Department of Cardiology, Rostock University Medical Center, 18057 Rostock, Germany.
Department of Cardiac Surgery, Rostock University Medical Center, 18057 Rostock, Germany.
Cells. 2020 May 30;9(6):1358. doi: 10.3390/cells9061358.
Angiogenesis plays a central role in the healing process following acute myocardial infarction. The PET tracer [Ga]-NODAGA-RGD, which is a ligand for the αβ integrin, has been investigated for imaging angiogenesis in the process of healing myocardium in both animal and clinical studies. It´s value as a prognostic marker of functional outcome remains unclear. Therefore, the aim of this work was to establish [Ga]-NODAGA-RGD for imaging angiogenesis in the murine infarct model and evaluate the tracer as a predictor for cardiac remodeling in the context of cardiac stem cell therapy. [Ga]-NODAGA-RGD PET performed seven days after left anterior descending coronary artery (LAD) occlusion in 129S6 mice showed intense tracer accumulation within the infarct region. The specificity was shown in a sub-group of animals by application of the competitive inhibitor cilengitide prior to tracer injection in a subgroup of animals. Myocardial infarction (MI) significantly reduced cardiac function and resulted in pronounced left ventricular remodeling after three weeks, as measured by cardiac MRI in a separate group. Cardiac induced cells (CiC) that were derived from mESC injected intramyocardially in the therapy group significantly improved left ventricular ejection fraction (LVEF). Surprisingly, CiC transplantation resulted in significantly lower tracer accumulation seven days after MI induction. Accordingly, we successfully established the PET tracer [Ga]-NODAGA-RGD for the assessment of αβ integrin expression in the healing process after MI in the mouse model. Yet, our results indicate that the mere extent of angiogenesis following MI does not serve as a sufficient prognostic marker for functional outcome.
血管生成在急性心肌梗死后的愈合过程中起着核心作用。PET 示踪剂 [Ga]-NODAGA-RGD 是 αβ 整合素的配体,已在动物和临床研究中用于成像愈合心肌过程中的血管生成。它作为功能结局的预后标志物的价值仍不清楚。因此,本工作的目的是建立 [Ga]-NODAGA-RGD 用于成像小鼠梗死模型中的血管生成,并评估示踪剂作为心脏干细胞治疗中心脏重构的预测因子。在 129S6 小鼠左前降支(LAD)闭塞后 7 天进行 [Ga]-NODAGA-RGD PET 显示梗塞区域内有强烈的示踪剂积聚。通过在注射示踪剂前在亚组动物中应用竞争性抑制剂 cilengitide,在亚组动物中证明了其特异性。心肌梗死(MI)显著降低了心脏功能,并导致三周后左心室重构明显,这是在另一组动物中通过心脏 MRI 测量得出的。心脏诱导细胞(CiC)源自注射到治疗组心肌内的 mESC,显著改善了左心室射血分数(LVEF)。令人惊讶的是,CiC 移植导致 MI 诱导后 7 天示踪剂积聚显著降低。因此,我们成功地建立了用于评估 MI 后小鼠模型中愈合过程中 αβ 整合素表达的 PET 示踪剂 [Ga]-NODAGA-RGD。然而,我们的结果表明,MI 后血管生成的程度本身并不能作为功能结局的充分预后标志物。