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The thyrotropin receptor (TSHR) mutation database, consisting of all known TSHR mutations and their clinical characterizations, was established in 1999. The database contents are updated here with the same website (tsh-receptor-mutation-database.org). The new database contains 638 cases of TSHR mutations: 448 cases of gain of function mutations (7 novel mutations and 41 new cases for previously described mutations since its last update in 2012) and 190 cases of loss of function mutations (28 novel mutations and 31 new cases for previously described mutations since its last update in 2012). This database is continuously updated and allows for rapid validation of patient TSHR mutations causing hyper- or hypothyroidism or insensitivity to TSH. [ABSTRACT FROM AUTHOR]

Objectives: Congenital hypothyroidism (CH) is the most common congenital endocrine disorder. Recent advances in genetic testing have revealed its causative mutations in some CH patients. However, the underlying etiology remains unknown in most patients. This study aimed to perform clinical and genetic investigation in Japanese CH patients to uncover genotype-phenotype correlations. Methods: We enrolled 136 Japanese patients with transient or permanent CH between April 2015 and March 2017, and performed next-generation sequencing of 19 genes implicated in CH. Results: We identified potentially pathogenic bi-allelic variants in DUOX2, TSHR, and TPO in 19, 5, and 1 patient, respectively (autosomal recessive), and a potentially pathogenic mono-allelic variant in NKX2-1 (autosomal dominant) in 1 patient. Molecular genetic diagnosis was highly suggested in 26 patients (19%) from 23 families. We also detected a potentially pathogenic mono-allelic variant in five recessive genes (DUOX2, TSHR, TG, DUOXA2, and TPO) in 31 unrelated patients (23%), although the pathogenicity of these variants remains inconclusive. Patients with bi-allelic DUOX2 variants showed a more severe clinical presentation in infancy than those with bi-allelic TSHR variants. However, this trend reversed beyond infancy. There were no statistical differences in initial thyroid stimulating hormone, free thyroxine, thyroglobulin, and levothyroxine dose as of March 2017 between patients with bi-allelic and mono-allelic DUOX2 variants. Conclusions: The prevalence of potentially-pathogenic variants in Japanese CH patients was similar to that found by previous reports. Our study demonstrates a genotype-phenotype correlation in Japanese CH patients. [ABSTRACT FROM AUTHOR]

Thyrotropin hormone (TSH) was reported to exhibit biphasic regulation of cAMP production in human thyroid slices; specifically, upregulation at low TSH doses transitioning to inhibition at high doses. We observed this phenomenon in HEK293 cells overexpressing TSH receptors (TSHRs) but in only 25% of human thyrocytes (hThyros) in vitro. Because TSHR expression in hThyros in vitro was low, we tested the hypothesis that high, in situ levels of TSHRs were needed for biphasic cAMP regulation. We increased expression of TSHRs by infecting hThyros with adenoviruses expressing human TSHR (AdhTSHR), measured TSH-stimulated cAMP production and TSHR homodimerization. TSHR mRNA levels in hThyros in vitro were 100-fold lower than in human thyroid tissue. AdhTSHR infection increased TSHR mRNA expression to levels found in thyroid tissue and flow cytometry showed that cell-surface TSHRs increased more than 15-fold. Most uninfected hThyro preparations exhibited monotonic cAMP production. In contrast, most hThyro preparations infected with AdhTSHR expressing TSHR at in vivo levels exhibited biphasic TSH dose responses. Treatment of AdhTSHR-infected hThyros with pertussis toxin resulted in monotonic dose response curves demonstrating that lower levels of cAMP production at high TSH doses were mediated by Gi/Go proteins. Proximity ligation assays confirmed that AdhTSHR infection markedly increased the number of TSHR homodimers. We conclude that in situ levels of TSHRs as homodimers are needed for hThyros to exhibit biphasic TSH regulation of cAMP production. [ABSTRACT FROM AUTHOR]

Untreated hyperthyroidism may develop serious complications. This attempt was made to investigate the potential of Aloe vera gel in regulating experimentally induced hyperthyroidism in rats. Female Wistar rats were made hyperthyroid with L-thyroxine (L-T4) at 0.5 mg/kg/day, i.p. for 14 days and the effects of Aloe vera methanolic fraction (AVMF) (50 or 500 mg/kg/day, p.o.,) and a conventional antithyroid drug propylthiouracil (PTU) (10 mg/kg, i.p.) for 30 days were studied in those hyperthyroid rats. At the end, alterations in serum thyroid hormones and thyroid stimulating hormone (TSH); hepatic 5′mono-deiodinase-1(5′D1) activity, oxidative stress markers and antioxidants; serum inflammatory cytokines and the expression of thyrotropin receptor in thyroid gland were evaluated in all experimental animals. Hyperthyroid condition was confirmed by an increase in thyroid hormone levels and hepatic 5′D-1 activity with a decrease in TSH. However, either AVMF or PTU treatment in hyperthyroid rats decreased the levels of thyroid hormones and 5′D1 activity. AVMF administration in T4-induced rats also decreased the oxidative stress markers such as thiobarbituric acid reactive substances and lipid hydroperoxides and increased the antioxidant levels in liver tissues. Levels of liver marker enzymes, cytokines and different lipids were decreased in T4-induced AVMF treated rats. Further, a down regulation in the TSHR expression in thyroid was observed in AVMF or PTU treated groups. All these thyroid inhibiting effects were supported by an improvement in thyroid histology in hyperthyroid rats. It appears, about 15 compounds, as evidenced by LC–MS/MS study, mostly phenolics are involved in this anti-thyroid effects of the test compound. [ABSTRACT FROM AUTHOR]

