Proliferation, differentiation, and cytokine secretion of human umbilical cord blood-derived mononuclear cells in vitro.
OBJECTIVE
Human umbilical cord blood (hUCB)-derived mononuclear cells were previously shown to exert therapeutic effects in a number of animal models of nervous system impairment. However, the mechanisms underlying the structural and functional improvements are still unclear. As cell replacement seems to be a rare or absent event in vivo, we suggest secondary mechanisms, by which the therapeutic effect of transplanted mononuclear cells might be mediated. We investigated the potential of hUCB-derived mononuclear cells in vitro to proliferate, differentiate, and to secrete factors possibly beneficial for the host brain tissue in vivo.


METHODS
Using a succession of distinct culture media, mononuclear cells were stimulated by growth factor combinations, e.g., epidermal growth factor (EGF)/fibroblast growth factor-2 (FGF-2) or nerve growth factor (NGF)/retinoic acid (RA). Expression of hematological and neural marker proteins was investigated by immunoblotting, immunocytochemistry, and fluorescence-activated cell analysis. Secretion of proteins was assayed using a human cytokine antibody array, and quantified via enzyme-linked immunosorbent assay.


RESULTS
Mononuclear cells were shown to undergo proliferation in the presence of EGF/FGF-2. When cells were cultured in NGF/RA-containing medium, neuronal and glial marker proteins were expressed, indicating differentiation. In the presence of either growth factor combination, cells in vitro secrete interleukins, growth factors, and chemotactic proteins.


CONCLUSIONS
Although capable of incipient differentiation, cytokine secretion of hUCB-derived mononuclear cells envisages the potential of an indirect effect in vivo. Most factors detected in conditioned medium are renowned for their anti-inflammatory, neuroprotective, angiogenic, or chemotactic actions, thus, providing the means for a therapeutic outcome mediated by secondary effects.
Neuhoff
Sandra
S
Experimental Neurobiology, Department of Neuroanatomy and Molecular Brain Research, Institute of Anatomy, Ruhr-University Bochum, Bochum, Germany.
Moers
Janet
J
Rieks
Maike
M
Grunwald
Thomas
T
Jensen
Arne
A
Dermietzel
Rolf
R
Meier
Carola
C
D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D018925:Chemokines / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis*; D005312:Fetal Blood / Q000166:cytology*; D006133:Growth Substances / Q000096:biosynthesis; D006801:Humans; D007378:Interleukins / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000276:immunology; D020574:Proto-Oncogene Proteins c-sis / Q000502:physiology
D018925:Chemokines; D016207:Cytokines; D006133:Growth Substances; D007378:Interleukins; D020574:Proto-Oncogene Proteins c-sis