| 摘要: |
| 【目的】探讨在结核分枝杆菌（Mycobacterium tuberculosis,MTB）感染小鼠早期，其肺脏上皮细胞中NF-κB和p53信号通路参与机体的免疫调控作用。【方法】将C57BL/6 Cnc小鼠30只（雄、雌各15只）,按5只/组设空白对照组、阴性对照组（腹腔注射生理盐水）和MTB感染组(腹腔注射牛结核分枝杆菌减毒株（卡介苗，BCG）)，感染4 d后经安乐死处死小鼠，摘取小鼠肺脏和脾脏进行形态学观察；将小鼠肺脏进行冰冻超薄切片，HE染色分析其肺脏病理变化；利用免疫组织荧光技术和激光共聚焦显微镜，标记SP-C阳性肺泡Ⅱ型上皮细胞(AECⅡ)的位置，观察NF-κB和p53蛋白在肺泡上皮细胞中的表达情况。提取小鼠肺脏组织细胞总蛋白，以β-actin为内参，通过Western blot分析NF-κB和p53信号通路相关因子TLR4、TRAF6、NF-κB、p53、MDM2和CBP在蛋白水平上的变化。【结果】 在MTB感染小鼠4 d后，小鼠肺脏形态无明显变化，脾脏1/3尖部瘀血变黑；HE染色发现肺脏组织炎性细胞浸润。在小鼠肺脏上皮细胞中NF-κB与p53蛋白免疫荧光表达较空白对照组和阴性对照组增强。TLR4、NF-κB、p53、MDM2和CBP蛋白在雄性与雌性小鼠中都呈现出显著上调。【结论】当结核分枝杆菌感染小鼠时，小鼠肺脏上皮细胞通过NF-κB和p53信号通路活化来参与宿主抗结核分枝杆菌病感染的免疫调控作用。 |
| 关键词: 结核分枝杆菌（MTB） 肺脏上皮细胞 免疫调控 |
| DOI： |
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| 基金项目:国家自然科学基金项目（31560694）；宁夏高校科学研究项目（NGY2015052，NGY2016008） |
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| Regulation of MTB infection on NF-κB and p53 signaling pathways in lung epithelial cells of mice |
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BAI Guibin,WANG Yuan,YAN Chao,et al
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| Abstract: |
| 【Objective】This study investigated the role of p53 and NF-κB signaling pathways in the immune regulation of lung epithelial cells of mice infected with Mycobacterium tuberculosis (MTB).【Method】Thirty C57BL/6 Cnc mice (15 male and 15 female) were divided into 3 groups including blank control group,negative control group by intraperitoneal injection of normal saline and MTB infection group.The early MTB infected C57BL/6 mouse model was established by euthanizing mice 4 d after intraperitoneal injection of attenuated strain of Mycobacterium tuberculosis (bacillus calmette guérin,BCG).Lungs and spleens of mice were separated for morphological analysis.Lungs were also subjected to frozen ultrathin sections and HE staining was performed to analyze pathological changes.Using the immunofluorescence technique and confocal microscope,the position of alveolar type Ⅱ epithelial cells was identified with SP-C positive,and the expression of NF-κB and p53 protein in alveolar epithelial cells was also analyzed.The total protein of mice lung was extracted and the relative protein expressions of TLR4,TRAF6 and NF-κB in NF-κB signaling pathways and p53,MDM2 and CBP in p53 signaling pathways related proteins were analyzed by Western blot using β-actin as an internal reference.【Result】Four days after BCG infection,there was no significant change in lung morphology,and 1/3 of spleen tip showed blood stasis syndrome.HE staining revealed inflammatory cell infiltration in lungs.The fluorescence expressions of NF-κB and p53 protein in lung epithelial cells were stronger than in control groups.The TLR4,NF-κB,p53,MDM2 and CBP proteins were significantly up-regulated in lungs of both male and female mice.【Conclusion】When infected with M. tuberculosis,NF-κB and p53 signaling pathways of mice were activated to participate in immune regulation of host against M.tuberculosis infection in lung epithelial cells. |
| Key words: Mycobacterium tuberculosis（MTB） lung epithelial cells immune regulation |
