骨髓单个核细胞移植后心肌梗死区的血管生成及细胞因子分泌

Effect of bone marrow mononuclear cell transplantation on angiogenesis and expression of cytokines following myocardial infarction

背景:干细胞移植为治疗心肌梗死带来新的希望,但研究结果不一致,存在争议。细胞移植能否长期持久地改善心脏功能、改善缺血心功能的机制这些问题均不明确。目的:观察经冠状动脉自体骨髓单个核细胞移植对急性心肌梗死犬心功能、血管生成和细胞因子分泌的影响。方法:杂种犬分为骨髓单个核细胞组(n=10)和生理盐水组(n=6),前上嵴或髂后上棘穿刺分离得到骨髓单个核细胞,结扎冠状动脉前降支建立急性心肌梗死模型,于心肌梗死后2h分别经冠状动脉内移植骨髓单个核细胞和生理盐水,心肌梗死后2h及6周时分别测定超声心动图指标,骨髓单个核细胞移植后6周vWF免疫组化染色检测心肌组织的毛细血管密度,RT-PCR检测血管内皮生长因子(血管内皮生长因子188、血管内皮生长因子164)、碱性成纤维细胞生长因子、基质金属蛋白酶9mRNA的表达。结果与结论:经冠状动脉自体骨髓单个核细胞移植后6周,超声心动图显示,骨髓单个核细胞组射血分数和每搏输出量比生理盐水组显著升高;梗死边缘区新生血管数量明显高于生理盐水组。骨髓单个核细胞组梗死区血管内皮生长因子188、血管内皮生长因子164和碱性成纤维细胞生长因子mRNA表达水平显著高于生理盐水组。骨髓单个核细胞组梗死区基质金属蛋白酶9mRNA表达水平显著低于生理盐水组。结果说明自体骨髓单个核细胞经冠状动脉内注射移植,改善急性心肌梗死后心功能,促进梗死边缘区血管生成,提高促血管生长因子血管内皮生长因子188、血管内皮生长因子164和碱性成纤维细胞生长因子的mRNA表达水平,减少基质金属蛋白酶9mRNA表达水平。

BACKGROUND： Cell transplantation offers a new promise of rebuilding the damaged myocardium. But the results of them are not consistent. It is not clear if the transplanted cells can permanently improve heart function and the mechanism underlying this therapeutic effect. OBJECTIVE： To study the effect of intracoronary autologous bone marrow mononuclear cell transplantation on cardiac function, and angiogenesis and cytokine production in canines with acute myocardial infarction. METHODS： Left anterior descending coronary artery ligation was used to produce acute myocardial infarction models in hybrid canines. Bone marrow mononuclear cells were harvested by using puncture of anterior crest and posterior superior iliac spine to prepare cell suspension. Sixteen hybrid canines were randomly divided into transplantation group （n=10） and control group （n=6）. Bone marrow mononuclear cells （transplantation group, n=10） or normal saline （control group, n=6） were intracoronarily infused into infarction-related arteries 2 hours after acute myocardial infarction. To evaluate the heart function, we used echocardiography at 2 hours and 6 weeks after acute myocardial infarction. Capillary density was assessed 6 weeks after transplantation by using von Willebrand factor test. The mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, basic fibroblast growth factor and matrix metalloproteinase-9 in the infarct area were determined by reverse transcription-PCR at 6 weeks after transplantation. RESULTS AND CONCLUSION： In contrast to the control group, ejection fraction and stroke volume at 6 weeks after transplantation increased significantly in the transplantation group. The transplantation group had a greater amount of new vessels in the peri-infarct area than the control group. Compared with the control group, the mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, and basic fibroblast growth factor significantly increased in the transplantation group, but the mRNA level of matrix metalloproteinase-9 significantly decreased in the transplantation group. These findings suggest that intracoronary transplantation of autologous bone marrow mononuclear cells may improve the cardiac function, and increase capillary density, especially in the border zone of infarcted myocardium. Otherwise, bone marrow mononuclear cell transplantation can increase the mRNA levels of vascular endothelial growth factor 188, vascular endothelial growth factor 164, and basic fibroblast growth factor, but decrease the mRNA level of matrix metalloproteinase-9.