Publications

Abstract OBJECTIVE Calcitonin has been suggested to have chondroprotective effects. One signaling pathway of calcitonin is via the second messenger cAMP. We undertook this study to investigate whether increased cAMP levels in chondrocytes would be chondroprotective. METHODS Cartilage degradation was induced in bovine articular cartilage explants by 10 ng/ml oncostatin M (OSM) and 20 ng/ml […]

Abstract OBJECTIVE Aggrecan is the major proteoglycan in articular cartilage and is known to be degraded by various proteases, including matrix metalloproteinases (MMPs). The present study was undertaken to develop immunoassays detecting aggrecan and its fragments generated by MMP and non-MMP-mediated proteolysis. METHODS Two immunoassays were developed: (1) the G1/G2 sandwich assay employing a monoclonal […]

Abstract OBJECTIVE Calcitonin was recently reported to counter progression of cartilage degradation in an experimental model of osteoarthritis, and the effects were primarily suggested to be mediated by inhibition of subchondral bone resorption. We investigated direct effects of calcitonin on chondrocytes by assessing expression of the receptor and pharmacological effects on collagen type II degradation […]

Abstract OBJECTIVE Both matrix metalloprotease (MMP) activity and cathepsin K (CK) activity have been implicated in cartilage turnover. We investigated the relative contribution of MMP activity and CK activity in cartilage degradation using ex vivo and in vivo models. METHODS Bovine articular cartilage explants were stimulated with oncostatin M (OSM) 10 ng/ml and tumor necrosis […]

Abstract Genetic diseases and knockout mice stress the importance of matrix metalloproteinases (MMPs) in skeletal turnover. Our study aims at clarifying which MMPs are expressed by osteoclasts. Previous analyses of this basic question led to conflicting reports in the literature. In the present study, we used a variety of approaches: PCR, Northern blots, Slot blots, […]

Abstract The best established proteolytic event of osteoclasts is bone matrix solubilization by the cysteine proteinase cathepsin K. Here, however, we draw the attention on osteoclastic activities depending on matrix metalloproteinases (MMPs). We discuss the observations supporting that MMPs contribute significantly to bone matrix solubilization in specific areas of the skeleton and in some developmental […]

Abstract Upon termination of bone matrix synthesis, osteoblasts either undergo apoptosis or differentiate into osteocytes or bone lining cells. In this study, we investigated the role of matrix metalloproteinases (MMPs) and growth factors in the differentiation of osteoblasts into osteocytes and in osteoblast apoptosis. The mouse osteoblast cell line MC3T3-E1 and primary mouse calvarial osteoblasts […]