Sheedlo H J, Siegel G J
J Neurosci Res. 1986;16(4):629-41. doi: 10.1002/jnr.490160405.
Brain fractions of adult control (+/+) and shiverer (Shi/Shi) mice were investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Immunostaining with specific antisera against rat brain myelin-associated glycoprotein (MAG) was detected at about the 96-kD region of gels in electrophoresed samples of the total homogenate, low-speed supernatant fraction, and low- and high-speed sedimentable portions of brain from +/+ mice. Reduced immunostaining was observed in the corresponding samples of brain fractions from Shi/Shi mice. The cerebrum, cerebellum, and medulla of +/+ and Shi/Shi mice were examined immunocytochemically for MAG on paraffin-embedded sections. Periaxonal immunostaining for MAG was observed in all the regions and the highest concentrations were in the corpus callosum, in the central cores of cerebellar folia, and in the medulla. Patterns of distribution were similar in +/+ and Shi/Shi mice, although the density of immunostaining around individual axons and the number of immunostained axons were significantly reduced in Shi/Shi mice. In addition, the three brain regions of Shi/Shi mice exhibited oligodendrocyte-like cells that contained immunostaining for MAG in the cytoplasm and periphery of their perikarya. This type of immunostained cell was not observed in +/+ mice. In this study, immunoblotting with brain fractions and immunocytochemistry revealed strong evidence for reduced concentrations of MAG in the CNS of Shi/Shi mice compared to control mice. In addition, there is immunocytochemical evidence for abnormal accumulation of MAG in perikarya of oligodendroglial-like cells, suggesting the possibility of a transport block for myelin proteins in the shiverer mutant.
通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和免疫印迹法对成年对照（+/+）和颤抖小鼠（Shi/Shi）的脑部分进行了研究。用抗大鼠脑髓鞘相关糖蛋白（MAG）的特异性抗血清进行免疫染色，在+/+小鼠脑总匀浆、低速上清液部分以及低速和高速可沉淀部分的电泳样品凝胶的约96-kD区域检测到。在Shi/Shi小鼠脑部分的相应样品中观察到免疫染色减弱。对+/+和Shi/Shi小鼠的大脑、小脑和延髓进行免疫细胞化学检查，以检测石蜡包埋切片上的MAG。在所有区域均观察到轴突周围对MAG的免疫染色，最高浓度出现在胼胝体、小脑叶的中央核心和延髓。+/+和Shi/Shi小鼠的分布模式相似，尽管Shi/Shi小鼠中单个轴突周围的免疫染色密度和免疫染色轴突的数量显著减少。此外，Shi/Shi小鼠的三个脑区显示出少突胶质细胞样细胞，其胞质和核周含有对MAG的免疫染色。在+/+小鼠中未观察到这种类型的免疫染色细胞。在本研究中，用脑部分进行的免疫印迹和免疫细胞化学显示，与对照小鼠相比，Shi/Shi小鼠中枢神经系统中MAG浓度降低的有力证据。此外，有免疫细胞化学证据表明少突胶质细胞样细胞核周存在MAG异常积聚，提示颤抖突变体中髓鞘蛋白可能存在转运障碍。
