title: Technetium-99 conjugated with methylene diphosphonate inhibits receptor activator of nuclear factor-κB ligand-induced osteoclastogenesis.
abstract: 1. In the present study, we investigated the effects of technetium-99 conjugated with methylene diphosphonate ((99)Tc-MDP), an agent used in radionuclide therapy, on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and explored the underlying mechanisms. 2. The murine macrophage cell line RAW264.7 and bone marrow-derived-macrophages from C57BL/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 RAW264.7 cells was investigated by flow cytometry and real-time reverse transcription-polymerase chain reaction (RT-PCR). To detect multinucleated osteoclast formation, RAW264.7 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. 3. Osteoclastogenesis was evaluated using the osteoclast markers CD51, matrix metalloproteinase (MMP)-9 and cathepsin K. At 0.01 μg/mL, (99)Tc-MDP significantly inhibited RANKL-induced osteoclastogenesis without any cytotoxicity. In addition, (99)Tc-MDP abolished the appearance of multinucleated osteoclasts. 4. Real-time RT-PCR analysis of transcription factor expression revealed that (99)Tc-MDP inhibited the expression of c-Fos and nuclear factor of activated T cells. In addition, (99)Tc-MDP inhibited the expression of the inflammatory factors interleukin (IL)-6, tumour necrosis factor-α and IL-1β. Finally, (99)Tc-MDP inhibited the activation of mitogen-activated protein kinases in RAW264.7 cells following RANKL stimulation. 5. In conclusion, (99)Tc-MDP possesses anti-osteoclastogenic activity against RANKL-induced osteoclast formation.
authors.affiliation: Immunology and Reproductive Biology Laboratory, Medical School and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gong
authors.forename: Huan
authors.initials: H
authors.lastname: Dou
authors.forename: Xianqin
authors.initials: X
authors.lastname: Liu
authors.forename: Lingyun
authors.initials: L
authors.lastname: Sun
authors.forename: Yayi
authors.initials: Y
authors.lastname: Hou
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D001862:Bone Resorption / Q000188:drug therapy* / Q000378:metabolism; D056657:Cathepsin K / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D005260:Female; D039564:Integrin alphaV / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D050778:NFATC Transcription Factors / Q000378:metabolism; D016761:Oncogene Proteins v-fos / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects* / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000494:pharmacology; D000071681:Tartrate-Resistant Acid Phosphatase; D013669:Technetium Tc 99m Medronate / Q000494:pharmacology*
chemical_list: D039564:Integrin alphaV; D053583:Interleukin-1beta; D015850:Interleukin-6; D007527:Isoenzymes; D016328:NF-kappa B; D050778:NFATC Transcription Factors; C494005:Nfatc1 protein, mouse; D016761:Oncogene Proteins v-fos; D053245:RANK Ligand; D019275:Radiopharmaceuticals; C505689:Tnfsf11 protein, mouse; D016173:Macrophage Colony-Stimulating Factor; D020928:Mitogen-Activated Protein Kinases; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D056657:Cathepsin K; C534132:Ctsk protein, mouse; D020780:Matrix Metalloproteinase 9; D013669:Technetium Tc 99m Medronate