超声联合一氧化氮微泡介导间充质干细胞移植对心肌梗死大鼠心功能的影响

The effect of ultrasound and nitric oxide microbubbles-mediated mesenchymal stem cells transplantion therapy on cardiac function in rats with myocardial infarction

目的探讨超声联合一氧化氮（NO）微泡介导间充质干细胞（MSCs）移植对心肌梗死大鼠心功能的影响，并探讨其可能作用机制。 方法选用冠状动脉左前降支结扎法制作心肌梗死模型大鼠28只，采用随机数字表法将其分为对照组（经尾静脉注入磷酸盐缓冲液）、MSCs组（经尾静脉注入MSCs）、普通微泡组（经尾静脉注入普通微泡，同时给予超声干预，然后经尾静脉注入MSCs）及NO微泡组（经尾静脉注入NO微泡，同时给予超声干预，然后经尾静脉注入MSCs），每组7只。各组大鼠分别经治疗4周后行M型心功能彩超检查，计数比较各组大鼠缺血心肌局部平均毛细血管密度，采用蛋白免疫印迹法及实时PCR检测各组大鼠心肌局部血管内皮生长因子（VEGF）表达。 结果治疗4周后发现NO微泡组射血分数［（56.27±3.66）%］较普通微泡组［（51.31±3.22）%］、MSCs组［（45.81±3.37）%］及对照组［（43.66±4.79）%］均显著提高（P〈0.05）；NO微泡组心肌缺血区域平均毛细血管密度［（45.96±9.01）个/每高倍镜视野］较普通微泡组［（28.07±4.93）个/每高倍镜视野］、MSCs组［（21.41±5.27）个/每高倍镜视野］及对照组［（18.04±4.82）个/每高倍镜视野］均显著增加（P〈0.05）。NO微泡组VEGF相对表达量（0.67±0.024）较普通微泡组（0.54±0.011）、MSCs组（0.44±0.020）及对照组（0.12±0.009）均显著增强（P〈0.05）。 结论超声联合NO微泡介导MSCs移植治疗心肌梗死大鼠，能进一步提高模型大鼠心功能，其治疗机制可能与促进局部VEGF表达、加速梗死区域血管生成有关。

Objective To study the effect and possible mechanisms of mesenchymal stem cells （MSCs） transplantion therapy mediated by ultrasound in combination with nitric oxide （NO） microbubbles （MBs）on cardiac function in rats with myocardial infarction （MI）. Methods Twenty-eight rats with MI were randomly divided into the following groups by use of random digits table： phosphate buffered saline group （ injection of PBS into the tail vein） , MSCs group （injection of MSCs into the tail vein） , ultrasound ＋ MBs ＋ MSCs group （ultrasound interven- tion when injection of ordinary MBs into the tail vein followed by injection of MSCs） and ultrasound ＋ NO MBs ＋ MSCs group （ultrasound intervention when injecting NO-MBs into the tail vein followed by injection of MSCs） （n = 7, each group）. After four weeks, the left ventricular systolic function was evaluated with M-mode ultrasound for each group, capillaries density of myocardial ischemic area was counted in each group, and the expression of vascular endothelial growth factor （VEGF） was detected by Western blot and real time PCR. Results The ejection fraction （EF） of NO-MBs group was significantly higher than the other groups （ P 〈 0.05 ）. The number of capillaries in NO- MBs group was also much more than that in the other groups （P 〈 0.05）. The expression of VEGF in infarcted zone was much higher in the NO-MBs group than that in the other groups （ P 〈 0.05 ）. Conclusion Ultrasound and NO MBs-mediated MSCs transplantation therapy could improve the cardiac function of rats after MI, and the possible mechanism was the upregulation of VEGF and angiogenesis.