Reduction of myocardial infarct size by doxycycline: A role for plasmin inhibition
Reduction of myocardial infarct size by doxycycline: A role for plasmin inhibition
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DOI：
10.1007/s11010-005-2540-3
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发表时间：
2005-02-01
影响因子：
4.3
通讯作者：
Villarreal, FJ
中科院分区：
文献类型：
--
作者：
Griffin, MO;Jinno, M;Villarreal, FJ
心肌缺血-再灌注（I/R）与基质金属蛋白酶（MMPs）和丝氨酸蛋白酶的激活有关。我们假设基质金属蛋白酶和丝氨酸蛋白酶纤溶酶的激活有助于I/R后的早期心肌细胞死亡，而多西环素（DOX）的广谱蛋白酶抑制剂可保护心肌细胞的活力。在实验前48小时开始每天用或不用DOX处理的大鼠进行30分钟的冠状动脉闭塞和2天的再灌注。DOX预处理使梗死面积减少37%。DOX减弱MMP-9和纤溶酶水平的增加，分别通过明胶酶谱法和免疫印迹法测定。通过髓过氧化物酶（MPO）活性评估，DOX未改变神经元外渗。为了检查MMP-9和纤溶酶对肌细胞损伤的贡献，在存在或不存在DOX的情况下，用83 kDa MMP-9或纤溶酶原处理新生大鼠心室肌细胞（NRVM）培养物48小时。MMP-9处理不影响肌细胞活力。纤溶酶原治疗导致纤溶酶活性增加，导致β（1）-整联蛋白丢失，NRVM脱离和细胞凋亡。DOX共处理抑制纤溶酶活性并保留NRVM附着，而与广谱MMP抑制剂GM 6001的共处理没有效果。这些结果表明，纤溶酶导致破坏的肌细胞附着和活力的MMP激活在体外和DOX的抑制纤溶酶可能会减少I/R诱导的心肌细胞死亡在体内通过抑制纤溶酶。
Myocardial ischemia-reperfusion (I/R) is associated with the activation of matrix metalloproteinases ( MMPs) and serine proteases. We hypothesized that activation of MMPs and the serine protease plasmin contribute to early cardiac myocyte death following I/R and that broad-spectrum protease inhibition with doxycycline (DOX) preserves myocyte viability. Rats treated daily with or without DOX beginning 48 h prior to experimentation were subjected to 30 min of coronary occlusion and 2 days of reperfusion. DOX pre-treatment reduced infarct size by 37%. DOX attenuated increases in MMP-9 and plasmin levels as determined by gelatin zymography and immunoblot, respectively. Neutrophil extravasation was unaltered by DOX as assessed by myeloperoxidase (MPO) activity. To examine the contribution of MMP-9 and plasmin to myocyte injury, cultures of neonatal rat ventricular myocytes (NRVMs) were treated for 48 h with 83 kDa MMP-9 or plasminogen in the presence or absence of DOX. MMP-9 treatment did not affect myocyte viability. Plasminogen treatment led to increased plasmin activity, resulting in loss of beta(1)-integrin, NRVM detachment and apoptosis. DOX co-treatment inhibited plasmin activity and preserved NRVM attachment, whereas co-treatment with the broad-spectrum MMP inhibitor GM6001 had no effect. These results indicate that plasmin causes disruption of myocyte attachment and viability independently of MMP activation in vitro and that inhibition of plasmin by DOX may reduce I/R-induced myocyte death in vivo through the inhibition of plasmin.