Effects of macrophages and noggin suppression on the BMP-2-induced osteogenesis of human bone marrow mesenchymal stem cells

The osteogenic effects of bone morphogenetic protein-2 (BMP-2) on human mesenchymal stem cells (MSCs) are less profound than expected as compared with rodent cells, and supraphysiological dose of BMP-2 is required to achieve desired clinical outcome. The mechanism for this phenomenon is unclear. In this study, we examined the effects of macrophages and noggin suppression on the BMP-2-induced osteogenesis of human bone marrow MSCs in vitro.;In summary, our studies demonstrated that macrophages and knocking down the expression of noggin decreased BMP-2-induced osteogenesis of human MSCs in vitro. In the future, manipulation on macrophage activation and noggin expression may allow us to achieve higher BMP-2-induced osteogenesis that leads to better bone healing.;Our data show that macrophage conditioned medium significantly decreased the migration capacity, metabolic activity and BMP-2-induced osteogenesis of MSCs. In addition, knocking down noggin by small interfering RNA (siRNA) also significantly decreased BMP-2-induced osteogenesis and proliferation of MSCs.