过表达NKx2.5基因间充质干细胞增强SDF-1/CXCR4轴促归巢改善心梗心功能

Overexpressed NKx2.5 genes in mesenchymal stem cells improve myocardial function in patients with myo⁃cardial infarction via enhancing SDF⁃1/CXCR4⁃axis homing

目的探讨过表达NKx2.5基因骨髓间充质干细胞(BMSC)通过增强SDF-1/CXCR4轴促BMSC归巢改善心梗后心功能。方法采用慢病毒使骨髓间充质干细胞内过表达NKx2.5(BMSC^(NKx2.5)),将空载体组及BMSC组作为对照组。采用RT-PCR检测各组细胞SDF-1、CXCR4及NKx2.5的表达及同时采用western-blot检测NKx2.5及SDF-1、CXCR4蛋白的表达。将BMSC^(NKx2.5)、BMSC、及BMSC空载体经尾静脉注射入小鼠心梗模型,同时设立BMSC^(NKx2.5)+AMD3100组,将心梗未处理组、假手术组、正常小鼠组作为对照组。采用心脏彩超检测心梗小鼠心功能的变化及采用western blot检测NKx2.5及SDF-1、CXCR4蛋白的表达。结果体外BMSC^(NKx2.5)组SDF-1及CXCR4及转录因子NKx2.5的表达最高(P<0.05)。体内实验证实BMSC^(NKx2.5)组心梗心功能改善最为明显(P<0.05),但当加入SDF-1-CXCR4轴抑制剂AMD3100后,心功能改善不明显。BMSC^(NKx2.5)组转录因子NKx2.5及SDF-1及CXCR4因子的表达最高(P<0.05),但加入AMD3100组后SDF-1及CXCR4的表达明显下降。结论BMSC^(NKx2.5)可以通过增强SDF-1/CXCR4轴促BMSC归巢改善心梗心功能。

Objective To investigate the effect of the overexpressed NKx2.5 genes in bone marrow mesen⁃chymal stem cells(BMSCs)on cardiac function after myocardial infarction by enhancing the SDF⁃1/CXCR4 axis to promote BMSC homing.Methods Lentivirus was used to overexpress NKx2.5 in BMSCs(BMSC^(NKx2.5)).The empty body group,BMSC group,and mouse cardiomyocyte group were used as the control groups.The expressions of SDF⁃1,CXCR4 and NKx2.5 in each group were detected by RT⁃PCR,and the expression of transcription factors NKx2.5,SDF⁃1 and CXCR4 proteins was detected by western⁃blot.BMSC^(NKx2.5),BMSC,and BMSCempty body were injected into the mouse myocardial infarction model through the tail vein.The BMSC^(NKx2.5)+AMD3100 group was set up.The untreated myocardial infarction group,sham operation group,and normal mouse group were used as the control groups.Changes in the cardiac function of mice with myocardial infarction were detected via Color Dop⁃pler ultrasound.The expression of NKx2.5,SDF⁃1 and CXCR4 proteins was detected by western⁃blot.Results NKx2.5,SDF⁃1 and CXCR4 in the BMSC^(NKx2.5) group had the highest expression(P<0.05).In vivo experiments confirmed that the BMSC^(NKx2.5) group exhibited the most significant improvement in cardiac function after myocardial infarction(P<0.05).The expression of transcription factors NKx2.5,SDF⁃1 and CXCR4 in BMSC^(NKx2.5) group was the highest(P<0.05).However,when the SDF⁃1⁃CXCR4 axis inhibitor AMD3100 was added,the improvement in cardiac function was insignificant.Conclusion BMSC^(NKx2.5) can improve myocardial function after myocardial infarction by enhancing the SDF⁃1/CXCR4 axis to promote BMSC homing.