Project description:PurposeCOVID-19 (Coronavirus Disease 2019) was first reported in December 2019 and quickly swept across China and around the world. Levels of anxiety and depression were increased among pregnant women during this infectious pandemic. Thyroid function is altered during stressful experiences, and any abnormality during early pregnancy may significantly affect fetal development and pregnancy outcomes. This study aimed to determine whether the COVID-19 pandemic induces thyroid hormone changes in early pregnant women.MethodsThis study comprised two groups of pregnant women in Shanghai in their first trimester - those pregnant women before the COVID-19 outbreak from January 20, 2019, to March 31, 2019 (Group 1) and those pregnant during the COVID-19 outbreak from January 20, 2020, to March 31, 2020 (Group 2). All women were included if they had early pregnancy thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3), and total thyroxine (TT4) concentrations, thyroid peroxidase (TPO) antibody or thyroglobulin antibody (TgAb) available and did not have a history of thyroid diseases or received thyroid treatment before or during pregnancy. We used propensity score matching to form a cohort in which patients had similar baseline characteristics.ResultsAmong 3338 eligible pregnant women, 727 women in Group 1 and 727 in Group 2 had similar propensity scores and were included in the analyses. Pregnant women in Group 2 had significantly higher FT3 (5.7 vs. 5.2 pmol/L, P<0.001) and lower FT4 (12.8 vs. 13.2 pmol/L, P<0.001) concentrations compared with those in Group 1. Pregnant women in Group 2 were more likely to develop isolated hypothyroxinemia (11.6% vs. 6.9%, OR, 1.75 [95% CI, 1.20-2.53], P=0.003) than those in Group 1 but had a significantly lower risk of TgAb positivity (12.0% vs. 19.0%, OR, 0.58 [95% CI, 0.43-0.78], P<0.001).ConclusionPregnant women in their first trimester in Shanghai during the COVID-19 outbreak were at an increased risk of having higher FT3 concentrations, lower FT4 concentrations, and isolated hypothyroxinemia. The association between thyroid hormones, pregnancy outcomes, and the COVID-19 outbreak should be explored further.
Project description:BackgroundThyroid-stimulating hormone (TSH) suppression is recommended for patients who undergo thyroidectomy for differentiated thyroid cancer (DTC). However, the impact of TSH suppression on clinical outcomes in low-risk DTC remains uncertain. Therefore, we investigated the effects of postoperative TSH levels on recurrence in patients with low-risk DTC after thyroid lobectomy.MethodsPatients (n=1,528) who underwent thyroid lobectomy for papillary thyroid carcinoma between 2000 and 2012 were included in this study. According to the mean and dominant TSH values during the entire follow-up period or 5 years, patients were divided into four groups (<0.5, 0.5 to 1.9, 2.0 to 4.4, and ≥4.5 mIU/L). Recurrence-free survival was compared among the groups.ResultsDuring the 5.6 years of follow-up, 21 patients (1.4%) experienced recurrence. Mean TSH levels were within the recommended low-normal range (0.5 to 1.9 mIU/L) during the total follow-up period or 5 years in 38.1% or 36.0% of patients. The mean and dominant TSH values did not affect recurrence-free survival. Adjustment for other risk factors did not alter the results.ConclusionSerum TSH levels did not affect short-term recurrence in patients with low-risk DTC after thyroid lobectomy. TSH suppression should be conducted more selectively.
Project description:Thyroxine and triiodothyronine (T3) are classical thyroid hormones and with relatively well-understood actions. In contrast, the physiological role of thyroid hormone metabolites, also circulating in the blood, is less well characterized. These molecules, namely, reverse triiodothyronine, 3,5-diiodothyronine, 3-iodothyronamine, tetraiodoacetic acid and triiodoacetic acid, mediate both agonistic (thyromimetic) and antagonistic actions additional to the effects of the classical thyroid hormones. Here, we provide an overview of the main factors influencing thyroid hormone action, and then go on to describe the main effects of the metabolites and their potential use in medicine. One section addresses thyroid hormone levels in corona virus disease 19 (COVID-19). It appears that i) the more potently-acting molecules T3 and triiodoacetic acid have shorter half-lives than the less potent antagonists 3-iodothyronamine and tetraiodoacetic acid; ii) reverse T3 and 3,5-diiodothyronine may serve as indicators for metabolic dysregulation and disease, and iii) Nanotetrac may be a promising candidate for treating cancer, and resmetirom and VK2809 for steatohepatitis. Further, the use of L-T3 in the treatment of severely ill COVID-19 patients is critically discussed.
