title: The effect of hypoxia mimetic cobalt chloride on the expression of EC-SOD in 3T3-L1 adipocytes.
abstract: It is well known that adipose tissue is not only a passive reservoir for energy storage but also produces and secretes a variety of bioactive molecules called adipocytokines, including adiponectin and tumor necrosis factor-alpha (TNF-alpha). Recently, it has been reported that adipose tissue can suffer a chronic hypoxic condition during hypertrophy of adipocytes, and this condition leads to the dysregulation of adipocytokines. Further, hypoxic adipocytes are in an increased oxidative stress. Extracellular-superoxide dismutase (EC-SOD) is an anti-inflammatory enzyme that protects cells from reactive oxygen species (ROS) by scavenging superoxide anion. Previous reports showed that plasma EC-SOD levels in type 2 diabetes patients were significantly and inversely related to the body mass index, homeostasis model assessment-insulin resistance index; however, the mechanisms of EC-SOD and adiponectin reductions during hypoxia remain poorly understood. Here, we demonstrate that cobalt chloride (CoCl(2)), a hypoxia mimetic, decreases EC-SOD and adiponectin in 3T3-L1 adipocytes by intracellular ROS-independent, but TNF-alpha and c-jun N-terminal kinase (JNK)-dependent mechanisms. From these results, it is possible that TNF-alpha is a key regulator of the reduction of EC-SOD and adiponectin in CoCl(2)-treated 3T3-L1 adipocytes, and we speculated that the reduction of EC-SOD and adiponectin would lead to and/or promote metabolic disorders.
authors.affiliation: Department of Biomedical Pharmaceutics, Laboratory of Clinical Pharmaceutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan. tekamiya@gifu-pu.ac.jp
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kamiya
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hara
authors.forename: Naoki
authors.initials: N
authors.lastname: Inagaki
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Adachi
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000201:enzymology; D052242:Adiponectin / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D015687:Cell Hypoxia; D002839:Chromans / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D052242:Adiponectin; D000975:Antioxidants; D002839:Chromans; D007527:Isoenzymes; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D003035:Cobalt; C499090:Sod3 protein, mouse; D013482:Superoxide Dismutase; D048031:JNK Mitogen-Activated Protein Kinases; C018021:cobaltous chloride; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid