BACKGROUND Although early reperfusion is the most desirable intervention after ischemic myocardial insult, it may add to damage through oxidative stress. OBJECTIVES This study investigated the cardioprotective effects of a single intravenous dose of heat shock protein-72 (HSP72) coupled to a single-chain variable fragment (Fv) of monoclonal antibody 3E10 (3E10Fv) in a rabbit ischemia-reperfusion model. The Fv facilitates rapid transport of HSP72 into cells, even with intact membranes. METHODS A left coronary artery occlusion (40 min) reperfusion (3 h) model was used in 31 rabbits. Of these, 12 rabbits received the fusion protein (Fv-HSP72) intravenously. The remaining 19 control rabbits received a molar equivalent of 3E10Fv alone (n = 6), HSP72 alone (n = 6), or phosphate-buffered saline (n = 7). Serial echocardiographic examinations were performed to assess left ventricular function before and after reperfusion. Micro-single-photon emission computed tomography imaging of 99mTc-labeled annexin-V was performed with micro-computed tomography scanning to characterize apoptotic damage in vivo, followed by gamma counting of the excised myocardial specimens to quantify cell death. Histopathological characterization of the myocardial tissue and sequential cardiac troponin I measurements were also undertaken. RESULTS Myocardial annexin-V uptake was 43% lower in the area at risk (p = 0.0003) in Fv-HSP72-treated rabbits compared with control animals receiving HSP72 or 3E10Fv alone. During reperfusion, troponin I release was 42% lower and the echocardiographic left ventricular ejection fraction 27% higher in the Fv-HSP72-treated group compared with control animals. Histopathological analyses confirmed penetration of 3E10Fv-containing molecules into cardiomyocytes in vivo, and treatment with Fv-HSP72 showed fewer apoptotic nuclei compared with control rabbits. CONCLUSIONS Single-dose administration of Fv-HSP72 fusion protein at the time of reperfusion reduced myocardial apoptosis by almost one-half and improved left ventricular functional recovery after myocardial ischemia-reperfusion injury in rabbits. It might have potential to serve as an adjunct to early reperfusion in the management of myocardial infarction.

中文翻译：

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HSP72 给药对缺血再灌注损伤的心脏保护作用

背景虽然早期再灌注是缺血性心肌损伤后最理想的干预措施，但它可能会通过氧化应激增加损伤。目的 本研究在兔缺血再灌注模型中研究了单次静脉注射热休克蛋白 72 (HSP72) 与单克隆抗体 3E10 (3E10Fv) 的单链可变片段 (Fv) 的心脏保护作用。Fv 促进 HSP72 快速转运到细胞中，即使细胞膜完整。方法 31 只兔采用左冠状动脉闭塞（40 分钟）再灌注（3 小时）模型。其中，12 只兔子接受了融合蛋白 (Fv-HSP72) 静脉注射。其余 19 只对照兔接受摩尔当量的 3E10Fv 单独（n = 6）、HSP72 单独（n = 6）或磷酸盐缓冲盐水（n = 7）。进行系列超声心动图检查以评估再灌注前后的左心室功能。99mTc 标记的膜联蛋白-V 的微单光子发射计算机断层扫描成像通过微计算机断层扫描来表征 体内 凋亡损伤，然后对切除的心肌标本进行伽马计数以量化细胞死亡。还进行了心肌组织的组织病理学表征和连续的心肌肌钙蛋白 I 测量。结果 与单独接受 HSP72 或 3E10Fv 的对照动物相比，接受 Fv-HSP72 治疗的兔子在风险区域 (p = 0.0003) 的心肌膜联蛋白-V 摄取降低了 43%。在再灌注过程中，与对照动物相比，Fv-HSP72 治疗组的肌钙蛋白 I 释放降低 42%，超声心动图左心室射血分数升高 27%。组织病理学分析证实了含有 3E10Fv 的分子在体内渗透到心肌细胞中，与对照兔相比，用 Fv-HSP72 处理显示出更少的凋亡细胞核。结论 再灌注时单剂量给予 Fv-HSP72 融合蛋白可使家兔心肌缺血再灌注损伤后心肌细胞凋亡减少近一半，并改善左心室功能恢复。它可能有可能作为早期再灌注治疗心肌梗死的辅助手段。与对照兔相比，用 Fv-HSP72 处理显示出更少的凋亡细胞核。结论 再灌注时单剂量给予 Fv-HSP72 融合蛋白可使家兔心肌缺血再灌注损伤后心肌细胞凋亡减少近一半，并改善左心室功能恢复。它可能有可能作为早期再灌注治疗心肌梗死的辅助手段。与对照兔相比，用 Fv-HSP72 处理显示出更少的凋亡细胞核。结论 再灌注时单剂量给予 Fv-HSP72 融合蛋白可使家兔心肌缺血再灌注损伤后心肌细胞凋亡减少近一半，并改善左心室功能恢复。它可能有可能作为早期再灌注治疗心肌梗死的辅助手段。