title: Platelet-rich plasma suppresses osteoclastogenesis by promoting the secretion of osteoprotegerin.
abstract: OBJECTIVE
  Platelet-rich plasma is characterized by containing fundamental protein growth factors. Although many in vitro studies have documented the capability of platelet-rich plasma to induce the growth of osteoblasts or osteoblast-like cells, the effect of platelet-rich plasma on osteoclastogenesis has not yet been studied. The aim of the present study was to evaluate the effects of platelet-rich plasma and platelet-poor plasma on osteoclastogenesis with rat bone marrow cell culture.
  
  
  METHODS
  Platelet-rich plasma and platelet-poor plasma were produced from the whole blood of rat. For cell culture, rat bone marrow cells were isolated from rat tibiae and then treated with 1,25alpha dihydroxy vitamin D(3) and with different concentrations of platelet-rich plasma or platelet-poor plasma. After 4 d of culture, rat bone marrow cells were stained with tartrate-resistant acid phosphatase (TRAP), and TRAP-positive cells that had more than three nuclei (TRAP-positive multinucleated cells) were counted as osteoclast-like cells. Osteoprotegerin, known as an osteoclastogenesis-related factor, cells was quantified using an enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Although platelet-poor plasma had no effect on the formation of TRAP-positive multinucleated cells, platelet-rich plasma decreased the number of TRAP-positive multinucleated cells in a dose-dependent manner. The amount of osteoprotegerin produced from rat bone marrow cells and from MC3T3-E1 cells was enhanced in platelet-rich plasma-treated groups.
  
  
  CONCLUSIONS
  Under our experimental conditions, platelet-rich plasma decreased the formation of TRAP-positive multinucleated cells and increased the secretion of osteoprotegerin. This study suggests that platelet-rich plasma suppresses osteoclastogenesis, therefore inhibiting bone resorption. In addition we also demonstrated that platelet-rich plasma increased the secretion of osteoprotegerin, an inhibitor for osteoclast formation, thus suggesting that the enhancement of osteoprotegerin secretion induces this inhibitory effect.
authors.affiliation: Department of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan. ogino@dent.kyushu-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Ogino
authors.forename: Y
authors.initials: Y
authors.lastname: Ayukawa
authors.forename: T
authors.initials: T
authors.lastname: Kukita
authors.forename: I
authors.initials: I
authors.lastname: Atsuta
authors.forename: K
authors.initials: K
authors.lastname: Koyano
mesh_terms: D016475:3T3 Cells; D000135:Acid Phosphatase / Q000096:biosynthesis; D000818:Animals; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism; D049109:Cell Proliferation; D002478:Cells, Cultured; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis; D008297:Male; D051379:Mice; D010006:Osteoblasts / Q000378:metabolism; D010010:Osteoclasts / Q000187:drug effects*; D053244:Osteoprotegerin / Q000819:agonists / Q000096:biosynthesis*; D010949:Plasma; D053657:Platelet-Rich Plasma; D051381:Rats; D017207:Rats, Sprague-Dawley; D000071681:Tartrate-Resistant Acid Phosphatase; D014807:Vitamin D / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D050071:Bone Density Conservation Agents; D036341:Intercellular Signaling Peptides and Proteins; D007527:Isoenzymes; D053244:Osteoprotegerin; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase