TY - JOUR
T1 - Delayed ischemic postconditioning protects hippocampal CA1 neurons by preserving mitochondrial integrity via Akt/GSK3β signaling
AU - Zhou, Caifeng
AU - Tu, Jingyi
AU - Zhang, Quanguang
AU - Lu, Dongshuang
AU - Zhu, Ying
AU - Zhang, Wenli
AU - Yang, Fang
AU - Brann, Darrell W
AU - Wang, Ruimin
N1 - Funding Information:
This work was supported by a grant from the National Natural Science Foundation of China (No. 30970664 ) and the Natural Science Foundation of Hebei Province, China (No. 2008140 ). The funding agencies had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
PY - 2011/11
Y1 - 2011/11
N2 - Delayed ischemic postconditioning (Post C), which involves a brief ischemia followed by reperfusion 2 days after 8-10 min global cerebral ischemia (GCI), has been shown to exert a remarkable protection of the vulnerable hippocampal CA1 region of the brain and attenuation of behavioral deficits, although the mechanisms remain poorly understood. The purpose of the current study was to explore the effect of Post C upon mitochondrial integrity, cytochrome c release and Bax translocation as a potential key mechanism for Post C protection of the critical hippocampal CA1 region neurons. The results of the study revealed that ischemic Post C (3 min) administered 2 days after 8-min GCI exerted a robust preservation from GCI injury, as evidenced by the increase of NeuN-positive and the decrease of TUNEL-positive cells, as well as morphological features of mitochondrial integrity in the hippocampal CA1 region. We also found that Post C significantly blocked inner mitochondrial membrane potential depolarization, as shown by JC-1 staining, and attenuates cytochrome c release and Bax translocation induced by GCI. Pre-treatment of the PI3K inhibitor LY294002, 20 min prior to Post C, significantly attenuated Post C-induced elevation of p-Akt and p-GSK3β, as well as prevented Post C enhancement of mitochondrial integrity and Post C neuroprotection. The results suggest that phosphorylation of Akt and subsequent inactivation of GSK3β signaling is critical in mediating Post C beneficial effects upon mitochondrial integrity, function and neuroprotection following GCI injury.
AB - Delayed ischemic postconditioning (Post C), which involves a brief ischemia followed by reperfusion 2 days after 8-10 min global cerebral ischemia (GCI), has been shown to exert a remarkable protection of the vulnerable hippocampal CA1 region of the brain and attenuation of behavioral deficits, although the mechanisms remain poorly understood. The purpose of the current study was to explore the effect of Post C upon mitochondrial integrity, cytochrome c release and Bax translocation as a potential key mechanism for Post C protection of the critical hippocampal CA1 region neurons. The results of the study revealed that ischemic Post C (3 min) administered 2 days after 8-min GCI exerted a robust preservation from GCI injury, as evidenced by the increase of NeuN-positive and the decrease of TUNEL-positive cells, as well as morphological features of mitochondrial integrity in the hippocampal CA1 region. We also found that Post C significantly blocked inner mitochondrial membrane potential depolarization, as shown by JC-1 staining, and attenuates cytochrome c release and Bax translocation induced by GCI. Pre-treatment of the PI3K inhibitor LY294002, 20 min prior to Post C, significantly attenuated Post C-induced elevation of p-Akt and p-GSK3β, as well as prevented Post C enhancement of mitochondrial integrity and Post C neuroprotection. The results suggest that phosphorylation of Akt and subsequent inactivation of GSK3β signaling is critical in mediating Post C beneficial effects upon mitochondrial integrity, function and neuroprotection following GCI injury.
KW - Akt
KW - GSK3β
KW - Ischemic postconditioning
KW - Mitochondrial integrity
KW - Neuroprotection
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U2 - 10.1016/j.neuint.2011.08.008
DO - 10.1016/j.neuint.2011.08.008
M3 - Article
C2 - 21867737
AN - SCOPUS:80053376294
SN - 0197-0186
VL - 59
SP - 749
EP - 758
JO - Neurochemistry International
JF - Neurochemistry International
IS - 6
ER -