title: Impact of inflammation on the osteoblast in rheumatic diseases.
abstract: Normal bone remodeling depends upon a balance between the action of bone-resorbing cells, osteoclasts, and bone-forming cells, osteoblasts. When this balance is disrupted, as is seen in inflammatory diseases such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS), abnormal bone loss or bone formation occurs. In RA, proinflammatory cytokines induce osteoclast differentiation and inhibit osteoblast maturation, leading to articular bone erosions. In contrast, the inflammatory milieu in AS leads to excessive osteoblast activation and bone formation at sites of entheses. While much information exists about the effects of proinflammatory cytokines on osteoclast differentiation and function, more recent studies have begun to elucidate the impact of inflammation on the osteoblast. This review will summarize the mechanisms by which inflammation perturbs bone homeostasis, with a specific focus on the osteoblast.
authors.affiliation: Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School, Lazare Research Building, Suite 223, 364 Plantation Street, Worcester, MA, 01605, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Baum
authors.forename: Ellen M
authors.initials: EM
authors.lastname: Gravallese
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology*; D016723:Bone Remodeling / Q000276:immunology*; D001862:Bone Resorption / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D016207:Cytokines; D006801:Humans; D007249:Inflammation / Q000276:immunology; D018836:Inflammation Mediators / Q000276:immunology; D010006:Osteoblasts / Q000166:cytology*; D010010:Osteoclasts / Q000166:cytology*; D013167:Spondylitis, Ankylosing / Q000276:immunology*
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators