Eagle Bioscience’s Calprotectin ELISA Assay Kit was recently used in a study dealing with bone loss in relation to arthritis and other inflammatory diseases. The Calprotectin ELISA Assay is part of our line of Gastrointestinal Assays which is a line of highly sensitive and specific kits used to detect the concentration of a variety of samples in serum, plasma, tissue, urine, and saliva.
Hemophilic arthropathy (HA) is a debilitating degenerative joint disease that is a major manifestation of the bleeding disorder Hemophilia A. HA typically begins with hemophilic synovitis (HS) that resembles inflammatory arthritides such as rheumatoid arthritis (RA) and frequently results in bone loss in patients. A major cause of RA is inappropriate release of the pro-inflammatory cytokine tumor necrosis factor α (TNFα) by the TNFα convertase (TACE, also referred to as ADAM17) and its regulator, iRhom2. Therefore, we hypothesized that iRhom2/ADAM17-dependent shedding of TNFα also has a pivotal role in mediating HA. Here, we show that addition of blood or its components to macrophages activates iRhom2/ADAM17-dependent TNFα shedding, providing the premise to study the activation of this pathway by blood in the joint in vivo. For this, we turned to hemophilic FVIII-deficient mice (F8-/- mice), which develop a hemarthrosis following needle puncture injury with synovial inflammation and significant osteopenia adjacent to the affected joint. We found that needle puncture-induced bleeding leads to increased TNFα levels in the affected joint of F8-/- mice. Moreover, inactivation of TNFα or iRhom2 in F8-/- mice reduced the osteopenia and synovial inflammation that develops in this mouse model for HA. Taken together, our results suggest that blood entering the joint activates the iRhom2/ADAM17/TNFα pathway, thereby contributing to osteopenia and synovitis in mice. Therefore, this pro-inflammatory signaling pathway could emerge as an attractive new target to prevent osteoporosis and joint damage in HA patients.
Haxaire, Coline, et al. “Blood-Induced Bone Loss in Murine Hemophilic Arthropathy Is Prevented by Blocking the iRhom2/ADAM17/TNFα Pathway.” Blood, 18 May 2018,