弹性蛋白酶加重急性中耳炎的炎症应答和中耳组织损伤  

Elastase exacerbates inflammatory response and tissue damage in acute otitis media

作　　者：马毓蓉 范芳梅 王子萌[1] 王维[1] 董益麟 何纤 张欣欣 何於娟[1] 

机构地区：[1]重庆医科大学检验医学院临床检验诊断学教育部重点实验室,400016

出　　处：《免疫学杂志》2018年第1期34-40,共7页Immunological Journal

基　　金：国家自然科学基金(csfc81373151)

摘　　要：目的初步探讨中性粒细胞弹性蛋白酶(neutrophil elastase,NE)在急性中耳炎模型中对细菌清除和组织损伤的作用。方法采用鼓膜穿刺法接种肺炎链球菌6B,构建C57BL/6小鼠急性中耳炎模型,腹腔注射特异性NE抑制剂检测NE在中耳炎中的作用。分别于建模后第1、3、5天处死小鼠,分离中耳组织制备石蜡切片,HE染色观察小鼠中耳上皮组织损伤程度,同时收集中耳灌洗液(MELF)检测NE活性、细菌载量、炎症细胞数量、损伤标志物和炎症因子的变化。结果与PBS对照组比较,肺炎链球菌处理组NE活性明显升高,且在第3天达峰值。与对照组比较,NE抑制剂处理组MELF中总蛋白含量、乳酸脱氢酶活性、肿瘤坏死因子(TNF-α)和白细胞介素1β(IL-1β)表达水平明显下调,炎症反应及中耳组织损伤明显减轻,但细菌载量无显著差异。结论在肺炎链球菌中耳炎模型中,NE发挥了促进炎症应答,加重中耳组织损伤的作用,但不参与细菌的清除。To study the role of neutrophil elastase （NE） in the sterilization process and tissue injury, we developed a mouse model of acute otitis media （AOM） by direct transtympanic inoculation with Streptococcus pneumoniae （S. pn） and intraperitoneal injection of NE specific inhibitors. We collected the middle ear tissues for histological examination and the middle ear lavage fluid （MELF） for NE enzyme activity detection, S. pn load determination, inflammatory cells quantification and cytokines measurement at day 1, 3, 5 after inoculation, respectively. Data showed that the activity of NE in MELF supernatant significantly increased and peaked at day 3 in S. pn infected mice, as compared with the PBS group. The levels of TP, LDH, TNF-α and IL-1β in MELF decreased after Sivelestat treatment, a NE specific inhibitor, while the S. pn load had no significant difference compared with control group. In summary, our study demonstrats that NE can enhance inflammatory response and aggravate tissue damage, but do not involve in bacterial clearance during S. pn AOM.

关 键 词：急性中耳炎 肺炎链球菌 中性粒细胞 弹性蛋白酶 

分 类 号：R392.12[医药卫生—免疫学]