Therapeutic effects of anti-HMGB1 monoclonal antibody on pilocarpine-induced status epilepticus in mice

Li Fu,Tadashi Yoshino,Hideo Takahashi,Keyue Liu,Shuji Mori,Hidenori Wake,Masahiro Nishibori,Kiyoshi Teshigawara

doi:10.1038/s41598-017-01325-y

Li Fu, Tadashi Yoshino + Show 6 more

Open Access

https://doi.org/10.1038/s41598-017-01325-y

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Abstract

Inflammatory processes in brain tissue have been described in human epilepsy of various etiologies and in experimental models of seizures. High mobility group box-1 (HMGB1) is now recognized as representative of damage-associated molecular patterns (DAMPs). In the present study, we focused on whether anti-HMGB1 antibody treatment could relieve status epilepticus- triggered BBB breakdown and inflammation response in addition to the seizure behavior itself. Pilocarpine and methyl-scopolamine were used to establish the acute seizure model. Anti-HMGB1 mAb showed inhibitory effects on leakage of the BBB, and on the HMGB1 translocation induced by pilocarpine. The expression of inflammation-related factors, such as MCP-1, CXCL-1, TLR-4, and IL-6 in hippocampus and cerebral cortex were down-regulated by anti-HMGB1 mAb associated with the number of activated astrocytes, microglial cells as well as the expression of IL-1β. Both hematoxylin & eosin and TUNEL staining showed that the apoptotic cells could be reduced after anti-HMGB1 mAb treatment. The onset and latency of Racine stage five were significantly prolonged in the anti-HMGB1 mAb group. These results suggested that anti-HMGB1 mAb prevented the BBB permeability, reduced HMGB1 translocation while inhibiting the expression of inflammation-related factors, protected against neural cell apoptosis and prolonged Racine stage 5 seizure onset and latency.

Highlights

Epilepsy is a disabling neurological disorder affects around 60 million people of all ages worldwide[1, 2]
After anti-High mobility group box-1 (HMGB1) mAb treatment the concentration of Evans blue dye decreased during pilocarpine-induced acute status epilepticus, while the control IgG group did not show any reduction in blood-brain barrier (BBB) leakage
The quantitative analysis revealed that the Evans blue levels were significantly increased in the PBS and control IgG groups compared to the sham and anti-HMGB1 treatment groups

Summary

Introduction

Epilepsy is a disabling neurological disorder affects around 60 million people of all ages worldwide[1, 2]. Some models of epilepsy have revealed neuronal cell damage and loss in the CA1 and CA3 regions and dentate gyrus of the hippocampus[9]. Inflammatory processes in brain tissue have been described in human epilepsy of various etiologies and in experimental models of seizures. Recent data suggest that inflammation may play an important role in the pathogenesis of epilepsy[6]. The permeability of brain capillary vessels was examined by intravenously injecting Evans blue (100 mg/kg, i.v.). Anti-HMGB1 mAb (1 mg/kg), control IgG, PBS was administered intravenously to mice which reached. The leakage of Evans blue into the brain parenchyma was quantified at 4 h after anti-HMGB1, control IgG or PBS injection, and the results are expressed as the means ± SEM of 5 mice. The results were expressed as the means ± SEM of 7 mice. *p < 0.05 compared with Pilo + HMGB1 100 μg (e)

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