Expressions And Neuroprotective Effects Of Hsp22 And HIF-1α After Brain I/R Injury In Gerbils

Object: In this study we investigated the expressions andneuroprotective effects of Hsp22 and HIF-1αin brain tissue followingcerebral ischemic reperfusion in gerbils and whether they are correlative.Method:(1)Animal Groups: forty five gerbils were randomly divided intothere groups: Normal Group (n=5), Sham-operated Group, Ischemia-Reperfusion Group (I/R). Sham-operated Group and I/R Group aredivided into four subgroups (each group has five animals): 6 hours group,1day group, 3days group, 7days group.(2)Model: Each subject except normal group was anesthetized with3% pentobarbital (30mg/kg, ip), then a midline incision was made in theneck and surgical silk was loosely placed around both sides isolatedcommom carotid arteries. A traumatic miniature aneurysm clips wereattached to occlude both carotid arteries for 10 min. At the end of theocclusion period, blood flow was reestablished. In sham-operated group,the arteries were exposed but not occluded. The wound was then sutured,and the animals were allowed to recover. The animals were sacrificed bydecapitation at corresponding time and the brains were removed to makeslices.(3)Histological analysis of tissue injury: staining with haematoxylinand eosin haematoxylin and eosin (HE).(4)Immunohistochemical Methods.(5)Experimental results were analyzed with the statistic soft ofSPSS13.0Result:(1)Staning with HE: The tissues of normal group and sham-operatedgroup were integrate, but tissues of I/R groups were changed with gliocyte hyperplasia and hypertrophia, interstitial edema, cellular edema,gliocyte and neuron edema, neuron necrosis.(2)Immunohistochemical Methods: The normal group andsham-operated group was measured low Hsp22 and HIF-1α, Weexplored the overexpression of Hsp22 and HIF-1α6 hours after I/R,with peak expression at 3days, but appeared to decline by 7 days andthere was significance between groups(p＜0.05). The data presentedherein provide a link between expression of Hsp22, resist to stress andexpression of HIF-1α, mediate the transcriptional activation ofhypoxia-responsive genes.Conclusions:(1) We report that for the first time that the expression of Hsp22 wasincreased after brain I/R injury and can exert neuroprotective effects.(2) Expression of HIF-1αwas upregulated and can exertneuroprotective effects following cerebral ischemic reperfusion.(3) There was a link between expression of Hsp22 and expression ofHIF-1αafter brain I/R injury.