The cytokine IL-1 induces joint inflammation and cartilage degradation. A new subset of the IL-1 receptor family, represented by the Toll receptors, has been identified. Our results indicate that the 5 known forms of human Toll receptors are expressed by chondrocytes. The gene has homology with a murine gene that reportedly encodes a nuclear protein in lymphocytes. The gene for TRIP-1 is the first member of a new family of genes that encode signal transducers of Toll receptors.
TRIPs interact with Toll receptors and upon activation translocate to the nucleus.
One of the ligands of Toll-4 is bacterial lipopolysaccharide. This bacterial product is responsible for the induction of many of the symptoms that complicate infections. TRIP-1 is a new target for the development of drugs that inhibit the effects of lipopolysaccharide. Chemokines in Synovial Inflammation and Cartilage Degradation N. Alaaeddine, M. Lotz Cartilage is a source of several chemokines. Recently, we found that chemokines not only contribute to the recruitment of leukocytes to arthritic joints but also can contribute to cartilage degradation.