骨髓间充质干细胞自体移植促进兔缺血肢体的血管生成

背景：常规药物治疗、介入或血管旁路移植手术对下肢动脉闭塞症的远期疗效均不理想。近年来采用干细胞的血管再生疗法在梗死部位修复或重新建立有效侧支循环逐渐成为可能。 目的：验证骨髓间充质干细胞自体移植对兔缺血后肢血管再生的促进作用。 设计、时间及地点：随机对照动物实验，于2005-08/2006-11在江苏省血吸寄生虫病防治研究所完成。 材料：选用新西兰大白兔8只，制备兔后肢缺血模型。按随机数字表法分为2组，实验组及对照组各4只。 方法：分离培养实验组兔骨髓间充质干细胞，5-溴-2-脱氧尿苷标记，将骨髓间充质干细胞制成悬液注射于实验组兔后肢缺血部位；对照组注射等量生理盐水。 主要观察指标：2 周后行兔股动脉二维及彩色多普勒超声检测，观察移植前后的血管内径、血流峰值速度及血流加速时间等；取缺血部位肌肉组织，通过免疫荧光及苏木精-伊红染色观察移植细胞分布及血管生成情况。 结果：细胞移植2周后实验组兔的股动脉内径、血流峰值速度均大于对照组(P < 0.01)，血流加速时间短于对照组(P < 0.01)。免疫荧光染色结果显示实验组兔移植部位有抗5-溴-2-脱氧尿苷染色阳性细胞存在；苏木精-伊红染色结果显示实验组缺血部位血管密度高于对照组。 结论：骨髓间充质干细胞具有促进血管生成的作用，自体移植可望成为一种简单的、有效的治疗下肢缺血的方法。

Promotive effect of autologous bone marrow mesenchymal stem cell transplantation on angiogenesis in rabbit ischemic limbs

BACKGROUND: Long-term therapeutic effects of routine drug treatment, intervention or vascular bypass transplantation on lower extremity arterial occlusion are not ideal. During recent years, angiogenesis of stem cells possibly becomes a new method to repair or rebuild an effective collateral circulation at infarct regions. OBJECTIVE: To verify the effect of autologous bone marrow mesenchymal stem cell transplantation on promoting angiogenesis in rabbit ischemic hind limbs. DESIGN, TIME AND SETTING: A randomized controlled animal study was performed in Jiangsu Institute of Schistosomiasis Control between August 2005 and November 2006. MATERIALS: Eight rabbits were used to prepare ischemic models of hind limbs, and then they were randomly divided into experimental group (n=4) and control group (n=4). METHODS: Bone marrow mesenchymal stem cells were isolated and cultured from New Zealand rabbits in the experimental group, and they were then marked 5-bromo-2-deoxyuridine (Brdu). Suspension of bone marrow mesenchymal stem cells was injected into the ischemic hind limbs in the experimental group, while the same volume of saline was injected into the controls. MAIN OUTCOME MEASURES: After two weeks, two-dimensional and color Doppler ultrasound detection was used on rabbit femoral artery to measure inner diameter of blood vessel, peak velocity and acceleration time of blood flow before and after transplantation. Muscle tissues were obtained from ischemic regions to observe distribution of transplant cells and state of angiogenesis using immunofluorescence staining and hematoxylin-eosin (HE) staining. RESULTS: Two weeks after transplantation, the inner diameter of femoral artery and the peak velocity of blood flow in the experimental group were higher than those in the control group (P < 0.01), but the acceleration time of blood flow was shorter than that in the control group (P < 0.01). Immunofluorescence staining showed that anti-Brdu-staining positive cells were found out in transplant part in the experimental group; while HE staining indicated that vessel density of ischemic region in the experimental group was higher than that in the control group. CONCLUSION: Bone marrow mesenchymal stem cells can promote angiogenesis, while autologous bone marrow mesenchymal stem cell transplantation will become a simple and effective method to treat lower limb ischemia.