The aim of the present study was to investigate the effects of adiponectin on bone marrow-derived monocytes (BMMs) in the process of osteoclastogenesis. Primary BMMs derived from the mouse bone marrow were cultured, which were then treated with different concentrations of adiponectin and macrophage colony stimulating factor (M-CSF). Cell viability was determined by measuring the absorbance after 24 h with Cell Counting Kit-8 reagent. BMM cells treated with adiponectin and receptor activator of nuclear factor-κB ligand (RANKL) were induced and differentiated to mature osteoclasts for 1 week, and then stained with tartrate-resistant acid phosphatase (TRAP). The number of osteoclasts was evaluated under light microscopy. The expression of adiponectin in BMMs at the gene and protein levels was further assessed with reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. The cellular proliferation experiment demonstrated that the optical density value decreased gradually with an increase of adiponectin concentration, with statistically significant differences detected among groups. In addition, the number of osteoclasts in the adiponectin-treated group was significantly reduced compared with that in the control group. Adiponectin expression was confirmed in BMMs at both the protein and mRNA levels. In conclusion, the present data demonstrated that adiponectin has a significant inhibitory effect on the osteoclast differentiation and proliferation of BMMs, suggesting a novel strategy for preventing osteoporosis.
Keywords: adiponectin; bone marrow-derived monocytes; nuclear factor-κB signaling; osteoclastogenesis; osteoporosis.