摘要
目的探讨c—Jun氨基末端激酶（JNK）信号转导途径在哮喘气道重塑过程中的作用；IL-1β是否通过JNK信号途径参与哮喘气道重塑形成过程。方法SD大鼠随机分为对照组（C）和哮喘组（A），以卵白蛋白致敏和激发复制哮喘气道重塑模型，A组根据激发时间不同，分为4、8、12周组（分别为A4、A8、A12组），同时设立相应C组（分别为C4、C8、C12组）。电镜观察肺组织超微结构变化，图像分析技术测定支气管壁厚度（Wat）和平滑肌厚度（Warn）；EL／SA法测定血清、BALF中IL—1β浓度；免疫组化（IHC）检测肺内磷酸化JNK（P—JNK）及其下游物磷酸化c—Jun蛋白表达；Western Blot检测肺匀浆JNK磷酸化水平，对Wat、Wam与P—JNK蛋白平均吸光度值（mA）、P—JNK蛋白（mA）与血清、BALF IL-1β浓度进行直线相关分析。结果4、8、12周A组Wat、Warn均相应地高于4、8、12周C组（均P〈0．01），12周时，A组二者均高于4周、8周（均P〈0．01）；各哮喘组血清、BALF IL-1β浓度均高于同时期C组（均P〈0．01），A组BALF中IL-1β浓度，12周时，高于4周、8周（P〈0．05或P〈0．01），血清中IL-1β浓度，三者差异无统计学意义；P—JNK及其下游物P—c-Jun（mA值），各哮喘组均高于同时期C组（均P〈0．01），12周时，A组二者均高于4周、8周（均P〈0．01）；Western Blot检测P—JNK蛋白吸光度值（A值），各哮喘组均高于同时期C组（均P〈0．01），A组中12周高于4周（P〈0．01），与8周组差异无统计学意义（P〉0．05）；Wat、Warn与P—JNK（mA）均呈高度正相关（分别为r=0．823、r=0．818，均P〈0．01）；P—JNK mA与血清、BALF IL-1β浓度均呈高度正相关（分别为r=0．717、r=0．803，均P〈0．01）。结论P—JNK及其下游物P-c-Jun在哮喘大鼠气道重塑过程中表达增高，提示JNK信号通路在气道重塑进程中起重要作用；IL-1β可能部分通过激活JNK信号转导途径，参与哮喘气道重塑形成过程。
Objective To study the role of e-Jun N-terminal kinase （JNK） signal transduetion pathway in the course of asthma airway remodeling, to explore whether IL-1β participates in asthma airway remodeling mediated by JNK signal transduction pathway. Methods Totally 72 male Sprague-Dawlay rats （6-8 weeks old, weighing about 120 g） were randomly divided into control groups （36 rats） and asthma groups （36 rats）. The rats were sensitized for inducing asthma by intraperitoneal injection of ovalbumin and AL（OH） 3 and were repeatedly exposed to aerosolized ovalbumin for 4, 8, 12 weeks （A4, A8, or A12 group）, each had 12 rats, and correspondingly control rats were intraperitoneally injected with 0. 9% NaCl, then were repeatedly exposed to 0. 9% NaCl for 4, 8, 12 weeks （ CA, C8, or C12 group）, each had 12 rats. The ultrastructural changes of pulmonary tissues were observed by transmission electron microscope iTEM）. The total bronchial wall thickness （Wat） and the airway smooth muscle thickness （Warn） were measured by an image analysis system. The concentrations of IL-1β in serum and broncoalveolar lavage fluid （BALF） were tested by a ＂sandwich＂ ELISA. The protein expressions of P-JNK and P-c-Jun were detected by immunohistochemical technique. Lung tissue extracts were analyzed for phosphorylation of JNK by Western blotting. Linear correlation analysis showed the correlation between Wat and P-JNK protein, Wam and P-JNK protein, levels of IL-1β in serum and P-JNK protein, levels of IL-1β in BALF and P-JNK protein. Results In asthma groups, TEM showed alveolar septal proliferation and alveolus type Ⅱ epithelial cells swelling. Wat and Warn in all asthma groups were significantly higher than those in corresponding control groups （P〈0. 01, respectively ）, and compared with group A4 and group A8, War and Warn of group A12 significantly increased （P〈0. 01）. The concentrations of IL-1β in serum and BALF of asthma groups were all significantly higher than those of the corresponding control groups （ P 〈 0. 01, respectively ）, and compared with group A4 and group A8, the concentrations of IL-1β in BALF of group A12 significantly increased （P 〈0. 01 or P 〈 0. 05 ）, hut the levels of IL-1β in serum were not significantly different among them （P 〉0. 05）. Mean abserbance values （by immunohistochemistry） of P-JNK and P-c-Jan in asthma groups were significantly higher than those in corresponding control groups （P 〈0. 01, respectively）, and compared with group A4 and group A8, those of group A12 significantly increased （P 〈0. 01 or P 〈0. 05）. The absorbance （by Western Blot） of P-JNK in A4, A8, A12 group was significantly higher than that in C4, C8, C12 groups （ P 〈 0. 01, respectively）, and compared with group A4, that of P-JNK of A12 significantly increased （P〈0. 01）, and compared with group A8, there was no significant difference （P 〉 0. 05 ）. Strong positive correlations were found between War or Warn and P-JNK（ r = 0. 823 and r = 0. 818, P 〈0. 01, respectively, n =68） and between P-JNK and concentration of IL-1β in serum or BALF （r =0. 717 and r = 0. 803, P 〈 0. 01, respectively, n = 68 ） . Conclusions The expression of P-JNK and its downstream P-c-Jun in rats of asthma airway remodeling is increased, which implicates that JNK signal transduction pathway plays an important role in the course of asthma airway remodeling. IL-1β participates in asthma airway remodeling possibly partly through activating JNK signal transduction pathway.
出处
《中华儿科杂志》
CAS
CSCD
北大核心
2008年第7期535-539,共5页
Chinese Journal of Pediatrics
基金
国家自然科学基金资助项目（30271383）
