经冠脉自体骨髓干细胞移植改善左室重构机制的研究

The study of intracoronary transplant self bone marrow stem cells on the effects of ventricular remodeling after acute myocardial infarction

目的研究自体骨髓单个核细胞(BM-MNC)和间充质干细胞(MSCs)移植对急性心肌梗死(AMI)后心室重构的影响,探讨不同干细胞移植对心室重构影响的机理。方法以小型猪为研究对象,通过球囊导管压迫冠状动脉前降支的方法,建立小型猪AMI动物模型。在AMI 90 min时,经冠状动脉腔内进行自体BM-MNC和MSCs移植。于术前及干细胞移植后28 d,观察心功能、心肌微血管计数、心肌核因子_KB、心肌细胞凋亡、心肌血管内皮生长因子(VEGF)和碱性成纤维细胞生长因子(bFGF)的mRNA表达。与心功能进行相关性分析。结果(1)术后28 d,BM-MNC组、MSCs组EDD均明显低于AMI模型组(P=0.005),EF明显高于模型组(P=0.0001;P=0.0017)。(2)BM-MNC移植组血管数比梗死组及MSCs组增加(梗死区P=0.000 1,边缘区P=0.000 1)。(3)BM-MNC组及MSCs组心肌细胞凋亡率比梗死模型组减少(梗死区P=0.000 1,梗死边缘区P= 0.000 1,正常区P=0.005 2)。(4)BM-MNC组及MSCs组NF-_KB阳性率比单纯AMI模型组显著降低(P=0.001)。(5)梗死模型组、BM-MNC组以及MSCs组的梗死区及梗死边缘区的VEGF基因表达量与正常对照组的相比增加(梗死区P=0.0001;梗死边缘区P=0.000 1)。BM-MNC及MSCs移植组,心肌梗死区的bFGF基因表达量比梗死模型组及正常对照组均显著增加(P=0.000 1)。LVEF与心肌细胞凋亡呈负相关(r=-0.441 1,P= 0.027 3),与心肌NF-_KB负相关(r=-0.579 6,P=0.000 6);与梗死区、边缘区血管数正相关(r=0.775 0,P=0.000 3);与VEGF表达正相关(r= 0.565 1,P=0.018 1);与bFGF表达正相关(r=0.573 5,P=0.016 1)。结论经冠脉自体BM-MNC及MSCs移植均可减轻心肌梗死后左心室重构,改善急性心肌梗死后心功能,增加心肌血管数量,增加梗死区及梗死边缘区VEGF及bFGF表达,减少心肌细胞凋亡。心功能的改善与干细胞移植后增加心肌血管数量、增加心肌VEGF及bFGF表达、减少心肌细胞凋亡以及减少心肌组织NF-_KB水平有关。

Objective To study the influence of transplanting autologous bone marrow mononuclear cells （BM-MNCs） and mesenchymal stem cells （MSCs） in acute myocardial infarction （AMI） models on ventricular remodeling and to investigate its mechanism of transplanting different kinds of stem cells. Methods AMI swine models were established by obstructing left anterior descending （LAD） artery with Foley＇s tube. Self BM-MNCs and MSCs were transplanted into LAD artery 90 minutes after AMI. The heart function, the number of blood capillary, nuclear factor-κB （NF-κB） expression, myocardial apoptosis, the expressions of vascular endothelial growth factor （VEGF） and basic fibroblast growth factor （bFGF） were observed before operation and 28 days after transplantation. Results ①The swine＇s end-diastolic diamater （EDD） were obviously smaller （P = 0. 005） , and left ventricular ejection fraction （LVEF） and fractional shortening （FS） in sham-operated and BM-MNCs and MSCs groups were higher（ P = 0. 000 1 ;P = 0. 001 7 ）than those in AMI model group 28 days after transplantation.②The numbers of blood vessels in infarction region and marginal zone were significantly increased in AMI, BM-MNCs and MSCs groups than that in sham-operated group, that in BM-MNCs group were higher than that in MSCs group （ infarction zone P = 0. 000 1 ; marginal zone P = 0. 000 1 ）. ③The cadiocyte apoptosis rate in BM-MNCs and MSCs groups were lower than that in AMI model group （ infarction zone P =0. 000 1 ; marginal zone P =0. 000 1 ; normal zone P = 0. 005 2）, but there were no significant differences between BM- MNCs and MSCs groups. ④ NF-κB expression in BM-MNCs and MSCs groups were lower than that in AMI model group （P = 0. 001 ）. ⑤ The VEGF gene expressions in infarction region and marginal zone of AMI model, BM-MNCs and MSCs groups were higher than that in sham-operated group （ infarction zone P =0. 000 1 ; marginal zone P =0. 000 1 ）. The bFGF gene expression in infarction region of BM- MNCs and MSCs groups were higher than those in AMI model and sham-operated groups （ P =0.000 1 ）, that in margion zone of MSCs group were higher than that in AMI model, BM-MNCs and sham-operated groups （ P =0. 009 1 ）. The LVEF had a negative correlation with cadiocyte apoptosis （ r = - 0. 441 1, P = 0. 027 3 ） and NF-KB （ r = -0. 579 6 ,P =0. 000 6） ; and a postive correlation with the numbers of blood vessels （ r =0. 775 0, P = 0. 000 3 ） and bFGF （ r =0. 573 5, P = 0. 016 1 ） and VEGF expression （ r = 0. 565 1, P = 0. 018 1 ）. Conclusions The improvement of cardiac function relates to the increased blood vessels, enhanced VEGF and bFGF expressions, decreased apoptosis and NF-κB levels. The cardiac muscle vessels proliferation promoted by BM-MNCs are more than that by MSCs, VEGF expressions are higher in margion zone of BM-MNCs group than that in MSCs group. The bFGF expression in MSCs group is significantly higher than that in BM-MNCs group.