OBJECTIVE: We have previously demonstrated that reactive oxygen species (ROS) are involved in cartilage degradation. Decreased size of hyaluronan (HA), the major macromolecule in synovial fluid, to which it imparts viscosity, is reported in patients with arthritis. The purpose of this study was to determine the alteration in the molecular weight range of HA as a result of mechanical deformation loaded on the chondrocytes, as well as the involvement of ROS in this action. METHODS: ROS were generated via the oxidation of hypoxanthine by xanthine oxidase. Cyclic tensile stretch was loaded using a vacuum-operated instrument. Levels of HA were measured using a sandwich enzyme-binding assay. Superoxide dismutase (SOD) activity and ROS were measured using water-soluble tetrazolium and a chemiluminescent probe, respectively. RESULTS: ROS depolymerized HA molecules. Cyclic tensile stretch depolymerized HA and induced ROS. SOD inhibited not only ROS induction but also HA depolymerization caused by the mechanical stress. CONCLUSION: ROS play an important role in mechanical stress-induced HA depolymerization.
OBJECTIVE: We have previously demonstrated that reactive oxygen species (ROS) are involved in cartilage degradation. Decreased size of hyaluronan (HA), the major macromolecule in synovial fluid, to which it imparts viscosity, is reported in patients with arthritis. The purpose of this study was to determine the alteration in the molecular weight range of HA as a result of mechanical deformation loaded on the chondrocytes, as well as the involvement of ROS in this action. METHODS:ROS were generated via the oxidation of hypoxanthine by xanthine oxidase. Cyclic tensile stretch was loaded using a vacuum-operated instrument. Levels of HA were measured using a sandwich enzyme-binding assay. Superoxide dismutase (SOD) activity and ROS were measured using water-soluble tetrazolium and a chemiluminescent probe, respectively. RESULTS:ROS depolymerized HA molecules. Cyclic tensile stretch depolymerized HA and induced ROS. SOD inhibited not only ROS induction but also HA depolymerization caused by the mechanical stress. CONCLUSION:ROS play an important role in mechanical stress-induced HA depolymerization.
Authors: Igor Schepetkin; Andrei Potapov; Andrei Khlebnikov; Elena Korotkova; Anna Lukina; Galina Malovichko; Lilia Kirpotina; Mark T Quinn Journal: J Biol Inorg Chem Date: 2006-04-22 Impact factor: 3.358
Authors: Kuan-Jen Bai; Andrew P Spicer; Marcella M Mascarenhas; Lunyin Yu; Cristhiaan D Ochoa; Hari G Garg; Deborah A Quinn Journal: Am J Respir Crit Care Med Date: 2005-03-24 Impact factor: 21.405