Fukamauchi F, Wang Y J, Chuang D M
Department of Molecular Medical Science, Medical Research Institute, Tokyo Medical and Dental University, Japan.
Life Sci. 1998;62(5):389-96. doi: 10.1016/s0024-3205(97)01132-6.
Effects of sub-chronic ethanol treatment on the mRNA levels of muscarinc acetylcholine receptor (mAChR) subtypes were studied in two neurohybrid cell lines, NG108-15 and NCB-20. The former expresses only m4-mAChRs, while the latter expresses m1- and m4-mAChRs. Exposure to 200 mM ethanol for 1 to 3 days induced a time-dependent increase in the levels of m4-mAChR mRNA in NG108-15 and NCB-20 cells. In contrast, the levels of ml-mAChR mRNA and mAChR-mediated phosphoinositide hydrolysis in NCB-20 cells were unchanged. The ethanol-induced up-regulation of m4-mAChR mRNA was associated with a parallel increase in the levels of mAChR binding sites assessed by using [3H]quinuclidinyl benzilate. The mRNA up-regulation was closely correlated with a decrease in intracellular cyclic AMP concentration and the ethanol up-regulation was blocked by 8-bromo-cyclic AMP and forskolin, suggesting that m4-mAChR mRNA is under negative regulation by cyclic AMP. Thus, neurally-related cell lines are useful models for studying molecular mechanisms underlying ethanol-induced alteration of mAChR expression and function in the nervous system.
在两种神经杂交细胞系NG108 - 15和NCB - 20中研究了亚慢性乙醇处理对毒蕈碱型乙酰胆碱受体（mAChR）亚型mRNA水平的影响。前者仅表达m4 - mAChRs，而后者表达m1 - 和m4 - mAChRs。在NG108 - 15和NCB - 20细胞中，暴露于200 mM乙醇1至3天会导致m4 - mAChR mRNA水平呈时间依赖性增加。相比之下，NCB - 20细胞中m1 - mAChR mRNA水平和mAChR介导的磷酸肌醇水解未发生变化。乙醇诱导的m4 - mAChR mRNA上调与使用[3H]喹核醇基苯甲酸酯评估的mAChR结合位点水平的平行增加相关。mRNA上调与细胞内环磷酸腺苷（cAMP）浓度降低密切相关，并且乙醇上调被8 - 溴环磷酸腺苷和福司可林阻断，这表明m4 - mAChR mRNA受环磷酸腺苷的负调控。因此，神经相关细胞系是研究乙醇诱导的神经系统中mAChR表达和功能改变的分子机制的有用模型。
