纤维蛋白沉积对老年急性肺损伤大鼠肺组织内皮细胞功能的影响

The effect of fibrin deposition on endothelial cell function in pulmonary tissue of aged rats with acute lung injury

目的探讨纤维蛋白沉积对不同鼠龄大鼠肺组织血管内皮细胞功能的影响。方法青年及老年大鼠均随机分为4组,对照组(NC)腹腔注射生理盐水;脂多糖组(L)腹腔注射脂多糖;氨甲环酸组(LT)注射脂多糖加氨甲环酸;尿激酶组(LTU)注射脂多糖及氨甲环酸加尿激酶。应用免疫组化分析纤维蛋白沉积;应用W estern b lot和Northern b lot分别检测肺组织血栓调节蛋白(TM)、细胞间黏附分子-1(ICAM-1)、纤溶酶原激活剂抑制物-1(PAI-1)的表达。结果(1)正常青年和老年大鼠肺组织内均无纤维蛋白沉积,脂多糖刺激后纤维蛋白沉积增多,加用氨甲环酸纤维蛋白沉积更加明显(P<0.01),应用尿激酶后纤维蛋白沉积明显减轻(P<0.05);老年大鼠L组、LT组和LTU组均比相同干预组的青年大鼠肺组织纤维蛋白沉积明显(P<0.05)。(2)青年和老年大鼠给与脂多糖刺激后,ICAM-1和PAI-1表达明显上调(P<0.05),TM表达显著下降(P<0.01);加用氨甲环酸后ICAM-1和PAI-1表达上调更加明显(P<0.01),TM几乎无表达;给予尿激酶处理后,ICAM-1和PAI-1表达与LT组比较明显下调(P<0.05),TM表达增多(P<0.05);老年大鼠L组、LT组和LTU组ⅠCAM-1和PAI-1的表达均较青年大鼠相同干预组显著增多(P<0.05),TM表达则显著减少。(3)经纤维蛋白沉积量校正后,老年大鼠肺组织ICAM-1和PAI-1的表达量仍显著高于青年大鼠(P<0.05)。结论增龄能够促进脂多糖诱导的急性肺损伤大鼠肺组织纤维蛋白沉积,增强纤维蛋白的内皮细胞损伤作用。

Objective To investigate the effect of fibrin deposition on endothelial cell function in pulmonary tissue of rats with different ages.Methods Both young and aged rats were randomly divided into normal control group(NC group,intraperitoneal injection(i.p.) saline),lipopolysaccharide(LPS) group(L group,i.p.LPS),tranexamic acid group(LT group,i.p.LPS and tranexamic acid),and urokinase group(LTU group,i.p.LPS,tranexamic acid and urokinase). Immunohistochemical staining was used to examine and analyze fibrin deposition; Western blot and northern blot analysis were employed to determine the expressions of thrombomodulin(TM),intercellular adhesion molecule-1(ICAM-1) and plasminogen activator inhibitor-1(PAI-1) pulmonary tissues.Results ①There were no fibrin depositions in lung of both normal young and aged rats.The fibrin depositions increased in L group,significantly increased in LT group(P<0.01) and significantly alleviated in LTU group(P<0.05).The fibrin depositions in L,LT and LTU group of aged rats were more obvious than those of corresponding groups of young rats(P<0.05).②The expressions of ICAM-1 and PAI-1 upregulated(P<0.05),those of TM significantly reduced(P<0.01) in L group;those of ICAM-1 and PAI-1 obviously upregulated(P<0.01),those of TM hardly expressed in LT group;the expressions of ICAM-1 and PAI-1 significantly down-regulated,those of TM up-regualted in LTU group than those in LT group(P<0.05).The expressions of ICAM-1 and PAI-1 in L,LT and LTU group of aged rats were more than those of corresponding groups of young rats(P<0.05) versus the expressions of TM.③After adjusted by the value of fibrin deposition,the expressions of ICAM-1 and PAI-1 in aged rats were significantly higher than those in young rats(P<0.05).Conclusions Aging could accelerate fibrin deposition in pulmonary tissue of LPS-induced rat model of acute lung injury,and promote the injury of endothelial cell function caused by fibrin deposition.