Abstract
The development of biological therapies has improved management of rheumatoid arthritis. However, costs and unresponsiveness to therapy in a sizeable proportion of patients limit their use, making it imperative to identify new targets for drug development programs. Here we investigated the melanocortin-receptor type 3 (MC(3)) pathway. Gene-deficient mice were subjected to a model of serum-transfer-induced arthritis and joints analyzed for gene expression (cytokines, MCs) and morphology. Pharmacological analyses were also conducted in this model. Osteoclastogenesis was studied from bone marrow cells. Mc(3)(-/-) mice displayed an exacerbated inflammatory arthritis, associated with prominent bone erosion and higher articular expression of Rankl. Osteoclastogenesis studied from Mc(3)(-/-) bone marrow cells revealed a higher degree of responsiveness to Rankl, linked to prolonged NF-κB activation compared to wild types. Up-regulation of a discrete set of inflammatory genes, including Il-1β, Il-6, and Nos2, was measured in Mc(3)(-/-) mice, and a marked up-regulation of joint Mc(3) accompanied arthritis resolution in wild-type mice. Administration of an MC(3) agonist, D[Trp8]-γ-MSH, attenuated disease incidence and severity in wild-type but not Mc(3)(-/-) mice. Overall, these findings identify MC(3)-mediated signaling as a beneficial pathway in experimental arthritis; hence this receptor is a novel target for the development of therapeutics for arthritis.
Original language | English |
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Pages (from-to) | 4835-43 |
Number of pages | 9 |
Journal | FASEB journal : official publication of the Federation of American Societies for Experimental Biology |
Volume | 24 |
Issue number | 12 |
DOIs | |
Publication status | Published - Dec 2010 |
Keywords
- Animals
- Arthritis, Experimental
- Cell Differentiation
- Electrophoretic Mobility Shift Assay
- Flow Cytometry
- Interleukin-1beta
- Interleukin-6
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nitric Oxide Synthase Type II
- Oligonucleotide Array Sequence Analysis
- Osteoclasts
- Osteogenesis
- Polymerase Chain Reaction
- Receptor, Melanocortin, Type 3
- Journal Article
- Research Support, Non-U.S. Gov't