Neuroprotective Effects Of Isoflurane Against Lipopolysaccharide-induced Neuroinflammation In BV2 Microglial Cells By Regulating HMGB1/TLRs Pathway

Objective: The purpose of this study was to investigate whether isoflurane plays a protective role in lipopolysaccharide-induced neuroinflammation of BV2 microglia cells by regulating HMGB1/TLRs pathway.Methods: 1.BV2 microglia cells were set up in different groups,and BV2 cells were treated with 0.1 μg/ml,1 μg/ml and 10 μg/ml LPS for 4 hours to establish an inflammatory model,The control group was cultured normally,cell viability was tested by MTT method,and NO content was detected by Griess method.2.BV2 microglia cells were set up in different groups.After LPS-induced BV2 cell inflammatory model was established,BV2 cells were treated with isofluranine at concentrations of 0.1 μg/ml,1 μg/ml and 2 μg/ml for 12 hours,Cell viability was detected by MTT assay,NO release was detected by Griess assay,inflammatory cytokines IL-1β,IL-6 and TNF-α were detected by ELISA,HMGB1,RAGE,TLR4 and TLR2 were detected by q PCR and Western Blot,and HMGB1 expression was detected by immunofluorescence assay.3.BV2 microglia were transfected with overexpression adenoviruses of high-mobility group box 1 protein(HMGB1),and the above inflammatory model was established with LPS and isoflurane treatment were repeated.And then NO content,cell viability,levels of inflammatory cytokines IL-1β,IL-6 and TNF-α,and expressions of HMGB1,RAGE,TLR4 and TLR2 were detected.Results:1.Compared with the normal control group,the cell survival rate of LPS treatment group was significantly reduced.The NO level of BV2 cells treated with LPS was significantly higher than that BV2 cells treated with the same medium(control group),and the NO concentration gradually increased with the increase of LPS concentration.The inflammatory cytokines IL-1β,IL-6 and TNF-α in the LPS group were significantly increased,and the expressions of HMGB1,RAGE,TLR4 and TLR2 were significantly increased.2.Compared with the control group,isoflurane could reverse the LPS-induced decline in the survival rate of BV2 cells.Isoflurane inhibited NO release of BV2 microglia induced by LPS.The inflammatory cytokines IL-1β,IL-6 and TNF-α were significantly reduced in the isoflurane treatment group,and the expressions of HMGB1,RAGE,TLR4 and TLR2 were significantly decreased.3.The HMGB1 overexpression adenoviruses can reverse the protective effect of isoflurane on LPS-induced BV2 cells.Conclusion:Isoflurane may play a protective role in LPS-induced BV2 microglial neuroinflammation through the HMGB1/TLRs pathway.