骨髓间充质干细胞移植对心肌梗死后心功能的影响

Effect of mesenchymai stem cells transplantation on heart function after acute myocardial infarction

目的 探讨移植同种异体骨髓间充质干细胞（MSCs）是否具有改善家兔心肌梗死后心功能、缩小梗死面积的作用以及两者间的相关关系。方法 将24只大白兔随机分为急性心肌梗死（AMI）组和MSCs组,每组12只。采用局部注射法,将5-溴脱氧尿核苷（BrdU）标记的MSCs移植到兔梗死心肌边缘带和中心区。通过超声心动图测定两组手术前和术后6周心功能指标。取心脏标本用免疫组化法鉴定植入细胞,病理组织学测定梗死面积。分析心功能与梗死面积的关系。结果 MSCs组梗死心肌边缘带和中心区可见BrdU阳性细胞,AMI组未见BrdU阳性细胞。与AMI组比较,MSCs组术后6周左室舒张末期内径（LVEDD）、左室收缩末期内径（LVESD）均明显缩小（P均〈0.05）,左室射血分数（LVEF）、短轴缩短率（ΔFS%）明显增大（P均〈0.05）,组织学测量梗死面积明显缩小（P〈0.05）。两组LVEF与梗死面积均成显著负相关（P均〈0.01）。结论 MSCs移植可能通过缩小心肌梗死面积改善心功能,可用于心肌梗死的治疗。

Objective To investigate whether mesenchymal stem cells （MSCs） transplantation after acute myocardial infarction （AMI） can improve heart function and decrease infarct size in rabbits and their correlation. Methods Twenty- four rabbits were randomly derided into AMI group and MSCs group, each n=12. Exogenous MSCs labeled with bromodeoxyuridine （BrdU） were injected into the border and central area of the ischemic myocardium. Heart function was assessed with echocardiography before transplantation of MSCs and in 6 th week after the transplantation. Surviving MSCs in infarcted myocardium were identified by immunohistochemistry. Infarct size was measured histologically. Correlation of heart function and infarctsize were analysed. Results Immunohistochemical stain revealed that BrdU -positive cells were seen in the infarcted myocardium in MSCs group but not in AMI group. Transplantation of MSCs was associated with a significant diminution of left ventricular end-diastolic dimension （LVEDD）, and left ventricular end-systolic dimension （LVESD, both P〈 0.05）, and left ventricular ejection fraction （LVEF） and fractional shortening （△FS%） increased （both P〈0. 05） as compared with AMI group. Infarct size as measured histologically was significant smaller in MSCs group than AMI group （P〈0.05）. There were negative correlations between LVEF and infarct size in two groups（both P〈0. 01）. Conclusion Exogenous MSCs transplantation can improve heart function by decreasing infarct size and therefore it might be beneficial in the treatment of AMI .