DOCSLIB.ORG

Association of Serum Selenium with Thyroxin in Severely Iodine-Deficient

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Association of Serum Selenium with Thyroxin in Severely Iodine-Deficient European Journal of Clinical Nutrition (2016) 70, 929–934 © 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved 0954-3007/16 www.nature.com/ejcn ORIGINAL ARTICLE Association of serum selenium with thyroxin in severely iodine-deficient young children from the Amhara region of Ethiopia D Gashu1, BJ Stoecker2, A Adish3, GD Haki4, K Bougma5, FE Aboud6 and GS Marquis5 BACKGROUND/OBJECTIVES: Selenium (Se) as part of glutathione peroxidase and iodothyronine deiodinase enzymes influences thyroid metabolism. This study investigated the association of serum Se levels with thyroid metabolism of severely iodine-deficient young children from the Amhara region of Ethiopia. SUBJECTS/METHODS: In a cross-sectional study, Se, thyroid-stimulating hormone, total thyroxin, total triiodothyronine and thyroglobulin in serum of children (N = 628) 54–60 months of age from the Amhara region, Ethiopia, were analyzed. In addition, iodine in urine and household salt was analyzed, and the presence of goiter was assessed. RESULTS: The median serum Se concentration was 61.4 μg/l (10.7–290.9 μg/l). Selenium deficiency (serum Se o70 μg/l) was detected in 57.8% (N = 349) of the children. The median urinary iodine concentration (UIC) was 9.8 μg/l. The majority (86.6%, N = 449) of children had UIC below the recommended value (100 μg/l). In addition, 59.8% (N = 310) of children were severely iodine deficient (UICo20 μg/l). Only 12.7% of salt samples had iodine. Goiter was present in 44.6% (N = 280) of the children. Selenium- deficient children had higher serum thyroxin (T4) than children with normal serum Se concentration (Po0.001). CONCLUSIONS: Serum Se was negatively associated with T4 level in young children from the Amhara region of Ethiopia and may endanger the effectiveness of the salt iodization program. European Journal of Clinical Nutrition (2016) 70, 929–934; doi:10.1038/ejcn.2016.27; published online 16 March 2016 INTRODUCTION of Se deficiency on thyroid metabolism of severely iodine- The synthesis and normal metabolism of thyroid hormones deficient children are limited. The presence of Se deficiency in 10 require adequate intake of Se. This is because the Se-containing northwestern Ethiopia has been reported. In addition, iodine 11 iodothyronine deiodinase enzymes are involved in the conversion deficiency (ID) is a severe public health problem in the country. of the inactive thyroid hormone, thyroxin (T or 3, 5, 3′, Therefore, this study investigated the association of serum Se 4 fi 5′-tetraiodothyronine), into the biologically active thyroid hor- levels with thyroid metabolism of severely iodine-de cient young children from the Amhara region of Ethiopia. mone, triiodothyronine (T3 or 3, 5, 3′-triiodothyronine), or in to the inactive metabolite reverse triiodothyronine (rT3) and 3,3′-di-iodothyronine (T ). In addition, thioredoxin reductase, 2 MATERIALS AND METHODS which is another Se-dependent enzyme, protects the autoxidation of the thyroid gland by hydrogen peroxide (H2O2) produced Study participants during the synthesis of thyroid hormones.1,2 This study was part of a large randomized cluster trial ‘Effect of Iodized Salt The activity of selenoenzymes could be reduced in response to on Child Development in Amhara Region, Ethiopia’, which had mental inadequate Se nutrition and could in turn impair thyroid development of children 5 years of age and under as the primary outcome metabolism despite adequate iodine intake. Reports from (Clinicaltrials.gov #NCT01349634) in 60 randomly selected districts. In all selected districts, one village had been randomly selected and a census Uganda,3 Turkey4 and Iran5,6 attributed the persistence of goiter fi team enumerated all households with children of the required age and prevalence to Se de ciency despite of iodine replenishment. In children were further