Université Lille Nord de France, EA 2693, Lille, France.
Cell Transplant. 2011;20(7):1087-97. doi: 10.3727/096368910X544924. Epub 2010 Nov 19.
Injection of autologous bone marrow cells into infarcted myocardium has been proposed to limit the deterioration of cardiac function following myocardial infarction (MI); unfortunately, the beneficial effects observed have been modest. One of the limiting factors is believed to be poor local survival of the injected cells, but the potential impact of apoptosis among the injected cells has yet to be assessed. Therefore, this study aimed to quantify the apoptosis rate in bone marrow mononuclear cells (BMMCs) prepared for cardiac therapy, and to analyze their effects in vitro on cardiomyoblast apoptosis and in vivo on cardiac function recovery following MI. Using rabbit BMMCs prepared by Ficoll gradient, apoptotic cells were detected via Annexin V (AnV) staining. The effects of depleting the apoptotic cell population by means of AnV magnetic beads was tested in vitro after coculture with cardiomyoblasts (H9c2 cells) and in vivo after cell injection into the infarcted area. Left ventricular ejection fraction and scar extent were assessed by echography and histology 2 months later. After Ficoll gradient isolation, 37.3% (33.4-37.9%) of BMMCs were found to be apoptotic (Apo(Base) BMMCs). AnV depletion decreased the proportion of apoptotic cells to 20% (17.6-32%) (Apo(Low) BMMCs). Rabbits treated in vivo with Apo(Low) BMMCs after MI presented with significantly improved left ventricular ejection fraction [41.4% (41.0-43.6%) vs. 34.6% (34.6-35.9%), p = 0.03), reduced scar extent [20.4% (17.9-24.3%) vs. 25.6% (17.9-27.9%), p = 0.057], and reduced rate of cardiomyocyte apoptosis compared to those treated with Apo(Base) BMMCs. H9c2 apoptosis was found to be higher after coculture with Apo(Base) than with Apo(Low) BMMCs [25.6% (22.6-29.6%) vs. 10.1% (6.6-12.6%), p = 0.03], a result partially reproduced by cocultures with microparticle-rich supernatants from BMMCs. The presence of apoptotic cells among BMMCs impairs the efficacy of cardiac cell therapy after MI, an effect possibly mediated by apoptotic microparticles.
将自体骨髓细胞注射到梗死的心肌中，被提议用于限制心肌梗死后心脏功能的恶化；不幸的是，观察到的有益效果是适度的。据信，其中一个限制因素是注射细胞的局部存活不良，但尚未评估注射细胞中的细胞凋亡的潜在影响。因此，本研究旨在定量分析用于心脏治疗的骨髓单核细胞（BMMC）中的细胞凋亡率，并分析其在体外对心肌细胞凋亡的影响，以及在体内对心肌梗死后心脏功能恢复的影响。使用通过 Ficoll 梯度分离的兔 BMMC，通过 Annexin V（AnV）染色检测凋亡细胞。通过 AnV 磁珠耗竭凋亡细胞群体，在与心肌细胞（H9c2 细胞）共培养后在体外进行测试，并在细胞注射到梗死区域后在体内进行测试。2 个月后通过超声心动图和组织学评估左心室射血分数和疤痕范围。通过 Ficoll 梯度分离后，发现 37.3%（33.4-37.9%）的 BMMC 处于凋亡状态（Apo(Base) BMMC）。AnV 耗竭将凋亡细胞的比例降低至 20%（17.6-32%）（Apo(Low) BMMC）。在 MI 后用 Apo(Low) BMMC 进行体内治疗的兔子，左心室射血分数明显提高[41.4%（41.0-43.6%）vs. 34.6%（34.6-35.9%），p=0.03）]，疤痕范围减小[20.4%（17.9-24.3%）vs. 25.6%（17.9-27.9%），p=0.057]，与用 Apo(Base) BMMC 治疗的兔子相比，心肌细胞凋亡率降低。与 Apo(Base) BMMC 共培养后，发现 H9c2 凋亡更高[25.6%（22.6-29.6%）vs. 10.1%（6.6-12.6%），p=0.03]，这一结果部分通过来自 BMMC 的富含微粒体的上清液共培养得到再现。BMMC 中凋亡细胞的存在会损害 MI 后心脏细胞治疗的疗效，这种作用可能是由凋亡微粒介导的。
