血管紧张素Ⅱ1型受体在急性肺损伤小鼠肺核因子κB和激活蛋白1活化中的作用

Role of angiotensin Ⅱ type 1 receptor in activation of nuclear factor-κB and activator protein-1 in lung of mice with acute lung injury

目的 了解血管紧张素Ⅱ1型（AT1）受体在LPS诱导的急性肺损伤（ALI）小鼠肺脏NF-κB和激活蛋白1（AP-1）活化中的作用.方法 应用随机数字表法将88只BALB/c小鼠分为对照组8只、LPS组40只、LPS＋AT1受体拮抗剂ZD7155组40只.3组小鼠均行气管穿刺.LPS＋ZD7155组小鼠腹腔注射ZD7155（10 mg/kg）,对照组和LPS组小鼠腹腔注射等体积生理盐水.30 min后,将1 mg/mL LPS分别滴入LPS组和LPS＋ZD7155组小鼠气管中（2 mg/kg）,对照组小鼠以等体积生理盐水替代LPS经气管滴入.于滴注LPS后1、3、6、12、24 h,留取LPS组和LPS＋ZD7155组小鼠肺组织标本;对照组小鼠于滴注后24 h取肺组织标本.采用蛋白质印迹法检测肺组织AT1受体的表达,用凝胶电泳迁移率变化分析法检测肺组织NF-κB和AP-1活性.对各实验结果进行单因素方差分析.结果 LPS组小鼠各时相点肺组织AT1受体蛋白相对表达量较对照组（0.69±0.28）明显升高（F=9.356,P值均小于0.01）,6 h时达高峰（3.44±0.90）;LPS＋ZD7155组各时相点均低于LPS组（F=9.356,P值均小于0.01）.LPS组小鼠各时相点肺组织NF-κB活性较对照组（5.47±0.08）显著升高（P=26.443,P值均小于0.05）,3 h时达高峰（52.33±3.25）;LPS＋ZD7155组各时相点肺组织NF-κB活性均明显低于LPS组（F=26.443,P值均小于0.05）.LPS组小鼠各时相点肺组织AP-1活性较对照组（2.5±0.4）显著升高（F=34.685,P值均小于0.05）,其中6 h时达高峰（73.3±9.5）,LPS＋ZD7155组各时相点肺组织AP-1活性均明显低于LPS组（F=34.685,P值均小于0.05）.结论 AT1受体通过激活NF-κB和AP-1,参与LPS诱导的AL1发生.

Objective To explore the role of angiotensin Ⅱ type 1 （ATI） receptor in activation of nuclear factor-κB （ NF-κB） and activator protein-1 （ AP-1） in lung of mice with LPS-induced acute lung injury （ALI）. Methods Eighty-eight BABL/c mice were divided into control group （ n =8） , LPS group （ n =40） , and LPS ＋ AT1 receptor antagonist ZD7155 group （ n = 40） according to the random number table. Puncture of trachea was done in all mice. Mice in LPS ＋ ZD7155 group were intraperitoneally injected with 10 mg/kg ZD7155. Mice in LPS and control groups were intraperitoneally injected with normal saline in the same volume as that of ZD7155. Thirty minutes later, 1 mg/mL LPS was dripped into trachea of mice in LPS and LPS ＋ZD7155 groups （2 mg/kg）. Normal saline in the same volume as that of LPS was dripped into trachea of mice in control group. Lung tissue samples of mice in LPS and LPS ＋ ZD7155 groups were harvested at post dripping hour （PDH） 1 , 3 , 6, 12, and 24. Lung tissue sample of mice in control group was harvested at PDH 24. Expression of AT1 receptor was determined with Western blot. AP-1 and NF-κB activity in lung tissue was detected with electrophoretic mobility shift assay. Data were processed with one-way a-nalysis of variance. Results The relative expression amount of AT1 receptor protein in lung tissue of mice in LPS group at each time point was increased obviously as compared with that of mice in control group （0.69 ±0.28, F =9.356, with P values all below 0.01）, and it peaked at PDH 6 （3.44 ±0. 90） , while that of mice in LPS ＋ZD7155 group was less than that in LPS group at each time point （ F =9.356, with P values all below 0. 01）. NF-κB activity in mice lung was markedly increased in LPS group at each time point as compared with mice in control group （5.47 ± 0. 08, F = 26. 443 , with P values all below 0. 05 ） , and its peak value in LPS group was found at PDH 3 （52. 33 ± 3. 25）. While NF-κB activity in mice of LPS ＋ ZD7155 group was obviously lower than that in LPS group at each time point （ F =26.443, with P values all below 0. 05）. AP-1 activity in lung was enhanced significantly in LPS group at each time point as compared with that in control group （2.5 ±0.4, F =34.685, with P values all below 0.05） , and the activity peaked at PDH 6 （73. 3 ± 9. 5 ） in LPS group. The activity was obviously weaker in mice in LPS ＋ ZD7155 group as compared with that in LPS group at each time point （ F = 34. 685, with P values all below 0. 05）. Conclusions ATI receptor contributes to LPS-induced ALI through activating NF-κB and AP-1 in lung tissue.