Simultaneous harvesting of endothelial progenitor cells and mesenchymal stem cells from the human umbilical cord

The human umbilical cord (UC) is usually discarded as biological waste. However, it has attracted interest as a source of cells including endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs), which have demonstrated enormous potential in regenerative medicine. The present study describes a convenient protocol that has been developed to sequentially extract these two cell types from a single UC. EPCs which had properties of progenitor cells were successfully isolated from the UC vein. These cells had cobble-shaped morphology and expressed Flt-1, KDR, VE-cadherin, von Willebrand factor and CD31 mRNA, in addition to CD73, CD105 and vascular endothelial growth factor receptor-2. In addition to absorbing fluorescent-labeled acetylated low density protein and binding to fluorescein isothiocyanate-UEA-1, they were able to form vascular tube-like structures on Matrigel. Typical fibroblast-like cells, which were isolated from the Wharton's jelly, were confirmed to be MSCs by their expression of CD73, CD90 and CD105, and their ability to differentiate into adipocytes and osteoblasts. Thus, the human UC-derived cells may be suitable for use in tissue engineering and cell therapy.