丝裂原活化蛋白激酶通路对慢支大鼠肺泡巨噬细胞产生TNF-α的影响及枇杷叶三萜酸的作用机制

Effect of MAPK signal transduction pathway on the expression of TNF-α in alveolar macrophage of chronic bronchitis rats and the target of TAL

目的探究丝裂原活化蛋白激酶(MAPK)信号转导通路对慢性支气管炎(CB)大鼠肺泡巨噬细胞(AM)中肿瘤坏死因子α(TNF-α)生成的影响及枇杷叶三萜酸(TAL)的作用环节。为TAL治疗慢支的抗炎作用机制提供进一步的实验依据。方法以AM为实验平台分别给予MAPK 3条通路(ERK,p38,JNK)的特异性阻滞剂,用RT-PCR和Westernblot的方法来分别检测CB大鼠AM中TNF-α的mRNA及蛋白的表达水平。并采用析因实验设计,ELISA法检测AM培养上清中的TNF-α的水平。结果RT-PCR和Western blot的结果均显示ERK特异性阻滞剂(PD98059)和p38特异性阻滞剂(SB203580)对CB大鼠AM中TNF-α的表达有明显的抑制作用。析因分析结果表明TAL、特异性阻滞剂(PD98059和SB203580)及其交互作用项对TNF-α含量的影响存在统计学意义。结论TAL对TNF-α的抑制作用可能与其作用于ERK和p38通路有关,这可能是TAL治疗与防治慢支的主要作用环节之一。

Aim To investigate the effect of MAPK signal transduction pathway on the expression of TNF-α in AM （ alveolar macrophage ） of CB （ chronic bronchitis ） rats, meanwhile, to initially discuss the possible regulated target of TAL（ triterpene acids of loquat, leaf）, to explain the mechanism about anti-inflammatory action of TAL on CB rats. Methods The depurated AM was incubated with the special inhibitors of MAPK signal transduction pathway respectively （ERK, p38 or JNK） and the expression of TNF-α was observed by RT-PCR and Western blot. Using factorial design, TNF-α level in AM culture supernatant was detected by ELISA. Re suits The special inhibitors of ERK（PD98059） and p38（SB203580） could change the expression of TNF-α in AM of CB rats apparently. Factorial analysis shows there is statistical significance between TAL, PD98059/SB203580 and mixture of them. Conclusions TAL reducing the expression of TNF-α may be related with the inhibition of ERK and p38 signal transduction pathway. It may be one of the mechanisms by which TAL has the preventive and therapeutic effects on chronic bronchitis.