Role of Thyroid Hormones in Skeletal Development and Bone Maintenance

Abstract. Thyroid hormones play an important role in body homeostasis by facilitating metabolism of lipids and glucose, regulating metabolic adaptations, responding to changes in energy intake, and controlling thermogenesis. Proper metabolism and action of these hormones requires the participation of various nutrients. Among them is zinc, whose interaction with thyroid hormones is complex. It is known to regulate both the synthesis and mechanism of action of these hormones. In the present review, we aim to shed light on the regulatory effects of zinc on thyroid hormones. Scientific evidence shows that zinc plays a key role in the metabolism of thyroid hormones, specifically by regulating deiodinases enzymes activity, thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH) synthesis, as well as by modulating the structures of essential transcription factors involved in the synthesis of thyroid hormones. Serum concentrations of zinc also appear to influence the levels of serum T3, T4 and TSH. In addition, studies have shown that Zinc transporters (ZnTs) are present in the hypothalamus, pituitary and thyroid, but their functions remain unknown. Therefore, it is important to further investigate the roles of zinc in regulation of thyroid hormones metabolism, and their importance in the treatment of several diseases associated with thyroid gland dysfunction.

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Glucose disposal and lipid metabolism in man: role of thyroid hormones

Acta Endocrinologica ◽

10.1530/acta.0.117s130-a ◽

1988 ◽

Vol 117 (4_Suppl) ◽

pp. S130-S131

Author(s):

M. J. MÜLLER ◽

A. G. BURGER ◽

E. JEQUIER ◽

K.J. ACHESON

Keyword(s):

Lipid Metabolism ◽

Thyroid Hormones ◽

Glucose Disposal

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Evolution and expansion of the RUNX2 QA repeat corresponds with the emergence of vertebrate complexity

Communications Biology ◽

10.1038/s42003-020-01501-3 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Axel H. Newton ◽

Andrew J. Pask

Keyword(s):

Natural Variation ◽

Skeletal Development ◽

Skull Shape ◽

Morphological Novelty ◽

Transactivation Potential ◽

Repeat Domain ◽

Related Transcription Factor ◽

Mammalian Skull ◽

Evolutionary Tuning

AbstractRunt-related transcription factor 2 (RUNX2) is critical for the development of the vertebrate bony skeleton. Unlike other RUNX family members, RUNX2 possesses a variable poly-glutamine, poly-alanine (QA) repeat domain. Natural variation within this repeat is able to alter the transactivation potential of RUNX2, acting as an evolutionary ‘tuning knob’ suggested to influence mammalian skull shape. However, the broader role of the RUNX2 QA repeat throughout vertebrate evolution is unknown. In this perspective, we examine the role of the RUNX2 QA repeat during skeletal development and discuss how its emergence and expansion may have facilitated the evolution of morphological novelty in vertebrates.

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Inhibition of hepatic deiodination of thyroxine is caused by selenium deficiency in rats

Biochemical Journal ◽

10.1042/bj2480443 ◽

1987 ◽

Vol 248 (2) ◽

pp. 443-447 ◽

Cited By ~ 99

Author(s):

G J Beckett ◽

S E Beddows ◽

P C Morrice ◽

F Nicol ◽

J R Arthur

Keyword(s):

Thyroid Hormones ◽

Production Rate ◽

Selenium Deficiency ◽

Enzyme Complex ◽

Measurable Effect ◽

Direct Role ◽

Mechanism Of Inhibition ◽

Se Deficiency

Selenium (Se) deficiency produced up to a 14-fold decrease in hepatic tri-iodothyronine (T3) production from thyroxine (T4) in vitro. The T3 production rate could not be restored by the addition of a variety of cofactors, nor by the addition of control homogenate. The impairment in hepatic T3 production observed in Se deficiency was reflected in the concentrations of thyroid hormones circulating in plasma, T4 being increased approx. 40% and T3 being decreased by 30%. However, the fall in plasma T3 concentrations was smaller than might be expected in view of the marked decreased in T3 production. Se deficiency had no measurable effect on plasma reverse-tri-iodothyronine concentrations. The data suggest that Se deficiency produces an inhibition of both 5- and 5′-deiodination, consistent with the widely held view that these reactions are catalysed by the same enzyme complex. The mechanism of inhibition appears not be mediated by changes in thiol levels, but a direct role of Se in the activity of the deiodinase complex cannot be excluded.

