Beczkowska I W, Gracy K N, Pickel V M, Inturrisi C E
Department of Pharmacology, Cornell University Medical College, New York 10021, USA.
J Neurosci Res. 1997 Jan 1;47(1):83-9.
NG108-15 neuroblastoma cells differentiated with 0.1 M of all-trans retinoic acid (RA) were processed for immunohistochemical analysis using polyclonal antisera against the delta opioid receptor (DOR) and the N-Methyl-D-Aspartate receptor (NMDAR1) to determine the cellular sites for possible functional associations between DOR and NMDAR1 receptors. In this study, 6 days of RA treatment resulted in prominent morphological differentiation characterized by the appearance of numerous axon- and dendrite-like processes and formation of networks between the cell clusters. An immunocytochemical approach allowed the demonstration of antibody concentration-dependent differences, not evident in ligand binding studies, in the distribution of DOR and NMDA receptor protein between cell soma and processes. RA-differentiated cultures showed positive DOR-like immunostaining (DOR-LI) throughout the cell bodies as well as on the newly acquired processes. In contrast, NMDAR1-like immunoreactivity (NMDAR1-LI) in the RA-treated cells was detected in the cell soma and processes only with the higher concentration of the antiserum. With the lower concentration of the antibody the NMDAR1-LI was not detected in the processes and was limited to a punctuate subcellular distribution in the soma. The DOR-LI pattern of distribution in NG108-15 cells differentiated with RA appeared to be consistent with the DOR-LI detected in the CNS. The NMDAR1-LI distribution in these cells is similar to brain tissue with respect to its presence on the newly acquired processes. However, it differed from brain in that a much higher abundance of NMDAR1 receptors was observed in the cell soma. This differential distribution of DOR and NMDAR1 receptors in the RA-treated NG108-15 cells could provide a basis for future studies of drug-induced changes in these two receptors.
用0.1M全反式维甲酸（RA）诱导分化的NG108 - 15神经母细胞瘤细胞，使用抗δ阿片受体（DOR）和N - 甲基 - D - 天冬氨酸受体（NMDAR1）的多克隆抗血清进行免疫组织化学分析，以确定DOR和NMDAR1受体之间可能存在功能关联的细胞位点。在本研究中，RA处理6天导致显著的形态分化，其特征是出现大量轴突样和树突样突起以及细胞簇之间形成网络。免疫细胞化学方法显示，在细胞体和突起之间，DOR和NMDA受体蛋白的分布存在抗体浓度依赖性差异，这在配体结合研究中并不明显。RA分化的培养物在整个细胞体以及新形成的突起上均显示出阳性的DOR样免疫染色（DOR - LI）。相反，在RA处理的细胞中，仅在抗血清浓度较高时才能在细胞体和突起中检测到NMDAR1样免疫反应性（NMDAR1 - LI）。当抗体浓度较低时，在突起中未检测到NMDAR1 - LI，且其在细胞体中的分布局限于点状亚细胞分布。用RA分化的NG108 - 15细胞中DOR - LI的分布模式似乎与在中枢神经系统中检测到的DOR - LI一致。这些细胞中NMDAR1 - LI的分布在新形成的突起上与脑组织相似。然而，与脑组织不同的是，在细胞体中观察到NMDAR1受体的丰度要高得多。RA处理的NG108 - 15细胞中DOR和NMDAR1受体的这种差异分布可为未来研究这两种受体的药物诱导变化提供基础。
