TNF-α在肺炎支原体肺炎模型中的表达及机制的研究

发布时间：2018-05-08 15:43

本文选题：肺炎支原体 + 肿瘤坏死因子—alpha　；参考：《吉林大学》2012年硕士论文

【摘要】：目的肺炎支原体肺炎是由肺炎支原体感染引起的肺部炎症，近年来，肺炎支原体感染引起肺炎的发病率明显增加，据文献报道MP已被认为是社区获得性肺炎（CAP）的第三位病原体[1]，MP感染不仅成为儿科的常见病及多发病，在成年人及老年人亦不少见。肺炎支原体除引起肺炎外，还可以致神经系统、心血管系统、消化系统、血液系统、肌肉及关节等损害。TNF-α是具有多种生物活性的生物调节肽，正常情况下，血浆中有较低水平的TNF-α存在，具有多种生理功能如调节免疫应答、抗感染、抗肿瘤、促进细胞生长分化等。但如果体内TNF-α水平明显升高，则可介导炎症反应的许多病理生理过程，引起局部炎症反应，介导体内其他炎性介质的释放，引起组织细胞损伤，甚至多器官、系统受损害。而且其血清中水平越高，全身炎症反应越严重。而TNF-α能否成为判断肺炎支原体感染病情严重程度的指标之一，则观点不一。本实验应用RT-PCR方法和酶联免疫法、免疫组织化学技术分别从mRNA及蛋白质水平核酸水平研究TNF-α在小鼠肺炎支原体模型中的表达情况，探讨TNF-α表达的意义及相关作用机制，以期为肺炎支原体感染的临床诊断、肺外并发症的提示及治疗提供指导与靶点。方法 1、建立3组小鼠模型，分别为：①对照组：未感染肺炎支原体的小鼠；②感染组：感染肺炎支原体的小鼠；③治疗组：应用阿奇霉素治疗肺炎支原体感染的小鼠。 2、留取3组小鼠的血清、肺组织、心脏、肝脏、肾脏。通过双抗体夹心酶联免疫吸附试验测定其血清中肿瘤坏死因子的含量。提取小鼠肺组织中的细胞总RNA，，应用RT-PCR方法检测TNF-α的mRNA的表达水平。应用免疫组化技术，根据细胞核和细胞浆内的黄色计数，观察肺炎支原体感染小鼠肺组织、肝脏组织、肾脏组织、心肌组织的病变程度。采用SPSS13.0软件进行统计学处理。结果 1.感染组与治疗组血清TNF-α的水平高于对照组，感染组的水平高于治疗组，差异有统计学意义（P0.05）。 2.对照组肺脏、心脏、肝脏、肾脏无明显炎症反应。感染组可见支气管、细支气管、心肌组织、肝组织、肾组织血管旁有淋巴细胞浸润。治疗组淋巴细胞浸润较感染组轻。3.RT-PCR的结果显示感染组、治疗组肺组织中TNF-α的mRNA水平较对照组高。感染组中的TNF-α的mRNA表达水平高于治疗组。免疫组化结果显示对照组小鼠无阳性细胞或阳性率＜10%，感染组阳性率＞60％，治疗组阳性率多为31%-60%之间。结论 1.TNF-α在肺炎支原体肺炎的肺组织中的表达高于正常肺组织、治疗组肺组织；其阳性表达强度与肺炎支原体肺炎的病情严重程度有关。 2.免疫组织化学技术检测可看出TNF-α在有肺外炎症的阳性表达强度高于无肺外炎症的组织中的表达。TNF-α在感染组小鼠的心、肝、肾组织中有表达。表达有差异，具有统计学意义。
[Abstract]:Purpose Mycoplasma pneumoniae pneumonia is a pulmonary inflammation caused by mycoplasma pneumoniae infection. In recent years, the incidence of pneumonia caused by mycoplasma pneumoniae infection has increased significantly. According to the literature, MP has been considered as the third pathogen of community-acquired pneumonia (CAP) [1] MP infection is not only a common and frequent disease in pediatrics, but also not uncommon in adults and the elderly. In addition to causing pneumonia, mycoplasma pneumoniae can also cause damage to the nervous system, cardiovascular system, digestive system, blood system, muscles and joints. There is a low level of TNF- 伪 in plasma, which has many physiological functions such as regulating immune response, anti-infection, anti-tumor, promoting cell growth and differentiation. However, if the level of TNF- 伪 in vivo is obviously elevated, it can mediate many pathophysiological processes of inflammatory reaction, induce local inflammatory response, mediate the release of other inflammatory mediators in the body, cause tissue and cell damage, and even damage to many organs and systems. Moreover, the higher the serum level, the more serious the systemic inflammatory reaction. But whether TNF- 伪 can be one of the indexes to judge the severity of mycoplasma pneumoniae infection is different. The expression of TNF- 伪 in mouse mycoplasma pneumoniae model was studied by using RT-PCR method and enzyme-linked immunosorbent assay (Elisa). The expression of TNF- 伪 in mouse model of mycoplasma pneumoniae was studied from the level of mRNA and protein respectively, and the significance and mechanism of expression of TNF- 伪 were discussed. In order to provide guidance and target for clinical diagnosis extrapulmonary complications and treatment of mycoplasma pneumoniae infection. Method 1. Three groups of mice were established as control group: control group: no mycoplasma pneumoniae infection group; mice infected with mycoplasma pneumoniae group; mice treated with azithromycin in treatment of mycoplasma pneumoniae infection. 2, the serum, lung tissue, heart, liver and kidney of three groups of mice were collected. Serum tumor necrosis factor (TNF) levels were determined by double antibody sandwich enzyme linked immunosorbent assay (Elisa). Total RNAs were extracted from mouse lung tissue and the expression level of TNF- 伪 mRNA was detected by RT-PCR method. The pathological changes of lung, liver, kidney and myocardium of mice infected with Mycoplasma pneumoniae were observed by immunohistochemical technique according to the yellow count in nucleus and cytoplasm. SPSS13.0 software was used for statistical processing. Result 1. The level of serum TNF- 伪 in infection group and treatment group was higher than that in control group, and the level of TNF- 伪 in infected group was higher than that in treatment group (P 0.05). 2. There was no obvious inflammatory reaction in lung, heart, liver and kidney in control group. Lymphocytic infiltration was observed in bronchioles, bronchioles, myocardium, liver and kidney. The results of RT-PCR showed that the level of TNF- 伪 mRNA in lung tissue of the treatment group was higher than that of the control group. The expression of TNF- 伪 mRNA in infected group was higher than that in treatment group. The results of immunohistochemistry showed that there were no positive cells or positive rates in the control group < 10%, the positive rate of infection group was more than 60%, and the positive rate of treatment group was 31-60%. Conclusion 1. The expression of TNF- 伪 in the lung tissue of mycoplasma pneumoniae pneumonia was higher than that in the normal lung tissue, and the positive expression intensity of TNF- 伪 was related to the severity of mycoplasma pneumoniae pneumonia. 2. The positive expression of TNF- 伪 in the tissues with extrapulmonary inflammation was higher than that in the tissues without extrapulmonary inflammation. TNF- 伪 was expressed in the heart, liver and kidney of the infected mice. The expression was different and had statistical significance.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R725.6

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