OBJECTIVE: Beside matrix metalloproteinases, reactive oxygen species (ROS) are the main biochemical factors of cartilage degradation. To prevent ROS toxicity, chondrocytes possess a well-coordinated enzymatic antioxidant system formed principally by superoxide dismutases (SODs), catalase (CAT) and glutathione peroxidase (GPX). This work was designed to assess the effects of interleukin (IL)-1beta and IL-6 on the enzymatic activity and gene expression of SODs, CAT and GPX in bovine chondrocytes. METHODS: Bovine chondrocytes were cultured in monolayer for 4-96 h in the absence or in the presence of IL-1beta (0.018-1.8ng/ml) or IL-6 (10-100 ng/ml). To study signal transduction pathway, inhibitors of mitogen-activated protein kinases (MAPK) (PD98059, SB203580 and SP600125) (5-20 microM) and nuclear factor (NF)-kappaB inhibitors [BAY11-7082 (1-10 microM) and MG132 (0.1-10 microM)] were used. SODs, CAT and GPX enzymatic activities were evaluated in cellular extract by using colorimetric enzymatic assays. Mn SODs, Cu/Zn SOD, extracellular SOD (EC SOD), CAT and GPX gene expressions were quantified by real-time and quantitative polymerase chain reaction (PCR). RESULTS: Mn SOD and GPX activities were dose and time-dependently increased by IL-1beta. In parallel, IL-1beta markedly enhanced Mn SOD and GPX gene expressions, but decreased Cu/Zn SOD, EC SOD and CAT gene expressions. Induction of SOD enzymatic activity and Mn SOD mRNA expression were inhibited by NF-kappaB inhibitors but not by MAPK inhibitors. IL-6 effects were similar but weaker than those of IL-1beta. CONCLUSIONS: In conclusion, IL-1beta, and to a lesser extend IL-6, dysregulates enzymatic antioxidant defenses in chondrocyte. These changes could lead to a transient accumulation of H(2)O(2) in mitochondria, and consequently to mitochondria damage. These changes contribute to explain the mitochondrial dysfunction observed in osteoarthritis chondrocytes.
OBJECTIVE: Beside matrix metalloproteinases, reactive oxygen species (ROS) are the main biochemical factors of cartilage degradation. To prevent ROStoxicity, chondrocytes possess a well-coordinated enzymatic antioxidant system formed principally by superoxide dismutases (SODs), catalase (CAT) and glutathione peroxidase (GPX). This work was designed to assess the effects of interleukin (IL)-1beta and IL-6 on the enzymatic activity and gene expression of SODs, CAT and GPX in bovine chondrocytes. METHODS:Bovine chondrocytes were cultured in monolayer for 4-96 h in the absence or in the presence of IL-1beta (0.018-1.8ng/ml) or IL-6 (10-100 ng/ml). To study signal transduction pathway, inhibitors of mitogen-activated protein kinases (MAPK) (PD98059, SB203580 and SP600125) (5-20 microM) and nuclear factor (NF)-kappaB inhibitors [BAY11-7082 (1-10 microM) and MG132 (0.1-10 microM)] were used. SODs, CAT and GPX enzymatic activities were evaluated in cellular extract by using colorimetric enzymatic assays. Mn SODs, Cu/Zn SOD, extracellular SOD (EC SOD), CAT and GPX gene expressions were quantified by real-time and quantitative polymerase chain reaction (PCR). RESULTS:Mn SOD and GPX activities were dose and time-dependently increased by IL-1beta. In parallel, IL-1beta markedly enhanced Mn SOD and GPX gene expressions, but decreased Cu/Zn SOD, EC SOD and CAT gene expressions. Induction of SOD enzymatic activity and Mn SOD mRNA expression were inhibited by NF-kappaB inhibitors but not by MAPK inhibitors. IL-6 effects were similar but weaker than those of IL-1beta. CONCLUSIONS: In conclusion, IL-1beta, and to a lesser extend IL-6, dysregulates enzymatic antioxidant defenses in chondrocyte. These changes could lead to a transient accumulation of H(2)O(2) in mitochondria, and consequently to mitochondria damage. These changes contribute to explain the mitochondrial dysfunction observed in osteoarthritis chondrocytes.
Authors: Yao Fu; Michael Kinter; Joanna Hudson; Kenneth M Humphries; Rachel S Lane; Jeremy R White; Michael Hakim; Yong Pan; Eric Verdin; Timothy M Griffin Journal: Arthritis Rheumatol Date: 2016-08 Impact factor: 10.995
Authors: Hans-Willi Clement; Juan F Vazquez; Olaf Sommer; Philip Heiser; Henning Morawietz; Ulrich Hopt; Eberhard Schulz; Ernst von Dobschütz Journal: J Neural Transm (Vienna) Date: 2009-10-29 Impact factor: 3.575