miRNA-133b激活剂对过敏性鼻炎-哮喘综合征小鼠气道炎症的影响

EFFECT OF MICRORNA-133B ACTIVATOR ON AIRWAY INFLAMMATION IN MICE WITH COMBINED ALLERGIC RHINITIS AND ASTHMA SYNDROME

目的探讨microRNA-133b(miRNA-133b)激活剂对过敏性鼻炎-哮喘综合征(CARAS)小鼠气道炎症的影响。方法将BALB/c小鼠随机分为对照组、CARAS组和miRNA-133b组。后两组通过鼻腔滴注和鼠尾静脉注射卵清蛋白(OVA)致敏3周,并以20 g/L OVA连续5 d雾化激发,建立CARAS小鼠模型。miRNA-133b组在每次雾化激发前3 h分别鼻腔滴注和鼠尾静脉注射miRNA-133b激活剂,CARAS组则注射miRNA-133b阴性对照。采用实时荧光定量PCR(q-PCR)法检测各组小鼠鼻黏膜及肺组织中miRNA-133b的表达,酶联免疫吸附试验(ELISA)法检测血清中白细胞介素(IL)-17A和IL-1β的水平,蛋白印迹分析(Western blot)法检测肺组织中Toll样受体2(TLR2)、核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)和核因子-κB P65(NF-κB P65)蛋白表达。通过瑞氏染色计算支气管肺泡灌洗液(BALF)中白细胞总数及嗜酸性粒细胞比例,苏木精-伊红(HE)染色观察鼻黏膜及肺组织的病理学变化。结果miRNA-133b组小鼠鼻黏膜及肺组织中miRNA-133b的表达水平较对照组、CARAS组显著提高,差异具有统计学意义(F=8.11、10.65,P<0.05)。miRNA-133b组小鼠鼻黏膜及肺组织气道受损及炎性细胞浸润较CARAS组明显减轻。与CARAS组比较,miRNA-133b组小鼠擦鼻和打喷嚏的频率、BALF中白细胞总数和嗜酸性粒细胞比例、细胞因子(TLR2、NLRP3、NF-κB P65、IL-17A和IL-1β)的水平显著降低,差异均具有统计学意义(F=198.21~9685.00,P<0.05)。结论miRNA-133b激活剂可能通过抑制TLR2-NLRP3信号通路的激活改善CARAS小鼠气道炎症。

Objective To investigate the effect of microRNA-133b(miRNA-133b)activator on airway inflammation in mice with combined allergic rhinitis and asthma syndrome(CARAS).Methods BALB/c mice were randomly divided into control group,CARAS group,and miRNA-133b group.All mice except those in the control group were sensitized by nasal drip and tail vein injection of ovalbumin(OVA)for 3 weeks and were given aerosol challenge with 20 g/L OVA for 5 consecutive days to establish a mouse model of CARAS.The mice in the miRNA-133b group were given nasal drip and tail vein injection of miRNA-133b activator at 3 hours before each time of aerosol challenge,and those in the CARAS group were injected with miRNA-133b negative control.Quantitative real-time PCR was used to measure the expression of miRNA-133b in nasal mucosa and lung tissue;ELISA was used to measure the serum levels of interleukin-17A(IL-17A)and interleukin-1β(IL-1β);Western blot was used to measure the protein expression of Toll-like receptor 2(TLR2),nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),and nuclear factor-kappa B P65(NF-κB P65)in lung tissue.Wright’s staining was used to calculate total leukocyte count and eosinophil ratio in bronchoalveolar lavage fluid(BALF),and HE staining was used to observe the pathological changes of nasal mucosa and lung tissue.Results The miRNA-133b group had a significantly higher expression level of miRNA-133b in nasal mucosa and lung tissue than the control group and the CARAS group(F=8.11,10.65;P<0.05).Compared with the CARAS group,the miRNA-133b group had significant alleviation of airway damage and inflammatory cell infiltration in nasal mucosa and lung tissue.Compared with the CARAS group,the miRNA-133b group had significantly lower frequency of nasal wiping and sneezing,total leukocyte count and eosinophil ratio in BALF,and levels of cytokines(TLR2,NLRP3,NF-κB P65,IL-17A,and IL-1β)(F=198.21-9685.00,P<0.05).Conclusion This study shows that miRNA-133b activator can improve airway inflammation in CARAS mice by inhibiting activation of the TLR2-NLRP3 signaling pathway.