Project description:The thyroid hormone, T 3, regulates cell growth, differentiation and development through binding to the nuclear thyroid hormone receptor (THR), a member of the steroid/TR superfamily of ligand-dependent transcriptional factors. T 3 modulates lipid metabolism in liver, although the detailed molecular mechanisms are unclear at present. Here, by a microarray analysis, we identified a novel chromosome 19 open reading frame 80 (C19orf80) which was activated by T 3. T 3 stimulation led to upregulation of both mRNA and protein levels of C19orf80. Immunofluorescence analysis revealed a vesicle-like pattern of C19orf80 around lipid droplets or within the lysosome-associated compartment in cells. Furthermore, T 3 treatment as well as C19orf80 overexpression specifically activated the autophagic response and lipid metabolism, as observed from lipidated LC3 (LC3-II) and levels of oxygen consumption rate, respectively. Reciprocally, knockdown of C19orf80 obstructed T 3-activated autophagy and lipolysis. Moreover, treatment with autolysosome maturation inhibitors, ammonium chloride and chloroquine, not only suppressed the T 3-activated autophagic process but also lipid metabolism. Our results collectively suggested that T 3 regulates lipid metabolism through a C19orf80-activated autophagic process.
Project description:Selenocysteine insertion sequence binding protein 2 (SBP2) is an essential factor in selenoprotein synthesis. Patients with SBP2 defects have a characteristic thyroid phenotype and additional manifestations such as growth delay, male infertility, impaired motor coordination, and developmental delay. The thyroid phenotype has become pathognomonic for this defect, and putative deficiencies in the iodothyronine deiodinases selenoenzymes have been implicated. To investigate the role of SBP2 and selenoproteins in thyroid physiology and answer questions raised by the human syndrome, we generated a tamoxifen-inducible Sbp2 conditional knockout (iCKO) mouse model. These Sbp2-deficient mice have high serum thyroxine (T4), thyrotropin, and reverse triiodothyronine (T3), similar to the human phenotype of SBP2 deficiency, whereas serum T3 is normal. Their liver T4 and T3 content reflect the serum levels, and deiodinase 1 expression and enzymatic activity were decreased. In contrast, brain T3 content is decreased, indicative of local hypothyroidism, confirmed by the decreased expression of the thyroid hormone (TH) positively regulated gene hairless. Interestingly, the cerebrum T4 content did not parallel the high serum T4 levels, and the expression of TH transporters was decreased. Deiodinase 2 enzymatic activity and deiodinase 3 expression were decreased in cerebrum. The expression and/or activity of other selenoproteins were decreased in brain, liver, and serum, thus demonstrating a global deficiency in selenoprotein synthesis. Sbp2 iCKO mice replicate the thyroid phenotype of SBP2 deficiency and represent an important tool to advance our understanding of the role of SBP2 in thyroid homeostasis and for investigating selenoprotein biology relevant to human disease.
Project description:Animals adapt to environmental conditions by modifying the function of their internal organs, including the brain. To be adaptive, alterations in behavior must be coordinated with the functional state of organs throughout the body. Here, we find that thyroid hormone-a regulator of metabolism in many peripheral organs-directly activates cell-type-specific transcriptional programs in the frontal cortex of adult male mice. These programs are enriched for axon-guidance genes in glutamatergic projection neurons, synaptic regulatory genes in both astrocytes and neurons, and pro-myelination factors in oligodendrocytes, suggesting widespread plasticity of cortical circuits. Indeed, whole-cell electrophysiology revealed that thyroid hormone alters excitatory and inhibitory synaptic transmission, an effect that requires thyroid hormone-induced gene regulatory programs in presynaptic neurons. Furthermore, thyroid hormone action in the frontal cortex regulates innate exploratory behaviors and causally promotes exploratory decision-making. Thus, thyroid hormone acts directly on the cerebral cortex in males to coordinate exploratory behaviors with whole-body metabolic state.
