PM_(2.5)对变应性鼻炎大鼠NF-κB信号通路的影响

Effect of PM;on the NF-κB signaling pathway in rats with allergic rhinitis

目的探究大气PM_(2.5)对变应性鼻炎(allergic rhinitis,AR)大鼠核转录因子-κB(nuclear factor kappa B,NF-κB)信号通路的影响。方法将40只SPF级雄性Wistar大鼠分为对照组、AR组、AR+PM_(2.5)组和四氢化吡咯二硫代甲酸铵(pyrrolidin-edithiocarbamate ammonium,PDTC)组。采用卵清蛋白(ovalbumin,OVA)致敏法构建大鼠AR模型。AR+PM_(2.5)组和PDTC组进行PM_(2.5)吸入暴露和PDTC组同时给予腹腔注射PDTC处理,其余各组分别以等量生理盐水代替。采用AR行为学指标进行评分;PAS染色观察大鼠鼻黏膜杯状细胞增生情况;扫描电镜观察大鼠鼻黏膜超微结构;ELISA法检测大鼠鼻黏膜组织白细胞介素-4(IL-4)、白细胞介素-5(IL-5)、白细胞介素-6(IL-6)含量;q RT-PCR检测黏蛋白5AC(mucin 5AC,MUC5AC)、鼠钙激活氯通道3(mouse calcium-activated chloride channel3,mCLCA3)mRNA表达水平;Western Blot检测大鼠鼻黏膜NF-κB p65、免疫球蛋白E(IgE)蛋白的表达。结果与对照组相比,AR组和AR+PM_(2.5)组AR评分、IL-4、IL-5、IL-6含量、MUC5AC、mCLCA3 mRNA、NF-κB p65、IgE蛋白表达水平明显升高(P<0.05),黏膜杯状细胞增生及纤毛破坏更严重,且各指标AR+PM_(2.5)组高于AR组。经过PDTC干预后,PDTC组较AR+PM_(2.5)组上述指标均有所缓解(P<0.05)。结论PM_(2.5)通过激活NF-κB信号通路,增加下游炎症相关因子IL-4、IL-5、IL-6和IgE的表达,促进鼻黏膜杯状细胞增生,增加鼻黏液相关基因MUC5AC、mCLCA3的表达,从而加重鼻黏膜病理学变化和AR症状。

Objective To explore the effect of atmospheric fine particulate matter(PM_(2.5))on the nuclear factor-kappa B(NF-κB)signaling pathway in rats with allergic rhinitis(AR).Methods Forty specific pathogen-free male Wistar rats were divided into control group,AR group,AR+PM_(2.5) group,and ammonium pyrrolidine dithiocarbamate(PDTC)group.Ovalbumin(OVA)sensitiza-tion was used to establish an AR model in the rats.The AR+PM_(2.5) group and PDTC group were exposed to PM_(2.5) via inhalation,the PDTC group was treated by intraperitoneal injection of PDTC at the same time,and the remaining groups were treated with an equiva-lent amount of normal saline.Behavioral indicators for AR were used for scoring;PAS staining was used to observe goblet cell prolifera-tion in the nasal mucosa of the rats;scanning electron microscopy was used to observe the ultrastructure of the nasal mucosa of the rats;ELISA method was used to measure the content of IL-4,IL-5 and IL-6 in the nasal mucosa tissue of the rats;q RT-PCR assay was used to measure the mRNA expression levels of mucin 5AC(MUC5AC)and mouse calcium-activated chloride channel 3(mCLCA3);West-ern blot was used to measure the protein expression levels of NF-κB p65 and IgE in the nasal mucosa of the rats.Results Compared with the control group,the AR group and AR+PM_(2.5) group had significantly increased AR scores,content of IL-4,IL-5 and IL-6,m R-NA expression of MUC5AC and mCLCA3 and protein expression of NF-κB p65 and IgE(P<0.05);meanwhile,the latter two groups showed more severe goblet cell proliferation and cilia destruction in the mucosa,with each indicator higher in the AR+PM_(2.5) group than that in the AR group.After PDTC intervention,the PDTC group had significant improvement in all the above indicators compared with those in the AR+PM_(2.5) group(P<0.05).Conclusion By activating the NF-κB signaling pathway,PM_(2.5) increases the expression of downstream inflammation-related factors IL-4,IL-5,IL-6 and IgE,promotes the goblet cell proliferation in the nasal mucosa,and in-creases the expression of nasal mucus-related genes MUC5AC and mCLCA3,and thereby aggravates the pathological changes in the nasal mucosa and AR symptoms.