classified into three age groups (6–11, 18–22 and 54– addition, low serum Se level was associated with an increased 60 months) for the purpose of the larger study outcome (cognitive 7 concentration of T4. A large epidemiological study in populations development). Mothers of 32 children in the age group 54–60 months with adequate iodine nutrition from two counties in China refused to participate. Sample size in this part of the study was determined similar except their Se status reported a significantly higher risk by single population proportion with 50% prevalence of Se deficiency, 95% 8 confidence interval, 5% margin of error, design effect of 1.5 and 5% non- of thyroid diseases in the participants from the low-Se area. In an – fi response. Baseline data from all eligible children (N = 628), 54 60 months area of mild iodine de ciency, serum Se concentration was of age, from randomly selected 26 rural kebeles (smallest administrative negatively associated with thyroid volume. In that same study, low division) of six administrative zones (West Gojjam, East Gojjam, South serum Se concentration was reported to be a significant risk Gonder, North Wollo, South Wollo and Wagehmera) of the Amhara region factor for thyroid enlargement.9 Human studies on the association were included (Figure 1). 1Center for Food Science and Nutrition, Addis Ababa University, Addis Ababa, Ethiopia; 2Department of Nutritional Sciences, Oklahoma State University, Stillwater, OK, USA; 3Micronutrient Initiative Africa, Addis Ababa, Ethiopia; 4Department of Food Science and Technology, University of Botswana, Botswana College of Agriculture, Gaborone, Botswana; 5School of Dietetics and Human Nutrition, McGill University, Sainte Anne-de-Bellevue, QC, Canada and 6Department of Psychology, McGill University, Montreal, QC, Canada. Correspondence: Dr D Gashu, Center for Food Science and Nutrition, Addis Ababa University, PO Box 1176, Addis Ababa 1176, Ethiopia. E-Mail: [email protected] Received 2 August 2015; revised 29 January 2016; accepted 12 February 2016; published online 16 March 2016 Selenium predicts thyroxin in young children D Gashu et al 930 Figure 1. Study location. Blood collection and analysis mineral-free gloves and pipette tips were used during analysis of the 12 Blood was collected by experienced phlebotomists from the pediatric serum samples. Selenium deficiency was defined as serum Se o70 μg/l. department of the regional referral hospital (Felege Hiwote Hospital at Serum thyroid-stimulating hormone (TSH), T4,T3 and thyroglobulin (Tg) Bahir Dar) after refresher training. Blood was drawn by disposable butterfly were analyzed by electrochemilumenescenseimmunoassay using an vacutainer needles (BD Vacutainer butterfly needles, 23G, 3/4″, Franklin Elecsys2010 clinical analyzer (Cobas e411, Roche Diagnostics GmbH, Lakes, NJ, USA) by venipuncture using standard safety measures. Blood Mannheim, Germany) at the EPHI. The instrument for analyzing was collected into trace metal-free vacutainer blood tubes (BD Vacutainer, thyroid function biomarkers was calibrated using elecsys reagents every royal blue, trace element tube, 13 mm × 100 mm). The collected blood was time a fresh reagent was used as recommended by the manufacturer. In allowed to clot at an ambient temperature and centrifuged in the field addition, PrciControl Universal 1 and 2 reagents for T3,T4, TSH and Tg within an hour. The serum was separated and transferred into trace were used every 24 h or every time a fresh reagent was used for quality mineral-free vials using disposable plastic pipettes. The samples were control purpose. During the analysis of thyroid biomarkers, the inter- and transported to Bahir Dar (550 km from the capital Addis Ababa) in an intra-assay CV, respectively, for the serum samples (N = 20) was calculated icebox and kept at − 20 °C until they could be transferred to Addis Ababa’s to be 5.9 and 6.53% for T4, 7.6 and 9.5% for T3, 4.9 and 5.1% for TSH, Ethiopian Public Health Institute (EPHI) on dry ice, for storage at − 80 °C and 7.6 and 8.7% for Tg. Furthermore, the laboratory was participating in external quality assurance program ‘one world accuracy’.The until analysis of the thyroid metabolism markers. Duplicate vials of each normal reference range as recommended by the manufacturer was frozen sample were shipped on dry ice to the Department of Nutritional 0.27–4.2 mU/l for TSH, 12.9–181.4 nmol/l for T , 1.2–3.0 nmol/l for Sciences at Oklahoma State University, USA, for Se analysis. 