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Eph/Ephrin--B1通过Src酪氨酸激酶/丝裂原活化蛋白激酶信号抑制睫状神经节神经元的尼古丁乙酰胆碱受体电流

夏远鹏, 胡波, 周昱男, 毛玲, 戴若莲, 董丽萍

华中科技大学同济医学院附属协和医院神经内科.湖北,武汉 430022

摘要

该研究旨在探讨Eph/Ephrin--B1信号对急性分离的鸡胚睫状神经节(ciliary ganglion,CG)神经元上#alpha#3--尼古丁乙酰胆碱受体(nicotinic acetylcholine receptors,#alpha#3--nAChRs)和#alpha#7--尼古丁乙酰胆碱受体(nicotinic acetylcholine receptors,#alpha#7--nAChRs)电流的影响及可能机制。用膜片钳技术在急性分离的CG神经元上分别记录#alpha#3--nAChRs和#alpha#7--nAChRs全细胞电流。为检测Ephrin--B1对细胞nAChRs电流的影响,细胞被随机分为:对照组、Ephrin--B1Fc处理组(用Ephrin--B1与IgG重组后形成的Ephrin--B1Fc刺激细胞)、IgG处理组(用与Ephrin--B1Fc处理组重组所需的相同浓度的IgG刺激细胞)和Ephrin--B1处理组(用与Ephrin--B1Fc处理组重组所需的相同浓度的Ephrin--B1刺激细胞)。为探讨Ephrin--B1调节细胞nAChRs电流的机制,分别用Src信号抑制剂PP2和丝裂原活化蛋白激酶(mitogen--activated protein kinase,MAPK)信号抑制剂PD98095预处理细胞后,再用Ephrin--B1Fc处理细胞,观察#alpha#3--nAChRs和#alpha#7--nAChRs电流的变化,细胞被随机分为:对照组、Ephrin--B1Fc处理组、PP2或PD98095(PP2/PD)处理组、Ephrin--B1Fc+PP2或PD98095处理组。结果显示:对照组、IgG处理组和Ephrin--B1处理组之间#alpha#3--nAChRs和#alpha#7--nAChRs电流无显著差异,而Ephrin--B1Fc处理组可显著抑制#alpha#3--nAChRs和#alpha#7--nAChRs电流,与对照组比较有显著差异({sl P}=0.002、{sl P}=0.003);此外,PP2可部分恢复被Ephrin--B1Fc所抑制的#alpha#7--nAChRs电流,PD98095则可部分恢复被Ephrin--B1Fc所抑制的#alpha#3--nAChRs电流。以上结果提示,Eph/Ephrin--B1信号可能分别通过MAPK和Src信号途径抑制急性分离的CG神经元上#alpha#3--nAChRs和#alpha#7--nAChRs的电流,表明Eph/Ephrin--B1可能参与交感神经系统功能的调控。

关键词： 尼古丁乙酰胆碱受体; Eph/Ephrin-B1; 丝裂原活化蛋白激酶; Src酪氨酸激酶; 睫状神经节神经元

Suppression of nicotinic ACh receptors--mediated currents by activation of Eph/Ephrin--B1 signaling involves Src tyrosine kinase and mitogen--activated protein kinase in ciliary ganglion neurons

Xia Yuanpeng, Hu Bo, Zhou Yunan, Mao Ling, Dai Ruolian, Dong Liping

Department of Neurology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology.Wuhan 430022,Hubei

Abstract

Recent studies showed that Eph/Ephrin tyrosine kinase family plays an important role in the development and functional maintenance of the nervous system, but its function in the sympathetic nervous system is still obscure. In the present study, we examined the effect of Eph/Ephrin-B1 signaling on the whole-cell currents mediated by either #alpha#7 or #alpha#3-nicotinic acetylcholine receptors (nAChRs) in acutly dissociated ciliary ganglion (CG) neurons. Firstly, we detected the effect of Ephrin-B1 on nAChRs currents. The neurons were randomly divided into control group, Ephrin-B1Fc-treated group that was stimulated by recombinant Ephrin-B1Fc, IgG-treated group, and Ephrin-B1-treated group. Secondly, we studied the regulatory mechanism of Ephrin-B1Fc on nAChRs currents. The neurons were randomly divided into control group, Ephrin-B1Fc-treated group, PP2 (inhibitor of Src tyrosine kinase) or PD98095 (antagonist of mitogen-activated protein kinase)-treated group, Ephrin-B1Fc + PP2 or PD98095-treated group. The results showed that there was no significant difference between the currents in control group, IgG-treated group and Ephrin-B1-treated group, but Ephrin-B1Fc significantly suppressed both #alpha#3-nAChRs and #alpha#7-nAChRs-mediated currents (P=0.002, P=0.003). Pretreatment with PP2 or PD98095 could partially rescue the Ephrin-B1Fc-induced suppression of currents mediated by #alpha#3-nAChRs or #alpha#7-nAChRs respectively. These results suggest that the Eph/Ephrin-B1 signaling may inhibit #alpha#3-nAChRs and #alpha#7-nAChRs-mediated currents on CG neurons, involving Src tyrosine kinase and mitogen-activated protein kinase signaling in the regulation of sympathetic nervous system.

Key words: #alpha#3-nAChRs;#alpha#7-nAChRs;Eph/Ephrin-B1;mitogen-activated protein kinase;Src tyrosine kinase

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引用本文：

夏远鹏, 胡波, 周昱男, 毛玲, 戴若莲, 董丽萍. Eph/Ephrin--B1通过Src酪氨酸激酶/丝裂原活化蛋白激酶信号抑制睫状神经节神经元的尼古丁乙酰胆碱受体电流[J]. 生理学报 2008; 60 (4): 462-468.

Xia Yuanpeng, Hu Bo, Zhou Yunan, Mao Ling, Dai Ruolian, Dong Liping. Suppression of nicotinic ACh receptors--mediated currents by activation of Eph/Ephrin--B1 signaling involves Src tyrosine kinase and mitogen--activated protein kinase in ciliary ganglion neurons. Acta Physiol Sin 2008; 60 (4): 462-468 (in Chinese with English abstract).