老龄大鼠PA肺部感染时CINC及MCP-1表达的动态变化  

Dynamic changes of CINC and MCP-1 expression in old rats with pulmonary infection of P. Aeruginosa

作　　者：文婕[1] 殷少军[1] 

机构地区：[1]同济大学附属第十人民医院老年医学科,上海200072

出　　处：《同济大学学报（医学版）》2012年第1期5-12,共8页Journal of Tongji University(Medical Science)

基　　金：上海市卫生局科研基金(2010082)

摘　　要：目的探讨老龄宿主并发铜绿假单胞菌(P.Aeruginosa,PA)肺部感染时肺组织局部炎症细胞浸润及中性粒细胞趋化物(cytokine-induced neutrophil chemoattractants,CINC)、单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)表达的动态变化及意义,进而探讨增龄对肺局部趋化因子表达情况的影响。方法清洁级SD大鼠(青年组/老年组)气管接种PA建立肺部感染模型,分别取不同时间段(0、2、6、9、12、24 h)肺组织、肺泡灌洗液及心脏采血,行细菌学检测、病理学检测、全血白细胞分类计数,并采用实时荧光定量-聚合酶链反应(real time-polymerase chain reaction,RT-PCR),从基因转录水平研究PA肺部感染大鼠模型肺组织中CINC、MCP-1的表达。结果成功建模后,(1)老年组较青年组一般表现严重;(2)肺组织病理检查:青年组病变局限,炎症反应明显,肺组织结构破坏相对轻微;老年组病变弥散,炎症反应较轻,肺组织水肿、出血较多(2～12 h明显),相应时间点,肺组织中PMN、单核/巨噬细胞数少于青年组(P<0.05,24 h单核/巨噬细胞浸润数量差别无统计学意义);(3)接种PA后,两组大鼠CINCmRNA、MCP-1mRNA表达均增加,老年组峰值滞后于青年组。结论增龄能够减弱肺局部CINC、MCP-1趋化因子基因表达,进而下调CINC、MCP-1诱导的中性粒细胞及单核/巨噬细胞聚集,后者可能是导致老龄肺炎危险性增高的原因之一。Objective To investigate the dynamic changes cytokine-induced neutrophil chemoattrac- tants （CINC） mRNA and monocyte chemoattractant protein-1 （MCP-1） mRNA expression in old rats with pulmonary infection of P. Aeruginosa （PA）. Methods Sixty-eight male SD rats were divided into two groups： old group and young group. PA pulmonary infection model was induced by inoculation of bacteria into rat trachea. Lung tissue, bronchoalveolar lavage fluid and blood samples were collected at 0 h, 2 h, 6 h, 9 h, 12 h and 24 h. The expression of CINC mRNA and MCP-1 mRNA were detected by RT-PCR method. Results The general condition and manifestation were serious in old rats with PA lung infection than in young rats. Pathological examinations demonstrated that in lung tissue of young rats the inflammatory reaction was predominant and lung tissue structure damage was relatively mild; in the old rats the lung lesions were dispersion, inflammatory reaction was lighter, lung tissue edema and bleeding existed and more marked at 2 - 12 h samples. The infiltration of mononuclear cells and macrophages in lung tissue of old group was less than that in young group （ P 〈 0.05 ）, but there was no difference between two groups at 24 h （ P 〉 0.05 ）. The expression of CINC mRNA and MCP-1 mRNA was increased after PA inoculation, but peak value of old group lagged behind the young group. Conclusion Aging can weaken the expression of CINC mRNA and MCP-1 mRNA in lung tissue, thus reduce the infiltration of neutrophil and monocyte-macrophages, which may lead to increased risk of pneumonia in elderly patient.

关 键 词：趋化因子 中性粒细胞趋化物 单核细胞趋化蛋白-1 肺部感染 

分 类 号：R378.14[医药卫生—病原生物学]