DEHP致小鼠哮喘模型中Th17的介导作用

发布时间：2018-04-13 14:22

本文选题：DEHP + 哮喘模型　；参考：《华中师范大学》2013年硕士论文

【摘要】：DEHP是目前使用最广泛的一种增塑剂,因容易被释放到环境中,所以成为一种常见的环境污染物。DEHP多种毒性和对人类健康危险的研究日益增多,近年来的研究发现DEHP与过敏性疾病存在一定关系,有研究证明室内尘埃中的DEHP含量与儿童哮喘以及哮喘样症状的发生存在联系。关于DEHP致哮喘作用分子机理的研究,多从传统的Thl/Th2途径展开。近年来,机体内有别于Thl和Th2的CD4+效应T细胞另一种Th17细胞被发现,Th17细胞对炎症反应的促进作用受到越来越多的关注。为探究Th17细胞在DEHP致小鼠哮喘的发病机制中的作用,本实验在小鼠哮喘模型的基础上,研究DEHP在有无OVA致敏的条件下,IL-17在小鼠相关组织中的变化。雄性BalB/c小鼠随机分为：未处理对照组、DEHP单独染毒组、卵清蛋白致敏组、DEHP+OVA联合染毒组,每组6只。哮喘模型通过OVA致敏加激发的方式建立。DEHP染毒组连续54d进行10mg/kg/day DEHP灌胃。OVA染毒组、DEHP+OVA染毒组在第54～59d进行1%OVA雾化(30min/day),诱发小鼠哮喘症状。第60d进行以下操作：血清制备,肺功能测试,肺泡灌洗液样品收集和肺组织匀浆的制备。检测的指标包括哮喘模型相关指标和肺组织中IL-17的检测。结果表明,与OVA致敏组相比,DEHP+OVA联合染毒组小鼠气道高反应性显著增强,肺部的病理变化也非常严重,肺泡灌洗液中嗜酸性粒细胞和中性粒细胞占白细胞总数的比例均增加,血清中T-IgE含量也显著性增加；与对照组相比,DEHP染毒组小鼠肺组织匀浆和肺泡灌洗液中IL-17浓度均显著性增加(p0.05),DEHP与OVA联合染毒组小鼠BALF的IL-17则极显著增加(p0.01)。表明DEHP对小鼠哮喘的诱导作用可能通过Th17细胞群介导。综合分析实验结果发现,DEHP能对哮喘发生产生影响,我们推断：首先,DEHP+OVA联合染毒组与OVA致敏组相比,血清中T-IgE极显著增加,气道高反应性上升,嗜酸性粒细胞比例增加,气道重塑严重以及细胞炎症因子浓度增加,可知DEHP参与了小鼠哮喘的发生过程,并通过类似免疫“佐剂”的作用加剧了小鼠哮喘症状。其次,IFN-γ/IL-4比值的下降,说明在此过程中Th1/Th2的平衡向Th2类细胞群平移,这与前人的研究结论一致。最后,DEHP染毒组,DEHP+OVA联合染毒组小鼠肺组织和肺泡灌洗液中IL-17浓度增加,证明Th17类群细胞和Th2类群细胞一样通过增加分化,促进炎症作用,参与了哮喘发生的过程,表明Th1/Th2平衡是不完善的,DEHP促进炎症发生的过程涉及Th1、Th2和Thl7三类细胞群。
[Abstract]:DEHP is one of the most widely used plasticizers at present. Because it is easy to be released into the environment, it has become a common environmental pollutant.Recent studies have found that there is a relationship between DEHP and allergic diseases. It has been proved that the content of DEHP in indoor dust is associated with the occurrence of asthma and asthmatic symptoms in children.The study on the molecular mechanism of asthma induced by DEHP is mainly based on the traditional Thl/Th2 pathway.In recent years, more and more attention has been paid to the role of Th 17 cells in promoting inflammation in T cells of CD4 effect, which are different from those in Thl and Th2.In order to investigate the role of Th17 cells in the pathogenesis of mouse asthma induced by DEHP, the changes of DEHP IL-17 in mice with or without OVA sensitization were studied on the basis of mouse asthma model.Male BalB/c mice were randomly divided into untreated control group (n = 6) and ovalbumin sensitized group (n = 6).The asthmatic model was established by OVA sensitization and stimulation. The rats in the .DEHP exposed group were treated with 10mg/kg/day DEHP for 54 days. The DEHP OVA group was treated with 1%OVA nebulization for 30 min / day on the 54th day and induced the asthmatic symptoms in the mice.On day 60, the following procedures were performed: serum preparation, lung function test, alveolar lavage fluid sample collection and lung tissue homogenate preparation.The indicators included asthma model and IL-17 in lung tissue.The results showed that compared with the OVA sensitized group, the airway hyperresponsiveness and the pathological changes of the lungs were significantly increased in the mice treated with OVA OVA, and the proportion of eosinophils and neutrophils in the alveolar lavage fluid to the total number of leukocytes was increased.Compared with the control group, the concentration of IL-17 in the lung tissue homogenate and alveolar lavage fluid of the control group was significantly higher than that of the control group, and the IL-17 of the BALF of the mice exposed to OVA was significantly higher than that of the control group.The results suggest that the induction of asthma by DEHP may be mediated by Th17 cell group.The results of comprehensive analysis showed that DEHP could affect the occurrence of asthma. We inferred that: first, compared with OVA sensitized group, the serum T-IgE level was significantly increased, airway hyperresponsiveness and eosinophilic granulocyte ratio were increased.Severe airway remodeling and increased concentration of cytokines suggest that DEHP is involved in the development of asthma in mice and exacerbates the symptoms of asthma in mice through immune adjuvant.Secondly, the decrease of IFN- 纬 / IL-4 ratio indicates that the balance of Th1/Th2 shifts to Th2 cell group in this process, which is consistent with previous studies.Finally, the concentration of IL-17 in lung tissue and alveolar lavage fluid of mice exposed to DEHP OVA combined with DEHP was increased, which proved that Th17 group cells and Th2 group cells increased differentiation, promoted inflammation and participated in the process of asthma.The results suggest that the Th1/Th2 balance is imperfect and the process of promoting inflammation involves Th1Th _ 2 and Thl7.
【学位授予单位】：华中师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R562.25;R-332

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