Osteogenic differentiation of human mesenchymal stem cells from adipose tissue and Wharton’s jelly of the umbilical cord

Induced osteogenesis of mesenchymal stem cells (MSCs) may provide an important tool for bone injures treatment. Human umbilical cord and adipose tissue are routinely discarded as clinical waste and may be used as uncontroversial MSCs sources. It still remains to be verified which source of MSCs is the most suitable for bone regeneration.The aim of this research was to investigate the osteogenic potential of human MSCs derived from adipose tissue (ASCs) and Wharton’s jelly of the human umbilical cord (WJ-MSCs) differentiated under the same conditions.Osteogenic differentiation of MSCs was detected and quantified by ARS staining for calcium deposition and alkaline phosphatase (ALP) activity, osteoprotegerin (OPG), and osteocalcin (OC) secretion measurements. Under osteogenic conditions the measured ALP activity and calcium deposition were significantly higher in ASCs than in WJ-MSCs, while the OPG and OC secretion were higher in WJ-MSCs vs. ASCs. Low concentrations of OPG and high levels of OC in ASCs and WJ-MSCs, prove that these cells reached an advanced stage of the osteogenic differentiation. The levels of OC secreted by ASCs were lower than by WJ-MSCs what indicates that the differentiation process of the ASCs reached the stage when the extracellular matrix is overproduced and the down-regulation of OC begins.Both cell types, ASCs and WJ-MSCs possess potential to differentiate towards the osteogenic lineage. However, the observed differences in the levels of osteogenic markers suggest that ASCs may be better candidates for cell-based osteogenesis than WJ-MSCs.