Epigallocatechin-3-gallate enhances key enzymatic activities of hepatic thioredoxin and glutathione systems in selenium-optimal mice but activates hepatic Nrf2 responses in selenium-deficient mice
| Autor: | Ruixia Dong, Pingping Chen, Chung S. Yang, Xiaoxiao Wang, Ke Zhang, Jinsong Zhang, Dongxu Wang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Antioxidant medicine.medical_treatment Thioredoxin reductase NQO1 NAD(P)H:quinone oxidoreductase 1 Clinical Biochemistry Glutathione reductase GAPDH glyceraldehyde 3-phosphate dehydrogenase RIPA tissue fluid of fast pyrolysis AST aspartate aminotransferase Nrf2 response Biochemistry Nrf2 nuclear factor erythroid 2-related factor 2 Antioxidants Catechin GST glutathione S-transferase RT-PCR reverse transcriptase polymerase chain reaction chemistry.chemical_compound Mice EDTA ethylene diamine tetraacetic acid Thioredoxins Glutaredoxin GSH glutathione GR glutathione reductase Trx thioredoxin heterocyclic compounds IL-6 interleukin-6 lcsh:QH301-705.5 HO1 heme oxygenase 1 EGCG epigallocatechin-3-gallate lcsh:R5-920 GPx glutathione peroxidase Epigallocatechin-3-gallate GSSG oxidized glutathione food and beverages BSO buthionine sulfoximine IL-10 interleukin-10 FoxO Forkhead box class O Thioredoxin system Glutathione CDNB 1-chloro-2 4-dinitrobenzene Glutathione Reductase Grx glutaredoxin H2O2 hydrogen peroxide PBS phosphate buffer solution qPCR quantitative polymerase chain reaction RT room temperature Thioredoxin ECL enhanced chemiluminescense lcsh:Medicine (General) Signal Transduction Research Paper inorganic chemicals TrxR thioredoxin reductase Glutathione system Thioredoxin-Disulfide Reductase PVDF polyvinylidene fluoride SDS sodium dodecyl sulfate NF-E2-Related Factor 2 Rps6 ribosomal protein S6 UPLC ultra-high performance liquid chromatography Biology complex mixtures RNS reactive nitrogen species Se selenium 03 medical and health sciences Selenium ROS reactive oxygen species Sp1/Sp3 specificity protein 1/3 Thioredoxin Reductase 1 IL-2 interleukin-2 ALT alanine aminotransferase 4-HNE 4-hydroxynonenal SOD superoxide dismutase medicine Animals Glutaredoxins Organic Chemistry γ-H2AX phosphorylated histone 2AX NADHP nicotinamide-adenine dinucleotide phosphate SelP selenoprotein P 030104 developmental biology chemistry Gene Expression Regulation lcsh:Biology (General) Sec selenocysteine Keap1 kelch-like ECH-associated protein 1 Prx peroxiredoxin NAD+ kinase QQQ-MS/MS triple quadrupole mass spectrometer sense organs Reactive Oxygen Species TBS-T tris-buffered saline with 0.05% Tween 20 |
| Zdroj: | Redox Biology, Vol 10, Iss C, Pp 221-232 (2016) Redox Biology |
| ISSN: | 2213-2317 |
| Popis: | Selenium participates in the antioxidant defense mainly through a class of selenoproteins, including thioredoxin reductase. Epigallocatechin-3-gallate (EGCG) is the most abundant and biologically active catechin in green tea. Depending upon the dose and biological systems, EGCG may function either as an antioxidant or as an inducer of antioxidant defense via its pro-oxidant action or other unidentified mechanisms. By manipulating the selenium status, the present study investigated the interactions of EGCG with antioxidant defense systems including the thioredoxin system comprising of thioredoxin and thioredoxin reductase, the glutathione system comprising of glutathione and glutathione reductase coupled with glutaredoxin, and the Nrf2 system. In selenium-optimal mice, EGCG increased hepatic activities of thioredoxin reductase, glutathione reductase and glutaredoxin. These effects of EGCG appeared to be not due to overt pro-oxidant action because melatonin, a powerful antioxidant, did not influence the increase. However, in selenium-deficient mice, with low basal levels of thioredoxin reductase 1, the same dose of EGCG did not elevate the above-mentioned enzymes; intriguingly EGCG in turn activated hepatic Nrf2 response, leading to increased heme oxygenase 1 and NAD(P)H:quinone oxidoreductase 1 protein levels and thioredoxin activity. Overall, the present work reveals that EGCG is a robust inducer of the Nrf2 system only in selenium-deficient conditions. Under normal physiological conditions, in selenium-optimal mice, thioredoxin and glutathione systems serve as the first line defense systems against the stress induced by high doses of EGCG, sparing the activation of the Nrf2 system. Highlights • EGCG increases hepatic activities of TrxR, GR and Grx in selenium-optimal mice. • EGCG fails to manipulate the above-mentioned enzymes in selenium-deficient mice. • EGCG in turn activates hepatic Nrf2 response in selenium-deficient mice. • Selenium deficiency does not increase EGCG toxicity due to potent Nrf2 response. Graphical abstract fx1 |
| Databáze: | OpenAIRE |
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