Introduction: Thyroid eye disease (TED) is the most frequent extra-thyroid manifestation of Graves' disease and it is more frequent in middle age and in female gender. Nowadays, the causal mechanisms of this disease are not completely understood, but the current available studies suggest that the main causative factor is the thyroid stimulating hormone receptor. Materials and methods: To collect reports on TED medical management, a thorough literature search was performed in PubMed database. An additional search was made in Google Scholar to complete the collected items. Results: Among the indentified risk factors, tobacco habit is the most relevant. The main criteria to choose a suitable treatment are the activity and severity of the disease. Support measures can be used to improve the patient's symptoms in any phase of the disease. There is a large number of drugs proposed to manage TED, although with different reported rates of success. Conclusions: Currently, the drugs of choice are corticosteroids in moderate-to-severe and in sight-threatening forms. The main problem of corticosteroids is their spectrum of side effects. Therefore, other alternatives are being suggested for medical management of this disease. The efficacy of these alternatives remains unclear. [ABSTRACT FROM AUTHOR]

Summary: The thyroid‐stimulating hormone receptor (TSHR) has been indicated as a putative domestication gene in chicken. Comparison of WGS identified a variant in residue 558 of the transmembrane domain (TM) of TSHR, where the domestic chicken (GGD) presents an arginine, whereas the red jungle fowl (RJF) shares a conserved glycine with other vertebrates. This variant has been demonstrated to be associated with phenotypes that are important for domestication and related to thyroid regulation, such as less fearful behavior, reduced aggressive behavior and reduced dependence on seasonal reproduction in GGD as compared with RJF. By means of molecular dynamics simulations, we highlighted the structural and dynamic differences of variant Gly558Arg in the TSHR TM domain. Alterations in TM helix flexibility, structure and protein overall motion are described. The so‐called 'arginine snorkeling' of residue 568 in GGD is observed and we hypothesize it as the originating force that produces the observed whole‐protein perturbation in the helix bundle dynamics, capable of altering the TSHR signal transduction. The results are discussed in the context of their implications for a better understanding of biological mechanisms in chicken under control of the thyroid, such as body metabolism, as well as for their usefulness in biomedical research. [ABSTRACT FROM AUTHOR]

Graves' disease (GD) involves the presence of agonistic auto-antibodies against the thyrotropin receptor (TSHR), which are responsible for the clinical symptoms. While failure of TSHR tolerance is central to GD pathogenesis, the process leading to this failure remains poorly understood. Two mechanisms intimately linked to tolerance have been proposed to explain the association of SNPs located in TSHR intron 1 to GD: (1) differential alternative splicing in the thyroid; and (2) modulation of expression in the thymus. To elucidate the relative contribution to these two mechanisms to GD pathogenesis, we analyzed the level of full-length and ST4 and ST5 isoform expression in the thyroid (n = 49) and thymus (n = 39) glands, and the influence of intron 1-associated SNPs on such expression. The results show that: (1) the level of flTSHR and ST4 expression in the thymus was unexpectedly high (20% that of the thyroid); (2) while flTSHR is the predominant isoform, the levels are similar to ST4 (ratio flTSHR/ST4 = 1.34 in the thyroid and ratio flTSHR/ST4 in the thymus = 1.93); (3) next-generation sequencing confirmed the effect of the TSHR intron 1 polymorphism on TSHR expression in the thymus with a bias of 1.5 ± 0.2 overexpression of the protective allele in the thymus compared to the thyroid; (4) GD-associated intron 1 SNPs did not influence TSHR alternative splicing of ST4 and ST5 in the thyroid and thymus; and (5) three-color confocal imaging showed that TSHR is associated with both thymocytes, macrophages, and dendritic cells in the thymus. Our findings confirm the effect of intron 1 polymorphisms on thymic TSHR expression and we present evidence against an effect on the relative expression of isoforms. The high level of ST4 expression in the thymus and its distribution within the tissue suggest that this would most likely be the isoform that induces central tolerance to TSHR thus omitting most of the hinge and transmembrane portion. The lack of central tolerance to a large portion of TSHR may explain the relatively high frequency of autoimmunity related to TSHR and its clinical consequence, GD.

