Fert-Bober Justyna, Leon Hernando, Sawicka Jolanta, Basran Rashpal S, Devon Richard M, Schulz Richard, Sawicki Grzegorz
Dept. of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada.
Basic Res Cardiol. 2008 Sep;103(5):431-43. doi: 10.1007/s00395-008-0727-y. Epub 2008 May 28.
Previous studies have shown that the disruption of the coronary endothelium and the increase in its permeability during ischemia-reperfusion (I/R), are linked to matrix metalloproteinase-2 (MMP-2) activity. Studies from our group have shown that during I/R, activity of MMP-2 in the coronary effluent increases and this increase is associated with cardiac dysfunction, which in turn, can be prevented by MMP inhibitors. Therefore, we hypothesize that inhibiting MMPs reduces the MMP-2 dependent disruption of the coronary endothelium and subsequent protein release during I/R.
Isolated rat hearts were perfused in the Langendorff mode at a constant pressure and subjected to 15, 20 or 30 min no-flow ischemia followed by 30 min of reperfusion. The MMP inhibitors, o-phenanthroline (Phen, 100 microM) or doxycycline (Doxy, 30 microM) an inhibitors of MMPs, were added to the perfusion solution 10 min before ischemia and for the first 10 min of reperfusion. The coronary effluents were collected during perfusion for protein analysis. Creatine kinase was measured as an index of cellular damage. Endothelial integrity was assessed by measuring coronary flow and by measuring the levels of serotransferrin and interstitial albumin in the coronary effluent. Additionally, damage to the endothelium was assessed histologically by light microscopy analysis of the cellular structure of the myocardium. MMP-2 activity was measured by zymography in hearts subjected to 15, 20 and 30 min of ischemia without reperfusion.
MMP-2 activity was increased in heart tissue at the end of ischemia and was correlated with duration of ischemia. The post-ischemia decrease in coronary flow, and the increase in the release of serotransferrin and albumin were attenuated by Phen. Edema (another indirect marker of endothelial damage) was observed in I/R heart and the edema was abolished in I/R heart treated with MMP inhibitors.
MMP inhibition not only reduces cardiac mechanical dysfunction but also reduces endothelial damage resulting from cardiac I/R injury.
先前的研究表明，缺血再灌注（I/R）期间冠状动脉内皮的破坏及其通透性的增加与基质金属蛋白酶-2（MMP-2）活性有关。我们小组的研究表明，在I/R期间，冠状动脉流出液中MMP-2的活性增加，这种增加与心脏功能障碍有关，而心脏功能障碍又可以通过MMP抑制剂来预防。因此，我们假设抑制MMPs可以减少I/R期间MMP-2依赖性的冠状动脉内皮破坏和随后的蛋白质释放。
将离体大鼠心脏在Langendorff模式下以恒定压力灌注，进行15、20或30分钟的无血流缺血，随后再灌注30分钟。在缺血前10分钟和再灌注的前10分钟，将MMP抑制剂邻菲罗啉（Phen，100 microM）或强力霉素（Doxy，30 microM）添加到灌注液中。在灌注过程中收集冠状动脉流出液进行蛋白质分析。测量肌酸激酶作为细胞损伤的指标。通过测量冠状动脉血流量以及冠状动脉流出液中血清转铁蛋白和间质白蛋白的水平来评估内皮完整性。此外，通过对心肌细胞结构进行光学显微镜分析，从组织学上评估内皮损伤情况。在经历15、20和30分钟缺血但未再灌注的心脏中，通过酶谱法测量MMP-2活性。
缺血结束时心脏组织中MMP-2活性增加，且与缺血持续时间相关。Phen减轻了缺血后冠状动脉血流量的减少以及血清转铁蛋白和白蛋白释放的增加。在I/R心脏中观察到水肿（内皮损伤的另一个间接指标），而用MMP抑制剂处理的I/R心脏中水肿消失。
抑制MMP不仅可减轻心脏机械功能障碍，还可减少心脏I/R损伤导致的内皮损伤。
