The cartilage chondrolytic mechanism of fibronectin fragments involves MAP kinases: comparison of three fragments and native fibronectin
| Autor: | Lei Ding, G. A. Homandberg, D. Guo |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
p38 mitogen-activated protein kinases
Biomedical Engineering Cartilage chondrolysis Biology MAP2K7 Chondrocytes Rheumatology medicine Animals Orthopedics and Sports Medicine Fibronectin Cells Cultured MAPK14 Fibronectin fragments MAP kinase kinase kinase Kinase Cartilage Molecular biology Bovine Cartilage Matrix Metalloproteinases Peptide Fragments Fibronectins medicine.anatomical_structure MAP kinases Mitogen-activated protein kinase biology.protein Cattle Mitogen-Activated Protein Kinases |
| Zdroj: | Osteoarthritis and Cartilage. 16(10):1253-1262 |
| ISSN: | 1063-4584 |
| DOI: | 10.1016/j.joca.2008.02.015 |
| Popis: | Summary Objective To define the role of mitogen activated protein (MAP) kinases in fibronectin fragment (Fn-f) mediated matrix metalloproteinase (MMP) upregulation and damage to bovine cartilage and to compare activities of three Fn-fs with native fibronectin (Fn), which is inactive in terms of cartilage damage. Methods Bovine chondrocytes were cultured with three Fn-fs, an amino-terminal 29-kDa, a gelatin-binding 50-kDa and a central 140-kDa Fn-f or native Fn at concentrations from 0.01 to 1μM, concentrations lower than those found in osteoarthritis synovial fluids. Lysates were probed for activation of MAP kinases, extracellular signal-regulated kinase 1/2 (ERK1/2), p38 and stress activated protein kinase/c-jun N-terminal kinase (SAPK/JNK). Confocal fluorescent microscopy was used to visualize movement of activated kinases. Kinase inhibitors were tested for their abilities to block Fn-f mediated protein upregulation of MMP-3 and MMP-13 and Fn-f induced depletion of cartilage proteoglycan (PG) from cultured explants. Results The 29-kDa, the most potent Fn-f in terms of cartilage damage, enhanced phosphorylation of ERK1/2, p38 and JNK1/2 within a 1-h incubation while the 50 and 140-kDa Fn-fs required up to 4h for maximal activity and native Fn was only minimally active toward p38 and JNK, but did strongly activate ERK1/2. The activated kinases displayed a distribution toward the nuclear membrane and within the nucleus. MAP kinase inhibitors markedly decreased Fn-f mediated upregulation of MMP-3 or MMP-13 and Fn-f mediated cartilage PG depletion. Conclusions These results suggest that Fn-fs upregulate MMP-3 and MMP-13 in bovine chondrocytes through MAP kinases and that kinase inhibitors afford protection against this degenerative pathway. |
| Databáze: | OpenAIRE |
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