The Role Of Cholinergic Anti-inflammatory Pathway In The Electro-acupuncture Therapy Of COPD Rats

Purpose:The chronic obstructive pulmonary disease(COPD)is a common disease worldwide with high morbidity and mortality,currently,the drug can only improve the symptoms,and however,there are many side effects in drug treatment.And in recent years,the studies have shown that the acupuncture treatment could improve the pulmonary function of patients with COPD,but the mechanism of it was still not clearly,additionally,some studies have demonstrated that the cholinergic anti-inflammatory pathway(CAP)was related to the anti-inflammatory effect of acupuncture,and the inflammatory response is the basic pathological change of COPD,thereby,our study was to investigate the anti-inflammatory effect of electro-acupuncture at BL13(Feishu)and ST36(Zusanli)on rats with COPD,furthermore,to determine the role of CAP in the treatment of COPD model rats by electro-acupuncture.Methods: 1.The Sprague-Dawley(SD)rats weighing 200-250 g were used for making COPD models,and the model was established by cigarette smoking combined with intratracheal infusion of lipopolysaccharide(LPS).In addition,the rats smoked two times a day,and for one hour each time for 6 weeks,The COPD and EA rats were injected with LPS into the airway tract before smoking and on the15 th day after smoking cessation,the pathological changes of lung and pulmonary function were used to evaluate the COPD model.2.Acupuncture points BL13(Feishu)and ST36(Zusanli)were selected based on the principles and practice of Traditional Chinese Medicine for treating COPD,Electro-acupuncture(EA)treatments were carried out once a day for 30 min lasting 1week.And after the EA treatment,lung function and the levels of IL-6,TNF-? were measured to assess the effect of EA treatment by ELISA.3.In this study,to estimate the excitability of vagus nerve,the discharges of the vagus nerve were observed by stereotaxic apparatus and RM2000 multichannel physiological recorder,furthermore,the content of ACh and ACh E in lung tissue was also measured.4.The rats were injected with alpha-7 nicotinic acetylcholine receptors(?7n ACh R)antagonist alpha-bungarotoxin(?-BGT)to block the CAP,and the expression of?7n ACh R?NF-?B ?JAK2?STAT3 in lung tissue were observed by Immunohistochemistry,real time quantitative PCR,and Weston blot,and the level of IL-6,TNF-? were also measured to valuated whether the anti-inflammatory of EA treatment was blocked.Results: 1.The pulmonary function and the pathological changes were observed after 6 weeks smoke,compared with the normal group,the pulmonary function of COPD group showed the significant decreases in FVC,FEV0.1,FEV0.3,FEV0.1/FVC and FEV0.3/FVC(P<0.01),and pathological examination showed that a large number of inflammatory cells were infiltrated in the lungs and the alveolar space was ectasiad,and the alveolar wall was thickened.And Compared with normal group,the levels of IL-6,TNF-? in lung tissue and broncho alveolar lavage fluid(BALF)were increased significantly in COPD group(P<0.05).2.After the EA treatment for 1 week,the pulmonary function of COPD+EA group was increased significantly compared with COPD group(P<0.01),additionally,the levels of IL-6,TNF-? in lung tissue and BALF were decreased significantly(P<0.05).3.The results of electrophysiological experiment showed that the discharge frequency,area and amplitude of vagus nerve were significant increased(P<0.01).While,the level of ACh and ACh E was decreased after the EA treatment(P<0.01),and after the rats injected with ?-BGT,the level of ACh and ACh E in lung tissue was increased compared with the COPD+EA group(P<0.01).4.After the rats injected with ?-BGT,the levels of IL-6,TNF-? in COPD+?-BGT+EA group were higher than those in COPD+EA group(P<0.05).Compared with normal group,the real time quantitative PCR and Weston blot experiments indicted that the expression of ?7n ACh R,NF-?B,JAK2,STAT3 mRNA and protein in lung tissue were increased significantly in COPD group(P<0.01),while after the EA treatment,the expression of those were decreased in lung tissues(P<0.01),and compared with COPD+EA group,the expression of?7n ACh R,NF-?B,JAK2 and STAT3 were up-regulation in COPD+?-BGT+EA group(P<0.01);and the data demonstrated that the ?7n ACh R,NF-?B,JAK2,STAT3 positive cells in the lung tissue in COPD group were higher than that in normal group(P<0.01),and compared with COPD group,the positive cells in lung tissue were decreased significantly in COPD+EA group(P<0.01),but remained higher levels in COPD+?-BGT+EA group(P<0.01).Conclusions: 1.The COPD model was established successfully and the pathological changes of lung and the pulmonary function were consistent with the characteristics of these changes in COPD patients.2.After the EA treatment,the pulmonary function was improved and the release of inflammatory factors was decreased,and the data indicated that EA treatment could regulate the inflammatory response in COPD model rats.3.The results showed that the EA treatment could enhance the discharge of vagus nerve and activated the CAP.4.The expression of ?7n ACh R,NF-?B,JAK2,STAT3 mRNA and protein in lung tissue were decreased and the inflammatory response was also decreased after the EA treatment,and it was indicated that EA treatment could inhibit the abnormal activation of NF-?B and JAK2/STAT3 signal transduction pathway,while,the?-BGT,a selective ?7n ACh R inhibitor,could inhibit the anti-inflammatory effect of EA treatment,and it suggested that the CAP might involve in the anti-inflammatory effect of EA treatment.