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[目的]观察不同浓度大气PM_(2.5)对哮喘大鼠的影响,并初步探索PM_(2.5)诱导大鼠哮喘加重过程中miR155、STAT6、IL-13的变化。[方法]将50只SD大鼠随机分为:对照组,哮喘组,哮喘+PM_(2.5)低染毒组、哮喘+PM_(2.5)中染毒组及哮喘+PM_(2.5)高染毒组。对照组和哮喘组均给予生理盐水1.5 m L/kg(以每千克体重计,下同),哮喘+低、中、高染毒组分别给予PM_(2.5)生理盐水混悬液1.5、6.0、24.0 mg/kg。通过腹腔注射卵清蛋白(OVA)致敏,雾化吸入OVA构建大鼠哮喘模型,第25、28、31、34天予以PM_(2.5)气管滴注染毒。第36天处死大鼠后,观察肺脏HE染色病理切片,比较各组大鼠支气管肺灌洗液(BALF)中细胞总数及分类计数;通过RT-PCR检测大鼠肺组织中miR155、STAT6(信号转导和转录激活因子6)、IL-13的基因表达水平;ELISA检测大鼠BALF中IL-13蛋白水平。[结果]哮喘组大鼠BALF中嗜酸粒细胞百分比高于对照组,哮喘+PM_(2.5)中、高染毒组高于对照组及哮喘组,差异均有统计学意义(P<0.05);哮喘+PM_(2.5)中、高染毒组大鼠肺组织miR155及STAT6基因表达水平高于对照组,差异均有统计学意义(P<0.05);大鼠肺组织miR155与STAT6基因表达呈明显正相关(r=0.843,P<0.001);5组大鼠肺组织IL-13基因及BALF中IL-13蛋白表达水平间的差异无统计学意义(P>0.05)。[结论]miR155及STAT6可能在PM_(2.5)加重哮喘过程中起作用,并且miR155与STAT6之间存在关联。
[Objective] To observe the effect of different concentrations of atmospheric PM 2.5 on asthmatic rats, and to explore the changes of miR155, STAT6 and IL-13 in PM 2.5 -induced asthma exacerbation. [Methods] Fifty SD rats were randomly divided into control group, asthma group, asthma + PM 2.5 low exposure group, asthma + PM 2.5 exposure group and asthma + PM 2.5 high exposure group. Control group and asthma group were given saline 1.5 m L / kg (per kilogram of body weight, the same below), asthma + low, middle and high exposure groups were given PM 2.5 (2.5) saline suspension 1.5,6.0, 24.0 mg / kg. The model of asthma was induced by intraperitoneal injection of ovalbumin (OVA) and inhaled into OVA by atomization. PM25 (2.5) tracheal instillation was given on days 25, 28, 31 and 34. After the rats were sacrificed on day 36, the pathological sections of the lungs were stained with HE and the total number of cells and the number of bronchoalveolar lavage fluid (BALF) in each group were compared. The expressions of miR155, STAT6 Transduction and transcription activator 6), IL-13 gene expression levels; IL-13 protein levels in BALF of rats were detected by ELISA. [Results] The percentage of eosinophils in BALF of asthmatic rats was higher than that of control rats. The asthmatic + PM 2.5 rats were higher than those of control rats and asthma rats (P <0.05) (P <0.05). The expression of miR155 and STAT6 in lung tissue of asthmatic + PM 2.5 group were higher than those in control group (P <0.05) (R = 0.843, P <0.001). There was no significant difference in IL-13 gene expression and IL-13 protein expression in BALF among the 5 groups (P> 0.05). [Conclusion] miR155 and STAT6 may play a role in the process of PM 2.5 aggravating asthma, and there is a correlation between miR155 and STAT6.