The Effect of Tumor Necrosis Factor-α at Different Concentrations on Osteogenetic Differentiation of Bone Marrow Mesenchymal Stem Cells

Tumor necrosis factor-alpha (TNF-) has been demonstrated to have a close relationship with inflammation in the body. Although most researchers confirmed that TNF- can have an effect on the expression of osteoblast specific genes, they had not elucidated the regulation of inflammatory factors in osteogenic gene expression during the process of bone marrow mesenchymal stem cells (BMMSCs) differentiating to osteoblast. The aim of this study was to investigate the effect of TNF- at different concentrations on osteogenetic differentiation of BMMSCs. In this study, BMMSCs proliferation was analyzed by using cell counting kit-8 assay, cell osteogenic differentiation was evaluated by means of alkaline phosphatase activity assay and Von Koaas staining and the messenger RNA (mRNA) expression of bone morphogenetic proteins-2 (BMP-2) and drosophila mothers against decapentaplegic protein 1 (Smad1) was measured through real-time polymerase chain reaction. The results indicated that a low concentration of TNF- at short-term promotes the osteogenetic differentiation of BMMSCs and increases the mRNA expression of BMP-2 and Smad1, but inhibits the osteogenetic differentiation of BMMSCs and the expression of BMP-2 and Smad1 at long term. In addition, regardless of a short or long time, a high concentration of TNF- inhibits the osteogenetic differentiation of BMMSCs and the expression of Smad1, but results in a high expression of BMP-2.