Presence of a soluble inhibitor of thyroid iodination in primary cultures of thyroid cells

Bocanera, L.V.; Aphalo, Paula; Ma, Ping; Gärtner, Roland; Silberschmidt, Daniel; Juvenal, Guillermo; Beraldi, G; Krawiec, L.

doi:10.1530/eje.0.1410055

Cited by 5 publications

(9 citation statements)

References 14 publications

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“…However, the inhibitor is active on TPO isolated from fresh tissue and inhibits the iodide organification when it is added to free follicles. This inhibitor is thermostable, dialyzable, has a molecular mass of less than 2 kDa and it has no species specificity, as was shown in our previous work [1].…”

mentioning

confidence: 72%

“…Our previous studies [1] demonstrated that monolayer primary cultures of bovine thyroid cells, maintained in the presence of insulin, produced a cytosolic inhibitor of TPO activity. Its molecular mass of less than 2 kDa coincides with that reported previously for the insulin mediators [10].…”

Section: Discussionmentioning

confidence: 99%

“…Monolayer primary and free follicle cultures of bovine thyroid cells were obtained according to Bocanera et al . [1]. Briefly, bovine thyroids were obtained from a local slaughterhouse immediately after death and transported to the laboratory in ice‐cold saline containing 100 U·mL −1 penicillin and 100 µg·mL −1 streptomycin.…”

Section: Cell Culturesmentioning

confidence: 99%

“…Thyroid peroxidase was obtained according to Bocanera et al . [1]. Briefly, fresh glands were dissected, cut into small pieces and homogenized in 0.1 m phosphate buffer, 0.1 m m KI, pH 8.0 [1 : 5 (w/v)].…”

Section: Bovine Tpo Isolationmentioning

confidence: 99%

“…Bocanera et al . demonstrated that monolayer primary cultures of thyroid cells, in the presence of insulin, lose their iodide organification capacity several days before the disappearance of TPO activity, due to the presence of a cytosolic inhibitor, not detectable in fresh tissue [1]. However, the inhibitor is active on TPO isolated from fresh tissue and inhibits the iodide organification when it is added to free follicles.…”

mentioning

confidence: 99%

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Role of peroxidase inhibition by insulin in the bovine thyroid cell proliferation mechanism

Krawiec

Pizarro

Aphalo

et al. 2004

European Journal of Biochemistry

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Monolayer primary cultures of thyroid cells produce, in the presence of insulin, a cytosolic inhibitor of thyroid peroxidase (TPO), lacto peroxidase (LPO), horseradish peroxidase (HRPO) and glutathione peroxidase (GPX). The inhibitor, localized in the cytosol, is thermostable and hydrophylic. Its molecular mass is less than 2 kDa. The inhibitory activity, resistant to proteolytic and nucleolytic enzymes, disappears with sodium metaperiodate treatment, as an oxidant of carbohydrates, supporting its oligosaccharide structure. The presence of inositol, mannose, glucose, the specific inhibition of cyclic AMP-dependent protein kinase and the disappearance of peroxidase inhibition by alkaline phosphatase and a-mannosidase in purified samples confirms its chemical structure as inositol phosphoglycan-like. Purification by anionic interchange shows that the peroxidase inhibitor elutes like the two subtypes of inositol phosphoglycans (IPG)P and A, characterized as signal transducers of insulin action. Insulin significantly increases the concentration of the peroxidase inhibitor in a thyroid cell culture at 48 h. The addition of both isolated substances to a primary thyroid culture produces, after 30 min, a significant increase in hydrogen peroxide (H 2 O 2 ) concentration in the medium, concomitantly with the disappearance of the GPX activity in the same conditions. The presence of insulin or anyone of both products, during 48 h, induces cell proliferation of the thyroid cell culture. In conclusion, insulin stimulates thyroid cell division through the effect of a peroxidase inhibitor, as its second messenger. The inhibition of GPX by its action positively modulates the H 2 O 2 level, which would produce, as was demonstrated by other authors, the signal for cell proliferation.

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mentioning

confidence: 72%

Section: Discussionmentioning

confidence: 99%

Section: Cell Culturesmentioning

confidence: 99%

Section: Bovine Tpo Isolationmentioning

confidence: 99%

mentioning

confidence: 99%

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Role of peroxidase inhibition by insulin in the bovine thyroid cell proliferation mechanism

Krawiec

Pizarro

Aphalo

et al. 2004

European Journal of Biochemistry

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Inhibition of Peroxidase and Catalase Activities and Modulation of Hydrogen Peroxide Level by Inositol Phosphoglycan-like Compounds

Thomasz

Arán²,

Pizarro³

et al. 2007

Horm Metab Res

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Inositol phosphoglycan-like compounds are produced by the hydrolysis of the membrane bound glycosyl phosphoinositides. Besides being short term mediators of insulin action, they inhibit peroxidases and catalase, increasing the concentration of cellular hydrogen peroxide. Although high concentrations of hydrogen peroxide are toxic, moderate increases of its basal level are signals for different metabolic pathways. The inhibitor, localized in the cytosol of the cell, acts on peroxidases and catalase of the same tissue (homologous action) and of other tissues or organisms (heterologous action). The inositol phosphoglycan-like compound inhibits peroxidases with different prosthetic groups, i.e. containing iron such as: thyroid peroxidase, lactoperoxidase, horseradish peroxidase, soy bean peroxidase; and containing selenium such as glutathione peroxidase and 2-cys peroxiredoxin with no prosthetic group. Besides peroxidases, the inositol phosphoglycan-like compound inhibits catalase, another heme enzyme. The inhibition kinetics demonstrates a noncompetitive effect. The site of action is not the prosthetic group, given that the inhibitor does not produce any effect on the peak in the Soret region in the presence or absence of hydrogen peroxide. In conclusion, the inositol phosphoglycan-like compound is the general inhibitor of peroxidases and catalase involved in the modulation of hydrogen peroxide level that acts in different metabolic pathways as a signal transducer.

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Characteristics of immunoaffinity chromatography and a new method for isolation of human thyroid peroxidase from subcellular fractions of thyroid gland

Tsyganova

Kiseleva

Vashkevich

et al. 2006

Appl Biochem Microbiol

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Presence of a soluble inhibitor of thyroid iodination in primary cultures of thyroid cells

Cited by 5 publications

References 14 publications

Role of peroxidase inhibition by insulin in the bovine thyroid cell proliferation mechanism

Role of peroxidase inhibition by insulin in the bovine thyroid cell proliferation mechanism

Inhibition of Peroxidase and Catalase Activities and Modulation of Hydrogen Peroxide Level by Inositol Phosphoglycan-like Compounds

Characteristics of immunoaffinity chromatography and a new method for isolation of human thyroid peroxidase from subcellular fractions of thyroid gland

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