4 T and 1.4–78.0 μg/l for Tg. Serum Se was analyzed by inductively coupled plasma mass spectro- 3 meter (PerkinElmer, ELAN9000, Norwalk, CT, USA). Serum samples were diluted in 0.1% trace metal grade HNO3 (Fisher Scientific, Fair Lawn, NJ, Household salt collection and analysis USA). A series of calibration standards were prepared by diluting 1000 p.p. Mothers or care givers were asked to give a small sample of salt for iodine m. pure Se stock solution (PerkinElmer) in 0.1% HNO3 and 0.5% Triton determination. The collected salt samples were packed in plastic bags X-100 (Sigma Aldrich, St Louis, MO, USA) solution. Working standards were and labeled with the identification code of the respective child. In the prepared daily. All samples and standards were spiked with 10 μg/l gallium field, small portions of the collected salt samples were taken for (PerkinElmer) as an internal standard. The calibration curves were fairly qualitative iodine analysis using a rapid test kit containing iodate linear (r = 0.99). A trace mineral reference standard of freeze-dried human reagents (MBI Kits International, Chennai, Tamil Nadu, India). Later, serum (Utak Laboratories, Inc., Valencia, CA, USA) containing Se was iodine-positive salt samples were analyzed quantitatively for iodine analyzed in each analytical batch to verify method performance. Reported concentration at EPHI using a standard iodometric titration method as results from the analysis of the reference standard were in the acceptable described in WHO/UNICEF/ICCIDD.13 For quality control purpose, food- range (105.13–112.66 μg/l) and were comparable with the verified value grade salt sample of ⩽ 2 mm grain size was iodized in the laboratory with (111 μg/l) set by the supplier.
Load more

Recommended publications
  • Peroxidase and NADPH-Cytochrome C Reductase Activity During Thyroid Hyperplasia and Involution
    Peroxidase and NADPH-Cytochrome C Reductase Activity During Thyroid Hyperplasia and Involution KUNIHIRO YAMAMOTO AND LESLIE J. DEGROOT Thyroid Study Unit, Department of Medicine, University of Chicago, Chicago, Illinois 60637 ABSTRACT. The regulation of iodination was in- TSH injection, whether expressed per mg gland vestigated in male rats during physiological altera- weight, per mg protein, or per fxg DNA, suggesting tions in thyroid function. Thyroid hyperplasia was enzyme induction and cellular hypertrophy. Involu- Downloaded from https://academic.oup.com/endo/article/95/2/606/2618917 by guest on 30 September 2021 produced by giving 0.01% PTU in drinking water or tion by T4 administration caused a decrease in injection of TSH (2 USP U/day); involution was thyroid weight, DNA content, and enzyme activity per induced after PTU treatment by giving 3 fig L-T4/ml gland. The main reason for the decrease in enzyme in drinking water. Increase in activity of thyroid activity per gland was a diminution of cell numbers. peroxidase and NADPH-cytochrome c reductase per During thyroid hyperplasia and involution, perox- gland exceeded gains in thyroid weight and DNA idase and NADPH-cytochrome c reductase activity content early in hyperplasia, but increased essen- is regulated by TSH. During the onset of TSH tially in parallel manner during chronic PTU treat- action, peroxidase and NADPH-cytochrome c re- ment. Enzyme activity per /xg DNA increased to ductase increase to a greater extent than thyroid 155% of control after 4 days of PTU treatment, weight and DNA content, suggesting preferential decreased to 138% on the seventh day, and was at enzyme synthesis in addition to cell hypertrophy.