Background. Autoimmune thyroid diseases (AITD) including Graves' disease (GD) and Hashimoto's thyroiditis (HT) are complex genetic diseases. TSHR is considered as candidate gene in GD. This finding prompted us to investigate the association of TSHR gene polymorphism with the risk and the prognosis of AITD in Tunisia. Methods. A total of 84 healthy controls and 91 patients with AITD (69HT and 22 GD) were genotyped for TSHR rs74067403A>G polymorphism and 134 healthy controls and 149 patients with AITD (98 HT and 51 GD) were genotyped for TSHR rs1054708 T>C polymorphism. Results. For rs1054708, we found an association between HT, AITD and the heterozygous genotype TC, the mutated genotype CC and the genotypes presented the mutated allele C (TC+CC) and with mutated allele C. The heterozygous genotype TC and the genotypes that presented the mutated allele C of rs1054708 are associated with male patients with AITD evenly the heterozygous genotype TC is associated with age of onset of disease. Conclusions. These preliminary results suggest that TSHR rs1054708 polymorphism may be a protective factor against HT and AITD. This polymorphism can affect the etiology of AITD between men and women and also by age. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the association of potential functional tagging single nucleotide polymorphisms (tagSNPs) in BRAF and TSHR with papillary thyroid cancer (PTC). Two tagSNPs (rs6464149 and rs7810757) in BRAF and six tagSNPs (rs17630128, rs2075179, rs7144481, rs2371462, rs2268477, and rs2288496) in TSHR were genotyped in 300 cases of PTC and 252 healthy controls. There was no difference in the genotype frequencies of BRAF and TSHR between PTC patients and control subjects, suggesting no contribution of BRAF or TSHR polymorphisms to the susceptibility to PTC. We observed that a tagSNP located in the 3' untranslated region of TSHR, rs2288496, could affect the incidence of lymph node metastasis (LNM). The variant TC and TC + CC genotypes conferred an increased risk of LNM (for TC vs. TT: odds ratio (OR) = 2.01, 95% confidence interval (CI): 1.07–3.77; P = 0.030; for TC + CC vs. TT: OR = 1.87, 95% CI: 1.04–3.39, P = 0.038). Moreover, subjects carrying variant genotypes had higher TSH levels and lower thyroxine (T4) and Anti-TG levels compared with those in subjects carrying common genotypes. Our findings showed that PTC patients carrying the TSHR rs2288496 TC and CC variants were associated with higher TSH level and lower T4 and Anti-TG levels and were prone to developing LNM. To confirm these results, additional studies and functional experiments, especially in other ethnic populations, are needed. [ABSTRACT FROM AUTHOR]

Graves' hyperthyroidism can be treated but not cured. Antigen-specific immunotherapy would accomplish this goal, for which purpose an animal model is an invaluable tool. Two types of animal models are available. First, pathogenic TSHR antibodies (TSHRAb) can be induced by injecting mice with fibroblasts co-expressing the human TSHR (hTSHR) and MHC class II, or in mammals using plasmid or adenovirus vectors encoding the hTSHR or its A-subunit. Second, a mouse model that spontaneously develops pathogenic TSHRAb resembling those in human disease was recently described. This outcome was accomplished by transgenic intrathyroidal expression of the hTSHR A-subunit in NOD.H2h4 mice that are genetically predisposed to develop thyroiditis but, without the transgene, do not generate TSHRAb. Recently, novel approaches to antigen-specific immunotherapy have been tested, primarily in the induced model, by injecting TSHR A-subunit protein or cyclic TSHR peptides. T-cell tolerance has also been induced in "humanized" HLA-DR3 mice by injecting synthetic peptides predicted in silico to mimic naturally processed TSHR T-cell epitopes. Indeed, a phase 1 study based on the latter approach has been conducted in humans. In the spontaneous model (hTSHR/NOD.H2h mice), injection of soluble or nanoparticle-bearing hTSHR A-subunits had the unwanted effect of exacerbating pathogenic TSHRAb levels. A promising avenue for tolerance induction, successful in other conditions and yet to be tested with the TSHR, involves encapsulating the antigen. In conclusion, these studies provide insight into the potential outcome of immunotherapeutic approaches and emphasize the importance of a spontaneous model to test future novel, antigen-specific immunotherapies for Graves' disease. [ABSTRACT FROM AUTHOR]

Defects in the human thyroid stimulating hormone receptor (TSHR) gene are reported to be one of the causes of congenital hypothyroidism (CH). We aimed to identify mutations in Chinese patients with CH and analyze the relationships between TSHR phenotypes and clinical phenotypes. 220 patients with primary CH were screened for TSHR mutations by performing next-generation sequencing. All the exons and exon–intron boundaries of TSHR were analyzed. The function of 8 mutants in TSHR were further investigated in vitro. Among 220 patients with CH, 15 distinct TSHR mutations were identified in 13 patients (5.91%, 13/220, including our previous reported 110 patients, carried with 10 mutations in 8 patients). We found five distinct mutations in the additional cohort of 110 CH patients and identified 7 mutations (including a novel mutation, p.S567R) were loss-of-function mutations. Our study indicated that the prevalence of TSHR mutations was 5.91% among studied Chinese patients with CH. One novel TSHR variant was found and four genetic alterations revealed important role of the Ile216, Ala275, Asn372, Ser567 residues in signaling. • We identified that the prevalence of TSHR variants was 5.91% among patients with CH • We found one novel TSHR variation, expanding the mutational spectrum of the gene • Four uncharacterized TSHR variants were verified as loss-of-function variants [ABSTRACT FROM AUTHOR]

