title: Pulsed electromagnetic fields stimulation affects osteoclast formation by modulation of osteoprotegerin, RANK ligand and macrophage colony-stimulating factor.
abstract: Electromagnetic stimulation has been documented to treat recalcitrant problems of musculoskeletal system. Yet, the underlying mechanisms are not completely understood. In this study, we investigated effect of pulsed electromagnetic fields (PEMF) with parameters modified from clinical bone growth stimulator on osteoclast formation, bone resorption, and cytokines associated with osteoclastogenesis. Marrow cells were harvested from both femora and tibiae of 6 week-old mice and cultured in 8-well chamber slides or 16-well calcium phosphate apatite-coated multitest slides. After 1-day incubation, marrow cells were exposed to PEMF at different electric field intensities for 2h/day and continued for 9 days. Osteoprotegerin (OPG), receptor activator of NFkappaB-ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) concentrations of each group were determined after PEMF stimulation. Osteoclast identity was confirmed by both tartrate resistant acid phosphatase (TRAP) stain and bone resorption assay. A statistically significant increase and decrease of osteoclastogenesis and bone resorption areas were found when exposed to PEMF with different intensities. Besides, consistent correlations among OPG, RANKL, M-CSF, osteoclast numbers, and bone resorption after exposure to different intensities of PEMF were observed. These data demonstrated that PEMF with different intensities could regulate osteoclastogenesis, bone resorption, OPG, RANKL, and M-CSF concentrations in marrow culture system.
authors.affiliation: Department of Biomedical Engineering, Chung-Yuan Christian University, Chung-Li 32023, Taiwan. kylechang@nhri.org.tw
authors.forename: Kyle
authors.initials: K
authors.lastname: Chang
authors.forename: Walter Hong-Shong
authors.initials: WH
authors.lastname: Chang
authors.forename: Sherry
authors.initials: S
authors.lastname: Huang
authors.forename: Smile
authors.initials: S
authors.lastname: Huang
authors.forename: Chung
authors.initials: C
authors.lastname: Shih
mesh_terms: D000818:Animals; D001862:Bone Resorption / Q000209:etiology; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D004574:Electromagnetic Fields; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D010010:Osteoclasts / Q000502:physiology* / Q000528:radiation effects*; D010012:Osteogenesis / Q000528:radiation effects*; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor
chemical_list: D002352:Carrier Proteins; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C505687:Tnfrsf11a protein, mouse; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse; D016173:Macrophage Colony-Stimulating Factor