摘要
钠通道在各类神经元上高表达,参与细胞多种生理功能的调节,是神经元实现功能活动的基本单位.未成熟神经元上钠/钙通道所诱发和自发的电位活动对后期的发育成熟至关重要.然而,发育中的钠通道是否参与神经干细胞(neural stem cells,NSCs)分化的调控尚不清楚.本研究证明,未成熟的钠通道参与NSCs分化调控.Western印迹结果显示,在分化第1,3,5,7 d的NSCs上钠通道和胞外信号调节激酶(ERK)的蛋白表达与分化时间正相关.免疫组化结果发现,与对照组比较,加入电压门控钠通道阻断剂TTX可明显下调Neu N、GFAP和Gal-c在NSCs中的表达(P<0.05),提示钠通道参与NSCs分化的调控.当采用veratridine激动钠通道后,激光共聚焦检测到细胞内Ca^(2+)浓度明显升高,免疫组化和Western印迹结果显示细胞内Ca^(2+)浓度明显升高,p-ERK表达量明显上调;相反,TTX可明显阻断Veratridine所引起的细胞内Ca^(2+)浓度上调,并使p-ERK峰值明显降低和延后(P<0.05).研究结果表明,未成熟钠通道可通过激活ERK信号途径促进NSCs的分化.钠通道的这种作用可能是由钙离子介导的,其详尽机制有待进一步研究.
Sodium channel,the basic unit of neurons function activities,shows high expression in various types of neurons and is involved in the regulation of a lot of physiological process. It is very crucial for the development maturity of neurons to induce and spontaneous electrical activity by sodium / calcium channel. Whether developmental sodium channel are involved in regulating the differentiation of neural stem cells（NSCs） is not full unstood. Herein,we demonstrated that immature Na^＋channels regulated NSCs differentiation. In this study,Western blot showed that there were positive correlation between the expression of sodium channel,extracellular signal regulated kinase（ERK） and differentiation time of NSCs. Immunocytochemistry data revealed that inactivation of Na^＋channel with TTX could significantly inhibit the NSCs differentiation into neurons and glial cells（P〈0. 05 compared with control group）.This indicates that sodium channel was involved in the regulation of NSCs differentiation. Treatment of differentiating NSCs with veratridine produced a rapid increase intracellular Ca^2＋, and promotedexpression of p-ERK by confocal laser scanning microscope,immunocytochemistry and Western blotting（P〈0. 05 compared with control group）. This could be blocked by the pre-incubation of TTX. Our data suggest that the expression of neuron-like Na^＋channels in NSCs in vitro can be considered as strong evidence supporting the differentiation of NSCs via the Ca^2＋-ERK signaling pathway. This may be mediated through Ca^2＋,the detailed mechanism should be further researched.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2015年第1期80-87,共8页
Chinese Journal of Biochemistry and Molecular Biology
基金
重庆市渝中区科技计划(No.20110310)
国家教育部博士导师基金项目(No.20125503110006)~~
关键词
钠通道
神经干细胞分化
胞外信号调节激酶(ERK)
钙离子
odium channel
neural stem cell differentiation
extracellular signal regulated kinase（ERK）
Ca^（2＋）
