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Nimodipine represses AMPK phosphorylation and excessive autophagy after chronic cerebral hypoperfusion in rats
- Source :
- Brain research bulletin. 140
- Publication Year :
- 2017
-
Abstract
- Chronic cerebral hypofusion (CCH) after bilateral carotid artery occlusion (2VO) causes cognitive damage and neuronal degeneration in the cortex and hippocampal CA1 area, and influences the oxygen and glucose supply in the brain which often results in metabolic alterations and oxidative stress. AMP-activated protein kinase (AMPK) phosphorylation, a sensor of cellular energy status, directs metabolic adaptation to support cellular growth and survival after CCH. Autophagy is also likely to be involved in metabolic adaptation and plays an important role in neuronal deterioration and cognitive decline after CCH. Nimodipine, an L-type calcium channel antagonist, has been reported to exert neuroprotective effects. However, the potential role of nimodipine in autophagy and the energy sensing AMPK signal is not well understood. In addition, little is known about the relationship between autophagy and AMPK signal. Here, we designed a way to evaluate these issues. Adult male Wistar rats were subjected to 2VO and randomly divided into three groups: the Vehicle (2VO), Nimodipine (2VO + nimodipine 10 mg/kg) groups. A third group served as sham controls. Each group was investigated at 2 and 4 weeks post gavage and tested using the Morris water maze. The activities of LC3B and AMPK signal were examined using immunohistochemistry and western blotting. Nimodipine significantly alleviated spatial learning and memory impairments and the number of lesion neurons. At 2 weeks of durg administration, these drug effects, suppressing AMPK activation and excessive autophagy, were more pronounced at the cortex than at hippocampal CA1 area. The effects of nimodipine were significant in the hippocampal CA1 area after 4 weeks of administration. Furthermore, nimodipine inhibited expression of eIF2α/ATF4 signaling related to energy deficit stress in 2VO rats. These results suggest that excessive autophagy has promoted neuronal and tissue injury after 2VO in rats. Nimodipine protected the brain from CCH by inhibiting the autophagy activity. The p-AMPK and eIF2α/ATF4 pathway is likely part of an integrated pro-autophagy signaling network after CCH.
- Subjects :
- 0301 basic medicine
Male
Calcium Channels, L-Type
Morris water navigation task
Hippocampal formation
Pharmacology
AMP-Activated Protein Kinases
medicine.disease_cause
Neuroprotection
03 medical and health sciences
Random Allocation
0302 clinical medicine
medicine
Autophagy
Animals
Cognitive decline
Phosphorylation
Rats, Wistar
Maze Learning
Nimodipine
Spatial Memory
Neurons
Memory Disorders
business.industry
General Neuroscience
AMPK
Brain
Calcium Channel Blockers
Cerebrovascular Disorders
Disease Models, Animal
030104 developmental biology
Neuroprotective Agents
business
030217 neurology & neurosurgery
Oxidative stress
medicine.drug
Subjects
Details
- ISSN :
- 18732747
- Volume :
- 140
- Database :
- OpenAIRE
- Journal :
- Brain research bulletin
- Accession number :
- edsair.doi.dedup.....326ee3cce0e40f56cbac9921f309cc92