降钙素基因相关肽对局灶性脑缺血再灌注大鼠海马tau磷酸化影响

目的探讨降钙素基因相关肽(CGRP)对局灶性脑缺血再灌注大鼠海马神经元tau蛋白过度磷酸化的影响。方法应用免疫组织化学SABC法、Western Blotting和图像分析方法检测局灶性脑缺血再灌注大鼠海马CA1区tau蛋白在Ser199/202位点磷酸化程度和总tau蛋白表达、以及CGRP对缺血神经元tau蛋白过度磷酸化的影响。结果缺血再灌注大鼠海马CA1区tau蛋白在Ser199/202位点磷酸化水平和总tau表达水平明显增高,CGRP治疗后tau蛋白磷酸化水平和总tau表达水平明显低于缺血再灌注组(P<0.05)。结论CGRP明显减轻局灶性脑缺血再灌注大鼠海马tau蛋白磷酸化程度和总tau表达水平,可能对缺血神经元起保护作用。

Effect of CGRP on Tau Hyperphosphorylation in Rat Hippocampus after Focal Cerebral Ischemia-Reperfusion

Objective To explore the effect of exogenous calcitonin gene related peptide(CGRP)on tau hyperphosphorylation in rat hippocampus during focal cerebral ischemia/reperfusion(I/R).Methods Focal cerebral ischemia/reperfusion model was induced by occlusion of the right middle cerebral artery using the intraluminal suture method.The levels of tau hyperphosphorylation at Ser199/202 site and total tau in rat ipsilateral hippocampus during focal cerebral ischemia/reperfusion were detected by immunohistochemical SABC method and Western Blotting.The immunoreactive positive products were analyzed by image analysis system.Results The levels of tau protein hyperphosphorylation at Ser199/202 site and total tau protein in rat hippocampal CA1 region were significantly higher in I/R group than in sham group(P<0.05).CGRP significantly reduced the levels of tau protein hyperphosphorylation at Ser199/202 site and total tau protein.Conclusion CGRP can attenuate the tau hyperphosphorylation and the level of total tau protein in rat hippocampus during focal cerebral ischemia-reperfusion.Inhibition of tau hyperphosphorylation may be involved in the protective mechanism of CGRP to ischemic neuron.