title: RANKL increase in compressed periodontal ligament cells from root resorption.
abstract: The ligand receptor activator of NFkappaB (RANKL) plays an important role in osteoclast formation. However, very little is known about the relationship between external apical root resorption during orthodontic treatment and RANKL. We hypothesized that compressive force is responsible for RANKL formation and up-regulation of osteoclastogenesis in periodontal ligament (PDL) cells from patients with severe orthodontically induced external apical root resorption. RANKL and osteoprotegerin (OPG) production, TRAP-positive cells, and resorptive pits were determined. The increase of RANKL and the decrease of OPG were greater in the severe root resorption group than in the non-resorption group. The numbers of TRAP-positive cells and resorptive pits were also increased in the severe root resorption group than in the non-resorption group. These results support the hypothesis that the compressed PDL cells obtained from tissues with severe external apical root resorption may produce a large amount of RANKL and up-regulate osteoclastogenesis.
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry at Matsudo, 2-870-1 Sakaecho-Nishi, Matsudo City, Chiba 271-8587, Japan. yamaguchi.masaru@nihon-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: N
authors.initials: N
authors.lastname: Aihara
authors.forename: T
authors.initials: T
authors.lastname: Kojima
authors.forename: K
authors.initials: K
authors.lastname: Kasai
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D015153:Blotting, Western; D002352:Carrier Proteins / Q000096:biosynthesis*; D016022:Case-Control Studies; D002454:Cell Differentiation; D002478:Cells, Cultured; D018920:Coculture Techniques; D019245:Compressive Strength; D003799:Dental Stress Analysis; D005260:Female; D006023:Glycoproteins / Q000096:biosynthesis; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D010010:Osteoclasts / Q000166:cytology; D053244:Osteoprotegerin; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis; D012391:Root Resorption / Q000209:etiology / Q000378:metabolism*; D014087:Tooth Movement Techniques / Q000009:adverse effects*
chemical_list: D002352:Carrier Proteins; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C505686:TNFRSF11A protein, human; C506030:TNFRSF11B protein, human; C505688:TNFSF11 protein, human