Alterations in tau phosphorylation in rat and human neocortical brain slices following hypoxia and glucose deprivation
Alterations in tau phosphorylation in rat and human neocortical brain slices following hypoxia and glucose deprivation
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DOI：
10.1006/exnr.1998.6899
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发表时间：
1998-12-01
影响因子：
5.3
通讯作者：
Billingsley, ML
中科院分区：
文献类型：
--
作者：
Burkhart, KK;Beard, DC;Billingsley, ML
Tau是一种受磷酸化调控的微管相关蛋白。高度磷酸化的tau蛋白不结合微管，是阿尔茨海默氏症和相关神经退行性疾病中成对螺旋细丝的主要成分。最近的报道表明，tau磷酸化模式在体内缺血和/或再灌注后发生改变。我们使用体外模型，利用大鼠和人的新皮质切片来研究tau磷酸化在缺氧和葡萄糖剥夺时的变化。采用多克隆和磷酸化敏感的tau -1单克隆抗血清进行Western blotting，监测tau蛋白随缺氧和葡萄糖剥夺以及这些营养物质的重建而发生的变化。在体外低血糖/缺氧条件下，剥夺30和60分钟后，大鼠和人新皮质切片中的tau蛋白发生了显著的去磷酸化。用（32）Pi对tau和其他蛋白进行放射性标记后，免疫沉淀实验证实了这种去磷酸化。冈田酸，一种磷酸酶抑制剂，能够在对照和缺血切片中阻止tau去磷酸化。Lubeluzole是一种具有体内神经保护活性的苯并噻唑衍生物，并没有显著改变tau磷酸化的模式。在不同时间的体外缺氧/低血糖（15-60分钟）后恢复氧气和葡萄糖导致磷酸化tau的明显恢复。这些数据表明，在短暂的体外缺氧/低血糖后，脑切片中tau经历了快速但可逆的去磷酸化，tau磷酸化的变化有助于确定缺氧和葡萄糖剥夺后的恢复程度。(C) 1998学术出版社。
Tau is a microtubule-associated protein which is regulated by phosphorylation. Highly phosphorylated tau does not bind microtubules and is the main component of the paired helical filaments seen in Alzheimer's and related neurodegenerative diseases. Recent reports suggested that patterns of tau phosphorylation changed following ischemia and/or reperfusion in vivo. We used an in vitro model employing rat and human neocortical slices to investigate changes in tau phosphorylation which accompany oxygen and glucose deprivation. Western blotting with polyclonal and phosphorylation-sensitive Tau-1 monoclonal antisera was used to monitor changes in tau which accompanied conditions of oxygen and glucose deprivation and reestablishment of these nutrients. In vitro hypoglycemia/hypoxia caused tau to undergo significant dephosphorylation in both rat add human neocortical slices after 30 and 60 min of deprivation. This dephosphorylation was confirmed using immunoprecipitation experiments after radiolabeling tau and other proteins with (32)Pi. Okadaic acid, a phosphatase inhibitor, was able to prevent tau dephosphorylation in both control and ischemic slices. Lubeluzole, a benzothiazole derivative with in vivo neuroprotective activity, did not significantly alter patterns of tau phosphorylation. Restoration of oxygen and glucose following varied periods of in vitro hypoxia/hypoglycemia (15-60 min) led to an apparent recovery in phosphorylated tau. These data suggest that tau undergoes a rapid, but reversible dephosphorylation following brief periods of in vitro hypoxia/hypoglycemia in brain slices and that changes in tau phosphorylation help determine the extent of recovery following oxygen and glucose deprivation. (C) 1998 Academic Press.