人脐血干细胞移植对心肌梗死大鼠血管新生和血管内皮生长因子、促血管生成素-1表达的影响

Effects of transplantation of human umbilical cord blood stem cells on angiogenesis and expression of vascular endothelial growth factor and angiopoietn-1 in rats with experimental myocardial infarction

目的观察人脐血干细胞(hUCBSC)经静脉移植对心肌梗死(MI)大鼠血管新生和血管内皮生长因子(VEGF)、促血管生成素(Ang-1)表达的影响。方法雄性Sprague-Dawley大鼠40只,随机分为3组:(1)假手术组(10只):大鼠麻醉后开胸,将结扎线通过前降支动脉(LAD),不结扎,然后关胸;(2)对照组(15只):大鼠麻醉后开胸,结扎LAD,制备MI模型成功(经肉眼观察和心电图证实)后,经尾静脉注射0.9%生理盐水0.5 mL;(3)移植组(15只),大鼠麻醉后开胸,结扎LAD,制备MI模型后,经尾静脉注射hUCBSC 0.5 mL(含干细胞2×107/mL,由北京市脐血干细胞库提供)。术后4周行超声心动图检查和心导管检查,并取心脏组织行HE染色、抗Ⅷ因子免疫组化染色,观察心肌病理改变、肌毛细血管密度(MCD)的变化。同时用免疫组化和RT-PCT的方法检测VEGF、Ang-1及其mRNA的表达。结果与对照组相比,术后4周时移植组左室射血分数较对照组明显改善(55.35%±11.23%比40.23%±10.87%,P<0.01),左室舒张末压显著降低(10.56±4.69 mmHg比20.13±5.63 mmHg,P<0.01),而左室压力最大变化率明显增加(4.25±2.01 mmHg比6.53±2.38mmHg,P<0.05;3.83±2.69 mmHg比6.25±2.92 mmHg,P<0.05);移植组MCD明显高于对照组(每高倍视野4.2±0.5个比2.1±0.3个,P<0.01);移植组VEGF和Ang-1及其mRNA表达明显高于对照组和假手术组。结论经静脉移植hUCBSC促进MI大鼠VEGF和Ang-1表达,促进血管新生,改善心功能。

Objective To observe the effects of intravenous heterogeneity transplantation of human umbilical cord blood stem cell （hUCBSC） on angiogenesis, vascular endothelial growth factor （VEGF） and angiopoietn-1 （Ang-1） after myocardial infarction in rat models . Methods Forty male Sprague-Dawley rats were randomly divided into three groups： （1） Sham-operation group （Sham group, n = 10） in which the rats underwent thoracotomy without left anterior descending arteries （LADs） ligaton; （2） Control group （n = 15） in which the rats＇ LADs were ligated and 0. 5 mL saline was injected through tail vein; （3） Transplantation group （n = 15） in which the rats＇ LADs were ligated and 0. 5 mL hUCBSC suspension （2 × 10^7/mL, Beijing umbilical cord blood stem cell center offered） was injected through the tail vein. Cardiac function was assessed by echocardiography and left ventricular end-diastolic pressure （LVEDP） and 3= dp/dtmax were measured by cardiac catheter at 4 weeks pest-operation. Myocardial capillary density （MCD） was observed by Factor Ⅷ related antigen immunochemical stain. Expression of VEGF and Ang-1 in cardiac tissue was measured by immunological histochemical staining. RT-PCR was used to detect the mRNA product of VEGF and Ang-1. Results Cardiac function measured by echocardiography was improved in the transplantation group compared with the control group at 4 weeks pest-operation. LVEDP was reduced （10.56±4.69 mmHgvs 20. 13 ±5.63 mmHg, P 〈0.01）and 3= dp/dtmax increased in the transplantation group. MCD was increased in the transplantation group compared with the control group （4.2 ±0.5/HP vs 2. 1 ±0. 3/HP, P 〈0. 01 ）. Expression of VEGF and Ang-1 as well as the levels of their relative mRNA were more significant in the transplantion group than in the control group and in the sham group. Conclusion Transplantation of hUCBSC increases the expression of VEGF and Ang-1, which in turns enchances angiogenesis and improves cardiac function in rat models of myocardial infarction.