双氢杨梅树皮素对脂多糖诱导小鼠急性肺损伤及TLR4/MyD88/NF-κB信号通路的影响

The effects of ampelopsin on lipopolysaccharide-induced acute lung injury mice and the TLR4/MyD88/NF-κB signaling pathway

为研究双氢杨梅树皮素(Ampelopsin,APS)对脂多糖(Lipopolysaccharide,LPS)诱导急性肺损伤(Acute lung injury,ALI)小鼠模型的保护作用及其对TLR4/MyD88/NF-κB信号通路的影响,将72只KM小鼠按体重随机分为正常组、模型组、地塞米松阳性组(7.5 mg/kg)及APS高、中、低剂量组(200、100、50 mg/kg),每组12只。除正常组外,其余各组通过无创式气管内滴注LPS复制ALI小鼠模型。在LPS滴注8 h后,应用小动物呼吸功能测定仪监测各组小鼠呼吸功能(包括气道阻力、肺动态顺应性、每分钟最大通气量等)相关指标;ELISA法检测支气管肺泡灌洗液(Bronchoalveolar lavage fluid,BALF)中炎症因子TNF-α以及IL-1β的含量;比色法检测肺组织匀浆液中过氧化物酶(MPO)活力;HE染色法观察肺组织病理学变化并进行评分;Western blotting法测定肺组织匀浆液中TLR4、MyD88、IκBα、p-IκBα、p65及p-p65蛋白表达。结果表明,APS给药后,小鼠的吸气阻力降低,肺动态顺应性以及每分钟最大通气量增加,肺组织病理损伤症状减轻。BALF中TNF-α及IL-1β含量降低。肺组织匀浆液中MPO活力降低,TLR4、MyD88、p-IκBα、p65及p-p65蛋白表达量均下调,IκBα蛋白表达量上调。双氢杨梅树皮素对LPS诱导的ALI小鼠具有保护作用,其机制可能与TLR4/MyD88/NF-κB信号通路有关。

Aiming to investigate the effects of ampelopsin(APS)on lipopolysaccharide(LPS)-induced acute lung injury in mice and its underlying mechanism,the acute lung injury mouse model was established by intratracheal instillation of LPS.Seventy-two KM mice were randomly divided into 6 groups as follows:normal,model,dexamethasone and APS high-dosage,medium-dosage,and low dosage group.After 8 h of LPS induction,the animal lung function analysis system was employed to monitor pulmonary function(airway resistance,pulmonary dynamic compliance and minute ventilation volume)of mice.ELISA assay was carried out to measure the content of inflammatory factors TNF-αand IL-1β.Colorimetric assay was performed to determine MPO activity.H&E staining was performed to reveal pathological changes in lung tissues.Western blotting was performed to measure the protein expression of TLR4,MyD88,IκBα,p-IκBα,p65 and p-p65.Results showed that APS administration decreased airway resistance and increased pulmonary dynamic compliance and minute ventilation volume compared to those in the model group.Also,APS reduced TNF-α,IL-1βcontent and MPO activity.Further,Western blotting results demonstrated that APS down-regulated the protein expression of TLR4,MyD88,p-IκBα,p65 and p-p65,and up-regulated IκBαprotein expression in LPS-induced acute lung injury.APS exerted a protective effect on LPS-induced acute lung injury in mice through regulating the TLR4/MyD88/NF-κB signaling pathway.