| Intracerebral hemorrhage（ICH）is one of the most lethal stroke subtypes. Itremains a serious clinical problem lacking effective treatment. Available evidencefrom preclinical and clinical studies suggests that inflammatory mechanisms areinvolved in the progression of ICH-induced secondary brain injury. High mobilitygroup box-1(HMGB1) is a ubiquitous and aboundant nonhistone DNA-bindingprotein. HMGB1is also an important proinflammatory cytokine that mediatesinflammation, once releasing from cell nucleus. Recent research shows that, anti-highmobility group box-1monoclonal antibody (-HMGB1mAb) has protective effectson the marked translocation of HMGB1in the brain, disruption of the blood-brainbarrier(BBB), and the resultant brain edema in both traumatic brain injury andischemia-induced disruption[6,7,8]. The ICH models were established. BBB integrity byevans blue(EB), enzyme-linked immunosorbent assay (ELISA), hematoxylin-eosin(HE) staining, and immunohistochemistry methods were used to explore the role ofα-HMGB1mAb in ICH rats.Methods:65male Waster rats were randomly divided into3groups (3rats wereeliminated): a group of sham group (16), a group of class-matched control mAbtreatment group (23), the other one of-HMGB1group(23). First, the rat wereanesthetized with2%halothane in a mixture of50%N2O and50%O2using a facemask, and then placed in a stereotaxic frame. Following disinfection and incision, ahole was drilled in the skull. Collagenase IV(0.03U,2μl) was injected through a tracesyringe into the striatum at0.2mm anterior,3.0mm lateral, and6mm ventral from thebregma. The syringe was kept in position for2min to prevent backflow ofcollagenase, then slowly removed. After that, an anti-HMGB1mAb(#10-22, IgGasubclass,1mg/kg) or class-matched control mAb(anti-Keyhole Limpet hemocyanin)was administered intravenously immediately and at6hour after ICH. Sham group, which was subjected to the same procedures as the control IgG and anti-HMGB1mAb groups, and rats were infused with2μl saline into the striatum to mimic thecollagenase infusion described above,150μl sterile saline was administered i.v. For3days Observation after ICH, the rats were administered once again at48hour afterICH. At the indicated times blood was taken for ELISA test. Rats were killed byperfusion with saline and4%paraformaldehyde. Brains were embedded in paraffinfor HE staining and immunofluorescence analysis. After perfusion with saline, ratstriatum samples were homogenized for western blotting. Ipsilateral brain wereharvested for brain water content analysis. Evans blue was extracted for BBBdistruption analysis.Results: The rat ICH models were established successfully, and the success ratewas95.38percent. Western blot results showed that there was no significantdifference of HMGB1levels among groups in contralateral brain hemispherer.However, ICH significantly down-regulated the expression of HMGB1in thehemorrhage side as compared with the sham group. Anti-HMGB1mAb suppressedthe disappearance of HMGB1. Plasma levels of HMGB1was increased24h after ICH,but treatment with anti-HMGB1mAb can inhibit the increase. Increased BBBpermeability was apparent6hours after ICH, anti-HMGB1treatment significantlyinhibited Evans blue leakage.3days later, the difference was also obvious betweentwo groups. In sham group, the brain water content formed of79.03%the total weight.3days after ICH, in the rats treated with control IgG, the brain water contents in brainhemispherer of hemhemorrhage side had significantly increased to81.28%. Incontrast, the anti-HMGB1mAb attenuated the increase in water content by0.85%.Activated microglia were observed around the hematoma after ICH induction incontrol IgG group. However, there were few such microglia around the hematoma inanti-HMGB1mAb-treated rats.Conclusion: Administration of anti-HMGB1mAb, to a certain extend, caninhibit HMGB1releasing into the extracellular space and decreased activatedmicroglia after intracerebral hemorrhage. Administration of anti-HMGB1mAb inhibit vascular leakage and attenuated brain edema in the ICH as well. |
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