Effect of bone marrow blood versus peripheral blood on the hemostatic balance of osteoblasts and endothelial cells

Bone and bone-marrow (BM) have the same blood supply and thus may be considered as one organ. We previously demonstrated that the microcirculation hemostatic balance that includes heparanase, tissue factor (TF), TF pathway inhibitor (TFPI) and TFPI-2 are organ dependent. The present study aim was to investigate the effect of BM microcirculation blood on osteoblasts and human umbilical vein endothelial cells (HUVECs) compared with peripheral-blood (PB). Fourteen patients were recruited. BM blood was drawn from the pelvis and PB from the arm of each patient. Mesenchymal stem cells (MSCs) from the bone pellet were differentiated to osteoblasts. Cells were evaluated by ELISA, chromogenic assays and immunostaining. We found that levels of heparanase, TF, TFPI, and TFPI-2 were reduced in osteoblasts compared with MSCs (p < 0.05). Level of heparanase was lower in BM plasma compared with PB (p < 0.05). BM plasma attenuated heparanase procoagulant activity and level and increased proliferation in osteoblasts and HUVECs compared to PB plasma or the control. BM plasma increased HUVECs tube-formation compared with PB and control. Peptide 16AC, derived from heparanase that interacts with TF, enhanced, while peptide 6, that inhibits the interaction of heparanase-TF-complex, decreased heparanase level, procoagulant activity, and proliferation in osteoblast and HUVECs. In conclusion, osteoblasts acquire an attenuated hemostatic characteristic during differentiation. The microcirculation blood of the bone supports low hemostatic parameters in osteoblasts and enhances proliferation of cells and angiogenesis. The present data support the growing notion that the local microcirculation within a tissue or organ uniquely affects local hemostasis and angiogenesis.