Background: Graves' disease is associated with thyrotropin receptor (TSHR) antibodies of variable bioactivity. Recently, antibodies have been characterized that bind to the cleavage region of the TSHR ectodomain (C-TSHR-Ab), and their ability to induce thyroid cell apoptosis in vitro via excessive cell stress involving multiple organelles was demonstrated. Methods: To investigate the in vivo effects of C-TSHR-Ab, first a murine monoclonal antibody (mAb) directed against residues 337 to 356 of the TSHR cleavage region was developed, and then it was injected into mice. Results: These injections caused reduced serum total triiodothyronine and thyroxine and increased TSH levels compared to control mAb-injected mice. The C-TSHR-mAb induced histological evidence of endoplasmic reticulum stress, mitochondrial stress, and apoptosis in the thyroid glands. C-TSHR-mAb-mediated apoptosis was associated with cellular infiltrates consisting mostly of macrophages, dendritic cells, and neutrophils, while T- and B-lymphocytes were scarce. In addition, in the treated mouse thyroid tissue, hyper-citrullination of histone H3 was also found. This is known to occur via peptidylarginine deiminase 4 and plays an important role in the formation of neutrophil extracellular traps, which are likely to be partly responsible for thyroid infiltration, as seen in many autoimmune diseases. Examination of thyroid tissue from patients with Graves' disease also showed increased stress and some thyrocyte apoptosis compared to normal thyroid tissues. Conclusions: The fact that the C-TSHR-mAb induced accumulation of macrophages, neutrophils, and dendritic cells indicates that innate immunity plays a central role in shaping the adaptive immune response to the TSHR. In addition, this study provides further evidence that the hinge region of the TSHR ectodomain is intimately involved in the immune response in autoimmune thyroid disease. [ABSTRACT FROM AUTHOR]

The crystal structures of the thyroid-stimulating hormone receptor (TSHR) leucine-rich repeat domain (amino acids 22-260; TSHR260) in complex with a s timulating human monoclonal autoantibody (M22TM) and in complex with a blocking human autoantibody (K1-70™) have been solved. However, attempts to purify and crystallise free TSHR260, that is not bound to an autoantibody, have been unsuccessful du e to the poor stability of free TSHR260. We now describe a TSHR260 mutant that has been stabilised by the introduction of six mutations (H63C, R112P, D143P, D151E, V169R and I253R) to form TSHR260-JMG55TM, which is approximately 900 times more thermostable than wild-type TSHR260. These six mutations did not affect the binding of human TSHR monoclonal autoantibodies or patient serum TSHR autoantibodies to the TSHR260. Furthermore, the response of full-length TSHR to stimulation by TSH or human TSHR monoclonal autoantibodies was not affected by the six mutations. Thermostable TSHR260-JMG55TM has been purified and crystallised without ligand and the structure solved at 2.83 Å resolution. This is the first reported structure of a glycoprotein hormone receptor crystallised without ligand. The unbound TSHR260-JMG55TM structure and the M22 and K1-70 bound TSHR260 structures are remarkably similar except for small changes in side chain conformations. This suggests that neither the mutations nor the binding of M22TM or K1-70TM change the rigid leucine-rich repeat domain structure of TSHR260. The solved TSHR260-JMG55TM structure provides a rationale as to why the six mutations hav e a thermostabilising effect and provides helpful guidelines for thermostabilisation strategies of other soluble protein domains. [ABSTRACT FROM AUTHOR]

Background: The risk factors for rapid growth and early metastasis of papillary thyroid carcinoma (PTC) and the role of coexisting Graves' disease in the clinical course of PTC remain uncertain in children. Case Description: We report on a Japanese girl, whose PTC rapidly grew and metastasized within 4 years. Graves' disease was diagnosed by the presence of serum TSH receptor antibodies at 8 years of age when thyroid ultrasonography detected no nodules. After 4 years of effective treatment with thiamazole, multifocal nodules – up to 47 mm in diameter – were detected on thyroid ultrasonography. Chest CT scan revealed multiple metastatic lesions in the lung. After total thyroidectomy, PTC was pathologically diagnosed. The patient underwent two courses of radioactive iodine (RAI) treatment, but the pulmonary metastatic lesions did not take up the RAI. Molecular analyses of the PTC tissue identified a TFG/NTRK1 chimeric gene and disclosed the preserved expression of TSHR and the reduced expression of SLC5A5 compared with non-tumor thyroid tissue. Conclusions: Rapid growth and early metastasis of PTC with coexisting Graves' disease in this patient can be related to a combination of multiple factors including preserved TSHR expression, reduced SLC5A5 expression, and TFG/NTRK1 rearrangement. [ABSTRACT FROM AUTHOR]

Summary: Objective: Patients with hyperthyroidism lacking autoimmune features but showing diffuse uptake on thyroid scintigram can have either Graves' disease or germline activating TSH receptor (TSHR) mutation. It is important to identify patients with activating TSHR mutation due to treatment implication, but the overlapping clinical features with Graves' disease make it difficult to discriminate these two conditions without genetic testing. Our study aimed to assess the potential of systematic TSHR mutation screening in adults with hyperthyroidism, showing diffuse uptake on thyroid scintigraphy but absence of TSH receptor antibodies (TRAb) and clinical signs of autoimmunity. Design: A cross‐sectional study of Caucasian adults with hyperthyroidism, managed at three endocrine centres in the South West, UK, from January 2006 to April 2017. Methods: We recruited 78 adult Caucasian patients with hyperthyroidism showing diffuse uptake on 99mTc‐pertechnetate thyroid scintigraphy but without TRAb and other autoimmune clinical features of Graves' disease (such as thyroid‐associated ophthalmopathy or dermopathy). Genomic DNA of these patients was analysed for variants in the TSHR gene. Results: Genetic analysis identified 11 patients with four variants in TSHR [p.(Glu34Lys), p.(Asp36His), p.(Pro52Thr) and p.(Ile334Thr)]. None of these variants were pathogenic according to the American College of Medical Genetics and Genomics guideline. Conclusions: Activating TSHR mutations are a rare cause of nonautoimmune adult hyperthyroidism. Our study does not support the routine genetic testing in adult patients with hyperthyroidism showing diffuse uptake on scintigraphy but negative TRAb and lacking extrathyroidal manifestations of Graves' disease. [ABSTRACT FROM AUTHOR]

