心肌梗死后单个核细胞促间充质干细胞迁移的作用

Mononuclear cells promote mesenchymal stem cell migration after myocardial infarction

背景:心肌梗死后间充质干细胞定向心肌迁移的机制尚不甚明了。目的:探讨基质细胞衍化因子1和趋化因子受体4生物轴在心肌梗死后单个核细胞促间充质干细胞迁移中的作用。方法:分离培养SD乳鼠心肌细胞及SD大鼠间充质干细胞。12只SD大鼠其中6只建立心肌梗死模型,6只行假手术处理,分离循环血单个核细胞,采用三室共培养模型,分别将DAPI标记的间充质干细胞、心肌细胞和单个核细胞培养于三室模型的上、中、下室内,设立心肌梗死组、趋化因子受体4受体阻断剂AMD3100组、假手术组和空白对照组。培养48 h后,荧光显微镜下观察并比较迁移细胞数目,免疫细胞化学和免疫荧光染色分别检测心肌细胞基质细胞衍化因子1和迁移细胞趋化因子受体4的表达。结果与结论:除空白对照组外,各组中室内均可见迁移细胞,迁移细胞阳性表达趋化因子受体4,心肌梗死组迁移细胞数目显著高于其他各组,加入肿瘤坏死因子α中和抗体和趋化因子受体4受体阻断剂AMD3100后,迁移细胞数目明显减少(P<0.05)。各组心肌细胞阳性表达基质细胞衍化因子1,心肌梗死组及AMD3100组心肌细胞基质细胞衍化因子1表达灰度值显著高于假手术组及空白对照组(P<0.05)。表明基质细胞衍化因子1/趋化因子受体4生物轴在心肌梗死后大鼠单个核细胞促间充质干细胞向心肌细胞迁移中发挥了一定作用。

BACKGROUND：The mechanisms of mesenchymal stem cells directional y homing to infarcted myocardium post myocardial infarction are stil unclear. OBJECTIVE：To investigate the role of stromal cellderived factor-1 （SDF-1）/C-X-C chemokine receptor 4 （CXCR4） axis on mesenchymal stem cellmigration promoted by mononuclear cells after myocardial infarction. METHODS：Cardiomyocytes and mesenchymal stem cells were respectively isolated from suckling and adult Sprague-Dawley rats. Twelve healthy Sprague-Dawley rats were selected （six rats for myocardial infarction models and six for sham models）, then circulating mononuclear cells were isolated. 4,6-Diamino-2-phenyl indole-labeled mesenchymal stem cells, cardiomyocytes and mononuclear cells were cultured into the upper, middle and lower layers of the tri-chamber coculture system, respectively. In this experiment, there were four groups：myocardial infarction group, AMD3100 （CXCR4 inhibitor） group, sham group and blank control group. After 48 hours, the number of migrating mesenchymal stem cells with blue-lighting nucleus was calculated under fluoroscope. Immunocytochemistry and immunofluorescent staining was used to detect SDF-1 expression in cardiomyocytes and CXCR4 expression in mesenchymal stem cells, respectively. RESULTS AND CONCLUSION：Migrating mesenchymal stem cells with positive expression of CXCR4 were observed in each group other than the blank control group. The number of migrating mesenchymal stem cells was higher in the myocardial infarction group than in the other groups. Tumor necrosis factor-αneutralizing＆amp;nbsp;antibody and CXCR4 inhibitor AMD3100 could obviously reduce the number of migrating mesenchymal stem cells （P＆lt;0.05）. Cardiomyocytes in each group expressed SDF-1 positively. The gray values of SDF-1 expression in the myocardial infarction and AMD3100 groups were significantly higher than those in the sham and blank control groups （P＆lt;0.05）. SDF-1/CXCR4 axis plays a certain role in mesenchymal stem cells migration promoted by mononuclear cells after myocardial infarction.