The Expression And Distribution Of HMGB1in The Sombatis Cell And Kainic Acid Epilepsy Models

Chapter Ⅰ The Expression ofHigh-mobility group box-1in the Sombati’scell epilepsy model【Objective】 To investigate the expression of High-mobility group box-1(HMGB1) in Sombati’s cell model.【Method】 Hippocampal neurons were collected from Sprague Dawleyrats and cultured in Mg2+-free extracellular fluid to establish Sombati’s cellmodel while the control group were cultured in normal Mg2+levelsextracellular fluid. The expression of HMGB1in the neurons of these twogroups were determined at the time points of12h、24h and72h by westernblotting.【Results】 By western blotting, we found that at the time points of12hand24h,the expression of HMGB1in the model group was lower than thecontrol group (P<0.05), but at the time point of72h, the model group was higher(P=0.006,P<0.05). In addition, from time points of12h（0.2477±0.11810）,24h（0.3331±0.21602）to the time point of72h（0.8570±0.25280）,the expressionof HMGB1show upward trend. 【Conclusion】 We demonstrated that the expression of HMGB1showtime dependence in the epilepsy of Sombati model, HMGB1may plays animportant role in the pathophysiology of epilepsy. ChapterⅡ Change of HMGB1expression in rat hippocampus followingkainic acid-induced epileptic seizure【Objective】 On the basis of the result of chapter I, to investigate thechange of HMGB1expression in rat hippocampus after a microinjection of KAinto the right lateral ventricle of rats with kainic acid(KA)-induced epilepticseizure, in this part, we detected the expression of HMGB1at the time point of24h and72h.【Methods】Forty males Sprague-Dawley rats were divided into fourgroups randomly, the normal control groups (24h and72h) and the modelgroups(24h and72h). The rats of model groups were injected KA into the rightlateral ventricle while the rats of the control groups were injected normal saline(NS). By means of HE stain and immunohistochemistry, the morphologicalchanges of neurons and the expression of HMGB1were observed at diferenttime points after drug injection.【Results】Neurons from the model groups show sparse arrangement,confusion, nuclear condensation and the contour is fuzzy. FollowingKA-induced seizure, at24h, the expression of HMGB1in the model group(0.1398±0.01801) was lower than the control group (0.2154±0.02873)(p=0.000), but at the time point of72h, the model group (0.3652±0.08330) washigher than the control group (0.2354±0.00836)(p=0.012). In addition, HMGB1showed in the cytoplasm in the kainic acid model of epilepsy in the rat.【Conclusions】 The same as the Sombati’s cell epilepsy model, theexpression of HMGB1show increases in rat hippocampus following kainicacid-induced epileptic seizure at72h, epileptic seizure may induce HMGB1expression and secretion in the hippocampus.