摘要
Background:Asthma is a common cause of breathing difficulty in children and adults,and is characterized by chronic airway inflammation that is poorly controlled by available treatments.This results in severe disability and applies a huge burden to the public health system.Methane has been demonstrated to function as a therapeutic agent in many diseases.The aim of the present study was to explore the effect of methane-rich saline(MRS)on the pathophysiology of a mouse model of asthma and its underlying mechanism.Methods:A murine model of ovalbumin(OVA)-induced allergic asthma was applied in this study.Mice were divided into three groups:a control group,an OVA group,and OVA-induced asthmatic mice treated with MRS as the third group.Lung resistance index(RI)and dynamic compliance(Cdyn)were measured to determine airway hyper-responsiveness(AHR).Haematoxylin and eosin(H&E)staining was performed and scored to show histopathological changes.Cell counts of bronchoalveolar lavage fluid(BALF)were recorded.Cytokines interleukin(IL)-4,IL-5,IL-13,tumor necrosis factorα(TNF-α),and C-X-C motif chemokine ligand 15(CXCL15)from BALF and serum were measured by enzyme-linked immunosorbent assay(ELISA).The oxidative stress indexes,including malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT),glutathione(GSH),myeloperoxidase(MPO),and 8-hydroxydeoxyguanosine(8-OHdG),were determined using commercial kits.Apoptosis was evaluated by western blot,quantitative real-time polymerase chain reaction(qRT-PCR),and biochemical examination.Results:MRS administration reversed the OVA-induced AHR,attenuated the pathological inflammatory infiltration,and decreased the cytokines IL-4,IL-5,IL-13,TNF-α,and CXCL15 in serum and BALF.Moreover,following MRS administration,the oxidative stress was alleviated as indicated by decreased MDA,MPO,and 8-OHdG,and elevated SOD and GSH.In addition,MRS exhibited an anti-apoptotic effect in this model,protecting epithelial cells from damage.Conclusions:Methane improves pulmonary function and decreases infiltrative inflammatory cells in the allergic asthmatic mouse model.This may be associated with its anti-inflammatory,antioxidative,and anti-apoptotic properties.
目的:研究通过腹腔注射甲烷生理盐水对哮喘动物模型的保护作用及其可能的机制。创新点:通常我们认为甲烷生理盐水对人体并不发挥生理性的影响,但近年来涌现出的研究发现甲烷生理盐水可以发挥对多种脏器缺血再灌注损伤的保护作用。我们采用卵清蛋白刺激的小鼠哮喘模型,发现腹腔注射甲烷生理盐水的方式可以发挥对哮喘小鼠的保护作用,减轻哮喘小鼠氧化应激指标,缓解炎症和凋亡水平。方法:通过卵清蛋白刺激诱导小鼠气道高反应性的方式建立小鼠哮喘模型,治疗组小鼠给予甲烷生理盐水腹腔注射。通过测量小鼠气道阻力指数(RI)和动态肺顺应性(Cdyn)来检测小鼠气道高反应性;通过苏木精-伊红染色法(H&E)检测小鼠肺组织形态学;对小鼠肺泡灌洗液进行细胞测量;通过酶联免疫吸附试验(ELISA)测定灌洗液和采集的血清中白介素4(IL-4)、IL-5、IL-13和肿瘤坏死因子(TNF-α);通过生物化学的方式检测氧化应激指标(如丙二醛(MDA)、超氧歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GSH)、髓过氧化物酶(MPO)和8羟基脱氧鸟苷(8-OHdG));通过蛋白免疫印迹实验、实时定量聚合酶链式反应(qRT-PCR)和生化检测试剂盒检测凋亡相关蛋白。结论:甲烷生理盐水可以改善哮喘小鼠的气道功能,减少肺组织中浸润的炎性细胞。其保护作用有可能是通过甲烷抗氧化、抗炎和抗凋亡的生物学特性发挥的。
基金
Project supported by the National Natural Science Foundation of China(No.81371316)