电针对慢性阻塞性肺疾病大鼠巨噬细胞迁移抑制因子及其受体复合物表达的影响

Electroacupuncture Improves Pulmonary Function of Rats with Chronic Obstructive Pulmonary Disease by Down-regulating Inflammatory Reaction and Expression of Macrophage Migration Inhibitory Factor/CD 74-CD 44/p 38 MAPK Signaling in Lung Tissues

目的:观察电针"足三里"和"肺俞"对慢性阻塞性肺疾病(COPD)大鼠巨噬细胞迁移抑制因子(MIF)及其受体复合物CD 74-CD 44等相关因子表达的影响,并从免疫角度探讨电针在COPD大鼠发病过程中的作用机制。方法:SD大鼠随机分为正常组、模型组和电针组,每组10只。采用气管滴注脂多糖结合香烟烟熏的方法复制COPD大鼠模型。电针组电针大鼠双侧"足三里"和"肺俞",每次30min,连续7d。各组大鼠于处死前进行肺功能检测;HE染色法观察各组大鼠肺组织病理学变化;ELISA法分别检测各组大鼠血清、肺泡灌洗液(BALF)和肺组织中MIF、肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、IL-8含量;实时荧光定量PCR和Western blot法分别检测肺组织内MIF、CD 74、CD 44及p 38MAPK mRNA和蛋白表达;免疫组化法观察肺组织中CD 74、CD 44的表达。结果:与正常组比较,模型组大鼠用力肺活量(FVC)、第0.1秒用力呼气量(FEV 0.1)、第0.3秒用力呼气量(FEV 0.3)、FVC 0.1占FVC比值(FEV 0.1/FVC)、FEV 0.3占FVC比值(FEV 0.3/FVC)均显著降低(P<0.01)。与模型组比较,电针组FVC、FEV 0.1、FEV 0.3、FEV 0.1/FVC、FEV 0.3/FVC均显著升高(P<0.01,P<0.05)。与正常组比较,模型组大鼠血清、BALF、肺组织内MIF、TNF-α、IL-1β和IL-8含量均显著升高(P<0.01),电针组以上各指标较模型组明显降低(P<0.01)。模型组较正常组肺组织内MIF、CD 74、CD 44、p 38MAPK mRNA和蛋白表达水平以及CD 74、CD 44阳性表达水平均显著升高(P<0.01),电针组较模型组以上各指标表达水平均显著下降(P<0.01)。其中大鼠肺组织内MIF与p 38MAPK蛋白及mRNA表达呈正相关(P<0.01)。结论:电针"足三里"和"肺俞"穴对大鼠COPD具有治疗作用,其作用机制可能与抑制MIF及其受体复合物活性及受体介导的p 38MAPK信号通路有关。

Objective To observe the effect of electroacupuncture(EA)at"Zusanli"(ST 36)and"Feishu"(BL 13)on pulmonary function,inflammatory reaction and expression of macrophage migration inhibitory factor(MIF)and its receptor complex CD 74-CD 44,etc.in rats with chronic obstructive pulmonary disease(COPD),so as to explore its mechanism underlying improvement of COPD.Methods Thirty male SD rats were randomly divided into normal,model and EA groups(n=10 in each group).The COPD model was established by intratracheal infusion of Lipopolysaccharide(LPS,1 mg/mL)and forced smoke-inhaling.EA was applied to bilateral ST 36 and BL 13 for 30 min,once daily for 7 days.The rat's lung function(forced vital capacity[FVC],forced expiratory capacity ratio([FEV 0.1/FVC]and[FEV 0.3/FVC])was detected under anesthesia.Pathological changes of the lung tissue were detected by H.E.staining,and the contents of MIF,tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and IL-8 in serum,bronchoalveolar lavage fluid(BALF)and lung tissue were assayed by ELISA.The immunoactivity of CD 74 and CD 44 was detected by immunohistochemistry,and the expression levels of MIF,CD 74,CD 44 and p 38 MAPK mRNAs and proteins were examined by quantitative RT-PCR and Western blot,respectively.Results Compared with the normal group,the FVC,FEV 0.1,FEV 0.3,FEV 0.1/FVC and FEV 0.3/FVC levels were significantly decreased in the model group(P<0.01).After EA treatment,the FVC,FEV 0.1,FEV 0.3,FEV 0.1/FVC and FEV 0.3/FVC were significantly increased(P<0.01,P<0.05),suggesting an improvement of the pulmonary function after EA.H.E.staining showed that the severity of modeling induced alveolar expansion and inflammatory cell infiltration in the lung tissue was relatively milder in the EA group relevant to the model group.The contents of MIF,TNF-α,IL-1βand IL-8 in the serum,BALF and lung tissues were significantly higher in the model group than in the normal group(P<0.01),and significantly down-regulated in the EA group relevant to the model group(P<0.01).The expression levels of MIF,CD 74,CD 44 and p 38 MAPK mRNAs and proteins and the immunoactivity levels of CD 74,CD 44 in the lung tissue were obviously higher in the model group than those in the normal group(P<0.01),and considerably lower in the EA group than those in the model group(P<0.01).There was a positive correlation between p 38 MAPK and MIF in mRNA and protein expression levels(P<0.01).Conclusion EA intervention can improve the pulmonary function in COPD rats,which may be related to its effects in inhibiting inflammatory reaction,and MIF/CD 74-CD 44/p 38 MAPK signaling pathway.