title: Effects of heterologous expression of thioredoxin reductase on the level of reactive oxygen species in COS-7 cells.
abstract: Thioredoxin reductase (TrxR), a component of the redox control system involving thioredoxin (Trx), is implicated in defense against oxidative stress, control of cell growth and proliferation, and regulation of apoptosis. In the present study a stable transfectant was made by introducing the vector pcDNA3.0 harboring the fission yeast TrxR gene into COS-7 African green monkey kidney fibroblast cells. The exogenous TrxR gene led to an increase in TrxR activity of up to 3.2-fold but did not affect glutathione (GSH) content, or glutaredoxin and caspase-3 activities. Levels of reactive oxygen species (ROS), but not those of nitric oxide (NO), were reduced. Conversely, 1-chloro-2,4-dinitrobezene (CDNB), an irreversible inhibitor of mammalian TrxR, enhanced ROS levels in the COS-7 cells. After treatment with hydrogen peroxide, the level of intracellular ROS was lower in the transfectants than in the vector control cells. These results confirm that TrxR is a crucial determinant of the level of cellular ROS during oxidative stress as well as in the normal state.
authors.affiliation: Division of Life Sciences, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea.
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Kang
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Hong
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Kim
authors.forename: Eun-Hee
authors.initials: EH
authors.lastname: Park
authors.forename: Kisup
authors.initials: K
authors.lastname: Ahn
authors.forename: Chang-Jin
authors.initials: CJ
authors.lastname: Lim
mesh_terms: D000818:Animals; D019556:COS Cells / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002522:Chlorocebus aethiops; D054477:Glutaredoxins; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D010088:Oxidoreductases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013880:Thioredoxin-Disulfide Reductase / Q000096:biosynthesis*; D014162:Transfection
chemical_list: D054477:Glutaredoxins; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D013880:Thioredoxin-Disulfide Reductase; D053148:Caspase 3; D020169:Caspases; D005978:Glutathione