超声破裂微泡介导骨髓间充质干细胞移植对心肌梗死兔心室重构和血管新生的影响

摘要

目的:观察超声破裂微泡介导的骨髓间充质干细胞(BM-MSCs)移植对兔急性心肌梗死后心室重构和血管新生的影响.方法:取日本大耳白兔52只随机均分为4组:超声组(US组):采用超声波经兔胸壁辐照；微泡组(MB组):经静脉输注微泡造影剂；超声微泡联合组(US+ MB组):经静脉输注微泡造影剂后采用超声辐照破裂微泡；空白对照组:不予超声及微泡处理.各组取骨髓体外培养BM-MSCs.结扎兔左冠脉前降支建立急性心肌梗死(AMI)模型,分别于再灌注1h后对各组动物采取超声或微泡处理后(对照组不予处理),经梗死相关动脉注射BM-MSCs悬液.术后24h和4周,测量各组兔左室舒张末期内径(LVEDd)、左室收缩末期内径(LVESd)、室间隔厚度(IVST)和左室后壁厚度(LVPWT).术后4周,处死动物检测各组兔左心室质量(LVM)、左心室质量指数(LVMI)、兔新生血管数目和血管内皮生长因子(VEGF)浓度.结果:术后4周,与US组、MB组和空白对照组相比,US+MB组LVEDd[(12.77±0.65) mm、(12.97±1.00) mm、(12.78±0.71) mm比(11.71±0.54) mm]、LVESd[(9.63±0.57) mm、(9.92±0.90) mm、(9.69±0.51) mm比(8.39±0.32) mm]、IVST[(2.69±0.11) mm、(2.65±0.14) mm、(2.63±0.10) mm比(2.48±0.07) mm]和LVPWT[(2.74±0.19)mm、(2.66±0.12) mm、(2.68±0.16) mm比(2.51±0.11) mm]明显减小(P＜0.05或＜0.01),LVM[(5931.76±120.61) mg、(6022.35±116.87) mg、(6076.28±122.73) mg比(4930.66±172.30) mg]及LVMI[(2.17±0.19)mg/g、(2.24±0.07) mg/g、(2.33±0.25) mg/g比(1.83±0.01) mg/g]明显降低(P＜0.01),新生血管数目[(4.00±1.61)个、(4.20±1.23)个、(4.18±1.72)个比(8.82±2.52)个]明显增多(P＜0.01),VEGF浓度[(0.33±0.17) μg/g、(0.32±0.08) μg/g、(0.29±0.05) μg/g比(0.65±0.24) μg/g]明显升高(P＜0.01).结论:超声微泡破裂介导的BM-MSCs移植可提高梗死心肌VEGF表达,促进血管新生,改善心肌梗死后心室重构,提高心脏功能.%Objective: To observe influence of bone marrow mesenchymal stem cells (BM-MSCs) transplantation mediated by ultrasound rupturing microbubble on ventricular remodeling and angiogenesis in rabbits after myocardial infarction. Methods: A total of 52 Japanese big-ear white rabbits were randomly and equally divided into ultrasound group (US group, received ultrasound irradiation via rabbit chest wall), microbubble group (MB group, received intravenous infusion of MB contrast agent), US+ MB group (received ultrasound irradiation after intravenous infusion of MB contrast agent) and blank control group (didn't receive US or MB treatment). Bone marrow was taken from each group for BM-MSCs culture in vitro. Rabbit left anterior descending artery was ligated to establish model of a-cute myocardial infarction (AMI), rabbits in each group received US or MB treatment one hour after reperfusion except blank control group, then BM-MSCs suspension was injected via infarct related artery. Left ventricular end-diastolic dimension (LVEDd), left ventricular end-systolic dimension (LVESd), interventricular septal thickness (IVST) and left ventricular posterior wall thickness (LVPWT) were measured 24h and four weeks after operation. Four weeks after operation, rabbits were executed and left ventricular mass (LVM), left ventricular mass index (LVMI), number of new vessels and concentration of vascular endothelial growth factor (VEGF) of rabbits were measured. Results: Compared with US, MB and blank control group four weeks after operation, there were significant decrease in LVEDd [(12. 77 ±0.65) mm, (12.97 ±1.00) mm, (12.78 ±0.71) mm vs. (11.71 ± 0.54) mm], LVESd [(9.63 ±0.57) mm, (9.92 ±0.90) mm, (9. 69 ±0.51) mm vs. (8. 39±0.32) mm], IVST [ (2. 69± 0.11) mm, (2. 65 ± 0. 14) mm, (2. 63 ± 0. 10) mm vs. (2. 48 ± 0. 07) mm], LVPWT [ (2. 74 ± 0. 19) mm, (2. 66 ± 0.12) mm, (2.68 ± 0. 16) mm vs. (2. 51 ±0.11) mm, P<0. 05 or <0. 01], LVM [ (5931. 76± 120. 61) mg, (6022. 35± 116. 87) mg, (6076. 28 ± 122. 73) mg vs. (4930. 66 ± 172. 30) mg] and LVMI [ (2. 17 ± 0. 19) mg/g, (2. 24 ± 0. 07) mg/g, (2. 33 ± 0. 25) mg/g vs. (1. 83 ± 0. 01) mg/g, P<0. 01 all], and significant increase in number of new vessels [ (4. 00 ± 1. 61), (4. 20 ± 1. 23), (4. 18 ± 1. 72) vs. (8. 82 ± 2. 52)] and VEGF concentration [ (0. 33 ± 0. 17) μg · g-1, (0.32 ±0.08) μg · g-1 (0.29 ±0.05) μg · g-1 vs. (0.65 ± 0.24) μg · g-1] in US+MB group, P<0. 01 all. Conclusion: BM-MSCs transplantation mediated by ultrasound rupturing microbubble can increase VEGF expression in infracted myocardium, promote angiogenesis, improve ventricular remodeling after myocardial infarction and increase cardiac function.