母孕期脂多糖暴露对小鼠子代过敏性哮喘发生的影响

Effect of maternal exposure to lipopolysaccharide during pregnancy on allergic asthma in offspring in mice

目的探讨母孕期脂多糖暴露对小鼠子代过敏性哮喘发生的影响。方法动物实验研究,2019年6月至2021年6月将10只C57BL/6J孕鼠于妊娠第15.5天采用随机数字表法进行分组,根据予以腹腔注射7μg/kg脂多糖或磷酸盐缓冲液(PBS)分为脂多糖组和PBS组。采用随机数字表法在脂多糖组及PBS组产生的子代小鼠中各选取6只(共12只),从4周龄起分别进行屋尘螨或PBS刺激,分为脂多糖+PBS组、脂多糖+屋尘螨组、PBS+PBS组、PBS+屋尘螨组,每组各3只。观察仔鼠咳喘表现,通过HE染色观察其肺组织病理改变,同时应用高通量液相蛋白芯片检测法测定肺组织炎症因子[白细胞介素(IL)4、6、17A、23,干扰素α、β]的表达,组间比较采用t检验或秩和检验。结果12只小鼠中,通过观察PBS+屋尘螨组哮喘样表现相对于PBS+PBS组明显,而脂多糖+屋尘螨组哮喘样表现轻于PBS+屋尘螨组。肺组织HE染色显示,PBS+屋尘螨组炎性细胞聚集高于PBS+PBS组[4.0(3.5,4.0)比0(0,0.5)分,Z=2.02,P=0.043],脂多糖+屋尘螨组炎症细胞水平低于PBS+屋尘螨组[1.0(0.5,1.5)比4.0(3.5,4.0)分,Z=1.99,P=0.046]。肺组织高通量液相蛋白芯片检测可见PBS+屋尘螨组的IL-6、IL-23、干扰素β均高于PBS+PBS组[(114±3)比(94±4)ng/L、(210±4)比(173±7)ng/L、(113±2)比(94±4)ng/L,t=4.37、4.84、3.96,均P<0.05],脂多糖+屋尘螨组的IL-6、IL-23、干扰素α、干扰素β水平均明显低于PBS+屋尘螨组[(87±5)比(114±3)ng/L、(171±7)比(210±4)ng/L、(16.1±0.6)比(20.9±0.3)ng/L、(95±1)比(113±2)ng/L,t=5.07、5.07、7.28、7.47,均P<0.05]。结论孕期低剂量脂多糖暴露可减轻子代过敏性气道炎症发展,降低过敏性疾病发生,这提示母孕期细菌感染可能改变了子代过敏性哮喘的发生和发展。

Objective To investigate the effect of maternal exposure to lipopolysaccharide during pregnancy on allergic asthma in offspring in mice.Methods Animal experimental research was carried out from June 2019 to June 2021.Pregnant C57BL/6J mice were randomly divided into 2 groups by intraperitoneal injection with 7μg/kg lipopolysaccharide(LPS)or phosphate buffered saline(PBS)at day 15.5 of gestation.After birth,6 offspring were randomly chosen from each group at the age of 4 weeks,and stimulated with house dust mites(HDM)or PBS,further divided into 4 groups,such as LPS+PBS group,LPS+HDM group,PBS+PBS group,PBS+HDM group,with 3 mice in each group.The cough and wheezing were observed,the histological changes in lung tissue were examined after HE staining,and the expression of inflammatory factors including interleukin(IL)-4,IL-6,IL-17A,IL-23,interferon(IFN)-αand IFN-βin the lung tissue were detected by high-throughput liquid protein chip detection.T test or rank sum test was used for the comparison among these groups.Results The asthma-like airway inflammation was more obvious in PBS+HDM group after stimulated by HDM than that in PBS+PBS group,nevertheless,this manifestation in LPS+HDM group was milder than that in PBS+HDM group.HE staining showed that inflammatory cell aggregation in the lung tissue in PBS+HDM group was significantly higher than that in PBS+PBS group(4.0(3.5,4.0)vs.0(0,0.5),Z=2.02,P=0.043),while it was much lower in LPS+HDM group compared to PBS+HDM group(1.0(0.5,1.5)vs.4.0(3.5,4.0),Z=1.99,P=0.046).High-throughput liquid protein chip detection of lung tissue showed that IL-6,IL-23 and IFN-βlevels were significantly higher in PBS+HDM group when compared to those in PBS+PBS group((114±3)vs.(94±4)ng/L,(210±4)vs.(173±7)ng/L,(113±2)vs.(94±4)ng/L,t=4.37,4.84,3.96,all P<0.05),while the levels of IL-6,IL-23,IFN-α,IFN-βin LPS+HDM group were significantly lower than those in PBS+HDM group((87±5)vs.(114±3)ng/L,(171±7)vs.(210±4)ng/L,(16.1±0.6)vs.(20.9±0.3)ng/L,(95±1)vs.(113±2)ng/L,t=5.07,5.07,7.28,7.47,all P<0.05).Conclusions Prenatal low dose LPS exposure can reduce offspring′s airway inflammatory reactions and prevent the development of allergic disease.Maternal infection during pregnancy may affect the occurrence and development of allergic asthma in offspring.