In vitro MR imaging of Fe2O3-arginine labeled heNOS gene modified endothelial progenitor cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the feasibility of in vitro magnetic resonance imaging on Fe2O3-arginine labeled heNOS gene modified endothelial progenitor cells (EPCs).</p><p><b>METHODS</b>Fe2O3 was incubated with arginine to form Fe2O3-arginine complex. Rabbit peripheral blood mononuclear cells (MNCs) were isolated and EPCs were isolated by adherence method, expanded and modified with heNOS gene using Lipofectamine 2000. After 48 hours, genetically modified EPCs were incubated with Fe2O3-arginine for 24 hours. Intracellular iron was detected by Prussian blue stain. The expression of heNOS gene was detected by Western blot. MTT assay was used to evaluate cell survival and proliferation of Fe2O3-arginine labeled heNOS-EPCs. Flow cytometry was used to measure cell apoptosis. The cells underwent in vitro MR imaging with various sequences.</p><p><b>RESULTS</b>Iron-containing intracytoplasmatic vesicles could be clearly observed with Prussian blue staining, and the labeling rate of labeled heNOS-EPCs were similar to that of labeled EPCs (around 100%). Survival and apoptosis rates obtained by MTT and flow cytometry analysis were similar among labeled heNOS-EPCs, labeled EPCs and unlabeled EPCs with Fe2O3-arginine. The signal intensity on MRI was equally decreased in labeled heNOS-EPCs and labeled EPCs compared with that in unlabeled cells. The percentage change in signal intensity (DeltaSI) was most significant on T2*WI and DeltaSI was significantly lower in cells labeled for 7 days than that labeled for 1 days.</p><p><b>CONCLUSIONS</b>The heNOS gene can be successfully transfected into rabbit peripheral blood EPCs using Lipofectamine2000. The heNOS-EPCs can be labeled with Fe2O3-arginine without significant change in viability and proliferation capacity. The labeled heNOS-EPCs can be imaged with standard 1.5 T MR equipment. The degree of MR signal intensity may indirectly reflect the cell count, growth and division status.</p>

In vitro MR imaging of Fe(2)O(3)-PLL labelled rabbit peripheral blood endothelial progenitor cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>To perform in vitro magnetic resonance imaging on magnetic iron oxide (Fe(2)O(3)-PLL) labeled rabbit peripheral blood endothelial progenitor cells (EPCs).</p><p><b>METHODS</b>Fe(2)O(3) was incubated with PLL for 2 hours to form Fe(2)O(3)-PLL. Rabbit peripheral blood mononuclear cells (MNCs) were isolated and EPCs were selected by adherence method, expanded and incubated with Fe(2)O(3)-PLL. Intracellular iron was detected by Prussian blue stain and under electron microscope. MTT assay was used to evaluate cell survival and proliferation of Fe(2)O(3)-PLL labeled EPCs. Flow cytometry was used to analysis cell cycle and apoptosis. The cells underwent in vitro MR imaging with various sequences.</p><p><b>RESULTS</b>Iron-containing intracytoplasmatic vesicles could be observed clearly with Prussian blue staining and electron microscope observation. Survival, life cycle and apoptosis values obtained by MTT and flow cytometry analysis were similar among unlabelled EPCs and EPCs labeled with various concentrations Fe(2)O(3)-PLL. The signal intensity on MRI was significantly decreased in labeled cells compared with that in unlabeled cells. The percentage change in signal intensity (DeltaSI) was most significant on T(2)*WI and DeltaSI was significantly lower in cells labeled for 7 days than that labeled for 1 day.</p><p><b>CONCLUSIONS</b>The rabbit peripheral blood EPCs can be labeled with Fe(2)O(3)-PLL without significant change in viability and proliferation. The labeled EPCs can be imaged with standard 1.5 T MR equipment. The degree of MR signal decreasing may indirectly reflect the cells count, growth state and division.</p>

Local transplantation of endothelial progenitor cells to reduce restenosis after angioplasty in rabbit model / 介入放射学杂志

Objective To investigate homografting vascular endothelial progenitor cells(EPCs)for preventing restenosis formation of carotid artery in New Zealand white rabbit models.Methods EPCs of New Zealand white rabbits were isolated,confirmed and expanded though the injured carotid arterial endothelium of rabbit model induced by dilatation with a 2.5 F balloon;and then EPCs were transplanted into the injured endothelium of the cells transplantation group(n=13,3 of them were transplanted with fluorencently-labeled- EPCs),while equal volume of saline without EPCs was injected into the injured endothelium in the control group(n=8).Histopathology was performed at 4 days after transplantation for the 2 rabbits,with fluorencently-labeled-EPCs.All of the rest remained rabbits were killed 4 weeks later for histological examinations.Results The histopathological slides showed that the fluorescence-positive expression existed in the injured endothelium 4 days after transplantation.At 4 weeks after the EPCs transplantation,there were less restenosis and less vascular wall thickening in the rabbits of cells transplantation group than those of the control group(P＜0.01).Conclusion The local interventional homografting heterogeneous endothelial progenitor cells can prevent restenosis after the carotid artery angioplasty in New Zealand White rabbit model. (J Intervent Radiol,2007,16:95-98)