二甲双胍抑制慢性哮喘小鼠气道炎症、重塑及新生血管形成

摘要

AIM: To investigate the effects of metformin on airway inflammation, remodeling and neovascularization in a mouse model of chronic asthma and its possible mechanisms.METHODS: BALB/c mice were randomly divided into saline group, ovalbumin (OVA) group and OVA+metformin group, with 8 in each.At the end of OVA exposure, blood and bronchoalveolar lavage fluid (BALF) were collected for the measurement of OVA specific IgE and leukocyte counts.Lung tissue sections were stained with hematoxylin-eosin, periodic acid-Schiff and Masson's trichrome to detect inflammatory cell infiltration, goblet cell hyperplasia, and collagen deposition around the airway, respectively.Immunohistochemistry was used to evaluate the number and percentage area of new blood vessels (CD31+), and the protein level of phosphorylated AMP-activated protein kinase (p-AMPK) in the airway.RESULTS: Compared with saline group, the eosinophil percentage and OVA specific IgE in serum in OVA group were all increased obviously (P<0.01).Metformin inhibited the above increases (P<0.05).Compared with control group, a marked increase in inflammation infiltration, PAS+ cells and collage deposition in the airway mucosa in OVA group were observed.Metformin partially relieved the above changes.CD31+ vessels in the wall of bronchi showed the abundance of blood vessels observed in OVA group compared with control group, which was suppressed by the treatment with metformin (P<0.05).The protein level of p-AMPK was reduced in the lung tissue challenged with OVA as compared with control group (P<0.05), while metformin increased the protein level of p-AMPK (P<0.01).CONCLUSION: The protein level of p-AMPK in the airway in OVA group is attenuated.Metformin effectively inhibits airway inflammation, remodeling and neovascularization possibly via activating AMPK signaling pathway.%目的: 探讨二甲双胍对慢性哮喘气道炎症、重塑及新生血管形成的影响及可能机制.方法: 采用卵白蛋白(OVA)致敏并激发制备慢性哮喘小鼠模型,给予二甲双胍干预,与生理盐水对照组和慢性哮喘模型组相比,观察支气管肺泡灌洗液(BALF)细胞计数、外周血免疫球蛋白、气道重塑及磷酸化腺苷酸活化蛋白激酶(p-AMPK)蛋白水平的变化.结果: 慢性哮喘小鼠BALF细胞总数及嗜酸性粒细胞百分比较对照组升高(P<0.01),血清OVA特异性IgE明显升高(P<0.01),给药组可降低上述指标(P<0.05).肺组织HE染色可见气道壁炎症细胞浸润、杯状细胞增生、上皮下胶原沉积等病理改变,免疫组化CD31染色观察到气道上皮下新生血管数目和面积增加;二甲双胍部分抑制了上述病理过程.肺组织免疫组化p-AMPK染色观察到其在模型组气道壁的表达较对照组下降(P< 0.05),给药组升高明显(P<0.01).结论: 慢性哮喘中AMPK磷酸化表达水平受抑制.二甲双胍可能通过激活AMPK来抑制慢性哮喘气道炎症、重塑及新生血管的形成.