地龙对肺炎支原体感染小鼠肺组织中表皮生长因子EGF表达的影响

Effect of earthworm on the expression of epidermal growth factor in lung tissue of mice infected with mycoplasma pneumoniae

目的探讨地龙对肺炎支原体感染小鼠肺上皮组织的影响。方法利用Biacore技术检测地龙提取液在体外与表皮生长因子(EGF)蛋白的结合能力,再配合体内药效学实验进行验证。将60只雌雄各半的BALB/c小鼠随机分为空白组,模型组,阳性对照组(阿奇霉素22.5 mg·kg^(-1)),地龙高(4.7 g·kg^(-1))、中(2.35 g·kg^(-1))、低剂量组(1.175 g·kg^(-1));经鼻滴入20μL 1×10^(6) CCU肺炎支原体培养液建立肺炎支原体模型。模型小鼠经药物治疗两周后,HE染色法观察给药前后小鼠肺组织病理差异,通过免疫组化(IHC)、Western blot和RT-PCR方法测定各组小鼠肺组织中EGF蛋白和mRNA的表达量。结果Biacore实验结果表明在体外地龙提取液与EGF蛋白能较好地结合;HE染色显示,地龙中、高剂量组均能促进肺组织结构完整,减少炎性细胞;与模型组比较,地龙中、高剂量组小鼠的EGF蛋白和mRNA表达水平显著升高(P<0.05)。结论地龙可通过影响EGF的表达,改善肺炎支原体感染症状,修复损伤的肺上皮组织。

Objective To determine the effect of earthworm on the lung epithelial tissue of mycoplasma pneumoniae(MP)infected mice.Methods The binding ability of earthworm extract to epidermal growth factor(EGF)protein in vitro was detected by Biacore technology,and was further verified by in vivo pharmacodynamic experiment.Sixty BALB/c mice,half male and half female,were randomly divided into a control group,a model group,a positive control group(azithromycin 22.5 mg·kg^(-1)),and earthworm high(4.7 g·kg^(-1)),medium(2.35 g·kg^(-1))and low(1.175 g·kg^(-1))dose groups.The MP models were established by the nasal instillation of 20μL 1×10^(6) CCU MP culture medium.After two weeks of treatment,the pathological differences in the lung tissues of mice before and after the treatment were observed by HE staining,and the expressions of EGF protein and mRNA in the cells of each group of mice were determined by immunohistochemistry,Western blot and RT-PCR.Results The results of Biacore assay showed that earthworm extract combined well with EGF protein in vitro.HE staining showed that earthworm medium and high dose groups promoted the integrity of the lung tissue structure and reduced inflammatory cells.Compared with the model group,the EGF protein and mRNA expression levels in earthworm medium and high dose groups were significantly increased(P<0.05).Conclusion Earthworm can improve the symptoms of MP infection and repair the damaged lung epithelial tissue by affecting the expression of EGF.