低氧预适应小鼠脑组织内CaMKⅡ磷酸化水平增高

Increased phosphorylation of CaMKⅡ in cerebral tissues from hypoxially preconditioned mice

目的探讨钙调蛋白依赖性蛋白激酶(CaMKⅡ)在小鼠脑低氧预适应(HPC)发生发展中的作用。方法成年雄性BALB/c小鼠随机分为正常对照(H0)、早期(H1～H4)和延迟性(H5～H6)低氧预适应等共计7组,制备小鼠HPC模型;用Western blot并结合GelDoc凝胶成像系统,检测小鼠脑组织内CaMKⅡ磷酸化水平和蛋白表达量;用免疫组化检测小鼠脑皮层和海马CaMKⅡ磷酸化水平。结果与H0组小鼠相比,H3～H5组海马和皮层的CaMKⅡ磷酸化水平明显升高(P<0.05);而H1～H6组的皮层和海马的CaMKⅡ蛋白表达量无明显变化;H3、H6组皮层和海马p-CaMKⅡ阳性细胞数目增多和灰度增强。结论CaMKⅡ磷酸化水平的升高可能参与了小鼠脑HPC的发生发展过程。

Objective To explore the role of calcium/calmodulin-dependent protein kinase Ⅱ （ CaMK Ⅱ ） in the development of cerebral hypoxic preconditioning（HPC）. Methods Healthy male BALB/c mice were randomly divided into 7 groups as follows ： normoxic control （ H0）, early（ H1 - H4） and delayed （ H5- H6） hypoxically precon- ditioned mice groups. SDS-PAGE, Western blot and Gel Doc imagine systems were applied to quantitatively analyze the level of CaMK Ⅱ phosphorylation and protein expression level in the brain of mice. Results Compared with H0 group, the phosphorylation level of CaMKⅡ increased in cortex and hippocampus of mice in H3 - H5 hypoxically preconditioned groups（P 〈 0. 05 ）. However, there was no significant changes in total CaMK Ⅱ protein expression in cortex and hippocampus of hypoxic preconditioned mice. Similarly, enhanced p-Thr286 CaMK Ⅱ was also observed in the hippocampus and cortex of mice by immunostaining following hypoxic exposures （ H3 and H6）. Conclusion The increased phosphorylation of CaMK Ⅱ may be involved in the development of cerebral HPC in mice.