title: TNF-α suppression and osteoprotegerin overexpression inhibits wear debris-induced inflammation and osteoclastogenesis in vitro.
abstract: OBJECTIVE
  Periprosthetic osteolysis, involving RANK/RANKL/osteoprotegerin (OPG) and TNF-α/NFκB signaling, contributes to bone resorption and inflammation. We constructed lentivirus vectors to inhibit TNF-α and enhance OPG expression and assessed their impacts on wear debris-induced inflammation and osteoclastogenesis in an osteoclast/osteoblast coculture system.
  
  
  METHODS
  We transduced mouse osteoblastic MC3T3-E1 cells with Lenti-negative control (Lenti-NC), Lenti-OPG or Lenti-siTNFα-OPG, and murine macrophage/monocyte RAW264.7 cells with Lenti-NC, Lenti-TNF-α siRNA or Lenti-siTNFα-OPG. Then, TNF-α and OPG protein levels were evaluated by enzyme-linked immunosorbent assay. We cocultured transduced MC3T3-E1 and RAW264.7 cells in transwell chambers in the presence of 0.1 mg/mL Ti particles to investigate the capacity of TNF-α inhibition to reduce wear debris-induced inflammation. We also assessed mRNA levels TNF-α, IL-1β, IL-6 and OPG by RT-PCR as well as osteoclastogenesis by tartrate-resistant acid phosphatase.
  
  
  RESULTS
  Lenti-siTNFα-OPG ameliorated Ti-particle-induced expression of TNF-α, IL-1β, IL-6 in MC3T3-E1/RAW264.7 cocultures, while enhancing mRNA and protein levels of OPG, and reducing the fraction of tartrate-resistant acid phosphatase (TRAP)+ cells.
  
  
  CONCLUSIONS
  Lenti-siTNFα-OPG can inhibit the wear debris-induced inflammatory responses and osteoclastogenesis in vitro, and may represent a promising therapeutic candidate for the treatment or prevention of wear particle-induced osteolysis.
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin - China.
authors.forename: Li
authors.initials: L
authors.lastname: Peng
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin - China.
authors.forename: Haowei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin - China.
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin - China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Li
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin - China.
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin - China.
authors.forename: Yunge
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: The Third Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin - China.
authors.forename: Keguan
authors.initials: K
authors.lastname: Song
mesh_terms: D000818:Animals; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D007249:Inflammation / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010010:Osteoclasts / Q000378:metabolism*; D010014:Osteolysis; D053244:Osteoprotegerin / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
chemical_list: D016207:Cytokines; D053244:Osteoprotegerin; D014409:Tumor Necrosis Factor-alpha