Background and Objectives. Familial non-autoimmune autosomal dominant hyperthyroidism (FNAH) is a rare cause of childhood hyperthyroidism. It is caused by the thyroid-stimulating hormone receptor (TSHR) gene variants. So far, only around 40 families with FNAH have been reported. Patients with activating TSHR variants demonstrated the same classical signs and symptoms of hyperthyroidism as seen in patients with Graves’ disease. Since 2012, ablative therapy is recommended to avoid relapses of hyperthyroidism and its consequences. Case Presentation. We presented a young adult male patient with a novel heterozygous TSHR disease-causing variant p.Arg418Lys (c.1253G>A) in the exon 10, who presented with a mild but progressive FNAH, with a follow-up since infancy. Discussion. Constantly suppressed TSH, including during the euthyreosis in childhood and hypothyreosis after iodine ablation therapy, suggested central dysregulation of the TSH secretion.

• Graves disease (GD), a typical organ-specific, antibody-mediated autoimmune disease, is caused by stimulating antibody which recognizes TSHR (TRAb) • Therefore, specifically, eliminating TRAb producing B lymphocytes may be an effective therapeutic strategy for GD. • In this study, we developed a chimeric receptor TSHR-CAR, which fused TSHR extracellular domain to the CD8 transmembrane and intracellular signal domain (4-1BB) • TSHR-CAR-T cells can specifically recognize and exert a cytotoxic effect on TRAb producing B lymphocytes of mice in vivo and in vitro. • The chimeric receptor CAR-T based on autoantigen may provide promising immunotherapy for antibody-mediated autoimmune diseases. Graves' disease (GD) is a prominent antibody-mediated autoimmune disorder characterized by stimulating antibodies (TRAb) that target the thyroid-stimulating hormone receptor (TSHR). Targeting and eliminating TRAb-producing B lymphocytes hold substantial therapeutic potential for GD. In this study, we engineered a novel chimeric antigen receptor T cell (CAR-T) therapy termed TSHR-CAR-T. This CAR-T construct incorporates the extracellular domain of the TSH receptor fused with the CD8 transmembrane and intracellular signal domain (4-1BB). TSHR-CAR-T cells demonstrated the ability to recognize and effectively eliminate TRAb-producing B lymphocytes both in vitro and in vivo. Leveraging this autoantigen-based chimeric receptor, our findings suggest that TSHR-CAR-T cells offer a promising and innovative immunotherapeutic approach for the treatment of antibody-mediated autoimmune diseases, including GD. [ABSTRACT FROM AUTHOR]

Two female dizygotic twins with subclinical primary hypothyroidism due to homozygous p.R450H mutation in TSHR gene are presented. A 5-year follow-up in both cases showed no progression of thyroid dysfunction. Indications for levothyroxine replacement in subclinical hypothyroidism are discussed.

Objectives: To examine the prevalence of genetic alterations of thyroid-stimulating hormone receptor (TSHR) gene and sodium-iodine symporter (NIS) in a series of thyroid fine needle biopsy (FNB) specimens with indeterminate cytology, and to assess the correlation of the type of genetic changes with clinical features and follow-up results in the target thyroid nodule.Methods: Between February 2015 and September 2017, 388 consecutive FNBs with indeterminate cytology were evaluated for TSHR mutations and NIS gene overexpression using ThyroSeqV.2 next-generation sequencing (NGS) panel. Medical records were reviewed for target nodules.Results: Among 388 indeterminate FNBs, TSHR mutations and/or NIS overexpression were detected in 25 (6.4%) nodules. Ten nodules (2.6%) harbored TSHR mutations only, 7 nodules (1.8%) over-expressed NIS gene only, and 8 nodules (2.1%) had both alterations. The TSHR mutations were located between codons 281 and 640, with codon 453 being the most frequently affected. The allelic frequency of the mutated TSHR ranged from 6 to 36%. One nodule with NIS overexpression was simultaneously detected EIF1AX mutation and GNAS mutation. Nodules with TSHR mutations and/or NIS overexpression presented hyperfunctioning (n = 4), hypofunctioning (n = 5), and isofunctioning (n = 3) on the available thyroid scintigraphies. Eight cases accompanied with hyperthyroidism in which only 1 was caused by the target nodule. Evidence of co-existing autoimmune thyroid disease (AITD) and multinodular goiter were found in 52% and 52% of cases, respectively. Seven nodules underwent surgeries and all were benign on final pathology. None of 9 nodules with follow-up by ultrasound (3~33 mon, median 12 mon) showed grow in size.Conclusions:TSHR mutations and/or NIS overexpression can be detected in pre-operative FNB specimens using the NGS approach. These genetic alterations occurred in 6.4% thyroid nodules in this consecutive series with indeterminate cytology. They present not only in hyperfunctioning nodules but also in hypo- or iso-functional nodules, indicating their prevalence may be higher than previously expected. Co-existing AITD was common in cases with these molecular alterations. None of our patients with TSHR mutations and/or NIS overexpression manifested malignant outcomes. How to use these two molecular markers in thyroid FNBs to guide our clinical practice warrants further investigation.

