Kugler P, Schmitt A
Institute of Anatomy, University of Würzburg, Würzburg, Germany.
Glia. 1999 Aug;27(2):129-42. doi: 10.1002/(sici)1098-1136(199908)27:2<129::aid-glia3>3.0.co;2-y.
Oligonucleotide and cRNA probes were used for non-radioactive in situ hybridization, carried out to identify the cell types in the nervous system of rat expressing the glutamate transporter EAAC1 mRNA. The results were compared with immunocytochemical data obtained using an antibody against a synthetic EAAC1 peptide. The present data confirm that EAAC1 is expressed in neurons of the CNS. Additionally, our findings indicate the localization of EAAC1 mRNA and protein in peripheral neurons (spinal ganglia) and in glial cells, i.e., oligodendrocytes in various white matter regions of the CNS, ependymal cells, and epithelial cells of the plexus choroideus of the four ventricles, as well as in satellite cells of spinal ganglia. Immunolabeling revealed a preferentially cytoplasmic staining of neurons and glial cells. The cytoplasmic staining was frequently granular, suggesting a localization of EAAC1 protein in vesicle membranes. A membrane localization of EAAC1 was also indicated by Western blotting, which showed immunoreactivity only in the 100,000 x g pellet of brain homogenate. We conclude that the glutamate transporter EAAC1 is not restricted to neurons but may also play an important role in glial cells, particularly in oligodendrocytes.
寡核苷酸和cRNA探针用于非放射性原位杂交，以鉴定大鼠神经系统中表达谷氨酸转运体EAAC1 mRNA的细胞类型。将结果与使用抗合成EAAC1肽抗体获得的免疫细胞化学数据进行比较。目前的数据证实EAAC1在中枢神经系统的神经元中表达。此外，我们的研究结果表明EAAC1 mRNA和蛋白在外周神经元（脊髓神经节）和神经胶质细胞中定位，即中枢神经系统各个白质区域的少突胶质细胞、室管膜细胞、四个脑室脉络丛的上皮细胞以及脊髓神经节的卫星细胞中。免疫标记显示神经元和神经胶质细胞优先进行细胞质染色。细胞质染色通常呈颗粒状，表明EAAC1蛋白定位于囊泡膜中。蛋白质印迹法也表明EAAC1存在膜定位，其仅在脑匀浆100,000×g沉淀中显示免疫反应性。我们得出结论，谷氨酸转运体EAAC1不仅局限于神经元，而且可能在神经胶质细胞中，特别是在少突胶质细胞中发挥重要作用。
