缺血后适应调控树鼩脑缺血海马CA1区Akt（pS473）和Akt（pT308）过磷酸化的抗凋亡机制

汤諹 李树清*

doi:10.16098/j.issn.0529-1356.2016.05.003

解剖学报 ›› 2016, Vol. 47 ›› Issue (5) : 591-598. DOI: 10.16098/j.issn.0529-1356.2016.05.003

神经生物学

缺血后适应调控树鼩脑缺血海马CA1区Akt（pS473）和Akt（pT308）过磷酸化的抗凋亡机制

汤諹¹李树清^2*

作者信息 +

Mechanism of ischemic postconditioning regulated Akt（pS473）and Akt（pT308）hyperphosphorylation and neuronal apoptosis in hippocampal CA1 area after cerebral ischemia in tree shrew

TANG Yang¹ LI Shu-qing^2*

Author information +

文章历史 +

摘要

观察树鼩脑缺血海马神经元Akt（pS473）和Akt（pT308）磷酸化改变对CA1区细胞凋亡的影响，探讨缺血后适应（PC）抑制细胞凋亡的可能机制。方法用光化学诱导法诱导树鼩脑缺血并建立缺血PC模型；用免疫组织化学TACS原位凋亡检测试剂盒检测皮层及海马CA1区神经元凋亡数量，用免疫组织化学法检测Akt（pS473）和Akt（pT308）表达的空间分布，用ELISA法检测海马CA1区神经元Akt（pS473）和Akt（pT308）磷酸化水平；用电子显微镜观察其神经元超微结构改变。结果脑缺血后神经元皱缩，核消失以缺血24h为著。脑缺血后4 h、24 h及72 h皮层及海马CA1区神经元TUNEL阳性细胞数明显增加（P<0.01），海马CA1区神经元Akt (pS473) 和Akt (pT308)的表达及磷酸化水平明显升高，以脑缺血4 h的改变最明显，分别为(152.3±3.5) units/mg、(130.8±2.6) units/mg和(149.5±4.7)units/mg和 (42.35±2.49) units/mg、(19.23±1.41) units/mg和(23.38±1.32) units/mg (P<0.01）。缺血PC组神经元损伤明显减轻，皮层及海马CA1区TUNEL阳性细胞明显减少（P<0.01），且与海马神经元Akt (pT308)活化水平呈平行改变(P<0.05）。结论树鼩脑缺血海马CA1区细胞凋亡与Akt(pS473) 和Akt (pT308)过磷酸化的信号机制有关，缺血PC抑制海马神经元Akt(pS473) 和Akt(pT308)双磷酸化可能具有抗凋亡作用。

Abstract

Objective To investigate the effects of Akt（pS473）and（pT308）phosphorylation on neurons apoptosis in hippocampal CA1 area after thrombotic cerebral ischemia, and to explore the possible mechanisms of ischemic postconditioning (PC) for inhibiting neuron apoptosis. Methods Thrombotic cerebral ischemia was induced by photochemical reaction and an ischemic PC model was established in tree shrews. The expression and phosphorylation of Akt（pS473）and Akt（pT308）in hippocampus CA1 area were determined, respectively, by immunohistochemistry and ELISA. The neuron apoptosis was detected by a kitsdetection of immunohistochemistry TACSin situ. Ultrastructures of cortex and hippocampal neurons were abserved under an electron microscope. Results The neurons shrinkaged, nuclear disappear in 24hours after cerebral ischemia.The expression and phosphorylation levels of Akt（pS473）and Akt（pT308）in hippocampal CA1 area were significantly higher ［Akt (pS473):(152.3±3.5)units/mg, (130.8±2.6)units/mg and (149.5±4.7)units/mg and AKT（pT308）：（42.35±2.49）units/mg,（19.23±1.41）units/mg and（23.38±1.32）units/mg, respectively,(P<0.01)］ than the control group, and the counts of TUNEL positive cells in hippocampal CA1 area were increased significantly than the control group (P<0.01) in the ischemic group in different time points, but the less TUNEL positive neurons decreased significantly (P<0.01). Neuron injury was reduced significantly in the ischemia PC group, and this change coincided with the level of Akt(pS473) and Akt (pT308) activation. Conclusion The level of phosphorylation of Akt（pS473）and Akt（pT308）is closely related to the neuron apoptosis of hippocampal CA1 area after brain ischemia in tree shrews, and the mutual phosphorylation of Akt (pS473) and Akt［pT308］ exerts an important role in inhibition of hippocampal cell apoptosis after ischemic PC treatment.

导出引用

汤諹李树清. 缺血后适应调控树鼩脑缺血海马CA1区Akt（pS473）和Akt（pT308）过磷酸化的抗凋亡机制[J]. 解剖学报. 2016, 47(5): 591-598 https://doi.org/10.16098/j.issn.0529-1356.2016.05.003

TANG Yang LI Shu-qing. Mechanism of ischemic postconditioning regulated Akt（pS473）and Akt（pT308）hyperphosphorylation and neuronal apoptosis in hippocampal CA1 area after cerebral ischemia in tree shrew[J]. Acta Anatomica Sinica. 2016, 47(5): 591-598 https://doi.org/10.16098/j.issn.0529-1356.2016.05.003

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