Institute of Neurosciences, the Fourth Military Medical University, 169 Chang Le Xi Road, Xi'an 710032, Shaanxi, China.
Neurochem Res. 2011 Jun;36(6):1129-34. doi: 10.1007/s11064-011-0460-z. Epub 2011 Apr 2.
Communication between astrocytes via the gap junction is crucial for maintaining homeostasis of the extra-neuronal microenvironment of the central nervous system. Dysfunction of astrocytic gap junctions is involved in many brain disorders. Our previous studies demonstrated a novel co-localization of Nogo-66 receptor at glial gap junctions in rat cerebellum and posterior pituitary. The present study was aimed at exploring whether Nogo-66 can modulate glial gap junctions in vitro. We confirmed the co-localization of Nogo-66 receptor with Cx43 in cultured astrocytes, and stimulated astrocytes with myelin extracts, or Nogo-66-Fc conditioned medium. Finally, we expressed and purified a functionally effective GST-Nogo-66 peptide. Lucifer yellow transfer assay was adopted to measure the gap junction permeability. The results showed that the spreading of Lucifer yellow was inhibited significantly by all three treatments as compared with their corresponding controls. Therefore, this study shows a novel inhibitory effect of Nogo-66 on the permeability of astrocytic gap junctions, suggesting a presumable role of Nogo-66 receptor in modulating the glial gap junction.
星形胶质细胞通过缝隙连接进行通讯对于维持中枢神经系统神经元外微环境的稳态至关重要。星形胶质细胞缝隙连接的功能障碍与许多脑部疾病有关。我们之前的研究表明，在大鼠小脑和垂体后叶，Nogo-66 受体与神经胶质缝隙连接有新的共定位。本研究旨在探讨 Nogo-66 是否可以在体外调节神经胶质缝隙连接。我们证实了 Nogo-66 受体与培养的星形胶质细胞中 Cx43 的共定位，并使用髓鞘提取物或 Nogo-66-Fc 条件培养基刺激星形胶质细胞。最后，我们表达和纯化了功能有效的 GST-Nogo-66 肽。采用荧光素黄转移实验测量缝隙连接通透性。结果表明，与相应对照相比，三种处理均显著抑制了荧光素黄的扩散。因此，本研究显示 Nogo-66 对星形胶质细胞缝隙连接通透性有新的抑制作用，提示 Nogo-66 受体可能在调节神经胶质缝隙连接中发挥作用。
