Changes And Significances Of Astrocytes Glial Fibrillary Acidity Protein And High Mobility Group Protein Expression In The Hippocampus Of Rats After Cerebral Ischemia

Objective To explore changes and significances of astrocytes glial fibrillary acidity protein and high mobility group protein expression in the hippocampus of rats following cerebral ischemic reperfusion and whether they are correlativeMethods1. Animals Sixty healthy,male Sprague-Dawley rats weighing 250g-310g was used (Supplied by experimental of animal center of An Hui Medical University ,Hefei, China)2. Animal Groups Sixty male Sprague Dawley(SD) rats were randomly divided into shamoperated group and ischeimia reperfusion(IR) group,The groups were divided into five subgroups:1 d ,3 d, 7 d ,14 d ,28 d,each subgroups had 6 rats.3. Model Refering to longa[1] method, making rats underwent a 2 h middle cerebral artery occlusion (MCAO) followed by various reperfusion times (1 d, 3 d, 7 d, 14 d, 28 d); for shamoperated group, no suture was inserted into the artery,but the rest of operation were the same as above.4. Hematoxylin-eosin(HE)staining HE was used to observe tissue pathological changes in the hippocampal CA1 subfield.5. Immunohistochemistry The expressions of GFAP and HMGB1 in the hippocampal CA1 subfield were detected by using immunohistochemistry technique at 1 d ,3 d, 7 d ,14 d and 28 d after MCAO.6. Fluorescent Double Staining Fluorescent double staining combined with confocal scanning were used to analyze the time course of expression of HMGB1 and GFAP in the hippocampl CA1 region after MCAO.7. Statistical analysis The data was handled with spss13.0 statistic software, The difference of two groups was compared with t-test. The difference of many groups was compared with one-factor analysis of variance,significant level isα=0.05, The experimental data were described by means±standard deviation(x±s)Result1,The tissues of Sham-operated group was integrate,but that of ischemia-reperfusion group were changed with gliocyte hyperplasia and hypertrophia, interstitial edema, celluler edema, neuron necrosis,nucleus atrophy, the inflammory cells around the infarct area increasing remarkablely.2,Compared with shamoperated group,the expressions of GFAP and HMGB1 in ischemia-reperfusion groups were evidently upregulated at all time points(P<0.05).3,The expressions of GFAP were approaching its peak value at 7 day of reperfusion(P<0.05); the expressions of HMGB1 were approaching its peak value at 14 day of reperfusion(P<0.05)4,The expression of GFAP and HMGB1 were a positive correlative and HMGB1 siginficantly co-localized with GFAP in the hippocampl CA1 region in ischemia-reperfusion group(r1=0.499, P<0.05; r2= 0.586 ,P<0.05)ConclusionsThe expression of HMGB1 in the hippocampal CA1 region was significantly related with astrocytes activation after cerebral ischemia ,excessive HMGB1 and activated astocytes contributed to the pathophysiological processes of delaying neuronal injury.