Glycomics of bone marrow-derived mesenchymal stem cells can be used to evaluate their cellular differentiation stage

Human mesenchymal stem cells (MSCs) are adult multipotent progenitor cells. They hold an enormous therapeutic potential, but at the moment there is little information on the properties of MSCs, including their surface structures. In the present study, we analyzed the mesenchymal stem cell glycome by using mass spectrometric profiling as well as a panel of glycan binding proteins. Structural verifications were obtained by nuclear magnetic resonance spectroscopy, mass spectrometric fragmentation, and glycosidase digestions. The MSC glycome was compared to the glycome of corresponding osteogenically differentiated cells. More than one hundred glycan signals were detected in mesenchymal stem cells and osteoblasts differentiated from them. The glycan profiles of MSCs and osteoblasts were consistently different in biological replicates, indicating that stem cells and osteoblasts have characteristic glycosylation features. Glycosylation features associated with MSCs rather than differentiated cells included high-mannose type N-glycans, linear poly-N-acetyllactosamine chains and α2-3-sialylation. Mesenchymal stem cells expressed SSEA-4 and sialyl Lewis x epitopes. Characteristic glycosylation features that appeared in differentiated osteoblasts included abundant sulfate ester modifications. The results show that glycosylation analysis can be used to evaluate MSC differentiation state.