连翘酯苷A通过TLR4/NF-κB p65/NLRP3轴对宫内感染所致新生大鼠肺损伤及免疫功能的影响研究

Effect of forsythiaside A on lung injury and immune function of neonatal mice induced by intrauterine infection through TLR4/NF-κB p65/NLRP3 axis

目的探讨连翘酯苷A对宫内感染所致新生大鼠肺损伤及免疫功能的影响,以及对Toll样受体4(TLR4)/核因子-κB(NF-κB)p65/NOD样受体3(NLRP3)轴的调节作用。方法40只孕鼠建立宫内感染模型,分为模型组、连翘酯苷A组、脂多糖组和脂多糖^(+)连翘酯苷A组,每组10只,另取10只孕鼠作为对照组。各组大鼠给予相应药物处理直至分娩,苏木素-伊红(HE)染色观察胎盘病理损伤,测定新生大鼠呼吸频率和肺指数,ELISA检测白细胞介素(IL)-6、IL-8和IL-1β水平,HE染色观察肺组织病理损伤,流式细胞仪检测外周血CD4^(+)和CD8^(+)淋巴细胞比例(CD4^(+)/CD8^(+)),Western blot检测肺组织TLR4、p-p65、NF-κB p65和NLRP3蛋白相对表达水平。结果与模型组比较,连翘酯苷A组新生大鼠呼吸频率、IL-8、IL-6、IL-1β、TLR4、p-p65和NLRP3水平更低,肺指数、CD4^(+)/CD8^(+)更高,差异有统计学意义(P<0.05)。与脂多糖^(+)连翘酯苷A组比较,脂多糖组新生大鼠呼吸频率、IL-8、IL-6、IL-1β、TLR4、p-p65和NLRP3水平更高,肺指数、CD4^(+)/CD8^(+)更低,差异有统计学意义(P<0.05)。结论连翘酯苷A可抑制TLR4/NF-κB p65/NLRP3信号通路改善宫内感染致新生大鼠肺损伤。

Objective To investigate the effects of forsythiaside A on lung injury and immune function in neonatal rats induced by intrauterine infection,and the regulation of toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB)p65/NOD-like receptor 3(NLRP3)axis.Methods A total of 40 pregnant rats were randomly divided into the model group,the forsythiaside A group,the lipopolysaccharide group and the lipopolysaccharide^(+)forsythiaside A group,with 10 rats in each group.Another 10 pregnant rats were selected as control group.Rats in each group were treated with corresponding drugs until delivery,and the placental pathological damage was observed by Hematoxylin eosin(HE)staining,respiratory rate and lung index were measured;levels of interleukin-6(IL-6),IL-8 and IL-1βwere detected by ELISA;lung tissue pathological damage was observed by Hematoxylin eosin(HE)staining;peripheral blood CD4^(+)and CD8^(+)lymphocyte ratio(CD4^(+)/CD8^(+))were detected by flow cytometry,and lung tissue TLR4,p-p65,NF-κB p65 and NLRP protein expression level were detected by Western blot.Results Compared with model group,the levels of respiratory rate,IL-8,IL-6 and IL-1β,TLR4,p-p65 and NLRP3 in forsythiaside A group were lower than those in forsythiaside A group,and lung index,CD4^(+)/CD8^(+)were higher than those in forsythiaside A group(P<0.05).Compared with lipopolysaccharide^(+)forsythiaside A group,the levels of respiratory r ate,IL-8,IL-6 and IL-1β,TLR4,p-p65 and NLRP3 in lipopolysaccharide group were higher than those in lipopolysaccharide group,and lung index,CD4^(+)/CD8^(+)were lower than those in lipopolysaccharide^(+)forsythiaside A group(P<0.05).Conclusion Forsythiaside A may inhibit TLR4/NF-κB p65/NLRP3 signaling pathway and improve lung injury induced by intrauterine infection in neonatal rats.