OCT4A transcript level correlates with proliferation potential of human mesenchymal stem cells

Mesenchymal stem cells (MSCs) are somatic stem cells capable of self-renewal and differentiation into multiple cell types. The biology of MSCs has been studied extensively, however, a defined marker to identify MSCs with high proliferation and osteogenic differentiation ability is still lacking. Here, we studied the endogenous transcript levels of embryonic transcription factor OCT4 as a measure to identify bone marrow MSCs (BMMSCs) with high proliferation and osteogenic differentiation ability. Firstly, the OCT4 promoter in MSCs was hypomethylated suggesting the gene activity. Secondly, OCT4 mRNA expression was identified in BMMSCs, importantly, BMMSCs express the isoform OCT4A which maintains self-renewal in embryonic stem (ES) cells. Thirdly, OCT4A expression levels in BMMSCs showed high correlation with osteogenic differentiation potential and expression of cell cycle genes. Thus OCT4A transcript levels might be used as an indicator of proliferation and osteogenic differentiation potential of BMMSCs.