移植心肌样细胞对心肌梗死后功能性室壁瘤大鼠心功能的影响

Effect of cardiomyocytes-like cells transplantation on cardiac function of rats with ventricular aneurysm after myocardial infarction

目的探讨心肌内注射心肌样细胞对心肌梗死（MI）后功能性室壁瘤大鼠心功能的影响。方法结扎大鼠冠状动脉前降支形成MI，4周后，用超声心动图检测并筛选形成功能性室壁瘤者，并随机分为两组，即移植组（n=10），在室壁瘤部位及周边点状注射5-氮杂胞苷（5-Aza）诱导骨髓间充质干细胞（MSCs）分化、并用4，6-二脒基-2-苯基吲哚（DAPI）标记的心肌样细胞（10^6-10^7个）；对照组（n=10）：注射生理盐水。另取10只健康大鼠作为假手术组，只开胸不做任何处理。4周后，用超声心动图和血流动力学方法测定功能性室壁瘤大鼠的心功能，在荧光显微镜下观察DAPI标记的移植细胞的存活情况。结果超声心动图的结果显示，对照组和移植组的左室舒张末内径（LVEDD）和左室收缩末内径（LVESD）均较假手术组增高（P〈0．01），而移植组较对照组有所降低[（8．749±0．091）、（5．109±0．171）VS（9．219±0．059）mm、（5．942±0．092）mm，P〈0．05]；对照组和移植组的短轴缩短率（△Fs）及左室射血分数（LVEF）均较假手术组明显降低（P〈0．01），移植组较对照组两者有所增高[（32．70±1．283）、（45．78±1．796）VS（22．80±0．593）％、（31．92±0．830）％，P〈0．05]。血流动力学检测结果显示，移植组、对照组和假手术组的左室舒缩压差（LVDP）和左室正负最大变化速率（±dp／dtmax），分别为（152．9±0．669）、（4109±33．86）、（-3579±49．09），（122．5±2．639）、（3823±73．50）、（-2828±60．96）和（183．6±2．348）mmHg、（6695±80．17）mmHg／s、（-6294±71．39）mmHg／s，假手术组优于对照组和移植组（P〈0．01），移植组优于对照组（P〈0．05）。在荧光显微镜下可以观察到移植组的心肌组织中有存活的标记细胞。结论移植心肌样细胞能显著改善MI后功能性室壁瘤大鼠的心功能，为治疗功能性室壁瘤提供-种新的治疗思路和为临床研究奠定基础。

AIM To observe the effect of cardiomyocytes-like cells induced from mesenchymal stem cells （MSCs） transplantation on the cardiac function of rats with functional ventricular aneurysm after myocardial infarction. METHODS Isolated MSCs from rats bone marrow were cultured in cell culture medium with 5-azacytidine （5-Aza） and labeled with 4,6-diamidino-2-phenylindole （DAPI）. Functional ventricular aneurysm model of rat was established by ligating the left enterior descending coronary artery and selected by ultrasonic cardiography （UCG） after 4 weeks. The rats with functional ventrieular aneurysm were divided into eardiomyocytes-like cells group and control group then cardiomyoeytes-like ceils （10^6- 10^7） or sodium chloride were injected at several different points into the broad area of ventrieular aneurysm. In addition, 10 SD rats served as sham operation group （ thoracotomy twice without ligation of coronary artery. Four weeks after transplantation, the cardiac function of the rats was measured by UCG and multichannel physiological recorder and the transplanted cardiomyocytes-like cells were detected by fluorescent micro- scope. RESULTS UCG showed that left ventricular end diastolic dimension （LVEDD） and left ventric- ular end systolic （LVESD） dimension in the three groups were （8. 749 ±0. 091 ）, （5. 109 ±0. 171 ）; （9.219±0.059）, （5.942 ±0.092） and （6.344 ±0.296） ram, （3. 116 ±0.275） ram, with sham operation group best （ P 〈 0.01 ） and cardiomyocytes-like cells group better than control group （ P 〈 0. 05）. Fractional shortening （GFS） and left ventrieular ejection fraction （LVEF） in the three groups were （32.70 ±1.283）, （45.78 ±- 1.796）; （22.80 ±0.593）, （31.92 ±0.830） and （54.90 ± 2. 742） %, （74. 12 ± 2. 760） %, with sham operation group highest （ P 〈 0.01 ） and cardiomyocytes-like cells group higher than control group （ P 〈 0.05 ）. Muhichannel physiological recorder showed that left ventricular developed pressure （LVDP） and （ ± dp/dtmax ） in the three groups were （ 152. 9 ±_ 0. 669 ）, （4 109±_33.86）, （-3579±49.09）; （122.5±2.639）, （3 823 ±73.50）, （ -2 828 ±_60.96） and （183.6 ±2. 348） mmHg, （6 695 ±80. 17） mmHg/s, （ -6 294 ±71.39） mmHg/s, with sham opera- tion group best（P 〈 0.01 ） and cardiomyocytes-like cells group better than control group （ P 〈 0. 05 ）. Labeled cardiomyocytes-like cells were found on the broad area of ventricular aneurysm in cardiomyo- cytes-like cells group. CONCLUSION Cardiomyocytes-like cells transplantation can improve the heart function of rat with functional ventricular aneurysm after myocardial infarction, provide a new therapeutic way and lay fundation for clinical reaserch.