摘要
本研究旨在探讨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α3-尼古丁乙酰胆碱受体(nicotinic acetylcholine receptors,α3-nAChRs)和α7-尼古丁乙酰胆碱受体(nicotinic acetylcholine receptors,α7-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α3-nAChRs和α7-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α3-nAChRs和α7-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α3-nAChRs和α7-nAChRs电流无显著差异,而Ephrin-B1Fc处理组可显著抑制α3-nAChRs和α7-nAChRs电流,与对照组比较有显著差异(P=0.002、P=0.003);此外,PP2可部分恢复被Ephrin-B1Fc所抑制的α7-nAChRs电流,PD98095则可部分恢复被Ephrin-B1Fc所抑制的α3-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α3-nAChRs和α7-nAChRs的电流,表明Eph/Ephrin-B1可能参与交感神经系统功能的调控。
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/EphrinB1 signaling on the whole-cell currents mediated by either α7 or α3-nicotinic acetylcholine receptors (nAChRs) in acutly dissociated ciliary ganglion (CG) neurons. Firstly, we detected the effect of EphrinB1 on nAChRs currents. The neurons were randomly divided into control group, EphrinB1Fc-treated group that was stimulated by recombinant EphrinB1Fc, IgG- treated group, and EphrinB1-treated group. Secondly, we studied the regulatory mechanism of EphrinB1Fc on nAChRs currents. The neurons were randomly divided into control group, EphrinB1Fc-treated group, PP2 (inhibitor of Src tyrosine kinase) or PD98095 (antagonist of mitogen-activated protein kinase)-treated group, EphrinB1Fc + PP2 or PD98095-treated group. The results showed that there was no significant difference between the currents in control group, IgG-treated group and EphrinB1-treated group, but EphrinB1Fc significantly suppressed both α3-nAChRs and α7-nAChRs-mediated currents (P=0.002, P=0.003). Pretreatment with PP2 or PD98095 could partially rescue the EphrinB1Fc-induced suppression of currents mediated by α3-nAChRs or α7-nAChRs respectively. These results suggest that the Eph/Ephrin-B1 signaling may inhibit α3-nAChRs and α7-nAChRs-mediated currents on CG neurons, involving Src tyrosine kinase and mitogen-activated protein kinase signaling in the regulation of sympathetic nervous system.
出处
《生理学报》
CAS
CSCD
北大核心
2008年第4期462-468,共7页
Acta Physiologica Sinica
基金
the Natural Science Foundation of Hubei Province (No. 2006ABA107)