Waldow Thomas, Witt Wolfgang, Buzin Anne, Ulmer André, Matschke Klaus
Clinic for Cardiac Surgery, University Hospital Dresden, Dresden, Germany.
J Surg Res. 2009 Apr;152(2):198-208. doi: 10.1016/j.jss.2008.03.014. Epub 2008 Apr 9.
Pulmonary ischemia/reperfusion (I/R) injury is associated with degradation of structural proteins. Preconditioning by short-term inhalation of nitric oxide (NO) ameliorates some of the severe consequences of an I/R cycle. The aim of this study was to evaluate the effects of NO preconditioning on I/R-induced changes of matrix metalloproteinase (MMP) activity.
Left lung in situ ischemia in rats was maintained for 1 h, followed by reperfusion for 30 min or 4 h. In the NO group, animals inhaled NO (15 ppm) for 10 min directly before ischemia. Changes of expression or activity of MMPs (MMP-2, MMP-7, MMP-9, MMP-14) and of neutrophil elastase (NE) in bronchoalveolar lavage fluid (BALF), lung tissue, and arterial plasma were analyzed by zymography and Western blotting. Western blotting was also used to detect tissue inhibitors of matrix proteases, the extracellular metalloproteinase inducer (EMMPRIN or CD147), and endostatin, a proteolytic collagen fragment.
Ischemia resulted in an increase of lavagable MMP activity (12.3-fold MMP-2, 8.1-fold MMP-7) at 30 min reperfusion. The activity of MMP-9 and NE in lung tissue progressively increased with time, whereas MMP-14 and MMP-2 were constant. Inhalation of NO prevented the early increase of MMP-2 and MMP-7 in BALF, but the level of MMP-9 and NE in tissue was not affected. The expression of tissue inhibitors of matrix proteases and EMMPRIN did not respond to any treatment. The release of endostatin proceeded in parallel to the level of MMPs in BALF. Significant correlations between MMP-9 and myeloperoxidase in lung tissue and between MMP-2/MMP-7 and plasma protein extravasation were found.
The early rise of MMP-2 and MMP-7 in BALF resulted from plasma protein extravasation, whereas MMP-9 and NE were imported into lung tissue via leukocyte invasion. The effect of NO inhalation on lavagable MMPs was secondary to the sealing of the permeability barrier.
肺缺血/再灌注（I/R）损伤与结构蛋白降解有关。短期吸入一氧化氮（NO）进行预处理可改善I/R循环的一些严重后果。本研究的目的是评估NO预处理对I/R诱导的基质金属蛋白酶（MMP）活性变化的影响。
大鼠左肺原位缺血维持1小时，随后再灌注30分钟或4小时。在NO组中，动物在缺血前直接吸入NO（15 ppm）10分钟。通过酶谱分析和蛋白质印迹法分析支气管肺泡灌洗液（BALF）、肺组织和动脉血浆中MMP（MMP-2、MMP-7、MMP-9、MMP-14）和中性粒细胞弹性蛋白酶（NE）的表达或活性变化。蛋白质印迹法还用于检测基质蛋白酶的组织抑制剂、细胞外金属蛋白酶诱导剂（EMMPRIN或CD147）以及内皮抑素（一种蛋白水解胶原片段）。
缺血导致再灌注30分钟时可冲洗出的MMP活性增加（MMP-2增加12.3倍，MMP-7增加8.1倍）。肺组织中MMP-9和NE的活性随时间逐渐增加，而MMP-14和MMP-2保持不变。吸入NO可防止BALF中MMP-2和MMP-7的早期增加，但组织中MMP-9和NE的水平不受影响。基质蛋白酶组织抑制剂和EMMPRIN的表达对任何处理均无反应。内皮抑素的释放与BALF中MMP的水平平行。发现肺组织中MMP-9与髓过氧化物酶之间以及MMP-2/MMP-7与血浆蛋白外渗之间存在显著相关性。
BALF中MMP-2和MMP-7的早期升高是由于血浆蛋白外渗，而MMP-9和NE是通过白细胞浸润进入肺组织的。吸入NO对可冲洗出的MMP的影响是通透性屏障封闭的继发效应。
