当前位置: X-MOL 学术Cell Calcium › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
On the special role of NCX in astrocytes: Translating Na+-transients into intracellular Ca2+ signals.
Cell Calcium ( IF 4.3 ) Pub Date : 2019-12-23 , DOI: 10.1016/j.ceca.2019.102154
Christine R Rose 1 , Daniel Ziemens 1 , Alexei Verkhratsky 2
Affiliation  

As a solute carrier electrogenic transporter, the sodium/calcium exchanger (NCX1-3/SLC8A1-A3) links the trans-plasmalemmal gradients of sodium and calcium ions (Na+, Ca2+) to the membrane potential of astrocytes. Classically, NCX is considered to serve the export of Ca2+ at the expense of the Na+ gradient, defined as a "forward mode" operation. Forward mode NCX activity contributes to Ca2+ extrusion and thus to the recovery from intracellular Ca2+ signals in astrocytes. The reversal potential of the NCX, owing to its transport stoichiometry of 3 Na+ to 1 Ca2+, is, however, close to the astrocytes' membrane potential and hence even small elevations in the astrocytic Na+ concentration or minor depolarisations switch it into the "reverse mode" (Ca2+ import/Na+ export). Notably, transient Na+ elevations in the millimolar range are induced by uptake of glutamate or GABA into astrocytes and/or by the opening of Na+-permeable ion channels in response to neuronal activity. Activity-related Na+ transients result in NCX reversal, which mediates Ca2+ influx from the extracellular space, thereby generating astrocyte Ca2+ signalling independent from InsP3-mediated release from intracellular stores. Under pathological conditions, reverse NCX promotes cytosolic Ca2+ overload, while dampening Na+ elevations of astrocytes. This review provides an overview on our current knowledge about this fascinating transporter and its special functional role in astrocytes. We shall delineate that Na+-driven, reverse NCX-mediated astrocyte Ca2+ signals are involved neurone-glia interaction. Na+ transients, translated by the NCX into Ca2+ elevations, thereby emerge as a new signalling pathway in astrocytes.

中文翻译:

关于NCX在星形胶质细胞中的特殊作用:将Na +瞬态转化为细胞内Ca2 +信号。

作为溶质载体的电转运体,钠/钙交换剂(NCX1-3 / SLC8A1-A3)将钠和钙离子(Na +,Ca2 +)的跨血浆梯度连接到星形胶质细胞的膜电位上。传统上,NCX被视为以Na +梯度(定义为“正向模式”操作)为代价来服务Ca2 +的输出。正向模式NCX活性有助于Ca2 +的挤出,因此有助于星形胶质细胞从细胞内Ca2 +信号的恢复。由于其化学计量比为3 Na +至1 Ca2 +,NCX的逆转电势接近于星形胶质细胞的膜电势,因此,即使星形胶质Na +浓度很小的升高或较小的去极化也将其转换为“逆转模式”。 ”(Ca2 +导入/ Na +导出)。尤其,谷氨酸或GABA摄取进入星形胶质细胞和/或通过响应神经元活性而打开Na +渗透性离子通道,诱导了毫摩尔范围内的瞬时Na +升高。活性相关的Na +瞬变导致NCX逆转,它介导Ca2 +从细胞外空间流入,从而产生独立于InsP3介导的细胞内储存释放的星形胶质细胞Ca2 +信号传导。在病理条件下,反向NCX促进胞质Ca2 +超载,同时抑制星形胶质细胞Na +升高。这篇综述概述了我们目前对这种引人入胜的转运蛋白及其在星形胶质细胞中的特殊功能的认识。我们将描述由Na +驱动,反向NCX介导的星形胶质细胞Ca2 +信号与神经元-胶质细胞相互作用有关。Na +瞬态
更新日期:2019-12-23
down
wechat
bug