title: In vivo osteoprotegerin gene therapy preventing bone loss induced by periodontitis.
abstract: OBJECTIVE
  The objective of this study was to investigate the effects of osteoprotegerin (OPG) gene therapy on alveolar bone resorption caused by experimental periodontitis in rats, thus forming a foundation for potential clinical applications of OPG gene therapy in the treatment of periodontitis and peri-implantitis.
  
  
  METHODS
  To study the effects of OPG on alveolar bone protection, an experimental periodontitis model was used by placing a bacterial plaque retentive silk ligature in the gingival sulcus around the maxillary second molar tooth, injection of Porphyromonas gingivalis and high carbohydrate diet. A total of 30 Sprague-Dawley rats were randomly divided into three groups, with 10 rats in each group: group I (control) was treated with 10 μL normal saline injection; group II with 10 μL mock vector; and group III with 10 μL local OPG gene transfer by transfection with in vitro constructed pcDNA3.1-human OPG (pcDNA3.1-hOPG). A subperiosteal injection was done adjacent to the second molars on days 0, 7, 14 and 21. Four weeks later, all animals were killed and radiographic, histological and immunohistochemical examinations were performed. Statistical analysis included ANOVA and LSD-Bonferroni test.
  
  
  RESULTS
  Group III (OPG gene therapy) had significantly enhanced (p < 0.05) integrated optical density of OPG, had significantly decreased alveolar bone resorption volume and active osteoclast number (p < 0.05) through descriptive histological examination when compared with the other two groups at week 4.
  
  
  CONCLUSIONS
  Local recombinant OPG plasmid-mediated gene therapy suppresses osteoclastogenesis in vivo and inhibits alveolar bone height reduction caused by experimental periodontitis in rats. OPG gene therapy may be beneficial in preventing progressive periodontal bone loss.
authors.affiliation: West China Hospital of Stomatology, Sichuan University, Chengdu, China.|The Prince Philip Dental Hospital, The University of Hong Kong, Hong Kong, China.
authors.forename: H
authors.initials: H
authors.lastname: Tang
authors.affiliation: The Prince Philip Dental Hospital, The University of Hong Kong, Hong Kong, China.
authors.forename: N
authors.initials: N
authors.lastname: Mattheos
authors.affiliation: West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Yao
authors.affiliation: West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Jia
authors.affiliation: West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: L
authors.initials: L
authors.lastname: Ma
authors.affiliation: West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: P
authors.initials: P
authors.lastname: Gong
mesh_terms: D016301:Alveolar Bone Loss / Q000382:microbiology / Q000517:prevention & control*; D000818:Animals; D002460:Cell Line; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000627:therapeutic use; D006801:Humans; D008855:Microscopy, Electron, Scanning; D032446:Myoblasts / Q000502:physiology; D010010:Osteoclasts / Q000473:pathology; D053244:Osteoprotegerin / Q000235:genetics* / Q000627:therapeutic use; D010518:Periodontitis / Q000150:complications* / Q000382:microbiology; D010957:Plasmids / Q000235:genetics; D016966:Porphyromonas gingivalis / Q000502:physiology; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014162:Transfection / Q000379:methods
chemical_list: D053244:Osteoprotegerin; C506032:Tnfrsf11b protein, rat
keywords: aggressive periodontitis; animal model; cytokines; genetics; host modulation therapy; periodontal therapy