Effects of AMP-activated protein kinase on the expression levels of caspase-8, -3 and apoptosis in the ischemic cortex following focal cerebral ischemia-reperfusion in mice

Zhanbo Wang ,Hua Li ,Tao Li ,Zhengqi Yang ,Shabier Tuerxun ,Zhao Xun ,Changliang Zheng ,Jingwen Cai

doi:10.3760/cma.j.issn.1673-4165.2016.07.005

Abstract

Objective To investigate the effects of inhibiting AMP-activated protein kinase (AMPK) activity on the infarct volume, expressions of caspase-8, -3 and apoptosis in the ischemic cortex following focal cerebral ischemia-reperfusion in mice. Methods A total of 72 male C57BL/6 mice were divided into a sham-operation group, an ischemia-reperfusion group, and an AMPK inhibitor group according to the random number table method. A mode of middle cerebral artery occlusion (MCAO) was induced by the suture method. Immediately after MCAO, the compound C (20 mg/kg) was injected intraperitoneally in the AMPK inhibitor group. The same volume of saline was injected intraperitoneally at the same time point in the sham operation group and the ischemia-reperfusion group. The infarct volume was measured by 2, 3, 5 triphenyltetrazolium chloride (TTC) staining. The expression levels of caspase-8 and -3 were detected by immunohistochemical staining. Apoptosis was detected by TUNEL staining. Results The sham-operation group had no infarction, no caspase-8, -3, and apoptotic positive cells. Compared with ischemia-reperfusion group, the infarct volume was significantly decreased (45.34±7.202 mm3vs. 2.71±4.93 mm3;t=5.730, P=0.037), the numbers of positive cells of caspase-8 (17.58±8.62/HP vs. 6.87±4.32 /HP; t=3.631, P=0.023), caspase-3 (16.21±5.46/HP vs. 8.22±4.64/HP; t=2.630, P=0.021), and apoptosis (78.44±8.32/HP vs. 55.73±6.71/HP; t=5.541, P=0.042) in the cerebral cortex in the AMPK inhibitor group was decreased significantly. Conclusions Inhibition of AMPK activity may reduce the infarct volume of cerebellar ischemia-reperfusion in mice. Its mechanism may be associated with the downregulation of expression levels of caspase-8, -3, and the decrease of apoptosis. Key words: Brain Ischemia; Reperfusion Injury; AMP-Activated Protein Kinases; Caspase 3; Caspase 8; Apoptosis; Disease Models, Animal; Mice

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