    [Show full text]
  • Thyroid Peroxidase Antibody Is Associated with Plasma Homocysteine Levels in Patients with Graves’ Disease
    Published online: 2018-07-02 Article Thieme Li Fang et al. Thyroid Peroxidase Antibody is … Exp Clin Endocrinol Diabetes 2018; 00: 00–00 Thyroid Peroxidase Antibody is Associated with Plasma Homocysteine Levels in Patients with Graves’ Disease Authors Fang Li1 * , Gulibositan Aji1 * , Yun Wang2, Zhiqiang Lu1, Yan Ling1 Affiliations ABSTRACT 1 Department of Endocrinology and Metabolism, Zhong- Purpose Homocysteine is associated with cardiovascular, shan Hospital, Fudan University, Shanghai, China inflammation and autoimmune diseases. Previous studies have 2 Department of Endocrinology and Metabolism, the shown that thyroid peroxidase antibody is associated with ho- Second Hospital of Shijiazhuang City, Shijiazhuang, mocysteine levels in hypothyroidism. The relationship between Hebei Province, China thyroid antibodies and homocysteine in hyperthyroidism re- mains unclear. In this study, we aimed to investigate the asso- Key words ciation of thyroid antibodies with homocysteine in patients human, cardiovascular risk, hyperthyroidism with Graves’ disease. Methods This was a cross-sectional study including 478 received 07.04.2018 Graves’ disease patients who were consecutively admitted and revised 10.05.2018 underwent radioiodine therapy. Homocysteine, thyroid hor- accepted 14.06.2018 mones, thyroid antibodies, glucose and lipids were measured. Results Patients with homocysteine levels above the median Bibliography were older and had unfavorable metabolic parameters com- DOI https://doi.org/10.1055/a-0643-4692 pared to patients with homocysteine levels below the median. Published online: 2.7.2018 Thyroglobulin antibody or thyroid peroxidase antibody was Exp Clin Endocrinol Diabetes 2020; 128: 8–14 associated with homocysteine levels (β = 0.56, 95 %CI 0.03- © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · 1.08, p = 0.04; β = 0.75, 95 %CI 0.23-1.27, p = 0.005).
    [Show full text]
  • The Deiodination of Thyroid Hormone in Rat Liver
    The deiodination of thyroid hormone in rat liver De dejodering van schildklierhormoon in de lever van de rat PROEFSCHRIFT T er verkrijging van de graad van doctor in de geneeskunde aan de Erasmus Universiteit Rotterdam op gezag van de rector magnificus prof. dr. M. W. van Hof en vo1gens bes1uit van het college van dekanen. De openbare verdediging zal p1aatsvinden op woensdag 12 juni 1985 te 15.45 uur door Jan Adrianus Mol geboren te Dordrecht BEGELEIDINGSCOMMISSIE PROMOTOR PROF. DR. G. HENNEMANN OVERIGE LEDEN PROF. DR. W.C. HuLSMANN PROF. DR. H.J. VANDER MOLEN PROF. DR. H.J. VAN EIJK The studies in this thesis were carried out under the direction of Dr. T.J. Visser in the laboratory of the Thyroid Hormone Research Unit (head Prof. Dr. G. Hennemann) at the Department of Internal Medicine III and Clinical ·Endocrinology (head Prof. Dr. J.c. Birkenhager), Erasmus University Medical School, Rotterdam, The Netherlands. The investigations were supported by grant 13-34-108 from the Foundation for Medical Research FUNGO. Kennis, zij zal afgedaan hebben •... zo blijven dan: Geloof, hoop en liefde •.•. (I Korintiers 13) aan mijn Ouders aan Ellen, Gerben en Jurjan CONTENTS List of abbreviations. 7 Chapter I General introduction. 9 Chapter II The liver, a central organ for iodothyronine 17 metabolism? Chapter III Synthesis and some properties of sulfate 45 esters and sulfamates o_f iodothyronines. Chapter IV Rapid and selective inner ring deiodination 61 of T4 sulfate by rat liver deiodinase. Chapter V Modification of rat liver iodothyronine 75 5'-deiodinase activity with diethylpyrocarbo­ nate and Rose Bengal: evidence for an active site histidine residue.
