经冠状动脉移植自体骨髓单个核细胞修复犬梗死心肌

Intracoronary autologous bone marrow mononuclear cell transplantation for treatment of canine myocardial infarction

背景:细胞移植治疗心肌梗死为重建受损心肌带来希望,但移植后的细胞分化以及细胞移植能否长期持久地改善心脏功能等问题均不明确。目的:观察骨髓单个核细胞经冠状动脉移植入犬梗死心肌后,在心肌组织的分布、分化情况以及对心功能的影响。设计、时间及地点:随机对照动物实验,于2007-07/2008-03在泰达国际心血管病医院完成。材料:成年杂种犬16只,随机分为细胞移植组10只、模型对照组6只。方法:细胞移植组于髂前上嵴或髂后上棘穿刺抽取骨髓,经Ficoll密度梯度离心法分离获取骨髓单个核细胞,行CM-DiI标记。两组犬均结扎冠状动脉前降支建立急性心肌梗死模型,于心肌梗死后2h,细胞移植组向心肌梗死区注射骨髓单个核细胞悬液1mL(3×107～1×108个细胞),模型对照组注射等量生理盐水。主要观察指标:血流动力学指标及超声心动图指标的变化,免疫荧光染色观察骨髓单个核细胞在心脏的迁移、分布及分化结果:与模型对照组比较,细胞移植后6周细胞移植组血流动力学指标左室舒张末压显著降低(P<0.01),心排出量明显升高(P<0.05);超声心动图指标左室收缩末容积、左室舒张末容积均得到显著改善(P<0.01),射血分数、每搏输出量亦明显改善(P<0.05)。自体骨髓单个核细胞经冠状动脉移植后,可分布于心肌梗死区及梗死周边区,并表达肌球蛋白重链、连接蛋白43。结论:自体骨髓单个核细胞经冠状动脉移植后可分化为心肌样细胞,改善急性心肌梗死后的心功能。

BACKGROUND： Cell transplantation for treating myocardial infarction offers a new promise of rebuilding the damaged myocardium. It is not clear if the transplanted cells can differentiate into cardiomyocytes and if this therapy can improve heart function in the long term. OBJECTIVE： To study distribution, differentiation and effects of bone marrow mononuclear cell （BM-MNC） transplantation on cardiac function through the coronary artery in canine infarcted myocardium. DESIGN, TIME AND SETTING： The randomized controlled animal study was performed at the TEDA International Cardiovascular Hospital from July 2007 to March 2008. MATERIALS： A total of 16 adult hybrid canines were randomly assigned into a cell transplantation group （n=10） and a model control group （n=6）. METHODS： Bone marrow was extracted from the anterior supervior iliac spine or the posterior superior iliac spine of canines of the cell transplantation group through puncture. BM-MNCs were isolated by the Ficoll density gradient isolation, and labeled with CM-DiI. Canines of both groups received anterior descending coronary ligation to establish models of acute myocardial infarction 2 hours following myocardial infarction, 1 mL BM-MNCs （3×10^7-1×10^8 cells） were injected into the infarct region in the cell transplantation group. Canines in the model control group were infused with an equal volume of saline. MAIN OUTCOME MEASURES： Changes in hemodynamics indices and echocardiography indices were measured. Migration, distribution and differentiation of BM-MNCs were observed using immunofluorescent staining. RESULTS： In contrast to the model control group, left ventricular end-diastolic pressure decreased significantly （P 〈 0.01）, cardiac output increased significantly （P 〈 0.05）; left ventricle end-systolic volume and left ventricle end-diastolic volume were significantly improved （P 〈 0.01 ）, and ejection fraction and stroke volume at 6 weeks after operation in cell transplantation group increased significantly （P 〈 0.05）. BM-MNCs was seen Jn the cardiac tissues of infarct and the border of infarct tissues following transplantation through the coronary artery. MHC and connexin-43 were positive in the implanted BM-MNCs. CONCLUSION： Autologous bone marrow mononuclear cells transplanted intracoronarily may differentiate into cardiac muscle cell-like cells and improve the cardiac function following acute myocardial infarction.