Solubilization and characteristics of the thyroid NADPH-dependent H2O2 generating system

Dupuy, Corinne; Virion, Alain; Hammou, N. Ait; Kaniewski, Jacques; Dème, Danielle; Pommier, Jacques

doi:10.1016/s0006-291x(86)80249-2

Cited by 13 publications

(5 citation statements)

References 8 publications

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“…Reactive oxygen species generation has been described in a wide variety of different cell types including human glomerular mesangial cells, fibroblasts, thyroid tissue, vascular smooth muscle, endothelial cells, and leukocytes [16,[18][19][20][21][22][23][36][37][38][39]. The results obtained in this study confirm that mammalian spermatozoa are also capable of generating ROS and indicate that in the rat this activity involves at least two independent mechanisms.…”

Section: Discussionsupporting

confidence: 72%

Analysis of Reactive Oxygen Species Generating Systems in Rat Epididymal Spermatozoa1

Vernet

Fulton

Wallace

et al. 2001

Biology of Reproduction

112

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Epididymal sperm maturation culminates in the acquisition of functional competence by testicular spermatozoa. The expression of this functional state is dependent upon a redox-regulated, cAMP-mediated signal transduction cascade that controls the tyrosine phosphorylation status of the spermatozoa during capacitation. Analysis of superoxide anion (O2(-.)) generation by rat epididymal spermatozoa has revealed a two-component process involving electron leakage from the sperm mitochondria at complexes I and II and a plasma membrane NAD(P)H oxidoreductase. Following incubation in a glucose-, lactate-, and pyruvate-free medium (-GLP), O2(-.) generation was suppressed by 86% and 96% in caput and cauda spermatozoa, respectively. The addition of lactate, malate, or succinate to spermatozoa incubated in medium -GLP stimulated O2(-.) generation. This increase could be blocked by rotenone and oligomycin (R/O) in the presence of malate or lactate but not succinate. Stimulation with all three substrates, as well as spontaneous O2(-.) production in +GLP medium, was blocked by the flavoprotein inhibitor, diphenylene iodonium. Diphenylene iodonium, but not R/O, suppressed NAD(P)H-induced lucigenin-dependent chemiluminescence. This NAD(P)H-dependent enzyme resided in the sperm plasma membrane and its activity was regulated by zinc and uncharacterized cytosolic factors. Reverse transcription-polymerase chain reaction analysis indicated that the sperm NAD(P)H oxidoreductase complex is quite distinct from the equivalent leukocyte system.

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Section: Discussionsupporting

confidence: 72%

Analysis of Reactive Oxygen Species Generating Systems in Rat Epididymal Spermatozoa1

Vernet

Fulton

Wallace

et al. 2001

Biology of Reproduction

112

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“…A flavoprotein complex was predicted to produce directly H 2 O 2 outside the cell with an activity mediated by NADPH and stimulated by calcium (10,35,39,40). In 2000, the cloning of two cDNAs encoding novel calcium-dependent NADPH oxidases, Duox1 and Duox2, revealed the molecular nature of the presumed thyroid H 2 O 2 -generating system (1, 2, 11).…”

Section: Discussionmentioning

confidence: 99%

Activation of Dual Oxidases Duox1 and Duox2

Rigutto

Hoste

Grasberger

et al. 2009

Journal of Biological Chemistry

186

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Dual oxidases were initially identified as NADPH oxidases producing H 2 O 2 necessary for thyroid hormone biosynthesis. The crucial role of Duox2 has been demonstrated in patients suffering from partial iodide organification defect caused by biallelic mutations in the DUOX2 gene. However, the Duox1 function in thyroid remains elusive. We optimized a functional assay by co-expressing Duox1 or Duox2 with their respective maturation factors, DuoxA1 and DuoxA2, to compare their intrinsic enzymatic activities under stimulation of the major signaling pathways active in the thyroid in relation to their membrane expression. We showed that basal activity of both Duox isoenzymes depends on calcium and functional EF-hand motifs. However, the two oxidases are differentially regulated by activation of intracellular signaling cascades. Duox1 but not Duox2 activity is stimulated by forskolin (EC 50 ‫؍‬ 0.1 M) via protein kinase A-mediated Duox1 phosphorylation on serine 955. In contrast, phorbol esters induce Duox2 phosphorylation via protein kinase C activation associated with high H 2 O 2 generation (phorbol 12-myristate 13-acetate EC 50 ‫؍‬ 0.8 nM). These results were confirmed in human thyroid cells, suggesting that Duox1 is also involved in thyroid hormonogenesis. Our data provide, for the first time, detailed insights into the mechanisms controlling the activation of Duox1-2 proteins and reveal additional phosphorylation-mediated regulation.

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“…Bjorkman & Ekholm (1984) have suggested that the NAD(P)H oxidase might be located on the apical membrane of thyroid follicles where iodination occurs. Virion and coworkers have characterized an NADPH-dependent H202 generating system associated with thyroid particulate fraction (Virion et al, 1984;Michot et al, 1985;Dupuy et al, 1986). Both groups of investigators provide evidence that Ca2+ seems to be an important factor in the NAD(P)H oxidase regulation of H202 generation (Bjorkman & Ekholm, 1984;Deme et al, 1985).…”

Section: Discussionmentioning

confidence: 99%

Monoamine oxidase activity and triiodothyronine biosynthesis in human cultured thyroid cells

Kraiem

Sadeh

Youdim

1989

British J Pharmacology

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1 The proposal that monoamine oxidase (MAO) is a source of peroxide in thyroid hormone biosynthesis has been examined by use of isolated cultured human thyroid cells which retain the ability to secrete triiodothyronine (T3) in response to thyroid stimulating hormone (TSH). 2 The results demonstrated the presence of MAO A and B in human thyroid cells which oxidized 5-hydroxytryptamine and 2-phenylethylamine, respectively, and were selectively inhibited by the MAO inhibitors clorgyline and (-)-deprenyl. 3 Addition of propylthiouracil to the culture system induced a 61% reduction in TSH-stimulated T3 secretion, indicating that the bulk of such secretion apparently derives from de novo iodothyronine synthesis. 4 The MAO A and B substrate, tyramine, was ineffective in stimulating T3 secretion.

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Solubilization and characteristics of the thyroid NADPH-dependent H2O2 generating system

Cited by 13 publications

References 8 publications

Analysis of Reactive Oxygen Species Generating Systems in Rat Epididymal Spermatozoa1

Analysis of Reactive Oxygen Species Generating Systems in Rat Epididymal Spermatozoa1

Activation of Dual Oxidases Duox1 and Duox2

Monoamine oxidase activity and triiodothyronine biosynthesis in human cultured thyroid cells

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