    [Show full text]
  • Thyroid Surgery for Patients with Hashimoto's Disease
    ® Clinical Thyroidology for the Public VOLUME 12 | ISSUE 7 | JULY 2019 HYPOTHYROIDISM Thyroid surgery for patients with Hashimoto’s disease BACKGROUND SUMMARY OF THE STUDY Hypothyroidism, or an underactive thyroid, is a common This study enrolled patients with hypothyroidism due to problem. In the United States, the most common cause Hashimoto’s thyroiditis who received treatment with thy- of hypothyroidism is Hashimoto’s thyroiditis. This is an roidectomy and thyroid hormone replacement or thyroid autoimmune disorder where antibodies attack the thyroid, hormone replacement alone. The outcome of the study causing inflammation and destruction of the gland. Char- was a patient-reported health score on the generic Short acteristic of Hashimoto’s thyroiditis are high antibodies Form-36 Health Survey (SF-36) after 18 months. to thyroid peroxidase (TPO Ab) on blood tests. Hypo- thyroidism is treated by thyroid hormone and returning Patients were in the age group of 18 to 79 years. They all thyroid hormone levels to the normal range usually had a TPOAb titer >1000 IU/L and reported persistent resolves symptoms in most patients. symptoms despite having normal thyroid hormone levels based on blood tests. Typical symptoms included fatigue, However, in some patients, symptoms may persist despite increased need for sleep associated with reduced sleep what appears to be adequate treatment based on blood quality, joint and muscle tenderness, dry mouth, and dry tests of thyroid function. This raises the possibility that eyes. Follow up visits were done every 3 months for 18 some symptoms may be related to the autoimmune months and the thyroid hormone therapy was adjusted as condition itself.
    [Show full text]
  • How Useful Are Autoantibodies in Diagnosing Thyroid Disorders?
    Evidence Based Answers CLINIcAL INQUiRiES from the Family Physicians Inquiries Network Heather Downs, DO, How useful are autoantibodies and Albert A. Meyer, MD New Hanover Regional Medical in diagnosing thyroid disorders? Center, Wilmington, NC Donna Flake, MSLS, MSAS Coastal Area Health Education Evidence-based answer Center, Wilmington, NC They’re useful in diagnosing Graves’ increases or decreases the probability disease and, to a lesser extent, of autoimmune thyroid disease by only autoimmune thyroid disease; they can also a small to moderate degree (SOR: B, 3 help predict hypothyroidism. Thyrotropin cross-sectional studies). receptor antibodies (TRAb) may be mildly Thyroid-stimulating hormone (TSH) elevated in a variety of thyroid disorders, levels >2 mU/L, although still in the normal but a TRAb level >10 U/L increases range, can be followed up with TPOAb ® the probability of Graves’ disease by Dowdentesting to determine Health whether Mediathe patient a moderate to large degree (strength has an increased probability of developing of recommendation [SORCopyright]: B, cross- hypothyroidism (SOR: B, cohort study sectional study). A positive or negativeFor personalwith a vague hypothyroidism use only reference thyroid peroxidase antibody (TPOAb) test standard). Clinical commentary FAST TRACK In equivocal situations and pregnancy, infiltrative disorders, Reidel’s thyroiditis, antibodies may help or subacute granulomatous thyroiditis are Thyroid Under most circumstances, hypo- and suspected. TPOAb may help predict the autoantibodies hyperthyroid disorders can be diagnosed development of clinical hypothyroidism in can help diagnose by testing TSH and free T , without thyroid patients with TSH in the range of 5-10 mU/L. 4 Graves’ disease antibody testing. Radionuclide uptake and Pregnancy-related hyperthyroidism scan provide diagnostic information for requires antibody testing because and autoimmune hyperthyroid states.
