Selenium, Iodine and Iron-Essential Trace Elements for Thyroid Hormone Synthesis and Metabolism

• Published in: International journal of molecular sciences Vol. 24; no. 4; p. 3393
• Main Author: Köhrle, Josef
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.02.2023; MDPI
• Subjects: Animals; Biosynthesis; Consumption; deiodinases; Disease prevention; Enzymes; essential trace elements; Follicles; Genetic disorders; Hormones; Humans; Hydrogen peroxide; Hydrogen Peroxide - metabolism; Hypothalamus; Hypothyroidism; Iodide peroxidase; Iodide Peroxidase - metabolism; Iodides - metabolism; Iodine; Iodine - metabolism; Iron; Iron - metabolism; Metabolic disorders; Metabolism; Negative feedback; Physiological aspects; Pituitary; Pituitary hormones; Review; Salt; Selenium; Selenium - metabolism; Selenocysteine; Selenoproteins; Selenoproteins - metabolism; Structure-function relationships; Thyrocytes; Thyroglobulin; Thyroid cancer; Thyroid diseases; Thyroid gland; Thyroid Gland - metabolism; thyroid hormone system; Thyroid hormones; Thyroid Hormones - metabolism; Thyroid-stimulating hormone; Thyrotropin; Trace elements; Trace Elements - metabolism; Vertebrates; Serbia; Switzerland; thyroid hormone system; thyroperoxidase; gene variants; SELENOP (selenoprotein P); biomarker; thioredoxin reductase; selenium; genetic predisposition; hemoprotein; deiodinases; iron; iodine; essential trace elements; glutathione peroxidase
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24043393

The adequate availability and metabolism of three essential trace elements, iodine, selenium and iron, provide the basic requirements for the function and action of the thyroid hormone system in humans, vertebrate animals and their evolutionary precursors. Selenocysteine-containing proteins convey both cellular protection along with H O -dependent biosynthesis and the deiodinase-mediated (in-)activation of thyroid hormones, which is critical for their receptor-mediated mechanism of cellular action. Disbalances between the thyroidal content of these elements challenge the negative feedback regulation of the hypothalamus-pituitary-thyroid periphery axis, causing or facilitating common diseases related to disturbed thyroid hormone status such as autoimmune thyroid disease and metabolic disorders. Iodide is accumulated by the sodium-iodide-symporter NIS, and oxidized and incorporated into thyroglobulin by the hemoprotein thyroperoxidase, which requires local H O as cofactor. The latter is generated by the dual oxidase system organized as 'thyroxisome' at the surface of the apical membrane facing the colloidal lumen of the thyroid follicles. Various selenoproteins expressed in thyrocytes defend the follicular structure and function against life-long exposure to H O and reactive oxygen species derived therefrom. The pituitary hormone thyrotropin (TSH) stimulates all processes required for thyroid hormone synthesis and secretion and regulates thyrocyte growth, differentiation and function. Worldwide deficiencies of nutritional iodine, selenium and iron supply and the resulting endemic diseases are preventable with educational, societal and political measures.