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Technetium‐99 conjugated with methylene diphosphonate inhibits receptor activator of nuclear factor‐ κ B ligand‐induced osteoclastogenesis
Author(s) -
Gong Wei,
Dou Huan,
Liu Xianqin,
Sun Lingyun,
Hou Yayi
Publication year - 2012
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.2012.12006.x
Subject(s) - rankl , osteoclast , chemistry , cathepsin k , microbiology and biotechnology , activator (genetics) , tumor necrosis factor alpha , cancer research , receptor , endocrinology , biology , biochemistry
Summary In the present study, we investigated the effects of technetium‐99 conjugated with methylene diphosphonate ( 99 T c‐ MDP ), an agent used in radionuclide therapy, on receptor activator of nuclear factor‐κ B ligand ( RANKL )‐induced osteoclastogenesis and explored the underlying mechanisms. The murine macrophage cell line RAW 264.7 and bone marrow‐derived‐macrophages from C 57 BL /6 mice ( BMM ) were used as models for osteoclastogenesis in vitro . The expression of some key factors in RANKL (50 ng/mL)‐induced osteoclastogenesis in RAW 264.7 cells was investigated by flow cytometry and real‐time reverse transcription–polymerase chain reaction ( RT‐PCR ). To detect multinucleated osteoclast formation, RAW 264.7 cells were induced with RANKL for 4 days, whereas BMM were induced by 50 ng/mL RANKL and 20 ng/mL macrophage colony‐stimulating factor for 7 days, before being stained with tartrate‐resistant acid phosphatase. Osteoclastogenesis was evaluated using the osteoclast markers CD 51, matrix metalloproteinase ( MMP )‐9 and cathepsin K . At 0.01 μg/mL, 99 T c‐ MDP significantly inhibited RANKL ‐induced osteoclastogenesis without any cytotoxicity. In addition, 99 T c‐ MDP abolished the appearance of multinucleated osteoclasts. Real‐time RT ‐ PCR analysis of transcription factor expression revealed that 99 T c‐ MDP inhibited the expression of c‐Fos and nuclear factor of activated T cells. In addition, 99 T c‐ MDP inhibited the expression of the inflammatory factors interleukin ( IL )‐6, tumour necrosis factor‐α and IL ‐1β. Finally, 99 T c‐ MDP inhibited the activation of mitogen‐activated protein kinases in RAW 264.7 cells following RANKL stimulation. In conclusion, 99 T c‐ MDP possesses anti‐osteoclastogenic activity against RANKL ‐induced osteoclast formation.