    [Show full text]
  • Biochemical Mechanisms of Thyroid Hormone Deiodination
    THYROID Volume 15, Number 8, 2005 © Mary Ann Liebert, Inc. Biochemical Mechanisms of Thyroid Hormone Deiodination George G.J.M. Kuiper, Monique H.A. Kester, Robin P. Peeters, and Theo J. Visser Deiodination is the foremost pathway of thyroid hormone metabolism not only in quantitative terms but also because thyroxine (T4) is activated by outer ring deiodination (ORD) to 3,3’,5-triiodothyronine (T3), whereas both T4 and T3 are inactivated by inner ring deiodination (IRD) to 3,3’,5-triiodothyronine and 3,3’- diiodothyronine, respectively. These reactions are catalyzed by three iodothyronine deiodinases, D1-3. Although they are homologous selenoproteins, they differ in important respects such as catalysis of ORD and/or IRD, deiodination of sulfated iodothyronines, inhibition by the thyrostatic drug propylthiouracil, and regulation during fetal and neonatal development, by thyroid state, and during illness. In this review we will briefly discuss recent developments in these different areas. These have resulted in the emerging view that the biological activity of thyroid hormone is regulated locally by tissue-specific regulation of the different deiodinases. HYROID HORMONE is essential for growth, development, thyrostatic drug 6-propyl-2-thiouracil (PTU). D1 activity is Tand regulation of energy metabolism (1–3). Amphibian positively regulated by T3, reflecting regulation of D1 ex- metamorphosis is an important example of thyroid hormone pression by T3 at the pretranslational level. actions on development (4). Equally well known is the crit- In humans, D2 activity is found in brain, anterior pitu- ical role of thyroid hormone in development and function itary, placenta, thyroid and skeletal muscle, and D2 mRNA of the human central nervous system (5,6).
    [Show full text]
  • NNT Mutations: a Cause of Primary Adrenal Insufficiency, Oxidative Stress and Extra- Adrenal Defects
    175:1 F Roucher-Boulez and others NNT, adrenal and extra-adrenal 175:1 73–84 Clinical Study defects NNT mutations: a cause of primary adrenal insufficiency, oxidative stress and extra- adrenal defects Florence Roucher-Boulez1,2, Delphine Mallet-Motak1, Dinane Samara-Boustani3, Houweyda Jilani1, Asmahane Ladjouze4, Pierre-François Souchon5, Dominique Simon6, Sylvie Nivot7, Claudine Heinrichs8, Maryline Ronze9, Xavier Bertagna10, Laure Groisne11, Bruno Leheup12, Catherine Naud-Saudreau13, Gilles Blondin13, Christine Lefevre14, Laetitia Lemarchand15 and Yves Morel1,2 1Molecular Endocrinology and Rare Diseases, Lyon University Hospital, Bron, France, 2Claude Bernard Lyon 1 University, Lyon, France, 3Pediatric Endocrinology, Gynecology and Diabetology, Necker University Hospital, Paris, France, 4Pediatric Department, Bab El Oued University Hospital, Alger, Algeria, 5Pediatric Endocrinology and Diabetology, American Memorial Hospital, Reims, France, 6Pediatric Endocrinology, Robert Debré Hospital, Paris, France, 7Department of Pediatrics, Rennes Teaching Hospital, Rennes, France, 8Pediatric Endocrinology, Queen Fabiola Children’s University Hospital, Brussels, Belgium, 9Endocrinology Department, L.-Hussel Hospital, Vienne, France, 10Endocrinology Department, Cochin University Hospital, Paris, France, 11Endocrinology Department, Lyon University Hospital, Bron-Lyon, France, 12Paediatric and Clinical Genetic Department, Correspondence Nancy University Hospital, Vandoeuvre les Nancy, France, 13Pediatric Endocrinology and Diabetology, should be
    [Show full text]
  • Independent Evolution of Four Heme Peroxidase Superfamilies
    Archives of Biochemistry and Biophysics xxx (2015) xxx–xxx Contents lists available at ScienceDirect Archives of Biochemistry and Biophysics journal homepage: www.elsevier.com/locate/yabbi Independent evolution of four heme peroxidase superfamilies ⇑ Marcel Zámocky´ a,b, , Stefan Hofbauer a,c, Irene Schaffner a, Bernhard Gasselhuber a, Andrea Nicolussi a, Monika Soudi a, Katharina F. Pirker a, Paul G. Furtmüller a, Christian Obinger a a Department of Chemistry, Division of Biochemistry, VIBT – Vienna Institute of BioTechnology, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria b Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, SK-84551 Bratislava, Slovakia c Department for Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, A-1030 Vienna, Austria article info abstract Article history: Four heme peroxidase superfamilies (peroxidase–catalase, peroxidase–cyclooxygenase, peroxidase–chlo- Received 26 November 2014 rite dismutase and peroxidase–peroxygenase superfamily) arose independently during evolution, which and in revised form 23 December 2014 differ in overall fold, active site architecture and enzymatic activities. The redox cofactor is heme b or Available online xxxx posttranslationally modified heme that is ligated by either histidine or cysteine. Heme peroxidases are found in all kingdoms of life and typically catalyze the one- and two-electron oxidation of a myriad of Keywords: organic and inorganic substrates. In addition to this peroxidatic activity distinct (sub)families show pro- Heme peroxidase nounced catalase, cyclooxygenase, chlorite dismutase or peroxygenase activities. Here we describe the Peroxidase–catalase superfamily phylogeny of these four superfamilies and present the most important sequence signatures and active Peroxidase–cyclooxygenase superfamily Peroxidase–chlorite dismutase superfamily site architectures.
