Correlations of neuronal apoptosis with expressions of c-Fos and c-Jun in rats with post-ischemic reconditioning damage

P. Xiao, X.-W. Liu, N.-N. Zhao, R. Fang, Q. Wen, K.-X. Zeng, Y.-L. Wang

Department of Rehabilitation, Shenzhen Dapeng New District Nan’ao People’s Hospital, Shenzhen, China. wangyulong@szu.edu.cn

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• Neurology

OBJECTIVE: Transcription factors (c-Fos and c-Jun) have been considered to play roles in the initiation of programmed nerve cell death. However, the roles of c-Fos and c-Jun protein expressions in neuronal apoptosis of rats with post-ischemic reconditioning damage were not clarified. Therefore, the aim of this study was to investigate the correlations of protein expressions of c-Fos and c-Jun with neuronal apoptosis of rats with post-ischemic reconditioning damage.

MATERIALS AND METHODS: Rat models of post-ischemic reconditioning were established firstly. Then, apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay, and the gene expression levels of apoptosis-related proteins [cytochrome c (Cyt c), B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax)] were detected by reverse transcription-polymerase chain reaction (RT-PCR). Lastly, Western blotting was used to determine the protein expression levels of c-Fos and c-Jun, and the expressions of c-Fos and c-Jun in brain tissues of models were measured by immunohistochemistry.

RESULTS: Treatment group had significantly increased malonaldehyde (MDA) level and significantly decreased superoxide dismutase (SOD) activity in rat cortex compared with those in control group (p<0.05). The number of TUNEL positive cells in the right cortex of rats in the treatment group was clearly higher than that in control group. Among them, post-ischemic reperfusion group had reduced level of Bax in the cytoplasm, but increased Bax level in the mitochondrion, and lowered expression level of Bcl-2 in both mitochondrion and cytoplasm in comparison with control group. Dynamic detection results of c-Jun were in synchronization with those of apoptosis proteins, and maximum expression occurred at 24 h after treatment.

CONCLUSIONS: c-Jun may play a role in the initiation of apoptotic cell death in these neurons.

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