['S100A4 has been shown to be increased in osteoarthritic (OA) cartilage and to stimulate chondrocytes to produce matrix metalloproteinase 13 (MMP-13) through activation of the receptor for advanced glycation end products (RAGE). The aim of this study was to examine the mechanism of S100A4 secretion by chondrocytes.', 'Human articular chondrocytes isolated from ankle cartilage were stimulated with 10 ng/ml of interleukin-1beta (IL-1beta), IL-6, IL-7, or IL-8. Cells were pretreated with either a JAK-3 inhibitor, brefeldin A, or cycloheximide. Immunoblotting with phospho-specific antibodies was used to determine the activation of signaling proteins. Secretion of S100A4 was measured in conditioned media by immunoblotting, and MMP-13 was measured by enzyme-linked immunosorbent assay.', 'Chondrocyte secretion of S100A4 was observed after treatment with IL-6 or IL-8 but was much greater in cultures treated with equal amounts of IL-7 and was not observed after treatment with IL-1beta. IL-7 activated the JAK/STAT pathway, with increased phosphorylation of JAK-3 and STAT-3, leading to increased production of S100A4 and MMP-13. Overexpression of a dominant-negative RAGE construct inhibited the IL-7-mediated production of MMP-13. Pretreatment of chondrocytes with a JAK-3 inhibitor or with cycloheximide blocked the IL-7-mediated secretion of S100A4, but pretreatment with brefeldin A did not.'] Does interleukin-7 stimulate secretion of S100A4 by activating the JAK/STAT signaling pathway in human articular chondrocytes?