Effect of stromal cell-derived factor-1α on osteoclast formation and bone resorption

Abstract

Objective To study the effect of Stromal cell-derived factor-1α (SDF-1α) on osteoclastogenesis and function, and to explore its possible regulatory mechanism. Methods Primary bone marrow mononuclear cells (BMM) was obtained from C57BL/6 mice. Receptor activator of nuclear factor kappa-Β ligand (RANKL) and Macrophage colony-stimulating factor (M-CSF) were used to induce BMM to osteoclasts. The cells were differentiated and divided into two groups during the induction: control group and 30 ng/ml SDF-1α intervention group. Then, tartrate-resistant acid phosphatase (TRAP) staining, bone plate absorption assay, and real-time quantitative polymerase chain reaction (PCR) were used. Results TRAP staining showed that BMM could successfully induce multinucleated osteoclasts; the number of osteoclasts in the SDF-1α intervention group [(91.2±15.7) cells] was higher than the control group [(45.6±10.2) cells], the difference was statistically significant (P<0.05); Bone resorption area in SDF-1α intervention group was (51.2±12.4)%, compared with the control group (25.1±6.3)%, the difference was statistically significant (P<0.05); TRAP, cathepsin K (CK), matrix metalloprotein (MMP)-9, nuclear factor of activated T cells 1 (NFATc1) and c-fos gene expression were also higher than the control group. The difference was statistically significant (P<0.05). Conclusion SDF-1α can promote the differentiation of osteoclasts and enhance the bone resorption of osteoclasts. These effects may be related to the upregulation of NFATc1 and c-fos, which may be one of the mechanisms. involved in osteoporosis and rheumatoid arthritis. Key words: Osteoclastogenesis; Stromal cell-derived factor-1α; Osteoporosis; Bone resorption