image: Blocking bone breakdown. (A) Inflamed synovial tissue stimulates local bone resorption and suppresses bone formation at sites where it touches the bone surface. This leads to erosions in the bone tissue below the articular cartilage. (B) TNFα directly stimulates bone resorption by osteoclasts and increases RANKL secretion by fibroblast-like synoviocytes, both of which further increase bone resorption. However, TNFα also induces these synoviocytes to express sclerostin, which is not only an inhibitor of osteoblastic bone formation but also diminishes TNFα signaling in synoviocytes. Thus, sclerostin indirectly helps to limit bone resorption activity by osteoclasts. This material relates to a paper that appeared in the March 16, 2016, issue of Science Translational Medicine, published by AAAS. The paper, by C. Wehmeyer at University Hospital Muenster in Muenster, Germany, and colleagues was titled, "Sclerostin inhibition promotes TNF-dependent inflammatory joint destruction." view more
Credit: F. Rauch <i>et al., Science Translational Medicine</i> (2016)