摘要
目的检测大鼠β防御素(ratβ-defensin,rBD)在分泌性中耳炎大鼠咽鼓管鼓室的表达,探讨β防御素在分泌性中耳炎发病机制中的作用。方法排除中耳感染的清洁级SD大鼠48只,随机分为4组,前3组36只行颈部切口经右侧听泡注入脂多糖(lipopolysaccharide,LPS)溶液(1mg/mL)30μL制作分泌性中耳炎动物模型,造模后分别于第1、3、7天断头取咽鼓管鼓室黏膜;对照组12只右侧听泡注入生理盐水30μL,左侧听泡作为正常组,3d后断头取咽鼓管鼓室黏膜。逆转录聚合酶链反应(RT-PCR)检测咽鼓管鼓室rBD-1mRNA和rBD-2mRNA的表达。结果正常大鼠咽鼓管鼓室存在rBD-1和rBD-2的表达,且rBD-1的表达较rBD-2强,差异有统计学意义;造模后第1、3、7天,rBD-1表达变化不明显;rBD-2则在造模后第1、3天明显增加,差异有统计学意义,第7天渐回复到正常水平。结论在大鼠,rBD-1可能参与正常咽鼓管鼓室的防御功能,造模后rBD-2的表达增加可能与病原体入侵后的清除相关。
Objective To compare the expression of β-defensin in normal rat tubotympanum mucosa with that in the rat model of otitis media （OME） with effusion induced by lipopolysaccharide （ LPS）,and to clarify the role of innate antimicrobial peptides in the pathogenesis of this disease. Methods A total of 48 Sprague-Dawley rats （200-250 g）,free of middle ear infection,were used in the current experiment. The bulla was exposed by neck approach. 30 μL LPS solution （1 mg/mL） was injected into the right bulla in 36 rats,30 μL physiological saline was injected into the right bulla in another 12 rats （control group）,the left bulla was intact to be normal group. The tubotympanum mucosa was obtained quickly after decapitation in 12 rats of the control group and 36 rats inoculated by LPS at 1,3,7 days （ 12 rats in each sub-group）. Reverse transcription polymerase chain reaction（ RT-PCR） was performed to detect the expression of rBD1 mRNA and rBD2 mRNA. Results Both rBD-1 and rBD-2 mRNA were detected in normal rat tubotympanum mucosa and the expression of rBD-1 mRNA was significantly higher than rBD-2 （ P〈0. 01）. rBD-2 mRNA increased dramatically in the inflammatory mucosa （ P〈0. 01） whereas rBD-1 mRNA did not show significant augmentation. The up-regulation of rBD-2 gene was notable in the 1-and 3-day groups and declined to normal in the 7-day group. Conclusion Our findings indicate that rBD-1 may be a part of defense system in the normal rat middle ear,and the induced expression of rBD-2 is related to the clearance of invading pathogens.
出处
《中国实验动物学报》
CAS
CSCD
2010年第4期322-325,I0006,共5页
Acta Laboratorium Animalis Scientia Sinica