Project description:In humans, inactivating mutations in the gene of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8; SLC16A2) lead to severe forms of psychomotor retardation combined with imbalanced thyroid hormone serum levels. The MCT8-null mice described here, however, developed without overt deficits but also exhibited distorted 3,5,3'-triiodothyronine (T3) and thyroxine (T4) serum levels, resulting in increased hepatic activity of type 1 deiodinase (D1). In the mutants' brains, entry of T4 was not affected, but uptake of T3 was diminished. Moreover, the T4 and T3 content in the brain of MCT8-null mice was decreased, the activity of D2 was increased, and D3 activity was decreased, indicating the hypothyroid state of this tissue. In the CNS, analysis of T3 target genes revealed that in the mutants, the neuronal T3 uptake was impaired in an area-specific manner, with strongly elevated thyrotropin-releasing hormone transcript levels in the hypothalamic paraventricular nucleus and slightly decreased RC3 mRNA expression in striatal neurons; however, cerebellar Purkinje cells appeared unaffected, since they did not exhibit dendritic outgrowth defects and responded normally to T3 treatment in vitro. In conclusion, the circulating thyroid hormone levels of MCT8-null mice closely resemble those of humans with MCT8 mutations, yet in the mice, CNS development is only partially affected.
Project description:BackgroundPotentially harmful effects of persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) on prenatal development and the endocrine system have been controversially discussed.MethodsWorking with a German cohort of 324 pregnant women, we assessed POP levels and used robust linear regression models to determine potential associations between maternal POP concentrations and pre- and postnatal development in the children, as well as the thyroid hormone status of the mother and child.ResultsMaternal p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and most measured PCBs positively correlated with postnatal weight gain. We detected no correlation between newborn birth weight and head circumference, respectively, and maternal PCB and p,p'-DDE serum levels, while body length at birth was negatively associated with the maternal serum concentration of PCB 183. Maternal p,p'-DDE and nearly all PCB serum levels showed a negative correlation with maternal free triiodothyronine (FT3). p,p'-DDE and PCB 74 and 118 were negatively associated with maternal thyroid-stimulating hormone levels. In addition, we identified significant associations between maternal POP levels and thyroid hormone parameters of the child.ConclusionsThese results indicate that POP exposure likely affects different aspects of pre- and postnatal development and impacts the thyroid hormone status of both mother and child.ImpactPregnant women in a German cohort display a substantial accumulation of POPs. Body mass index and age influence maternal serum POP levels. Maternal POP levels show correlations with the child's length at birth and weight gain, and FT3 levels in the mother and child. Our data provide additional evidence for the potentially harmful influence of POPs. Our data indicate that POPs influence pre- and postnatal development.
Project description:We previously demonstrated that the thyroid hormone, T(3), acutely stimulates mitochondrial metabolism in a thyroid hormone receptor (TR)-dependent manner. T(3) has also recently been shown to stimulate mitochondrial fatty acid oxidation (FAO). Here we report that TR-dependent stimulation of metabolism is mediated by the mitochondrial trifunctional protein (MTP), the enzyme responsible for long-chain FAO. Stimulation of FAO was significant in cells that expressed a nonnuclear amino terminus shortened TR isoform (sTR(43)) but not in adult fibroblasts cultured from mice deficient in both TRα and TRβ isoforms (TRα(-/-)β(-/-)). Mouse embryonic fibroblasts deficient in MTP (MTP(-/-)) did not support T(3)-stimulated FAO. Inhibition of fatty-acid trafficking into mitochondria using the AMP-activated protein kinase inhibitor 6-[4-(2-piperidin-1-yl-ethoxy)-phenyl)]-3-pyridin-4-yl-pyrrazolo[1,5-a]-pyrimidine (compound C) or the carnitine palmitoyltransferase 1 inhibitor etomoxir prevented T(3)-stimulated FAO. However, T(3) treatment could increase FAO when AMP-activated protein kinase was maximally activated, indicating an alternate mechanism of T(3)-stimulated FAO exists, even when trafficking is presumably high. MTPα protein levels and higher molecular weight complexes of MTP subunits were increased by T(3) treatment. We suggest that T(3)-induced increases in mitochondrial metabolism are at least in part mediated by a T(3)-shortened TR isoform-dependent stabilization of the MTP complex, which appears to lower MTP subunit turnover.