    [Show full text]
  • Illness-Induced Changes in Thyroid Hormone Metabolism: Focus on the Tissue Level
    r e V i e W illness-induced changes in thyroid hormone metabolism: focus on the tissue level J. Kwakkel*, E. Fliers, A. Boelen Department of Endocrinology & Metabolism, Academic Medical Center, University of Amsterdam, the Netherlands, *corresponding author: tel.: +31 (0)20-566 67 01, fax: +31 (0)20-691 76 82, e-mail: [email protected] a b s t r a C t during illness changes in thyroid hormone metabolism ring and the outer (tyrosyl) ring of T4 can be deiodinated, occur, collectively known as the non-thyroidal illness ultimately leading to the formation of 3,3’-di-iodothyronine syndrome (NTIS). NTIS is characterised by low serum (T2) (figure 1). thyroid hormone levels without the expected rise in serum thyroid-stimulating hormone, indicating a major change in thyroid hormone feedback regulation. recent studies n o n - t H yroidal illness syndro M e have made clear that during NTIS differential changes in thyroid hormone metabolism occur in various tissues, the During illness many aspects of thyroid hormone net effect of which may be either activation or inhibition of metabolism change, collectively known as the thyroid hormone action. in this review we discuss systemic non-thyroidal illness syndrome (NTIS). The hallmark of and local changes in thyroid hormone metabolism during NTIS is decreased serum thyroid hormone levels without illness, highlighting their physiological implications in an increase in TSH and TRH expression, indicating terms of disease course. the absence of negative feedback regulation. This may represent a useful adaptation of the body to counteract excessive catabolism observed during illness and can be K e y W o r d s viewed as a part of the acute phase response.4 However, especially during prolonged critical illness in the ICU Deiodinase, inflammation, non-thyroidal illness syndrome, setting NTIS may be maladaptative.5 thyroid hormone figure 1.
    [Show full text]
  • Thyroid-Modulating Activities of Olive and Its Polyphenols: a Systematic Review
    nutrients Review Thyroid-Modulating Activities of Olive and Its Polyphenols: A Systematic Review Kok-Lun Pang 1,† , Johanna Nathania Lumintang 2,† and Kok-Yong Chin 1,* 1 Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, Cheras 56000, Kuala Lumpur, Malaysia; [email protected] 2 Faculty of Applied Sciences, UCSI University Kuala Lumpur Campus, Jalan Menara Gading, Taman Connaught, Cheras 56000, Kuala Lumpur, Malaysia; [email protected] * Correspondence: [email protected]; Tel.: +60-3-91459573 † These authors contributed equally to this work. Abstract: Olive oil, which is commonly used in the Mediterranean diet, is known for its health benefits related to the reduction of the risks of cancer, coronary heart disease, hypertension, and neurodegenerative disease. These unique properties are attributed to the phytochemicals with potent antioxidant activities in olive oil. Olive leaf also harbours similar bioactive compounds. Several studies have reported the effects of olive phenolics, olive oil, and leaf extract in the modulation of thyroid activities. A systematic review of the literature was conducted to identify relevant studies on the effects of olive derivatives on thyroid function. A comprehensive search was conducted in October 2020 using the PubMed, Scopus, and Web of Science databases. Cellular, animal, and human studies reporting the effects of olive derivatives, including olive phenolics, olive oil, and leaf extracts on thyroid function were considered. The literature search found 445 articles on this topic, but only nine articles were included based on the inclusion and exclusion criteria. All included articles were animal studies involving the administration of olive oil, olive leaf extract, or olive pomace residues orally.