Differences in BRAF gene mutation frequency and thyroid-stimulating hormone receptor (TSHR) protein expression in thyroid tissues were detected to investigate their association with local tissue invasion and cervical lymph node metastasis potential of papillary thyroid microcarcinoma (PTMC). The BRAF gene mutation frequency and TSHR expression in PTMC patients were detected via qPCR and immunohistochemical method, and the association between them was discussed combined with the clinical and pathological parameters. Kruskal-Wallis test was used for the univariate correlation analyses and comparison of mutation rate and expression rate, and Chi-square test was used for the association of central lymph node metastasis with BRAF gene and TSHR. The BRAFV600E mutation only existed in patients with thyroid cancer. Τhe larger the number of metastatic central lymph nodes was, the higher the proportion of BRAFV600E mutation would be. Τhe BRAFV600E mutation was related to the primary lesion size, capsular infiltration and lymph node metastasis of PTMC (P<0.05). The expression of TSHR in PTMC tissues was < those in thyroid benign lesions and para-carcinoma normal tissues, which was positively associated with the central lymph node metastasis (P<0.05). Τhe low expression of TSHR was related to the primary lesion size, capsular infiltration and metastatic lymph nodes of PTMC (P<0.05). The BRAFV600E and TSHR may be involved in the occurrence and lymphatic metastasis of PTMC. The BRAFV600E mutation has no association with the TSHR protein expression (P=0.256), but the coincidence coefficient indicates that their diagnostic significance in PTMC is not similar, so BRAFV600E mutation and TSHR protein expression can be used jointly in the prediction of invasion and lymph node metastasis of PTMC, which may be more meaningful for clinical guidance. [ABSTRACT FROM AUTHOR]

In the last 3 years, the association of thyrotropin receptor gene (TSHR) variations to Graves' disease (GD) has been confirmed. It is now well established that a 30 Kb region of intron 1 of the TSHR gene is linked to GD predisposition. Elucidating the mechanism( s) by which these polymorphisms confer susceptibility is difficult but would constitute an important advance in endocrine autoimmunity in general. Two hypotheses, both postulating TSHR gene regulatory mechanisms, are discussed. One postulates differential level of expression in the thymus, involving central tolerance. The other postulates a shift in TSHR differential splicing leading to the production of soluble proteins that will have easy access to antigen presenting cells, so it is focused in peripheral tolerance. A combination of the 2 hypothesis is feasible, especially under the light of recent evidence that have identified epigenetic factors acting on TSHR intron 1. [ABSTRACT FROM AUTHOR]

Thyroid-stimulating hormone (TSH) is secreted by the pituitary gland and promotes thyroid growth and function, with increased TSH levels typically associated with hypothyroidism. By consulting the literature, we found that the TSHR, PAX8, and PDE4B genes are associated with thyroid function. Recently, copy number variations (CNVs) have been used as genetic markers to investigate inter-individual variation. Therefore, we investigated the relationship between the TSHR, PAX8, and PDE4B gene CNVs and TSH abnormalities, by calculating variations in gene copy number. Four hundred and eighty-one participants, 232 healthy controls and 249 patients with TSH abnormalities, were selected from three distinct areas in China with different iodine statuses. RT-PCR was used to detect CNVs. Urinary iodine concentrations (UIC) were measured by As3+-Ce4+ catalytic spectrophotometry. There was an association between a CNV at the TSHR gene and TSH abnormalities (p = 0.002). The distribution of PAX8 and PDE4B gene CNVs between patients with TSH abnormalities and healthy controls was not significantly different. UIC > 200 μg/l (OR = 1.49, 95% CI = 1.01-2.22) and the TSHR gene (OR = 6.01, 95% CI = 1.96-18.41) were found to be risk factors for TSH abnormalities. PAX8 and PDE4B gene CNVs were not significantly associated with TSH abnormalities. There was no significant interaction between UIC and any of the examined CNVs. In conclusion, the TSHR gene CNV was associated with the development of TSH abnormalities. No significant associations were revealed between urinary iodine levels and candidate gene CNVs. [ABSTRACT FROM AUTHOR]

