Effect Of ICS Ⅱ On Inflammatory Response Of Astrocytes Induced By Lipopolysaccharide

Objective:To study the effect of ICS Ⅱ on lipopolysaccharide(LPS)-induced astrocytes inflammatory response and explore its possible mechanismMethods:Primary astrocytes were isolated from cerebral cortex of neonatal SD rats and cultured.Astrocytes were divided into blank group,blank + ICS Ⅱ high concentration group(20 μM ICS Ⅱ),model group(1 μg/mL LPS),model +ICS Ⅱ low concentration group(1 μg/mL LPS + 5 μM ICS)Ⅱ),model + ICS Ⅱ medium concentration group(1μg/mL LPS+10 μM ICS Ⅱ),model+ICS Ⅱ high concentration group(1μg/mL LPS+20 μM ICS Ⅱ),model+dexamethasone group(1 μg/mL LPS+1 μM DXMS).Astrocytes were pretreated with ICS Ⅱ(5,10,20 μM)or dexamethasone(1 μM)for 1 h,then LPS was used to establish a model of inflammation in vitro,and IC.S Ⅱ or DXMS was added for another 24 h.MTT assay was used to detect the safe concentration range of ICS Ⅱ in astrocyte,and the effect of ICS Ⅱ on LPS-induced astrocyte inflammation was observed after determination of the safe concentrations.Enzyme-linked immunosorbent assay was used to detect the levels of TNF-α,IL-β,Aβ1-40 and Aβ1-42 in astrocyte.Detection of nitric oxide levels in astrocytes using Griess method.Western Blot was used to detect the protein expression of COX-2,iNOS,1κB-α,NF-κB(p65)(nucleus),NF-κB(p65)(cytoplasm),BACE1 and APP,as well as the phosphorylation levels of NF-κB(p65),IKK-α and IKK-βFurthermore,molecular docking was used to evaluated the relationship between ICS Ⅱ and BACE1Results:0-50 μM ICS Ⅱ did not exert toxic effects in astrocytes.The levels of TNF-a,IL-1β and NO were significantly increase in the astrocytes than those of the blank group after LPS insults(P<0.05).Moreover,LPS markedly increased COX-2,iNOS,NF-κB(nucleus),BACE1 and APP protein expressions(P<0.05)and significantly decreased IκB-α,NF-κB(cytoplasm)expressions(P<0.05);while,the phosphorylation levels of NF-κB(p65),IKK-α and IKK-β were increased by LPS(P<0.05).However,ICS Ⅱsignificantly reduced TNF-α,IL-1β and NO levels(P<0.05).ICS Ⅱ also down-regulated the COX-2,iNOS,NF-KB(nucleus)expression(P<0.05).Moreover,ICS Ⅱ not only up-regulated NF-κB(cytoplasmic)and IκB-α expressions(P<0.05),but also down-regulated phosphorylation levels of NF-κB(p65),IKK-α and IKK-β(P<0.05)Conclusion:In this study,ICS Ⅱ exerts neuroprotective effects on LPS-induced inflammation in astrocytes,through regulating IKK/IκB/NF-κB/BACE1 signaling pathway.