MRI Tracking of FePro Labeled Fresh and Cryopreserved Long Term In Vitro Expanded Human Cord Blood AC133+ Endothelial Progenitor Cells in Rat Glioma

Abstract

BackgroundEndothelial progenitors cells (EPCs) are important for the development of cell therapies for various diseases. However, the major obstacles in developing such therapies are low quantities of EPCs that can be generated from the patient and the lack of adequate non-invasive imaging approach for in vivo monitoring of transplanted cells. The objective of this project was to determine the ability of cord blood (CB) AC133+ EPCs to differentiate, in vitro and in vivo, toward mature endothelial cells (ECs) after long term in vitro expansion and cryopreservation and to use magnetic resonance imaging (MRI) to assess the in vivo migratory potential of ex vivo expanded and cryopreserved CB AC133+ EPCs in an orthotopic glioma rat model.Materials, Methods and ResultsThe primary CB AC133+ EPC culture contained mainly EPCs and long term in vitro conditions facilitated the maintenance of these cells in a state of commitment toward endothelial lineage. At days 15–20 and 25–30 of the primary culture, the cells were labeled with FePro and cryopreserved for a few weeks. Cryopreserved cells were thawed and in vitro differentiated or IV administered to glioma bearing rats. Different groups of rats also received long-term cultured, magnetically labeled fresh EPCs and both groups of animals underwent MRI 7 days after IV administration of EPCs. Fluorescent microscopy showed that in vitro differentiation of EPCs was not affected by FePro labeling and cryopreservation. MRI analysis demonstrated that in vivo accumulation of previously cryopreserved transplanted cells resulted in significantly higher R2 and R2* values indicating a higher rate of migration and incorporation into tumor neovascularization of previously cryopreserved CB AC133+ EPCs to glioma sites, compared to non-cryopreserved cells.ConclusionMagnetically labeled CB EPCs can be in vitro expanded and cryopreserved for future use as MRI probes for monitoring the migration and incorporation to the sites of neovascularization.

A critical role of CXCR2 PDZ-mediated interactions in endothelial progenitor cell homing and angiogenesis

“…The human EPCs were isolated from the cord blood and have been previously characterized by us and other investigators (Janic et al, 2010(Janic et al, , 2012Arbab et al, 2006;Silverman et al, 2007). Similar results were observed with human EPCs where CXCR2 regulates EPC migratory and angiogenic activities in vitro ( Supplementary Fig.…”

Differential biodistribution of intravenously administered endothelial progenitor and cytotoxic T-cells in rat bearing orthotopic human glioma

“…The embedded blocks were cut into serial 10 μm sections and prussian blue staining was used to visualize the iron within FePro labeled cells. Brain tissue sections were stained with prussian blue according to our published works to detect the migration of administered labeled cells to the tumor area [10,11,17]. Brief, fixed sections were de-paraffinized, rehydrated, washed, and incubated for 30 min with 5% potassium ferrocyanide in 5% hydrochloric acid, DAB enhanced, and counterstained with nuclear fast red.…”

“…Magnetic resonance imaging (MRI) has been used in animal models for cell tracking with the help of iron-oxide nanoparticles as probes [10,11]. Studies have shown the capability of iron-oxide nanoparticles for non-invasive MRI tracking of cell migration and engraftment [9,10].…”

Application of Umbilical Cord Blood Derived Stem Cells in Diseases of the Nervous System

“…Janic et al have reported that cord blood (CB)-derived AC133+ (CD133+) cells has the ability to amplify the numbers of autologous EPCs by long term in vitro expansion while preserving their angiogenic potential, which is critically important for developing EPC based therapies [76,77]. Previous studies including ours have shown the mechanism associated with the EPC’s migration to damage area.…”

“…Study by Varma et al, evaluated the dynamic biodistribution of systemically injected labeled human UCB derived EPCs and cytotoxic T-cells (CTLs)] in rat glioma model, which was monitored by In-111 oxine based SPECT imaging [87]. Magnetically labeled cord blood EPCs can be in vitro expanded and cryopreserved for future use as MRI probes for monitoring the migration and incorporation to the sites of neovascularization in an orthotopic glioma rat model [77]. Since, molecular and cellular imaging are essential in determination of bioavailability and efficacy of various drugs and targeting agents, exogenously labeled UCB cells can be used to determine the bio-distribution of cells and therapeutic effects of UCB in brain lesions by MRI and UCB cells can be used as imaging probes.…”