917973.
The ultrastructural localization of immunoreactivity for immunoglobulin G (IgG), F(ab')2 and complement C9 was examined with preembedding immunoelectron microscopy in the hypoglossal nucleus and gracile nucleus as well as in the L4 spinal cord dorsal horn 1 week following hypoglossal or sciatic nerve transection, respectively. Only a few scattered immunoreactive profiles were observed on the unoperated side. On the operated side, IgG and F(ab')2 immunoreactivity was present in the membranes of all reactive microglial cells observed. In addition, the cell membrane of some hypoglossal motoneurons showed IgG immunoreactivity. Complement C9 immunoreactivity was present in the cytoplasm of all reactive microglial cells examined. In addition, there was diffuse C9 immunoreactivity in motoneuron perikarya ipsilateral to nerve injury as well as in cell membranes in the neuropil, some of which could be identified as neuronal. Our interpretation of these findings is (1) that peripheral nerve injury results in binding of IgG to reactive microglia, as well as to some axotomized neurons, and (2) that C9 is synthesized by reactive microglia in response to axon injury and is also associated with axotomized motoneurons. These findings suggest that IgG and complement C9 are involved in microglia-neuron interactions after peripheral nerve injury.
分别在舌下神经或坐骨神经横断后1周，用包埋前免疫电子显微镜检查舌下神经核、薄束核以及L4脊髓背角中免疫球蛋白G（IgG）、F(ab')2和补体C9免疫反应性的超微结构定位。在未手术侧仅观察到少数散在的免疫反应性轮廓。在手术侧，观察到的所有反应性小胶质细胞膜上均存在IgG和F(ab')2免疫反应性。此外，一些舌下运动神经元的细胞膜显示出IgG免疫反应性。在所检查的所有反应性小胶质细胞的细胞质中均存在补体C9免疫反应性。此外，在神经损伤同侧的运动神经元胞体以及神经毡中的细胞膜中存在弥漫性C9免疫反应性，其中一些可被鉴定为神经元。我们对这些发现的解释是：（1）周围神经损伤导致IgG与反应性小胶质细胞以及一些轴突切断的神经元结合；（2）C9由反应性小胶质细胞响应轴突损伤而合成，并且也与轴突切断的运动神经元相关。这些发现表明，IgG和补体C9参与周围神经损伤后的小胶质细胞-神经元相互作用。
