title: Effect of recombinant human bone morphogenetic protein-2 on bisphosphonate-treated osteoblasts.
abstract: OBJECTIVE
  Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a side effect of bisphophonate therapy that has been reported in recent years. Osteoclastic inactivity by bisphosphonate is the known cause of BRONJ. Bone morphogenetic protein-2 (BMP-2) plays an important role in the development of bone. Recombinant human BMP-2 (rhBMP-2) is potentially useful as an activation factor for bone repair. We hypothesized that rhBMP-2 would enhance the osteoclast-osteoblast interaction related to bone remodeling.
  
  
  METHODS
  Human fetal osteoblast cells (hFOB 1.19) were treated with 100 µM alendronate, and 100 ng/mL rhBMP-2 was added. Cells were incubated for a further 48 hours, and cell viability was measured using an MTT assay. Expression of the three cytokines from osteoblasts, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF), were analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Cell viability was decreased to 82.75%±1.00% by alendronate and then increased to 110.43%±1.35% after treatment with rhBMP-2 (P<0.05, respectively). OPG, RANKL, and M-CSF expression were all decreased by alendronate treatment. RANKL and M-CSF expression were increased, but OPG was not significantly affected by rhBMP-2.
  
  
  CONCLUSIONS
  rhBMP2 does not affect OPG gene expression in hFOB, but it may increase RANKL and M-CSF gene expression.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: Taek-Kyun
authors.initials: TK
authors.lastname: Kwon
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Song
authors.affiliation: Department of Oral Anatomy and Cell Biology, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: In-Ryoung
authors.initials: IR
authors.lastname: Kim
authors.affiliation: Department of Oral Anatomy and Cell Biology, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: Bong-Soo
authors.initials: BS
authors.lastname: Park
authors.affiliation: Department of Dentistry, Dong-A University Hospital, Busan, Korea.
authors.forename: Chul-Hoon
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: In-Kyo
authors.initials: IK
authors.lastname: Cheong
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Yangsan, Korea.
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Shin
keywords: Alendronate; Bone morphogenetic protein-2; Macrophage colony-stimulating factor; Osteoblasts; RANK ligand