Sensitivity of chondrocytes of growing cartilage to reactive oxygen species

• Published in: Biochimica et biophysica acta Vol. 1425; no. 1; pp. 103 - 111
• Main Authors: Fragonas, Emanuela, Pollesello, Piero, Mlinárik, Vladimir, Toffanin, Renato, Grando, Cristina, Godeas, Cristiana, Vittur, Franco
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 16.09.1998
• Subjects: Adenosine Triphosphate - metabolism; Animals; Cartilage - drug effects; Cartilage - growth & development; Cartilage - metabolism; Catalase - metabolism; Cells, Cultured; Chondrocytes - drug effects; Chondrocytes - metabolism; Glutathione Peroxidase - metabolism; Growing cartilage; Hydrogen Peroxide - metabolism; Hydrogen Peroxide - pharmacology; Hypertrophic chondrocyte; L-Lactate Dehydrogenase - metabolism; Lipid Metabolism; Magnetic Resonance Spectroscopy; Matrix vesicle; NMR; Osteogenesis; Reactive oxygen species; Reactive Oxygen Species - metabolism; Superoxide Dismutase - metabolism; Swine; Reactive oxygen species; Growing cartilage; LDH, lactate dehydrogenase; MUFA and PUFA, mono and polyunsaturated fatty acid chains; HX, hypoxanthine; XO, xanthine oxidase; SOD, superoxide dismutase; Matrix vesicle; PHGPx, phospholipid hydroperoxide glutathione peroxidase; NMR; Hypertrophic chondrocyte; HCs, RCs and ACs, hypertrophic, resting and articular chondrocytes; ROS, reactive oxygen species
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/S0304-4165(98)00055-5

Vascular invasion of calcified cartilage, during endochondral ossification, is initiated and sustained by invasive cells (endothelial cells and macrophages) which degrade the tissue by releasing lytic enzymes. Concurrently, reactive oxygen species (ROS) are also released by these cells and we hypothesize that ROS also contribute to the degradation of the tissue. As a preliminary approach to this problem, the antioxidant activities and the effect of ROS on hypertrophic cartilage and chondrocytes (HCs) were investigated. Compared to resting or articular chondrocytes, HCs exhibited higher catalase but lower SOD specific activities and lower PHGPx concentration, thus revealing a defence activity specific against H 2O 2. Moreover, dose-dependent depletion of ATP occurred after few minutes of exposure to ROS, and a long-term treatment (16 h incubation with ROS) promoted the release of LDH activity and a significant variation of the poly- to mono-unsaturated fatty acid ratio. Finally, the incubation of HCs with low ROS doses induced the release of sedimentable alkaline phosphatase activity (matrix vesicles). How the obtained results fit the in vivo occurring events is discussed.