供体鼠龄对急性心肌梗死骨髓间充质干细胞移植后血管发生的影响

Effect of donor rat age on the angiogenesis of acute myocardial infarction rats following mesenchymal stem cell transplantation

目的:干细胞移植后可以通过改善梗死区域血管新生而发挥改善心功能的作用。实验观察不同鼠龄骨髓间充质干细胞移植后的效果,拟验证其对急性心肌梗死动物血管发生的影响。方法:实验于2006-02/2007-05在福建省高血压研究所完成。①实验材料:清洁级SD大鼠由上海实验动物公司提供。选用2周龄雄性SD大鼠作为幼年鼠骨髓间充质干细胞来源,选用1年龄雄性SD大鼠作为老年鼠骨髓间充质干细胞来源。实验过程中对动物处置符合动物伦理学标准。②实验方法:密度梯度离心法和贴壁筛选法获得SD大鼠骨髓间充质干细胞,观察老年与幼年大鼠骨髓间充质干细胞的凋亡情况。体外模拟梗死心肌缺血、缺氧条件,制备大鼠心肌梗死模型。将造模后大鼠随机分为3组:对照组(n=8)不进行干细胞移植,只在梗死心肌周围注入等量的生理盐水。老年鼠移植组(n=8)梗死心肌周围分4点注入同种异体老年鼠骨髓间充质干细胞,幼年鼠移植组(n=8)梗死心肌周围分4点注入同种异体幼年鼠骨髓间充质干细胞。③实验评估:干细胞移植4周后,采用Ⅷ因子免疫组织化学观察各组间血管密度的差别。结果:24只大鼠均进入结果分析。在缺血、缺氧条件下,幼年鼠骨髓间充质干细胞的抗凋亡能力强于老年鼠(P<0.05)。Ⅷ因子免疫组织化学检测显示,两移植组梗死区域均有新生血管生成,幼鼠移植组血管密度高于老年鼠移植组(P<0.05),老年鼠移植组高于对照组(P<0.05)。结论:供体年龄在一定程度上影响急性心肌梗死骨髓间充质干细胞移植后血管的发生。

AIM： Stem cell transplantation can improve heart function through improving angiogenesis of the infarction region. The study was aimed to determine the effect of mesenchymal stem cells （MSCs） transplantation in rats with different ages and verify the influence of the transplantation on the angiogenesis after acute myocardial infarction. METHODS： The experiment was carried out in the Hypertension Institute of Fujian Province from February 2006 to May 2007. （1）Clean-grade SD rats were provided by Experiment Animal Company of Shanghai. MSCs were harvested from male SD rats aged 2 weeks and male SD rats aged 1 year respectively. Rats in the experiment were disposed according to the animal ethics.（2）MSCs were collected from bone marrow, cultured and passageed in vitro, then purified by density gradient centrifugation and adhesive-screening method. The apoptosis of MSCs were tested under ischemia and anoxia condition. Myocardial infarction models were randomly divided into 3 groups. Rats in the control group （n =8） were not treated with stem cell transplantation, but saline of the same volume was injected. Rats in the myocardial infarction plus old rat MSCs transplantation group （n =8） received old rat MSCs at four infarcted myocardial regions.＇ Rats in the myocardial infarction plus young rat MSCs transplantation group （n =8） received young rat MSCs at four infarcted myocardial regions. （3）4 weeks later, blood vessel density was tested with immunohistochemistry of factor Ⅷ. RESULTS： All the 24 rats were involved in the result analysis. Under ischemia and anoxia condition, the number of apoptotic MSCs from old rats was more than that of young rats （P 〈 0.05）. Immunohistochemistry of factor ＇Ⅷ showed that the myocardial infarction plus young rat MSCs transplantation group displayed more blood vessel than that of the myocardial infarction plus old rat MSCs transplantation group （P 〈 0.05）, and the latter was more than control group （P 〈 0.05）. CONCLUSION： To some extent, MSCs from rats with different ages affects angiogenesis after myocardial infarction.