The down-regulation of microtubule proteins has been widely documented in the ischemic brain, but the temporal or spatial alteration of microtubules has not been systematically investigated in the vulnerable areas after ischemia. By examining the stability and distribution of microtubules following transient global ischemia, we found that the biomarkers of stable microtubules, MAP2 and acetylated α-tubulin, became significantly down-regulated in the CA1 stratum radiatum of rat hippocampus and that the neuron-specific microtubule protein, class III β-tubulin, was progressively decreased in the same region. Surprisingly, pan-β-tubulin, which is expressed at a low level in glial cells under physiological conditions, was significantly increased in reactive astrocytes after ischemia. The finding was supported by protein quantification and confocal microscopy analysis, and consistent with the different vulnerabilities of neuronal and glial cells to the ischemic insult. To our knowledge, the different responses of microtubules between neuronal and glial cells have not been described in the ischemic brain before. The deconstruction of microtubules in the neurons is expected to contribute to the selective and delayed neuronal death in the vulnerable brain regions, while the increased microtubules in the reactive astrocytes may play an important role in the shape conversion of astrocytes induced by ischemia.

中文翻译：

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短暂性缺血后CA1辐射层微管细胞骨架的时空变化

微管蛋白的下调已在缺血性脑中得到广泛记录，但在缺血后的脆弱区域尚未系统研究微管的时间或空间变化。通过检查短暂性全身缺血后微管的稳定性和分布，我们发现稳定微管的生物标志物 MAP2 和乙酰化 α-微管蛋白在大鼠海马的 CA1 辐射层中显着下调，并且神经元特异性微管蛋白III 类 β-微管蛋白在同一区域逐渐减少。令人惊讶的是，在生理条件下，在神经胶质细胞中以低水平表达的泛β-微管蛋白在缺血后在反应性星形胶质细胞中显着增加。这一发现得到了蛋白质定量和共聚焦显微镜分析的支持，并且与神经元和神经胶质细胞对缺血性损伤的不同脆弱性一致。据我们所知，神经元细胞和神经胶质细胞之间微管的不同反应以前没有在缺血脑中被描述过。预计神经元中微管的解构有助于易损脑区神经元的选择性和延迟死亡，而反应性星形胶质细胞中微管的增加可能在缺血诱导的星形胶质细胞形状转换中起重要作用。神经元细胞和神经胶质细胞之间微管的不同反应以前在缺血脑中没有被描述过。预计神经元中微管的解构有助于易损脑区神经元的选择性和延迟死亡，而反应性星形胶质细胞中微管的增加可能在缺血诱导的星形胶质细胞形状转换中起重要作用。神经元细胞和神经胶质细胞之间微管的不同反应以前在缺血脑中没有被描述过。预计神经元中微管的解构有助于易损脑区的选择性和延迟神经元死亡，而反应性星形胶质细胞中微管的增加可能在缺血诱导的星形胶质细胞形状转换中起重要作用。