A chronic mouse model of myocardial ischemia-reperfusion: essential in cytokine studies
A chronic mouse model of myocardial ischemia-reperfusion: essential in cytokine studies
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DOI：
10.1152/ajpheart.2000.278.4.h1049
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发表时间：
2000-04-01
影响因子：
4.8
通讯作者：
Entman, ML
中科院分区：
文献类型：
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作者：
Nossuli, TO;Lakshminarayanan, V;Entman, ML
缺血心肌的再灌注与反映细胞对损伤的反应的细胞因子级联反应有关。我们在小鼠中研究了这一级联反应，发现假手术动物的急性手术创伤掩盖了心肌缺血-再灌注(MI/R)期间细胞因子诱导的早期变化。因此，我们使用了一种新的植入性装置，允许闭合胸腔小鼠在内固定后的任何时间闭塞和再通左前降支。用核糖核酸酶保护法检测全心组织中IL-6和肿瘤坏死因子-α(TNF-α)mRNA的表达，并用荧光成像仪进行定量。术后3h，假手术组的IL-6m RNA水平高于对照组，而肿瘤坏死因子-α的m RNA水平直到1天后才开始升高。手术创伤导致I/R细胞因子诱导过度，反应差异较大。术后3d和1wk，假手术组的IL-6和TNF-αmRNA水平与幼稚心脏相当，而I/R诱导反应的差异较小。我们还发现，在所有恢复时间点(即血管内固定后3h、1、3和7d)，缺血1h和再灌流2h可显著增加IL-6和TNF-α的mRNA水平。此外，永久闭塞3h后1wk后未引起任何mRNA的增加，在一个急性准备的动物中引起了IL-6mRNA的显著上调。这项关于MI/R引起的早期细胞因子反应的研究强调了通过使用慢性闭胸小鼠制剂来消散急性外科创伤的必要性。
Reperfusion of the ischemic myocardium is associated with a cytokine cascade that reflects a cellular response to injury. We studied this cascade in the mouse and found that acute surgical trauma in sham-operated animals obscured early changes in cytokine induction that occur during myocardial ischemia-reperfusion (MI/R). Therefore, we utilized a new implantable device that allows occlusion and reperfusion of the left anterior descending coronary artery in a closed-chest mouse at any time after instrumentation. Induction of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha mRNA in the whole heart was examined by RNase protection assay and quantitated by Phosphor-Imager. At 3 h after instrumentation, levels of IL-6 mRNA in sham-operated animals increased above those of control naive hearts, whereas this increase did not occur until after 1 day for TNF-alpha mRNA. The surgical trauma led to exaggeration of I/R cytokine induction with greater variance in response. At 3 days and 1 wk after instrumentation, levels of both IL-6 and TNF-alpha mRNA in sham-operated animals were comparable to those of naive hearts and induction responses in I/R were much less variant. We also found that 1 h of ischemia and 2 h of reperfusion at all time points of recovery (i.e., 3 h and 1, 3, and 7 days after instrumentation) led to a significant increase in IL-6 and TNF-alpha mRNA levels. In addition, 3 h of permanent occlusion, which did not induce any mRNA increase after 1 wk postinstrumentation, caused marked upregulation of IL-6 mRNA in an acutely prepared animal. This study of early cytokine responses evoked by MI/R highlights the need for dissipation of acute surgical trauma by using a chronic, closed-chest mouse preparation.