Cord Blood Mesenchymal Stem Cells Are Enriched for Neural and Glial Progenitors.

Human bone marrow stroma is the primary source for mesenchymal stem cells (MSCs), a mixture of multipotent progenitors that differentiate into fibrous, cartilage, adipose, bone and reticular tissue cells. Recent reports suggest that human umbilical cord blood (UCB) is a feasible source for MSCs. In this study, we examined whether MSCs from umbilical cord blood contain progenitors that differentiate into cells of neural and glial lineages. UCB mononuclear cell fraction was cultured in Iscove’s MDM culture medium supplemented with 20% fetal bovine serum and L-glutamine. After 2 weeks in culture, adherent cells formed colony forming unit fibroblast (CFU-F)-like colonies. When adherent cells reached 70% confluency, they were further subcultured in the same medium for three more weeks before replacing IMDM with neurogenic differentiation medium. Cord blood MSCs were devoid of hematopoietic activity since they failed to produce CFU-GM, CFU-E, or CFU-GEMM hematopoietic colonies when cultured in methyl cellulose medium supplemented with the appropriate hematopoietic growth factors. Flow cytometric analysis showed a population of cells devoid of hematopoietic phenotype (CD34⁻, CD45⁻, CD38⁻, CD3⁻, CD19⁻). After 7 days incubation in serum free supplemented Neurobasal™ medium, cultured cord blood MSCs expressed neuron cell surface antigen A2B5, neurofilament polypeptide NF200, oligodendrocyte marker 04, and intermediate filament proteins, nestin and vimentin. Strong immunoreactivity was observed with astrocyte marker GFAP. A proportion of cultured MSCs developed into neuron-like cells that were positive for TUJ-1 neural progenitor marker. These results indicate that human UCB-derived MSCs are enriched for neuro-glial progenitors, and could be further developed for the treatment of stroke, spinal cord injury, and neurodegenerative diseases such as like Alzheimer’s, Parkinson’s and Multiple Sclerosis.