title: Effects of curcumin (diferuloylmethane) on nuclear factor kappaB signaling in interleukin-1beta-stimulated chondrocytes.
abstract: Curcumin (diferuloylmethane) is a nontoxic dietary pigment in tumeric and curry and a potent inhibitor of the common transcription factor Nuclear Factor kappaB (NF-kappaB) in several cell types. It is well established that some of the catabolic effects of the proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha in osteoarthritis are regulated by the activation of NF-kappaB. Therefore, the aim of this study was to determine whether curcumin modifies the catabolic response of chondrocytes to IL-1beta. Human articular chondrocytes were prestimulated with 10 ng/mL IL-1beta for 0, 4, 8, 12, or 24 h and then cotreated with 50 microM curcumin for 0, 12, 24, 36, or 48 h. Synthesis of the cartilage-specific collagen type II and matrix-degrading enzyme matrix metalloproteinase-3 (MMP-3) was investigated in chondrocytes by Western blot analysis. Activation and nuclear translocation of NF-kappaB were observed by immunofluorescence microscopy. IL-1beta induced a decrease in collagen type II and upregulation of MMP-3 in a time-dependent manner. Upregulation of MMP-3 was inhibited by curcumin in a time-dependent manner. In addition, IL-1beta-induced a decrease in type II collagen, which was relieved by curcumin treatment. In response to IL-1beta, NF-kappaB translocated to the nucleus, but translocation was inhibited by curcumin, as revealed by immunofluorescence microscopy. Taken together, these results confirmed an IL-1beta-mediated upregulation of proinflammatory MMP-3 in chondrocytes via an NF-kappaB activation mechanism. Curcumin protected chondrocytes from the catabolic effects of IL-1beta, such as MMP-3 upregulation, and interestingly also relieved cytokine-induced suppression of matrix protein synthesis. Therefore, curcumin antagonizes crucial catabolic effects of IL-1beta signaling that are known to contribute to the pathogenesis of osteoarthritis.
authors.affiliation: Charité University Medical School Berlin, Institute of Anatomy, Department of Cell and Neurobiology, Campus Benjamin Franklin, Königin-Luise-Strasse 15, D-14195 Berlin, Germany.
authors.forename: Gundula
authors.initials: G
authors.lastname: Schulze-Tanzil
authors.forename: Ali
authors.initials: A
authors.lastname: Mobasheri
authors.forename: Judith
authors.initials: J
authors.lastname: Sendzik
authors.forename: Thilo
authors.initials: T
authors.lastname: John
authors.forename: Mehdi
authors.initials: M
authors.lastname: Shakibaei
mesh_terms: D015153:Blotting, Western; D002358:Cartilage, Articular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D003474:Curcumin / Q000494:pharmacology*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D008856:Microscopy, Fluorescence; D016328:NF-kappa B / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D007375:Interleukin-1; D016328:NF-kappa B; D003094:Collagen; D019278:Matrix Metalloproteinase 3; D003474:Curcumin