C/EBPβ mediates osteoclast recruitment by regulating endothelial progenitor cell expression of SDF-1α.

Integration of tissue-engineered bone grafts with the host bone is vital for the healing of critical-size bone defects. An important aspect of this process is bone resorption, which must be carried out by osteoclasts derived from the host. However, the mechanism underlying recruitment of host osteoclast precursors to graft sites remains unclear.

Prevascularisation with endothelial progenitor cells improved restoration of the architectural and functional properties of newly formed bone for bone reconstruction.

Purpose: The aim of this study was to examine whether the addition of endothelial progenitor cells (EPCs) contributes to restoring the architectural and functional properties of newly formed bone for reconstruction of bone defects.

Methods: Bone marrow-derived EPCs and mesenchymal stem cells (MSCs) were co-seeded onto demineralized bone matrix (DBM) as a prevascularized tissue-engineered bone (TEB) for the repair of segmental bone defects to evaluate the effects of prevascularization of TEB on ameliorating morphological, haemodynamic and mechanical characteristics.

Results: The restoration of the intraosseous vasculature and medullary cavity was improved markedly compared to the non-prevascularized groups.

Co-culture with endothelial progenitor cells promotes survival, migration, and differentiation of osteoclast precursors.

In this study, we report the effect of endothelial progenitor cells (EPCs) on the biological behavior of osteoclast precursors in vitro by establishing an indirect co-culture system of mice EPCs and RAW 264.7 monocyte cells. Results show that the survival, migration, and differentiation of osteoclast precursors were greatly enhanced when co-cultured with EPCs.