Superior CKIP-1 sensitivity of orofacial bone-derived mesenchymal stem cells in proliferation and osteogenic differentiation compared to long bone-derived mesenchymal stem cells

Maxillofacial bone defects caused by multiple factors, including congenital deformations and tumors, have become a research focus in the field of oral medicine. Bone tissue engineering is increasingly regarded as a potential approach for maxillofacial bone repair. Mesenchymal stem cells (MSCs) with different origins display various biological characteristics. The aim of the present study was to investigate the effects of casein kinase-2 interaction protein-1 (CKIP-1) on MSCs, including femoral bone marrow-derived MSCs (BMMSCs) and orofacial bone-derived MSCs (OMSCs), isolated from the femoral and orofacial bones of wild-type (WT) and CKIP-1 knockout (KO) mice. MSCs were isolated using collagenase II and the main biological characteristics, including proliferation, apoptosis and osteogenic differentiation, were investigated. Subcutaneous transplantation of MSCs in mice was also performed to assess ectopic bone formation. MTT and clone formation assay results indicated that cell proliferation in the KO group was increased compared with the WT group, and OMSCs exhibited significantly increased levels of proliferation compared with BMMSCs. However, the proportion of apoptotic cells was not significantly different between CKIP-1 KO OMSCs and BMMSCs. Furthermore, it was revealed that osteogenic differentiation was increased in CKIP-1 KO MSCs compared with WT MSCs, particularly in OMSCs. Consistent with the in vitro results, enhanced ectopic bone formation was observed in CKIP-1 KO mice compared with WT mice, particularly in OMSCs compared with BMMSCs. In conclusion, the present results indicated that OMSCs may have a superior sensitivity to CKIP-1 in promoting osteogenesis compared with BMMSCs; therefore, CKIP-1 KO in OMSCs may serve as an efficient strategy for maxillofacial bone repair.