Quantification of Astrocyte Volume Changes During Ischemia In Situ Reveals Two Populations of Astrocytes in the Cortex of GFAP/EGFP Mice
Quantification of Astrocyte Volume Changes During Ischemia In Situ Reveals Two Populations of Astrocytes in the Cortex of GFAP/EGFP Mice
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DOI：
10.1002/jnr.21828
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发表时间：
2009-01-01
影响因子：
4.2
通讯作者：
Chvatal, Alexander
中科院分区：
文献类型：
--
作者：
Benesova, Jana;Hock, Miroslav;Chvatal, Alexander
缺血期间的能量消耗导致离子稳态紊乱和神经活性物质在细胞外空间积聚，随后导致星形胶质细胞的体积变化。共聚焦显微镜结合 3D 重建用于量化 GFAP/EGFP 转基因小鼠皮质切片中缺血诱导的星形胶质细胞体积变化。 20 分钟的氧糖剥夺 (OGD) 或氧糖剥夺结合酸化 (OGD(pH) (6.8)) 揭示了两种不同星形胶质细胞群的存在，第一个显示出较大的体积增加（HR 星形胶质细胞），第二个显示出较小的体积增加（LR 星形胶质细胞）。此外，通过膜片钳技术测量的静息膜电位（V-m）的变化支持存在两个对缺血有不同反应的星形细胞群。尽管一组在 OGD 或 OGD(pH) (6.8) 期间显着去极化，但在第二组中仅观察到 V-m 向更负值的微小变化。相反，酸化（ACF（pH）（6.8））导致所有星形胶质细胞的体积均匀减少，仅伴随少量去极化。有趣的是，在酸化过程中没有检测到两个不同反应的群体。采用免疫组织化学方法检测皮质星形胶质细胞内向整流钾通道（Kir4.1）、胶质纤维酸性蛋白（GFAP）和牛磺酸水平表达的差异。根据暴露于 OGD 或 OGD(pH) (6.8) 期间的体积和 V-m 变化，我们得出结论，GFAP/EGFP 小鼠的皮质中存在两种不同的星形胶质细胞群。免疫组织化学分析表明，Kir4.1 通道和 GFAP 的不同表达以及牛磺酸积累的差异可能导致星形胶质细胞调节其体积的独特能力。 (C) 2008 Wiley-Liss, Inc.
Energy depletion during ischemia leads to disturbed ionic homeostasis and accumulation of neuroactive substances in the extracellular space, subsequently leading to volume changes in astrocytes. Confocal microscopy combined with 3D reconstruction was used to quantify ischemia-induced astrocyte volume changes in cortical slices of GFAP/EGFP transgenic mice. Twenty-minutes of oxygen-glucose deprivation (OGD) or oxygen-glucose deprivation combined with acidification (OGD(pH) (6.8)) revealed the presence of two distinct astrocytic populations, the first showing a large volume increase (HR astrocytes) and the second displaying a small volume increase (LR astrocytes). In addition, changes in resting membrane potential (V-m), measured by the patch-clamp technique, supported the existence of two astrocytic populations responding differently to ischemia. Although one group markedly depolarized during OGD or OGD(pH) (6.8), only small changes in V-m toward more negative values were observed in the second group. Conversely, acidification (ACF(pH) (6.8)) led to a uniform volume decrease in all astrocytes, accompanied by only a small depolarization. Interestingly, two differently responding populations were not detected during acidification. Differences in the expression of inwardly rectifying potassium channels (Kir4.1), glial fibrillary acidic protein (GFAP), and taurine levels in cortical astrocytes were detected using immunohistochemical methods. We conclude that two distinct populations of astrocytes are present in the cortex of GFAP/EGFP mice, based on volume and V-m changes during exposure to OGD or OGD(pH) (6.8). Immunohistochemical analysis suggests that-the diverse expression of Kir4.1 channels and GFAP as well as differences in the accumulation of taurine might contribute to the distinct ability of astrocytes to regulate their volume. (C) 2008 Wiley-Liss, Inc.