title: Immunohistochemical localization of receptor activator of nuclear factor kappaB (RANK) and its ligand (RANKL) in human deciduous teeth.
abstract: Osteoblasts and osteoclasts are involved in bone formation and resorption. RANK and RANKL [receptor activator of nuclear factor kappaB (ligand)], two cytokine-like proteins of the tumor necrosis factor superfamily, are localized on these bone cells and are crucial for the regulation of osteoclastic cell differentiation from hematopoietic precursors and also for the upregulation of mature osteoclasts mediated by cell-to-cell contact and a subsequent cascade of diverse intracellular signaling processes in the osteoclasts. It was the aim of this study to examine the sites of expression of RANKL and RANK in the corresponding cells of human dental hard and periodontal tissues using immunohistochemical light microscopical methods on tissue sections of 15 paraffin-embedded human deciduous teeth undergoing root resorption. We detected granular cytoplasmic RANKL-immunoreactivity in odontoblasts, pulp fibroblasts, periodontal ligament fibroblasts, and in single odontoclasts, the latter finding suggesting an autocrine/paracrine role. RANK-positive cells were identified as multinucleated odontoclasts localized near the dentine surface in resorption lacunae or as mononucleated precursors. These findings indicate that human dental cells express key mediators of hard tissue resorption and, though the RANK/RANKL-system may not be the sole regulator of tooth root resorption, these factors could at least contribute to this complex process under both physiological and pathological conditions.
authors.affiliation: Center of Anatomy, Georg-August-Universität Göttingen, Dept. of Histology, Germany. S.lossdoerfer@gmx.de
authors.forename: S
authors.initials: S
authors.lastname: Lossdörfer
authors.forename: W
authors.initials: W
authors.lastname: Götz
authors.forename: A
authors.initials: A
authors.lastname: Jäger
mesh_terms: D000327:Adsorption; D015415:Biomarkers / Q000032:analysis; D002352:Carrier Proteins / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D006023:Glycoproteins / Q000032:analysis*; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000032:analysis*; D010006:Osteoblasts / Q000166:cytology; D010010:Osteoclasts / Q000166:cytology; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis*; D018124:Receptors, Tumor Necrosis Factor; D014094:Tooth, Deciduous / Q000737:chemistry / Q000166:cytology*
chemical_list: D015415:Biomarkers; 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