旁分泌效应联合超声生物学效应在MSCs归巢与修复缺血心肌的作用

目的 探讨超声联合微泡经静脉移植兔骨髓间充质干细胞(BM-MSCs)中旁分泌效应及超声生物学效应在MSCs归巢和修复缺血心肌中的价值与作用.方法 密度梯度离心法及贴壁细胞培养法培养兔BM-MSCs.培养细胞进行成脂及成骨诱导分化.细胞移植后行免疫组织化学检测心肌缺血区SDF-1表达,Western blotting检测VEGF蛋白的表达并行定量分析.透射电镜观察各组心肌缺血区血管内皮细胞及通透性.结果 培养的细胞可分化成脂肪与骨骼样细胞.免疫组织化学示SDF-1在3组中均有表达,以2个细胞移植组的阳性表达更强.Western blotting VEGF/GAPDH定量分析超声辐照+微泡+细胞组(236.59±47.13)与静脉移植细胞组(151.48±25.07)和对照组(89.43±20.43)比较,P<0.05.透射电镜示超声+微泡+细胞组缺血区血管内皮细胞间隔增大,红细胞漏出,血管通透性增加.结论 移植MSCs通过旁分泌机制促进SDF-1、VEGF等因子分泌,超声生物学效应通过增加心肌血管通透性、上调VEGF的表达,二者协同促进MSCs归巢和修复缺血心肌.

Targeting Homing and Repair Capacity of Bone-marrow Derived Mesenchymal Stem Cells on Rabbit Myocardial Ischemia under the Combination of the Paracrine Effect of MSCs and the Biological Effect of Ultrasound

Objective To explore the targeting homing and repair capacity of bone-marrow derived mesenchymal stem cells(MSCs) on rabbit myocardial ischemia under the paracrine effect of MSCs and the biological effect of ultrasound by intravenous injection of MSCs under the mediation of diagnostic ultrasound and microbubble.Methods Density gradient centrifugation and adherent culture method were used in the isolation and cultivation of MSCs.MSCs were cultured under the condition of osteogenic and adipogenesis induction.SDF-1 expression in heart was detected with immunohistochemisty(IHC).Western blotting was applied to detect the level of VEGF.Ischemic myocardium under ultrasound irradiation was observed under transmitted electronic microscope.Results The cultured cells could be successfully differentiated into osteoblasts，adipocytes and identified as BM-MSCs.There was positive expression of SDF-1 in 3 groups,and higher expression of SDF-1 in both MSCs implantation groups.The level of VEGF with western blotting in US+Microbubble+MSCs group(236.59±47.13) was significantly higher than that in the MSCs infusion group(151.48±25.07)and the control(89.43±20.43).There were RBCs leaking out of the vessel in US+Microbubble+MSCs group and the cellular spaces increased,while the endothelial cells and cellular spaces kept intact in other two groups.Conclusions The implanted MSCs could prompt the secretion of SDF-1 and VEGF through paracrine mechanism,and the biological effect of ultrasound might be involved in the upregulation of VEGF and enhance the myocardial permeability， both together prompt the homing of MSCs,stimulate the formation of new vessel and the renewal of ischemic heart.