    [Show full text]
  • REVIEW Iodothyronine Deiodinase Structure and Function
    189 REVIEW Iodothyronine deiodinase structure and function: from ascidians to humans Veerle M Darras and Stijn L J Van Herck Animal Physiology and Neurobiology Section, Department of Biology, Laboratory of Comparative Endocrinology, KU Leuven, Naamsestraat 61, PO Box 2464, B-3000 Leuven, Belgium (Correspondence should be addressed to V M Darras; Email: [email protected]) Abstract Iodothyronine deiodinases are important mediators of thyroid of each of them, however, varies amongst species, develop- hormone (TH) action. They are present in tissues throughout mental stages and tissues. This is especially true for 0 the body where they catalyse 3,5,3 -triiodothyronine (T3) amphibians, where the impact of D1 may be minimal. D2 production and degradation via, respectively, outer and inner and D3 expression and activity respond to thyroid status in ring deiodination. Three different types of iodothyronine an opposite and conserved way, while the response of D1 is deiodinases (D1, D2 and D3) have been identified in variable, especially in fish. Recently, a number of deiodinases vertebrates from fish to mammals. They share several have been cloned from lower chordates. Both urochordates common characteristics, including a selenocysteine residue and cephalochordates possess selenodeiodinases, although in their catalytic centre, but show also some type-specific they cannot be classified in one of the three vertebrate types. differences. These specific characteristics seem very well In addition, the cephalochordate amphioxus also expresses conserved for D2 and D3, while D1 shows more evolutionary a non-selenodeiodinase. Finally, deiodinase-like sequences diversity related to its Km, 6-n-propyl-2-thiouracil sensitivity have been identified in the genome of non-deuterostome and dependence on dithiothreitol as a cofactor in vitro.
    [Show full text]
  • Type 3 Lodothyronine Deiodinase: Cloning, in Vitro Expression, and Functional Analysis of the Placental Selenoenzyme
    Type 3 lodothyronine deiodinase: cloning, in vitro expression, and functional analysis of the placental selenoenzyme. D Salvatore, … , D L St Germain, P R Larsen J Clin Invest. 1995;96(5):2421-2430. https://doi.org/10.1172/JCI118299. Research Article Type 3 iodothyronine deiodinase (D3) catalyzes the conversion of T4 and T3 to inactive metabolites. It is highly expressed in placenta and thus can regulate circulating fetal thyroid hormone concentrations throughout gestation. We have cloned and expressed a 2.1-kb human placental D3 cDNA which encodes a 32-kD protein with a Km of 1.2 nM for 5 deiodination of T3 and 340 nM for 5' deiodination of reverse T3. The reaction requires DTT and is not inhibited by 6n- propylthiouracil. We quantitated transiently expressed D3 by specifically labeling the protein with bromoacetyl [125I]T3. The Kcat/Km ratio for 5 deiodination of T3 was over 1,000-fold that for 5' deiodination of reverse T3. Human D3 is a selenoenzyme as evidenced by (a) the presence of an in frame UGA codon at position 144, (b) the synthesis of a 32-kD 75Se-labeled protein in D3 cDNA transfected cells, and (c) the presence of a selenocysteine insertion sequence element in the 3' untranslated region of the mRNA which is required for its expression. The D3 selenocysteine insertion sequence element is more potent than that in the type 1 deiodinase or glutathione peroxidase gene, suggesting a high priority for selenocysteine incorporation into this enzyme. The conservation of this enzyme from Xenopus laevis tadpoles to humans implies an essential role for regulation of thyroid hormone inactivation during embryological development.
    [Show full text]