@phdthesis{oai:nagasaki-u.repo.nii.ac.jp:00004908,
 author = {山下, 恭德},
 month = {Aug},
 note = {Background
Osteoclasts differentiated from bone marrow macrophages (BMMs) induced by TNF-α alone do not have resorbing activity. When BMMs are stimulated with receptor activator of NF-κB ligand (RANKL) before TNF-α stimulation, pit-forming osteoclasts are differentiated. However, the details of the effect of RANKL pretreatment on the pit-forming osteoclast differentiation by TNF-α have not been established. The aim of this study is to examine the condition of RANKL pretreatment for differentiation of pit-forming osteoclasts induced by TNF-α.
Murine BMMs were stimulated with various concentrations of RANKL for 24 h in the presence of M-CSF, then the medium was changed and TNF-α was added. Osteoclasts and pits formation were examined. Osteoprotegerin (OPG), decoy receptor of RANKL, was added to the culture to examine the necessity of co-existing RANKL with TNF-α on the formation of pit-forming osteoclasts. To investigate the influence of RANKL of sufficient concentration as pretreatment for pit-forming osteoclast formation by TNF-α, dose- and time-dependent changes of osteoclast formation were checked.
Results
The pit formation by osteoclasts in response to TNF-α required 10 ng/mL RANKL pretreatment. Stimulation with this concentration of RANKL led to the differentiation of mature osteoclasts in the 72 h culture. The pit formation was not inhibited by the OPG.
Conclusion
These results suggested that the concentration of RANKL pretreatment, which also alone can differentiate BMMs into osteoclasts, may be important in the differentiation of pit-forming osteoclasts by TNF-α. In addition, the effects of TNF-α after RANKL treatment might be independent of RANKL., 長崎大学学位論文 学位記番号:博(医歯薬)甲第789号 学位授与年月日:平成27年8月5日, Author: Yasunori Yamashita, Takashi Ukai, Hirotaka Nakamura, Yasunori Yoshinaga, Hiroki Kobayashi, Yuzo Takamori, Satoshi Noguchi, Atsutoshi Yoshimura, Yoshitaka Hara, Citation: Archives of Oral Biology, 60(9), pp.1273-1282; 2015, Nagasaki University (長崎大学), 博士(歯学) (2015-08-05)},
 school = {Nagasaki University (長崎大学)},
 title = {RANKL pretreatment plays an important role in the differentiation of pit-forming osteoclasts induced by TNF-α on murine bone marrow macrophages},
 year = {2015}
}