Subcellular localization of glutamate-stimulated intracellular magnesium concentration changes in cultured rat forebrain neurons using confocal microscopy.
Subcellular localization of glutamate-stimulated intracellular magnesium concentration changes in cultured rat forebrain neurons using confocal microscopy.
复制标题
使用共聚焦显微镜对培养的大鼠前脑神经元中谷氨酸刺激的细胞内镁浓度变化进行亚细胞定位。
DOI：
10.1016/s0306-4522(99)00471-6
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发表时间：
2000
期刊：
影响因子：
3.3
通讯作者：
Reynolds,IJ
中科院分区：
文献类型：
--
作者：
Cheng,C;Reynolds,IJ
谷氨酸可刺激细胞内镁浓度（[Mg 2 +]i）增加并诱导神经毒性，两者均不依赖于Ca 2+变化。虽然Mg 2+在细胞内是必不可少的，但人们对它是如何调节的知之甚少，特别是在神经元中。因此，我们使用的荧光指示剂，magindo-1和共聚焦显微镜检查可能的细胞内池的Mg 2+培养的神经元，可以动态调节谷氨酸。magindo-1荧光信号存在于整个细胞体中，并延伸到神经元突起中。magindo-1405 nm/490 nm比值信号在细胞质和细胞核中相似，表明静息态[Mg ~（2+）]在整个神经元中是均匀的。在细胞外不含Ca 2+和Na+的缓冲液中加入100μM谷氨酸/10μM甘氨酸，刺激细胞核和细胞质区域的[Mg 2 +] i增加，幅度和持续时间相似。谷氨酸暴露还刺激神经元过程中[Mg 2 +] i增加，这可被N-甲基-d-天冬氨酸受体拮抗剂MK-801（10μM）抑制。谷氨酸刺激的[Mg ~（2+）] i在细胞体和神经元突起中的增加依赖于细胞外Mg ~（2+）浓度。这些发现表明，谷氨酸刺激的[Mg 2 +]变化可能不仅影响细胞质过程，而且直接触发涉及的核事件，例如，神经元损伤。
Glutamate can stimulate increases in intracellular magnesium concentration ([Mg2+]i) and induce neurotoxicity, both independent of Ca2+changes. Although Mg2+is essential within the cell, very little is known about how it is regulated, especially in neurons. Therefore we used the fluorescent indicator, magindo-1 and confocal microscopy to examine possible intracellular pools of Mg2+in cultured neurons that can be dynamically regulated by glutamate. The magindo-1 fluorescence signal was present throughout the cell body and extends into the neuronal processes. The magindo-1 405nm/490nm ratio signal was similar in the cytoplasm and nucleus, suggesting that resting [Mg2+]iis uniform across the neuron. The addition of 100μM glutamate/10μM glycine in an extracellular Ca2+- and Na+-free buffer stimulated an increase in [Mg2+]iin both the nuclear and cytoplasmic regions of similar magnitude and duration. This glutamate exposure also stimulated a [Mg2+]iincrease in neuronal processes which was inhibited by the N-methyl-d-aspartate receptor antagonist, MK-801 (10μM). The glutamate-stimulated [Mg2+]iincrease in both the cell body and neuronal processes was dependent on the extracellular Mg2+concentration. These findings suggest glutamate-stimulated [Mg2+]ichanges may not only impact cytoplasmic processes, but also directly trigger nuclear events involved, for example, in neuronal injury.