促红细胞生成素基因修饰内皮祖细胞移植治疗下肢动脉闭塞：磁标记MR成像评价

文章快速阅读：文题释义： 内皮祖细胞：是存在于外周血及骨髓中的重要前体细胞，是能够特异性归巢于血管新生组织并进行分化、增殖成为成熟内皮细胞的一群祖细胞，其在不同环境中可向不同的方向进行分化。 促红细胞生成素：是糖蛋白中的一种，可对哺乳动物中红细胞的生成进行调节，主要由肾小管周细胞产生，也有少部分来自于肝脏，主要功能是使延缓细胞凋亡，其可以协同其他生长因子加速红系组细胞的增殖及成熟，并能促进骨髓中红细胞的释放。 摘要 背景：促红细胞生成素及内皮祖细胞移植均对下肢动脉闭塞有一定的治疗作用。 目的：探讨超顺磁氧化铁纳米颗粒(super paramagnetic iron oxide，SPIO)标记的内皮祖细胞体外促红细胞生成素基因修饰效果及体外磁共振成像的可行性。 方法：将对数生长期的大鼠骨髓来源内皮祖细胞分4组培养，内皮祖细胞组，SPIO标记转染组将pcDNA3-EPO 重组质粒并转染至内皮祖细胞，随后进行SPIO标记；SPIO标记空载病毒组将空质粒转染至内皮祖细胞，随后进行SPIO标记；SPIO标记内皮祖细胞组直接进行SPIO标记。采用4.7 T MR成像SPIO标记的内皮祖细胞；检测4组细胞增殖、细胞周期分布及促红细胞生成素蛋白表达。 结果与结论：①MR成像：T1WI、T2WI、T2*WI序列均见细胞信号降低，随着细胞数目增多，信号降低逐渐明显；相同数量级细胞，T1WI信号降低最弱，T2*WI信号降低最明显；T1WI、T2WI、T2*WI所能检测到的最小细胞数分别为2×10⁴、1×10⁴、0.5×10⁴；②细胞增殖、细胞周期分布：3组标记内皮祖细胞增殖、细胞周期分布与内皮祖细胞组比较差异均无显著性意义；③促红细胞生成素蛋白表达：仅SPIO标记转染组可见促红细胞生成素蛋白表达；④结果表明：SPIO标记的内皮祖细胞体外促红细胞生成素基因修饰后对细胞增殖、细胞周期无影响，4.7 T MR能够在体外对SPIO标记的促红细胞生成素基因修饰内皮祖细胞成像。   中国组织工程研究杂志出版内容重点：干细胞；骨髓干细胞；造血干细胞；脂肪干细胞；肿瘤干细胞；胚胎干细胞；脐带脐血干细胞；干细胞诱导；干细胞分化；组织工程 ORCID: 0000-0002-2568-7449(徐广宇)

Transplantation of erythropoietin gene-modified endothelial progenitor cells to treat lower extremity artery occlusion: a magnetically-labeled MRI evaluation

BACKGROUND:Erythropoietin and progenitor cell transplantation both have therapeutic effects on lower extremity arterial occlusive disease. OBJECTIVE:To investigate the erythropoietin modification effect and magnetic resonance imaging feasibility of superparamagnetic iron oxide (SPIO)-labeled endothelial progenitor cells in vitro. METHODS:Rat bone marrow-derived endothelial progenitor cells at logarithmic growth phase were randomized into four groups: endothelial progenitor cell group, SPIO labeled transfection group (pcDNA3-EPO transfection followed by SPIO labeling), SPIO labeled empty vector group (empty plasmid transfection followed by SPIO labeling), and SPIO labeling group (only SPIO labeling). 4.7T MRI was used to observe SPIO-labeled endothelial progenitor cells. Cell proliferation, cell cycle distribution, and expression of erythropoietin protein in the four groups were measured. RESULTS AND CONCLUSION:MRI findings showed with the increasing cell number, gradually lowered signal intensity on T1-weighted imaging (T1WI), T2WI and T2*WI was seen, and the reduction in the signal intensity was the maximum on T2*WI sequence and the minimum on T1WI sequence. For T1WI, T2WI and T2*WI sequences, the minimum number of cells was 2×10⁴, 1×10⁴ and 0.5×10⁴, respectively. Cell proliferation and cell cycle distribution showed no significant difference among three SPIO labeling groups. In addition, the expression of erythropoietin protein was only found in the SPIO-labeled transfection group. These findings showed that under SPIO labeling, erythropoietin gene-modified endothelial progenitor cells show no changes in cell proliferation and cell cycle, and the 4.7T MR is capable of imaging SPIO-labeled erythropoietin gene-modified endothelial progenitor cells in vitro.