Cell Surface and Functional Features of Cortical Bone Stem Cells

The newly established mouse cortical-bone-derived stem cells (mCBSCs) are unique stem cells compared to mouse mesenchymal stem cells (mMSCs). The mCBSC-treated hearts after myocardial infarction have been reported to have greater improvement in myocardial structure and functions. In this study, we examined the stemness features, cell surface glycan profiles, and paracrine functions of mCBSCs compared with mMSCs. The stemness analysis revealed that the self-renewing capacity of mCBSCs was greater than mMSCs; however, the differentiation capacity of mCBSCs was limited to the chondrogenic lineage among three types of cells (adipocyte, osteoblast, chondrocyte). The cell surface glycan profiles by lectin array analysis revealed that α2-6sialic acid is expressed at very low levels on the cell surface of mCBSCs compared with that on mMSCs. In contrast, the lactosamine (Galβ1-4GlcNAc) structure, poly lactosamine- or poly N-acetylglucosamine structure, and α2-3sialic acid on both N- and O-glycans were more highly expressed in mCBSCs. Moreover, we found that mCBSCs secrete a greater amount of TGF-β1 compared to mMSCs, and that the TGF-β1 contributed to the self-migration of mCBSCs and activation of fibroblasts. Together, these results suggest that unique characteristics in mCBSCs compared to mMSCs may lead to advanced utility of mCBSCs for cardiac and noncardiac repair.