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Immunomodulatory role of thyroid hormones: in vivo effect of thyroid hormones on the blastogenic response of lymphoid tissues

Acta Endocrinologica ◽

10.1530/acta.0.1030095 ◽

1983 ◽

Vol 103 (1) ◽

pp. 95-100 ◽

Cited By ~ 30

Author(s):

Sadhana Chatterjee ◽

Amar Singh Chandel

Keyword(s):

Thyroid Hormones ◽

Pokeweed Mitogen ◽

Lymphoid Tissues ◽

Mesenteric Lymph Nodes ◽

Mesenteric Lymph ◽

Hormone Administration ◽

Blastogenic Response ◽

Significant Depression

Abstract. In an attempt to find out the mechanism of immunomodulation by thyroid hormones (T3 and T4), their in vivo effect on the blastogenic response of lymphocytes from various lymphoid tissues of hormonetreated and thyroidectomized rats were studied. The blastogenic response of lymphocytes from thymus, peripheral blood and mesenteric lymph nodes to pokeweed mitogen (PWM) was found to be increased significantly following T3 or T4 administration for 15 days or 30 days. However, the response to phytohaemagglutinin (PHA) increased only after 1 month of T3 or T4 administration. The blastogenic response of spleen cells to both PHA and PWM was, on the other hand, found to be depressed following 15 days of hormone administration. Thyroidectomy invariably induced significant depression in the blastogenic response to both PHA and PWM in lymphocytes of all the lymphoid tissues. Thyroid hormone (T3) administration was found to restore the blastogenic response of the lymphocytes of thyroidectomized animals.

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Role of the neural crest in development of the trabeculae and branchial arches in embryonic sea lamprey, Petromyzon marinus (L)

Development ◽

10.1242/dev.102.2.301 ◽

1988 ◽

Vol 102 (2) ◽

pp. 301-310 ◽

Cited By ~ 4

Author(s):

R.M. Langille ◽

B.K. Hall

Keyword(s):

Neural Crest ◽

Skeletal Development ◽

Petromyzon Marinus ◽

Branchial Arches ◽

Artificial Fertilization ◽

Vertebrate Skeleton ◽

The Brain ◽

Head Skeleton ◽

Neurula Stage

Lamprey embryos were obtained by artificial fertilization to ascertain the contributions made by the neural crest to the head skeleton. Early-neurula-stage embryos of Petromyzon marinus were subjected to neural crest extirpation along the anterior half from one of seven zones, raised to a larval stage at which control larvae exhibit well-developed skeletons and analysed by light microscopy for any abnormalities to the cranial and visceral skeleton. The removal of premigratory neural crest at the level of the anterior prosencephalon (zone I) and at the level of somites 6 to 8 (zone VII) had no effect on skeletal development. However, the extirpation of neural crest from the intervening regions was positively correlated with deletions/reductions to the trabeculae (basicranial elements) and to the branchial arches (viscerocranial elements). Alterations to the trabeculae (16/27 cases, or 59%) occurred only after extirpation of zones II-V (corresponding to the posterior prosencephalon to midrhombencephalon) while alterations to the branchial arches (21/28 cases, or 75%) occurred only after removal of neural crest from zones III-VI (corresponding to the mesencephalon to the level of the fifth somite). Furthermore, the first three branchial arches were correlated in a majority of cases with neural crest from zone III, the next two arches with zones IV, V and VI and the last two arches with zone VI. Organs that develop within or adjacent to the area of neural crest extirpation such as the brain, notochord and lateral mesodermal derivatives were not affected. Parachordals were never altered by the operations nor were there any discernible changes to developing mucocartilage or to the prechondrogenic otic capsule. The contributions of the neural crest to the petromyzonid head skeleton described herein are compared with the roles of neural crest in the development of cranial and visceral skeletal elements in other vertebrates. The importance of these findings to the current hypothesis of the phylogeny of the vertebrate skeleton and the central role of the neural crest in vertebrate cephalization is discussed.

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