MRI tracking of FePro labeled fresh and cryopreserved long term in vitro expanded human cord blood AC133+ endothelial progenitor cells in rat glioma.
BACKGROUND
Endothelial 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.


RESULTS
The 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 i.v. 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 i.v. 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.


CONCLUSIONS
Magnetically 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.
Cellular and Molecular Imaging Laboratory, Department of Radiology, Henry Ford Hospital, Detroit, Michigan, United States of America. bjanic@rad.hfh.edu
Branislava
B
Janic
Kourosh
K
Jafari-Khouzani
Abbas
A
Babajani-Feremi
A S M
AS
Iskander
Nadimpalli Ravi S
NR
Varma
Meser M
MM
Ali
Robert A
RA
Knight
Ali S
AS
Arbab
D000071916:AC133 Antigen; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002465:Cell Movement; D058948:Cell Tracking; D002478:Cells, Cultured; D003287:Contrast Media; D015925:Cryopreservation; D003911:Dextrans; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism / Q000637:transplantation; D004730:Endothelium, Vascular / Q000166:cytology*; D005312:Fetal Blood / Q000166:cytology*; D005910:Glioma; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles; D018919:Neovascularization, Physiologic; D010455:Peptides / Q000378:metabolism*; D061251:Primary Cell Culture; D011479:Protamines; D051381:Rats; D011923:Rats, Nude; D013194:Staining and Labeling; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
D000071916:AC133 Antigen; D015703:Antigens, CD; D003287:Contrast Media; D003911:Dextrans; D006023:Glycoproteins; D058185:Magnetite Nanoparticles; C000606023:PROM1 protein, human; D010455:Peptides; D011479:Protamines; C065507:ferumoxides