骨髓间充质干细胞不同移植方法对急性心肌梗死心功能的改善作用比较

Comparison of different bone marrow mesenchymal cell transplantation methods for improving heart function after acute myocardial infarction

目的:观察不同方法移植骨髓间充质干细胞对心功能的影响,分析移植方法与心功能改善的关系。方法:实验于2004-02/2005-10在郑州大学医学院干细胞中心和机能中心完成。体外获取、培养大鼠骨髓间充质干细胞。结扎左冠状动脉前降支制备大鼠急性心肌梗死模型,结扎后观察前壁心肌颜色变苍白、收缩力减弱、心电图相应导联ST段弓背向上抬高,确定心肌梗死模型建立。将建模成功的大鼠分成4组,每组10只,2周后进行细胞移植。静脉对照组:尾静脉注射L-DMEM0.6mL;静脉移植组:尾静脉注射5溴脱氧尿嘧啶标记骨髓间充质干细胞悬液0.6mL;心外膜对照组:在大鼠心肌梗死区分8点注射L-DMEM0.6mL;心外膜移植组:在大鼠心肌梗死区分8点注射5溴脱氧尿嘧啶标记的骨髓间充质干细胞悬液0.6mL。移植4周后检测大鼠左室射血分数、短轴缩短率、血流动力学指标评价心功能,采用免疫组织化学检测大鼠心肌组织中骨髓间充质干细胞对心肌肌钙蛋白T的表达。结果:40只大鼠均进入结果分析。①与移植前比较,静脉对照组与心外膜对照组心脏功能逐渐恶化,左室射血分数及短轴缩短率降低。静脉移植组与心外膜移植组左室射血分数及短轴缩短率均较移植前升高,并且心外膜移植组高于静脉移植组[移植前:左室射血分数:(27.09±2.46)%,(26.62±2.31)%,短轴缩短率:(24.09±3.13)%,(24.52±3.01)%;移植后:左室射血分数:(35.12±2.68)%,(46.31±3.15)%,短轴缩短率:(28.32±3.68)%,(32.38±2.35)%,P<0.05]。与静脉移植组相比,心外膜移植组左心室收缩压、左室压力变化最大上升速率、左室压力变化最大下降速率升高、左室舒张末期压降低[静脉移植组:(105.27±5.56)mm Hg,(18.02±3.63)mm Hg,(4595±389)mm Hg/s,(3768±525)mm Hg/s;心外膜移植组:(123.89±9.64)mm Hg,(13.79±3.92)mm Hg,(4988±513)mm Hg/s,(4193±563)mm Hg/s,P<0.05]。②心外膜移植组和静脉移植组梗死心肌内均可见5溴脱氧尿嘧啶阳性移植细胞,对心肌肌钙蛋白T呈阳性表达。结论:心外膜移植细胞和静脉移植细胞对急性心肌梗死心功能均有改善作用,并且心外膜途径移植对急性心肌梗死心功能改善程度强于静脉移植途径。

AIM： To observe the effects of transplanted bone marrow mesenchymal cells （MSCs） on heart function and analyze the relationship between transplanting methods and the improvement of heart function. METHODS： The experiment was performed at the Stem Cell Center and Function Center, Medical College, Zhengzhou University from February 2004 to October 2005. Bone marrow MSCs were taken and cultured in vitro. Acute myocardial infarct rat model was set up after deligating anterior descending of left coronary artery. Myocardium of anterior wall became pale, contraction force decreased, and increased convex type of electrocardiogram leaded ST segment, which defined the establishment of myocardial infarction models. Rats with myocardial infarction ware divided into 4 groups, i0 rats in each group. Cells ware transplanted 2 week later. Vein control group： 0.6 mL L-DMEM was injected into caudal vein of each rat. Vein transplantation group： 0.6 mL 5- BrdU marked MSCs suspension was injected into the caudal vein of each rat. Epicardium control group; 0.6 mL L-DMEM was injected into 8 points in myocardial infarction area. Epicardium transplantation group： 0.6 mL 5- BrdU marked MSCs suspension was injected into 8 points in myocardial infarction area. The heart function was evaluated bY left ventricular ejection fraction （EF）, the fraction of shortening for short axis （FS）, and the indexes of blood dynamics 4 weeks after transplantation. The expression of cardiac troponin T （cTnT） in MSCs was detected using immunohistochemistry. RESULTS： Totally 40 rats were involved in the result analysis. ①Compared with the heart function before transplantation, it became worse after transplantation in both vein control group and epicardium control group. EF and FS of these 2 control groups decreased. EF and FS of both vein transplantation group and epicardium transplantation group ware higher than those before transplantation, and it was higher in the epicardium transplantation group than the vein transplantation group [before transplantation：EF： （27.09±2.46）%, （26.62±2.31）% ,FS, （24.09±3,13）%, （24.52±3.01）% ; after transplantation：EF： （35.12±2,68）%, （46,31 ±3.15）% ,FS： （28.32±3.68）%, （32.38±2.35）% ,P 〈 0.05]. Compared with those of vein transplantation group, left ventricular systole pressure （LVSP） and the maximal rate of isovolumetric contraction （＋dp/dtmax, -dp/dtmax） increased, but left ventricular end diastole pressure （LVEDP） decreased in epicrdium transplantation group, respectively. [vein transplantation group： （105.27±5.56） mm Hg, （18.02±3.63） mm Hg, （4 595± 389）mm Hg/s, （3 768±525） mm Hg/s;epicardium transplantation group： （123.89±9.64） mm Hg, （13.79±3,92） mm Hg, （4 988±513） mm Hg/s, （4 193±563） mm Hg/s,P 〈 0,05]. ②5-BrdU positive MSCs ware found in both vein transplantation group and epicardium transplantation group and expressed cTnT. CONCLUSION： Improvement of heart function is effected by epicardium transplantation and vein transplantation. Epicardium transplantation is better than vein transplantation for acute myocardial infarction.