茯苓多糖通过NF-κB和NLRP3信号通路调节脂多糖引起的焦虑和抑郁样行为

Poria cocos Polysaccharides Regulate Anxiety and Depression-like Behaviors Induced by Lipopolysaccharide through NF-κB and NLRP3 Signaling Pathways

目的:探讨茯苓多糖(Poria cocos polysaccharide,PPS)对脂多糖(LPS)引起的焦虑和抑郁样行为的影响,并分析其机制。方法:BV-2细胞分成对照组、LPS组、LPS+氟西汀组、LPS+PPS(PPS分别为4、8、16μmol/L),处理24 h,二氯二氢荧光素二氢乙酸酯(DCFH-DA)荧光探针检测细胞内活性氧(ROS)水平,Griess法检测培养上清液NO水平,酶联免疫吸附试验(ELISA)检测培养上清液中TNF-α、IL-1β水平,Western blot实验检测CD206、CD16/32、NF-κB p65水平。动物实验将小鼠分为对照组、模型组、LPS+氟西汀组、LPS+PPS低剂量组(20 mg/kg)、LPS+PPS高剂量组(80 mg/kg),每组10只,测试抑郁样行为,检测海马组织TNF-α、IL-1β、IL-18的浓度,分析海马组织CD206、CD16/32、NF-κB p65、NLRP3、ASC、Cleaved caspase-1蛋白水平。结果:与LPS组比较,4、8、16μmol/L PPS能极显著降低ROS荧光相对强度(P<0.01),下调NO、TNF-α、IL-1β水平,降低CD16/32、NF-κB p65水平,增加CD206水平(P<0.05);与模型组比较,LPS+PPS低剂量组、LPS+PPS高剂量组蔗糖偏爱率极显著增加(P<0.01),旷场穿越次数、修饰次数极显著上调(P<0.01),悬尾不动时间、强迫游泳不动时间极显著降低(P<0.01);与模型组比较,LPS+PPS低剂量组、LPS+PPS高剂量组IL-1β、IL-18、TNF-α水平极显著降低(P<0.01),CD16/32、NF-κB p65水平显著下调(P<0.05),CD206显著上调(P<0.05),NLRP3、ASC、Cleaved caspase-1水平极显著降低(P<0.01)。结论:茯苓多糖能通过抑制NF-κB和NLRP3信号通路减轻LPS诱导的焦虑和抑郁样行为。

Objective:To explore the effect of Poria cocos polysaccharides(Poria cocos polysaccharide,PPS)on anxiety and depression-like behaviors induced by lipopolysaccharide(LPS)and analyze its mechanism.Methods:BV-2 cells were divided into control group,LPS group,LPS+fluoxetine group and LPS+PPS(PPS of 4,8,16μmol/L,respectively).After 24 h treatment,the level of intracellular reactive oxygen species(ROS)was detected by dichlorodihydrofluorescein dihydroacetate(DCFH-DA)fluorescence probe,the level of NO in culture supernatant was detected by griess method,and the levels of TNF-αand IL-1βin cell supernatant were detected by enzyme linked immunosorbent assay(ELISA).The levels of CD206,CD16/32 and NF-κB p65 were detected by western blot.In animal experiment,mice were divided into control group,model group,LPS+fluoxetine group,LPS+PPS low dose group(20 mg/kg)and LPS+PPS high dose group(80 mg/kg).Depression-like behavior test was performed,and the concentration of TNF-α,IL-1βand IL-18 in hippocampus was detected.The protein levels of CD206,CD16/32,NF-κB p65,NLRP3,ASC and Cleaved caspase-1 in hippocampus were analyzed.Results:Compared with LPS group,4,8,16μmol/L PPS significantly decreased the relative fluorescence intensity of ROS(P<0.01),decreased the levels of NO,TNF-αand IL-1β(P<0.01),decreased the levels of CD16/32 and NF-κB p65(P<0.05),and increased the level of CD206(P<0.05).Compared with the model group,the preference rate,crossing times and modification times in LPS+PPS low dose group and high dose LPS+PPS group significantly increased(P<0.01),while the tail suspension time and forced swimming immobility time significantly decreased(P<0.01).Compared with the model group,the levels of IL-1β,IL-18 and TNF-αin LPS+PPS low dose group and LPS+PPS high dose group significantly decreased(P<0.01),CD16/32 and NF-κB p65 level were significantly down-regulated,CD206 was significantly up-regulated,and the levels of NLRP3,ASC and Cleaved caspase-1 significantly decreased.Conclusion:Poria cocos polysaccharide can alleviate LPS-induced anxiety and depression-like behavior by inhibiting NF-κB and NLRP3 signal pathways.