Impaired spinal cord remyelination by long-term cultured adult porcine olfactory ensheathing cells correlates with altered in vitro phenotypic properties.
BACKGROUND
Extensive studies in rodents have identified olfactory ensheathing cells (OECs) as promising candidates for cell-based therapies of spinal cord and peripheral nerve injury. Previously, we demonstrated that short-term cultured adult porcine OECs can remyelinate the rodent and non-human primate spinal cord. Here, we studied the impact of the culturing interval on the remyelinating capacity of adult porcine OECs.


METHODS
Cells were maintained for 1, 2, and 4 to 6 weeks in vitro prior to transplantation into the demyelinated rat spinal cord. Parallel to this, the in vitro phenotypic properties of the OEC preparations used for transplantation were analyzed with regard to morphology, low affinity nerve growth factor receptor (p75(NTR)) expression and proliferation.


RESULTS
We report that prolonged culturing of adult porcine OECs resulted in impaired remyelination of the adult rat spinal cord. Animals receiving transplants of OECs maintained in vitro for 2 weeks displayed significantly less remyelinated axons than those animals that received OEC transplants cultured for 1 week. There was virtually no remyelination after transplantation of OECs cultured for 4 to 6 weeks. The adult porcine OECs displayed a progressive lost of p75(NTR)-expression as determined by immunostaining and flow cytometry with time in culture.


CONCLUSIONS
Taken together, the results indicate that porcine OECs undergo systematic changes with time in culture that result in reduced p75(NTR)-expression, decreased proliferation, and reduced remyelinating capability with time in vitro indicating that relatively short term cultures with limited expansion would be required for transplantation studies.
Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, CT, USA.
Christine
C
Radtke
Karen L
KL
Lankford
Konstantin
K
Wewetzer
Toshio
T
Imaizumi
William L
WL
Fodor
Jeffery D
JD
Kocsis
D000818:Animals; D018929:Cell Culture Techniques; D048430:Cell Shape; D017690:Cell Transplantation / Q000379:methods*; D002478:Cells, Cultured; D006801:Humans; D009186:Myelin Sheath / Q000378:metabolism*; D009416:Nerve Regeneration / Q000502:physiology*; D009833:Olfactory Pathways / Q000166:cytology*; D010641:Phenotype; D051381:Rats; D017207:Rats, Sprague-Dawley; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism; D013116:Spinal Cord / Q000473:pathology / Q000502:physiology* / Q000648:ultrastructure; D013119:Spinal Cord Injuries / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D013552:Swine; D013997:Time Factors
D020800:Receptor, Nerve Growth Factor