Objectives: To examine the prevalence of genetic alterations of thyroid-stimulating hormone receptor (TSHR) gene and sodium-iodine symporter (NIS) in a series of thyroid fine needle biopsy (FNB) specimens with indeterminate cytology, and to assess the correlation of the type of genetic changes with clinical features and follow-up results in the target thyroid nodule. Methods: Between February 2015 and September 2017, 388 consecutive FNBs with indeterminate cytology were evaluated for TSHR mutations and NIS gene overexpression using ThyroSeqV.2 next-generation sequencing (NGS) panel. Medical records were reviewed for target nodules. Results: Among 388 indeterminate FNBs, TSHR mutations and/or NIS overexpression were detected in 25 (6.4%) nodules. Ten nodules (2.6%) harbored TSHR mutations only, 7 nodules (1.8%) over-expressed NIS gene only, and 8 nodules (2.1%) had both alterations. The TSHR mutations were located between codons 281 and 640, with codon 453 being the most frequently affected. The allelic frequency of the mutated TSHR ranged from 6 to 36%. One nodule with NIS overexpression was simultaneously detected EIF1AX mutation and GNAS mutation. Nodules with TSHR mutations and/or NIS overexpression presented hyperfunctioning (n = 4), hypofunctioning (n = 5), and isofunctioning (n = 3) on the available thyroid scintigraphies. Eight cases accompanied with hyperthyroidism in which only 1 was caused by the target nodule. Evidence of co-existing autoimmune thyroid disease (AITD) and multinodular goiter were found in 52% and 52% of cases, respectively. Seven nodules underwent surgeries and all were benign on final pathology. None of 9 nodules with follow-up by ultrasound (3~33 mon, median 12 mon) showed grow in size. Conclusions: TSHR mutations and/or NIS overexpression can be detected in pre-operative FNB specimens using the NGS approach. These genetic alterations occurred in 6.4% thyroid nodules in this consecutive series with indeterminate cytology. They present not only in hyperfunctioning nodules but also in hypo- or iso-functional nodules, indicating their prevalence may be higher than previously expected. Co-existing AITD was common in cases with these molecular alterations. None of our patients with TSHR mutations and/or NIS overexpression manifested malignant outcomes. How to use these two molecular markers in thyroid FNBs to guide our clinical practice warrants further investigation. [ABSTRACT FROM AUTHOR]

G-protein-coupled receptors (GPCRs) can constitute complexes with non-GPCR integral membrane proteins, while such interaction has not been demonstrated at a single molecule level so far. We here investigated the potential interaction between the thyrotropin receptor (TSHR) and the monocarboxylate transporter 8 (MCT8), a member of the major facilitator superfamily (MFS), using fluorescence cross-correlation spectroscopy (FCCS). Both the proteins are expressed endogenously on the basolateral plasma membrane of the thyrocytes and are involved in stimulation of thyroid hormone production and release. Indeed, we demonstrate strong interaction between both the proteins which causes a suppressed activation of Gq/11 by TSH-stimulated TSHR. Thus, we provide not only evidence for a novel interaction between the TSHR and MCT8, but could also prove this interaction on a single molecule level. Moreover, this interaction forces biased signaling at the TSHR. These results are of general interest for both the GPCR and the MFS research fields. [ABSTRACT FROM AUTHOR]

Sex-steroids play important role in modulating uterine functions. We hypothesized that these hormones affect expression of proteins in the uterus related to thyroid hormone action. Therefore, changes in expression levels of receptors for thyroid hormone (TRα-1 and TRβ-1), thyroid stimulating hormone (TSHR), vitamin D (VDR) and retinoid acid (RAR) as well as extracellular signal-regulated kinase (ERK1/2) in uterus were investigated under sex-steroid influence. Methods Two rat models were used: (i) ovariectomised, sex-steroid replaced and (ii) intact, at different phases of oestrous cycle. A day after completion of sex-steroid treatment or following identification of oestrous cycle phases, rats were sacrificed and expression and distribution of these proteins in uterus were identified by Western blotting and immunohistochemistry, respectively. Results Expression of TRα-1, TRβ-1, TSHR, VDR, RAR and ERK1/2 in uterus was higher following estradiol (E 2 ) treatment and at estrus phase of oestrous cycle when E 2 levels were high. A relatively lower expression was observed following progesterone (P) treatment and at diestrus phases of oestrous cycle when P levels were high. Under E 2 influence, TRα, TRβ, TSHR, VDR, RAR and ERK1/2 were distributed in luminal and glandular epithelia while under P influence, TSHR, VDR abn RAR were distributed in the stroma. Conclusions Differential expression and distribution of TRα-1, TRβ-1, TSHR, VDR, RAR and ERK1/2 in different uterine compartments could explain differential action of thyroid hormone, TSH, vitamin D, and retinoic acid in uterus under different sex-steroid conditions. [ABSTRACT FROM AUTHOR]

The effect of thyroid-stimulating hormone receptor (TSHR) on hepatic lipid accumulation in vivo is not fully understood. Further, while TSHR in the thyroid has been studied extensively, whether and how the absence of TSHR in the liver affects systemic energy metabolism has not yet been reported. To examine these effects, we generated hepatic TSHR conditional knockout (LT-KO) mice using Cre/LoxP recombination technology. The liver-specific TSHR-knockout (LT-KO) mice exhibited not only lower hepatic triglyceride and cholesterol contents due to modified synthesis and catabolism of lipids in the liver, but also decreased serum lipids, especially serum LDL-C levels. Abnormalities of TSHR in the thyroid affect whole-body energy balance; however, measurements taken in metabolic chambers showed that the hepatic TSHR conditional deletion had no impact on systemic energy metabolism. Unlike its critical role in maintaining the normal growth and function of the thyroid gland, our results demonstrated that hepatic TSHR is involved in liver lipid metabolism and has little effect on energy metabolism. [ABSTRACT FROM AUTHOR]

