title: Increased expression of receptor activator of NF-kappaB ligand (RANKL), its receptor RANK and its decoy receptor osteoprotegerin in the colon of Crohn's disease patients.
abstract: Crohn's disease (CD) is associated with low bone mass due to chronic inflammation and other factors. Receptor activator of NF-kappaB ligand (RANKL), its receptor RANK and its decoy receptor osteoprotegerin (OPG) are potentially involved in this process as they regulate osteoclastogenesis and are influenced by pro-inflammatory cytokines. The aim of this study was to determine the levels of soluble RANKL (sRANKL), RANK and OPG expression both in the serum and in the colon of CD patients. Levels of sRANKL and OPG were assessed in the serum and the supernatants of cultured colonic biopsies in patients with CD and controls by ELISA. RANK expression was explored by immunostaining and immunofluorescence of fixed colonic samples. OPG and sRANKL levels were higher in the serum of CD patients as compared to age- and sex-matched controls. Levels of sRANKL and OPG were significantly enhanced in cultured colonic biopsies from CD, and OPG levels correlated with histological inflammation, and pro- and anti-inflammatory cytokine levels. No significant correlation was found for sRANKL. RANK+ cells were increased in the colon of CD, particularly in inflamed areas. These cells were positive for CD68 or S100 protein. We conclude that serum and local levels of sRANKL and OPG are increased in CD. Moreover, RANK is expressed in the colonic mucosa by subpopulations of activated macrophages or dendritic cells at higher levels in CD compared to normal colon.
authors.affiliation: Rheumatology Department, University of Liège, CHU Sart-Tilman, 4000 Liège, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Franchimont
authors.forename: C
authors.initials: C
authors.lastname: Reenaers
authors.forename: C
authors.initials: C
authors.lastname: Lambert
authors.forename: J
authors.initials: J
authors.lastname: Belaiche
authors.forename: V
authors.initials: V
authors.lastname: Bours
authors.forename: M
authors.initials: M
authors.lastname: Malaise
authors.forename: P
authors.initials: P
authors.lastname: Delvenne
authors.forename: E
authors.initials: E
authors.lastname: Louis
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002352:Carrier Proteins / Q000097:blood / Q000276:immunology*; D003106:Colon / Q000276:immunology*; D003424:Crohn Disease / Q000097:blood / Q000276:immunology*; D016207:Cytokines / Q000032:analysis; D005260:Female; D005455:Fluorescent Antibody Technique / Q000379:methods; D006023:Glycoproteins / Q000097:blood / Q000276:immunology*; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood / Q000276:immunology*; D008875:Middle Aged; D016328:NF-kappa B / Q000097:blood / Q000276:immunology; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear / Q000097:blood / Q000276:immunology*; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood / Q000276:immunology*; D046509:Tissue Culture Techniques / Q000379:methods
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D002352:Carrier Proteins; D016207:Cytokines; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D016328:NF-kappa B; 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