维生素D受体及cathelin相关抗菌肽在肺炎支原体感染小鼠肺组织中的动态表达及作用  

Function and Dynamic Expression of Vitamin D Receptor and Cathelin-related Antimicrobial Peptide in Lung of Mice Infected with Mycoplasma Pneumoniae

作　　者：王莉[1] 蔡栩栩[1] 张晗[1] 尚云晓[1] 李淼[1] 

机构地区：[1]中国医科大学附属盛京医院小儿呼吸内科,沈阳110004

出　　处：《中国医科大学学报》2013年第10期885-890,共6页Journal of China Medical University

基　　金：沈阳市科学技术计划(1081269-9-00)

摘　　要：目的建立肺炎支原体(MP)感染BALB/c小鼠模型,探讨感染后不同时间点(感染后3、7、14、21 d)肺组织中维生素D受体(VDR)和cathelin相关抗菌肽(CRAMP)的动态变化。方法64只小鼠随机分为MP感染3、7、14、21 d组和相应对照组(每组n=8),应用HE染色观察肺组织病理改变并采用PCR进行模型鉴定;免疫组化方法测定肺组织中VDR的表达;实时PCR测定肺组织中VDR mRNA的表达;Western blot检测肺组织中CRAMP的表达。结果 MP感染后小鼠肺组织呈间质性炎性改变,肺泡间隔增宽,大量淋巴细胞和巨噬细胞浸润在支气管、血管周围,肺泡内有渗出,且炎症程度于MP感染7 d表现最为严重。PCR检测支气管肺泡灌洗液中MP-DNA呈阳性表达,证明造模成功。免疫组化、实时PCR和Western blot结果显示VDR及CRAMP含量表达呈动态变化,在MP感染3 d出现一过性增加,MP感染7 d降低恢复正常,MP感染14和21 d再次增加,与对照组相比差异有统计学意义(P<0.05)。结论 VDR及CRAMP可能参与了MP感染的损伤和抗损伤过程;VDR及CRAMP在肺炎支原体感染中表达变化趋于一致,提示在MP肺部感染时可能通过VDR影响CRAMP的表达。Objective To establish a MP infection model with BALB/c mice,so as to study dynamic changes of the vitamin D receptor （VDR）,and cathelin-related antimicrobial peptide （CRAMP） in the lung tissue at different time points （3,7,14 and 21 days after infection）.Methods A total of 64 BALB / c mice were randomly divided into 3,7,14 and 21 days group after MP infection （n =8） and the corresponding control group （n =8）.Hematoxylin and eosin staining and PCR were used to detect the pathological changes in the lung tissue and model identification.Enzyme-linked immunosorbent immunohistochemical was used to measure the expression of VDR.Real-time quantitative PCR was used to measure the mRNA expression of VDR ; Western blot was adopted to determine the expression of CRAMP.Results The lung tissue from MP infection group showed interstitial inflammatory changes,widened alveolar septum,the infiltration of lymphocytes and macrophages in bronchial and perivascular,alveolar exudate,and the MP 7 d group showed the most significant pathological changes.MP-DNA PCR assay showed positive expression in BALF,which confirmed the success modeling.Protein and mRNA expression of VDR and protein expression of CRAMP indicated that increased on MP 3 d,back to normal on MP 7 d,and increased again on MP 14 d,21 d,the difference was statistically significant compared with the control group （P 〈 0.05）.Conclusion VDR and CRAMP may be involved in MP injury and anti-injury process; the changes of VDR and CRAMP expression are in the same trend after MP infection,suggesting that MP lung infection may affect the expression of CRAMP via VDR.

关 键 词：肺炎支原体 维生素D受体 CRAMP 固有免疫 小鼠 

分 类 号：R725.6[医药卫生—儿科]