内皮前体细胞自体移植促进缺血心肌血管的新生

Transplantation of endothelial progenitor cells enhances neovascularization following myocardial ischemia

目的:观察内皮前体细胞自体移植后能否促进血管新生、改善心肌灌注、进而改善心脏功能。方法:实验于2004-01/05在解放军总医院心内科实验室完成。①实验分组:雄性新西兰白兔32只,体质量3.0～3.5kg,随机分为治疗组和对照组,每组16只。②实验方法:治疗组自骨髓获取内皮前体细胞培养扩增。结扎动物冠状动脉前降支根部。心电图检测至少5个胸前导联出现ST段显著抬高作为模型制作成功标志。2.5g/L胰蛋白酶消化细胞,洗涤干净后5mL磷酸盐缓冲液悬浮细胞,结扎前降支2h后将细胞悬液从耳静脉注入动物体内,移植细胞数量为(9.8±2.9)×106个/只。对照组注射磷酸盐缓冲液5mL。饲养5周。③实验评估:分别行超声心动图检查和左心室压力曲线检测心脏功能和心肌组织的梗死情况以及通过免疫组织化学检测观察血管密度。结果:纳入新西兰白兔共32只,因前降支细小排除2只。对照组因心功能衰竭和腹泻各死亡1只。治疗组结扎前降支后突发室性心律失常死亡1只。最终27只进入实验。①体外培养的内皮前体细胞生长迅速,能够在2～3周达到预定移植细胞数量。②内皮前体细胞移植5周后,超声心动图检测显示治疗组动物心肌功能指数显著降低(P<0.01),左心室射血分数显著高于对照组(P<0.01),左心室舒张末压明显低于对照组(P<0.05),而等容收缩期左室压力最大上升速率显著升高(P<0.05)。③治疗组心肌梗死面积显著减小(P<0.01),而血管密度明显高于对照组(P<0.01)。④标记细胞主要位于梗死心肌组织,大部分整合至毛细血管中,参与血管新生。结论:内皮前体细胞自体移植能促进缺血心肌血管新生,有效改善缺血心肌的灌注,进而改善心脏功能。

AIM： To investigate whether the transplantation of endothelial progenitor cells can improve heart function by promoting angiogenesis and improving myocardial perfusion. METHODS： The experiment was carried out in the laboratory of Department of Cardiology, PLA General Hospital from January to May 2004. Thirty-two male New Zealand white rabbits （3.0-3.5 kg） were randomly divided into cell transplantation group （n =16） and control group （n =16）. （1） Mononuclear cells were isolated from bone marrow and cultured. （2）The roots of anterior descending coronary of rabbits were ligated. The animal models with ST segment elevation of more than 5 precordial leads measured by electrocardiogram were regarded as successfully established. Two hours after ligation, autologous endothelial progenitor cells or phosphate buffer solution （PBS） was transfused intravenously with cell number of （9.8±2.9）×10^8 every animal. The control group was injected with 5 mL PBS. （3）Five weeks later, cardiac function and the infarction size were evaluated by echocardiography and left ventricular pressure measurement. The vascular density was immunohistochemically studied. RESULTS： Among the 32 rabbits, 2 ones with stenotic anterior descending branch were excluded, 2 of the control group died of heart function failure and diarrhea; 1 of the treatment group died of sudden ventricular arrhythmia after ligation of anterior descending coronary. Finally, 27 rabbits were involved in the result analysis. （1）The cells cultured in vitro grew rapidly, and reached the expected number in 2 to 3 weeks. （2）Five weeks after transplantation, the ultrasonic cardiogram showed that the myocardial performance index of the treatment group was significantly decreased （P 〈 0.01 ）, left ventricular ejection fraction was higher than the control group （P 〈 0.01 ）, left ventricular end-diastolic pressure was obviously lower than the control group （P 〈 0.05）, while the ＋dp/dt max was significantly increased （P 〈 0.05）. （3） The infarction size of implanted group was significantly decreased （P 〈 0.01）, while the vascular density was significantly higher than the control group （P 〈 0.01）. （4）Most of labeled cells homed to ischemic myocardium tissues and incorporated into capillary wall. CONCLUSION： Autotransplantation of endothelial progenitor cells can improve the heart function by promoting angiogenesis and improving cardiac perfusion.