title: Differential patterns of receptor activator of nuclear factor kappa B ligand/osteoprotegerin expression in human periapical granulomas: possible association with progressive or stable nature of the lesions.
abstract: Receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) are expressed in apical periodontitis, suggesting a role for these molecules during lesion development. However, the profiles of RANKL/OPG expression in periapical lesions remain unknown. In this study we investigated the patterns of RANKL and OPG mRNA expression by real-time polymerase chain reaction in human periapical granulomas (N = 44) and compared them with sites presenting characteristic bone resorbing activity: healthy (n = 14) and orthodontically stretched and compressed periodontal ligament (n = 26), healthy gingiva (n = 24), chronic gingivitis (n = 32), and chronic periodontitis (n = 34) samples. Both RANKL and OPG mRNA expression was higher in periapical granulomas when compared with healthy periodontal ligament. Distinct patterns of RANKL and OPG expression ratio were found in the granulomas and in different physiologic and pathologic conditions, with characteristic bone resorption activity potentially being indicative of the stable or progressive nature of the lesions. Lesions with radiographic image smaller than 5 mm showed higher RANKL/OPG expression than images greater than 5 mm. Periapical granulomas presented heterogeneous patterns of RANKL and OPG expression, ranging from samples with RANKL/OPG ratio similar to that seen in sites with minimal or absent bone resorption to samples with RANKL/OPG expression pattern comparable with active bone resorption sites.
authors.affiliation: Department of Endodontics, Bauru Dental School, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Menezes
authors.forename: Thiago Pompermaier
authors.initials: TP
authors.lastname: Garlet
authors.forename: Ariadne
authors.initials: A
authors.lastname: Letra
authors.forename: Clóvis Monteiro
authors.initials: CM
authors.lastname: Bramante
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Campanelli
authors.forename: Rita de Cássia
authors.initials: Rde C
authors.lastname: Figueira
authors.forename: Mari Claide
authors.initials: MC
authors.lastname: Sogayar
authors.forename: José Mauro
authors.initials: JM
authors.lastname: Granjeiro
authors.forename: Gustavo Pompermaier
authors.initials: GP
authors.lastname: Garlet
mesh_terms: D000293:Adolescent; D000328:Adult; D016301:Alveolar Bone Loss / Q000378:metabolism* / Q000473:pathology; D016723:Bone Remodeling; D003799:Dental Stress Analysis; D018450:Disease Progression; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D053244:Osteoprotegerin / Q000096:biosynthesis*; D010484:Periapical Granuloma / Q000378:metabolism* / Q000473:pathology*; D010510:Periodontal Diseases / Q000378:metabolism; D010513:Periodontal Ligament / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D053245:RANK Ligand / Q000096:biosynthesis*; D014087:Tooth Movement Techniques
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand