title: Impact of 3-Amino-1,2,4-Triazole (3-AT)-Derived Increase in Hydrogen Peroxide Levels on Inflammation and Metabolism in Human Differentiated Adipocytes.
abstract: Obesity is characterized by an excessive accumulation of fat in adipose tissue, which is associated with oxidative stress and chronic inflammation. Excessive H2O2 levels are degraded by catalase (CAT), the activity of which is decreased in obesity. We investigated the effects of inhibition of catalase activity on metabolism and inflammation by incubating human differentiated adipocytes with 10 mM 3-amino-1,2,4-triazole (3-AT) for 24 h. As expected, the treatment decreased CAT activity and increased intracellular H2O2 levels significantly. Glutathione peroxidase (GPX) activity was also reduced, and the gene expression levels of the antioxidant enzymes GPX4 and peroxiredoxins (1, 3 and 5) were inhibited. Interestingly, this occurred along with lower mRNA levels of the transcription factors nuclear factor (erythroid 2-like 2) and forkhead box O, which are involved in redox homeostasis. However, superoxide dismutase activity and expression were increased. Moreover, 3-AT led to nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and increased tumor necrosis alpha and interleukin 6 protein and gene expression levels, while lowering peroxisome proliferator-activated receptor gamma (PPARγ) mRNA and protein levels. These alterations were accompanied by an altered glucose and lipid metabolism. Indeed, adipocytes treated with 3-AT showed reduced basal glucose uptake, reduced glucose transporter type 4 gene and protein expression, reduced lipolysis, reduced AMP-activated protein kinase activation and reduced gene expression of lipases. Our results indicate that increased H2O2 levels caused by 3-AT treatment impair the antioxidant defense system, lower PPARγ expression and initiate inflammation, thus affecting glucose and lipid metabolism in human differentiated adipocytes.
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n., Armilla, Granada, 18016, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Ruiz-Ojeda
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n., Armilla, Granada, 18016, Spain.|Instituto de Investigación Biosanitaria IBS.GRANADA, Granada, Spain.|CIBER Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Madrid, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Gomez-Llorente
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n., Armilla, Granada, 18016, Spain.|Instituto de Investigación Biosanitaria IBS.GRANADA, Granada, Spain.|CIBER Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Madrid, Spain.
authors.forename: Concepción María
authors.initials: CM
authors.lastname: Aguilera
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n., Armilla, Granada, 18016, Spain.|Instituto de Investigación Biosanitaria IBS.GRANADA, Granada, Spain.|CIBER Fisiopatología de la Obesidad y la Nutrición (CIBEROBN), Madrid, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Gil
authors.affiliation: Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology "José Mataix", Center of Biomedical Research, University of Granada, Avda. del Conocimiento s/n., Armilla, Granada, 18016, Spain.
authors.forename: Azahara Iris
authors.initials: AI
authors.lastname: Rupérez
mesh_terms: D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D000328:Adult; D000640:Amitrole / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism; D002374:Catalase / Q000037:antagonists & inhibitors / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007249:Inflammation / Q000378:metabolism*; D042541:Intracellular Space / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects; D047495:PPAR gamma / Q000378:metabolism
chemical_list: D000975:Antioxidants; D047495:PPAR gamma; D006861:Hydrogen Peroxide; D002374:Catalase; D005947:Glucose; D000640:Amitrole