The Relevance Research of Neuroglobin and Caspase-3 in the Hippocampus CA1 Regin in Global Cerebral Ischemia-reperfused Rats
|School||Zunyi Medical College,|
|Keywords||Cerebral ischemia/reperfusion injury Neuroglobin Caspase-3 Apoptosis|
Objective:To investigate the expression of neuroglobin (Ngb) and Caspase-3 in hippocampus CA1 region of the Sprague-Dawley (SD) rats with global cerebral ischemia/reperfusion(I/R) injury and analyze the expression regularity of Ngb and Caspase-3 in differernt time,meanwhile analyze the relevance of Ngb and Caspase-3 distribution;discuss the effect mechanism of neuroglobin and Caspase-3.provide a reference for clinical.Methods:60 healthy SD rats were randomly divided into 2 groups:sham operation (SO) group and I/R group.each group was assigned into 5 observing time-points: 3,6,12,24,48 hours (h) according to reperfusion time. The SD rats model of global cerebral ischemica/reperfusion was produced by means of simple Pulsinelli-Brierley’s four arteries occlusion method.SO and I/R groups were both intraperitoneally injected with 0.9% Sodium chloride (dose:0.5ml/kg) per six hours after reperfusion.Then SD rats’cerebrums were taken out of their skull at each of observing time-point.The expression activation of Caspase-3 and Ngb protein in pyramidal cells in hippocampus comuammonis (CA)1 region were examined by immunohistochemical method (SABC) and Caspase-3 mRNA and Ngb mRNA by in situ hybridization, measured their average optical density(OD),and hematoxylin and eosin (HE) staining was also performed to detect the number of surviving pyramidal cells,and terminal-deoxynucleotidy transferase medatd dUTP nick end labeling (TUNEL) was used to detect apoptotic pyramidal cells (positive cells), And calculated the apoptotic rate of cells.Results:SO group,the expression of average optical density (OD) of Caspase-3 protein and Caspase-3 mRNA,Ngb and Ngb mRNA were not statistically significant(P>0.05);the number of surviving neurons and apoptotic rate of cells was no significant changes,there was no statistically significant (P>0.05);In the I/R group, Caspase-3 protein and Caspase-3 mRNA began to express at 3h after reperfusion,at the top at 24h,decreased gradually after 48h,24h has variability conspicuous statistically significant compared with3、6、12、48h (P<0.05);Ngb protein and Ngb mRNA’s dispersively expressed at 3h,6h after reperfusion,3、12、24、48h compared with the SO group was statistically significant(p<0.05);the number of surviving neurons and apoptotic rate of cells was significant changes,there was statistically significant (P<0.05).In SO group,Caspase-3 compared with the Ngb was not statistically significant(P>0.05). In the I/R group was statistically significant(P<0.05). Correlated analysis showed that there was negative correlation between the expression levels of Ngb and Caspase-3(r=-0.882,p<0.05),Ngb and apoptotic rate of cells(r =-0.984, P<0.01);positive correlation between Caspase-3 and apoptotic rate of cells (r =0.994, P<0.01).Conclusion:(1) After cerebral ischemia-reperfusion injury Caspase-3’expression was increased with time,meanwhile Ngb was reduced; (2) Caspase-3 has a negative correlation with the Ngb after global cerebal ischemia/reperfusion injury,neuroglobin may inhibit neuronal apoptosis.