熊果苷通过PI3K/Akt/mTOR信号通路减轻脂多糖诱导的小鼠急性肺损伤

Arbutin alleviates LPS-induced acute lung injury in mice through PI3K/Akt/mTOR signaling pathway

目的探究熊果苷对脂多糖(LPS)所致急性肺损伤小鼠的保护作用及机制。方法SPF级BCLB/C小鼠随机分为对照组、模型组、熊果苷组、熊果苷+PI3K抑制剂组。熊果苷组及熊果苷+PI3K抑制剂组分别使用相应药物干预;LPS滴鼻构建急性肺损伤模型;建模6h后处死小鼠。肺组织切片染色后观察肺组织病理改变并行肺损伤评分,计算湿干重比(W/D);ELISA法测定血清及BALF中TNF-a与IL-6含量;测量肺内ROS含量、MDA水平、MPO活力;Western blot法检测自噬相关蛋白Beclin-1、LC3II/I及PI3K/Akt/mTOR通路蛋白表达。结果与对照组相比,模型组小鼠肺组织病理改变加重,W/D、肺损伤评分升高,血清及BALF中IL-6、TNF-α升高,肺内ROS含量、MDA表达、MPO活力升高,肺内Beclin-1、LC3II/I表达升高,肺内PI3K/Akt/mTOR通路蛋白表达降低(P<0.05)。熊果苷组较模型组小鼠肺组织病理改变减轻,W/D、肺损伤评分降低,BALF及血清中IL-6、TNF-α水平降低,肺内ROS含量、MDA表达、MPO活力降低;肺内Beclin-1、LC3II/I表达降低,PI3K/Akt/mTOR通路蛋白表达升高(P<0.05);而熊果苷+PI3K抑制剂组在使用PI3K抑制剂后,上诉表现被阻断。结论熊果苷通过PI3K/Akt/mTOR通路调节自噬改善LPS所致急性肺损伤小鼠的炎症反应及氧化应激,在LPS所致急性肺损伤中起保护作用。

Objective To investigate the protective effect and mechanism of arbutin on LPS induced Acute lung injury in mice.Methods SPF BCLB/C mice were randomly divided into control group,model group,arbutin group,and arbutin+PI3K inhibitor group.arbutin group and arbutin+PI3K group were intervened with corresponding drugs respectively;Constructing an ALI model by intranasal instillation of LPS into mice;After modeling for 6 hours,the mice were killed.After staining the lung tissue slices,observe the pathological changes of the lung tissue and evaluate the lung injury score,and calculate the wet to dry weight ratio(W/D);ELISA method was used to determine the levels of TNF-a and IL-6 in serum and bronchoalveolar lavage fluid(BALF);Measure the ROS content,MDA level,and MPO activity in the lungs;Western blot method was used to detect the expression of PI3K/Akt/mTOR pathway related proteins and autophagy related proteins Beclin-1 and LC3II/I.Results Compared with the control group,the pathological changes in the lung tissue of model group mice worsened,and the W/D and lung injury scores increased,The levels of IL-6 and TNFa in BALF and serum was increased,The ROS content,MDA expression and MPO activity in the lungs was increased,the expression of Beclin-1 and LC3II/I in the lungs was increased.The expression of PI3K/Akt/mTOR pathway related proteins in the lungs decreased(P<0.05).Compared with the model group,the pathological changes in the lung tissue of arbutin group mice were alleviated,with a decrease in W/D and lung injury score,The levels of IL-6 and TNF-a in BALF and serum decrease,ROS content,MDA expression and MPO activity in lung were decreased.The expression of PI3K/Akt/mTOR pathway related proteins in the lung was increased,The expression of Beclin-1 and LC3II/I decreased。However,the appeal performance was partially blocked in the arbutin+PI3K group after the administration of LY294002.Conclusions Arbutin regulates autophagy through PI3K/Akt/mTOR pathway to inhibit inflammatory response and oxidative stress in LPS-induced ALI mice,and plays a protective role in LPS-induced ALI.