Transplantation of erythropoietin gene-modified endothelial progenitor cells to treat lower extremity artery occlusion:a magnetically-labeled MRI evaluation / 中国组织工程研究

ABSTRACT

BACKGROUND:Erythropoietin and progenitor cel 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 cel s in vitro. METHODS:Rat bone marrow-derived endothelial progenitor cel s at logarithmic growth phase were randomized into four groupsendothelial progenitor cel group, SPIO labeled transfection group (pcDNA3-EPO transfection fol owed by SPIO labeling), SPIO labeled empty vector group (empty plasmid transfection fol owed by SPIO labeling), and SPIO labeling group (only SPIO labeling). 4.7T MRI was used to observe SPIO-labeled endothelial progenitor cel s. Cel proliferation, cel cycle distribution, and expression of erythropoietin protein in the four groups were measured. RESULTS AND CONCLUSION:MRI findings showed with the increasing cel number, gradual y 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 cel s was 2×104, 1×104 and 0.5×104, respectively. Cel proliferation and cel 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 cel s show no changes in cel proliferation and cel cycle, and the 4.7T MR is capable of imaging SPIO-labeled erythropoietin gene-modified endothelial progenitor cel s in vitro.