大鼠急性肺损伤过程中STAT-3的活化对caspase-3表达的影响

目的 探讨大鼠急性肺损伤（ALI）过程中信号转导和转录活化因子-3（STAT-3）的活化对caspase-3表达的影响.方法 60只成年雄性SD大鼠随机分为4组：对照组（n=6）,脂多糖组（LPS组,n=24）,酪氨酸蛋白激酶（JAK）抑制剂 AG490组（n=6,AG490用0.4%二甲亚砜溶解）,AG490＋LPS组（n=24）;LPS、AG490＋LPS组在注射LPS后1、2、4、6 h又被分为4个亚组（每组n=6）.分别采用Western blotting检测各组大鼠肺组织中磷酸化STAT-3（pSTAT-3）的表达并采用免疫组织化学法测定caspase-3的表达情况.结果 注射LPS1、2、4、6 h后STAT-3被明显活化（P〈0.05）,而相对应的AG490＋LPS组中STAT-3活性较LPS组减弱（P〈0.05）.同时LPS组中caspase-3表达较相应的AG490＋LPS组明显减少（P〈0.01）.结论 大鼠ALI过程中STAT-3通路的激活可减低caspase-3的表达.

The impact of STAT-3 activation on caspase-3 expression in rats with acute lung injury

Objective To investigate whether the activation of STAT - 3 has an effect on the expression of caspase -3 in rats with acute lung injury（ALI）. Methods Sixty healthy SD rats were randomized into 4 groups： control group （ normal saline, n = 6） , lipopolysaccharide （ LPS group, n = 24 ） , protein tyrosine kinase （JAK） inhibitor AG490 group （ STAT - 3 specific inhibitor, AG490 dissolved with 13. 4% DMSO, n = 6 ）, AG490 ＋ LPS group （ n = 24 ）. LPS and AG490 ＋LPS groups were subjected into 1 h, 2 h, 4 h and 6 b time/Joint subgroup （n =6 each） after LPS administration, phosphorylation of STAT - 3 （ pSTAT - 3） expression was determined using Western blotting, expression of caspase -3 was assessed using immunohistochemistry. Results After injection of LPS 1 h, 2 h, 4 h, 6 h, the activation of STAT - 3 was significantly increased （ P 〈 0.05 ）, while the corresponding AG490 ＋ LPS group, STAT - 3 activity decreased compared with LPS group （P 〈 0.05 ）. LPS group, while the expression of caspase - 3 compared with the corresponding AG490 ＋ LPS group was significantly reduced （P 〈 0.01 ）. Conclusion The activation of STAT - 3 pathway in ALI may cause descrease in caspase- 3 expression.