In vivo, osteogenesis is tightly connected with capillaries and endothelium assumed to be one of the main regulators of osteogenic differentiation of underling mesenchymal cell. In our experiments in vitro, we cultured human osteoblasts and human umbilical vein cord endothelial cells (HUVEC) in osteogenic conditions in direct joint culture and in separated joint culture where cells were separated with membrane permeable for proteins, but not for the cells. We revealed that in direct co-cultivation endothelial cells enhance osteoblast differentiation, but in separated co-cultures endothelium completely inhibit osteogenic differentiation. To understand molecular mechanisms of these osteoinductive/osteosupressive properties we performed shotgun proteomics analysis of control cultures and cells from joint cultures. To separate cells from direct co-culture we used magnetic sorting.