经冠状动脉移植自体骨髓基质干细胞改善成年心肌梗死犬的心功能

Improvement of heart function with the transplantation of autologous bone marrow stroma stem cells via coronary artery in adult canines with myocardial infarction

目的:观察经冠状动脉注射成年犬自体骨髓基质干细胞对梗死后心功能的影响。方法:本实验于2001-05/2002-04在解放军第二军医大学附属长征医院心内科实验室完成。选用成年犬8只,随机分为细胞移植组5只,对照组3只。结扎犬冠状动脉前降支制备心肌梗死模型;细胞移植组将体外培养、诱导的自体骨髓基质干细胞标记后在心肌梗死后4周经冠状动脉植入心脏;对照组植入等量培养基。胸内心脏超声检查测定左冠状动脉血流阻断前,再灌注后30min及移植后4周左心室射血分数;胸外心脏超声检查测定左冠状动脉血流阻断前、移植前、移植后4周左心室射血分数。用成组t检验和随机区组方差分析完成统计学分析。结果:进入结果分析犬8只。①植入的骨髓基质干细胞在移植犬心肌组织内存活情况:细胞移植组免疫组织化学检查结蛋白及肌钙蛋白I染色阳性,表示已生成心肌样细胞。对照组心脏标本中可见瘢痕组织;心肌细胞结蛋白染色阴性,肌钙蛋白I染色阳性。②移植犬左室功能的左室射血分数:经胸外心脏彩色多普勒超声检查提示,细胞移植组细胞移植前明显低于血流阻断前和移植后4周犤(54.86±7.12)%,(61.78±5.37)%,(61.74±2.93)%,P<0.01犦;细胞移植组细胞移植后4周接近血流阻断前(P>0.05);对照组移植后4周和移植前明显低于血流阻断前(P<0.01)。③移植犬左室功能的左室射血分数:经胸内心脏彩色多普勒超声检查反映,细胞移植组再灌注后30min明显低于血流阻断前和移植后4周犤(49.98±6.79)%;(61.56±3.71)%,(64.56±5.27)%,P<0.01犦。移植后4周明显高于血流阻断前(P<0.05)。对照组移植后4周和再灌注后30min明显低于血流阻断前(P<0.05,0.01)。结论:成年心肌梗死犬自体骨髓基质干细胞经冠状动脉移植后,在心肌组织内存活并分化为肌源性细胞使左心室功能改善。

AIM:To observe the effect of transplantation of autologous bone marrow stroma stem cells into myocardium of adult canine via coronary artery on heart function after myocardial infarction. METHODS:This experiment was completed at Cardiological Laboratory of Changzheng Hospital, Second Military Medical University of Chinese PLA from May 2001 to April 2002. Eight adult canines were randomly divided into cell transplantation group (n=5) and control group (n=3). Anterior descending coronary arteries of adult canines were ligated to establish the models of myocardial infarction. Autologous bone marrow stroma stem cells induced and cultured in vitro were labeled and transplanted into myocardium via coronary artery 4 weeks after myocardial infarction in the cell transplantation group, and the same volume of culture media was transplanted into those in the control group. Ejection fraction of left ventricle was measured with intra-thorax echocardiogram before the blocking of left coronary arterial blood, 30 minutes after reperfusion and 4 weeks after cell transplantation. Extra-thorax echocardiogram was used to measure the ejection fraction before the blocking of left coronary arterial blood, before cell transplantation and 4 weeks after cell transplantation. Statistical analysis was completed with grouping t test and random analysis of variance. RESULTS: Eight canines entered the final results. ①Survival condition of bone marrow stroma stem cells into myocardium implanted into canines' myocardial tissues: In cell transplantation group, desmin and Troponin I positive stain were tested with immunohistochemistry, the results showed that the myocardial cell was producted. Scar tissue was seen in the control group, and desmin was negative and Troponin I was positive in cardiomyocytes. ②Left functional left ventricular ejection fraction of transplanted canines: Extra-echocardiogram examinations showed that left ventricular ejection fraction in cell transplantation group was lower before cell transplantation than that before blood blocking and 4 weeks after cell transplantation[(54.86±7.12)%, (61.78±5.37)%, (61.74±2.93)%, respectively, P< 0.01]. Left ventricular ejection fraction of 4 weeks after cell transplantation in cell transplantation group was close to that before blood blocking (P >0.05). Left ventricular ejection fraction of 4 weeks after and before cell transplantation in control group was significantly lower than that before blood blocking (P< 0.01). ③Left functional left ventricular ejection fraction of transplanted canines: Intra-echocardiogram examinations showed that left ventricular ejection fraction of 30 minutes after reperfusion was significantly lower than that before blood blocking and 4 weeks after cell transplantation[(49.98±6.79)%; (61.56±3.71)%, (64.56±5.27)%, respectively, P< 0.01]. Left ventricular ejection fraction of 4 weeks after cell transplantation in cell transplantation group was significantly higher than that before blood blocking (P< 0.05). Left ventricular ejection fraction of 4 weeks after cell transplantation and 30 minutes after reperfusion in control group was significantly lower than that before blood blocking (P< 0.05, 0.01). CONCLUSION: Autologous bone marrow stroma stem cells of adult canine survive in myocardial tissues and differentiate into myogenic cells after the transplantation via coronary artery and the left ventricular function is improved gradually.