Changes in the expression pattern of mesenchymal and pluripotent markers in human adipose-derived stem cells

Pluripotent marker genes encode transcription factors that suppress differentiation and allow stem cells to continue proliferation while remaining poised to develop into cells from multiple lineages. Mesenchymal marker proteins are widely used to identify and characterize multipotent stem cells that are capable of differentiation into cells of the mesenchymal lineage. We examine here the expression pattern of mesenchymal and pluripotent markers in ADSCs (human adipose-derived stem cells) during culture. Flow cytometry indicates that a large fraction of ADSCs were positive for multiple mesenchymal markers, such as CD29, CD44 and CD90. The expression levels of these markers increase and become more uniform in cells that are cultured for long periods. Alternatively, mRNAs for several pluripotent genes, such as Nanog, Oct-4 and Rex-1, are detected only in cells from early passages. In addition, ADSCs cultured over long periods express several cardiac genes in response to serum deprivation and treatment with phorbol ester. Thus, these data demonstrate that ADSCs expanded in culture over multiple passages consistently express mesenchymal markers with the ability to differentiate towards the cardiac lineage.