Clinical evidence indicates that high periostin expression correlates with aggressive phenotype in thyroid carcinoma. However, the biological roles of periostin in thyroid carcinoma development and progression are still unclear. In this study, we explored the effects of periostin silencing on thyroid carcinoma cell growth, invasion, and tumorigenesis. We also studied the impact of periostin on the activation of phosphoinositide 3-kinase (PI3-K)/Akt signaling, which is involved in the pathogenesis of thyroid carcinoma. It was found that downregulation of periostin significantly inhibited the proliferation, colony formation, and invasion in both FTC-133 and BCPAP thyroid carcinoma cells. In vivo tumorigenic studies confirmed that periostin depletion retarded the growth of subcutaneous FTC-133 xenograft tumors, which was coupled with a significant decline in the percentage of Ki-67-positive proliferating cells. Western blot analysis demonstrated that periostin downregulation caused a marked inhibition of thyroid stimulating hormone receptor (TSHR) expression and Akt phosphorylation in FTC-133 and BCPAP cells. Co-expression of constitutively active Akt (CA-Akt) significantly reversed periostin-mediated downregulation of TSHR. Most importantly, overexpression of TSHR or CA-Akt rescued FTC-133 cells from periostin-induced growth and invasion suppression. Collectively, periostin regulates thyroid carcinoma growth and progression via the Akt/TSHR axis and represents a promising therapeutic target for this malignancy. [ABSTRACT FROM AUTHOR]

Thyroid hormones are important in the development and regulation of testes. This study was conducted to determine the effects of hyper- and hypothyroidism on testicular development in prepubertal rats aged 20-70 days. Weaning male rats (20 days old) until day 70 age were randomly divided into four groups: control, hyperthyroid (hyper-T), hypothyroid (hypo-T) and hypothyroid treated with thyroxine (T4) (hypo-T+T4). The results indicated that thyroid hormones caused a significant effect in body and testis weights, and food and water consumption. In addition there were changes in serum concentrations of tri-iodothyronine, T4, thyroid stimulating hormone ( TSH) and testosterone. Histomorphology showed a significant decrease in seminiferous tubule diameter in hyper-T compared to the other groups. Leydig cell numbers showed a significant elevation in hyper-T but not in hypo-T groups. Immunostaining indicated that TSH receptor ( TSHR), thyroid hormone receptors α/β ( TRαβ) and proliferating cell nuclear antigen ( PCNA) have the roles in testicular development. Our findings suggest that hyper- and hypo-thyroidism regulate testicular cell proliferation and spermatogenesis in prepubertal rats, indicating that expression of TSHR, TRαβ and PCNA may be regulated by thyroid hormones that are involved in testicular development; and that the administration of T4 to the hypo-T+T4 group leads to an improvement in the testicular condition. [ABSTRACT FROM AUTHOR]

In differentiated thyroid cancer (DTC), the association between thyroid‑stimulating hormone receptor (TSHR) and metastasis, and the underlying molecular mechanisms remain unclear. The role of TSHR in the epithelial‑mesenchymal transition (EMT) has not yet been reported, to the best of our knowledge. In the present study, the role of TSHR in the distant metastasis of DTC was investigated. TSHR was significantly downregulated in well‑differentiated thyroid cancer cells and tissues, and a lack of TSHR promoted thyroid cancer cell invasion and metastasis by inhibiting the EMT of thyroid cancer cells. In addition, the prognostic value of TSHR in thyroid cancer was analyzed. Immunohistochemical analysis of 172 DTC tissues revealed that a lack of expression of TSHR was associated with distant metastasis and a poor survival rate. Multivariate analyses demonstrated that TSHR expression was a significant prognostic factor for distant metastasis and survival time. The results from the present study demonstrated that TSHR inhibits metastasis through regulating EMT in vitro, and that a lack of expression of TSHR is a significant independent factor affecting distant metastasis and poor prognosis in DTC. [ABSTRACT FROM AUTHOR]

Thyroid carcinoma is the most common endocrine malignancy and its prevalence has recently been increasing worldwide. We previously reported that the level of sorting nexin 5 (Snx5), an endosomal translocator, is preferentially decreased during the progression of well-differentiated thyroid carcinoma into poorly differentiated carcinoma. To address the functional role of Snx5 in the development and progression of thyroid carcinoma, we established Snx5-deficient ( Snx5−/−) mice. In comparison to wild-type ( Snx5+/+) mice, Snx5−/− mice showed enlarged thyroid glands that consisted of thyrocytes with large irregular-shaped vacuoles. Snx5−/− thyrocytes exhibited a higher growth potential and higher sensitivity to thyroid-stimulating hormone (TSH). A high content of early endosomes enriched with TSH receptors was found in Snx5−/− thyrocytes, suggesting that loss of Snx5 caused retention of the TSH receptor (TSHR) in response to TSH. Similar data were found for internalized EGF in primary thyrocytes. The increased TSH sensitivities in Snx5−/− thyrocytes were also confirmed by results showing that Snx5−/− mice steadily developed thyroid tumors with high metastatic potential under high TSH. Furthermore, a thyroid cancer model using carcinogen and an anti-thyroidal agent revealed that Snx5−/− mice developed metastasizing thyroid tumors with activation of MAP kinase and AKT pathways, which are postulated to be major pathways of malignant progression of human thyroid carcinoma. Our results suggest that thyrocytes require Snx5 to lessen tumorigenic signaling driven by TSH, which is a major risk factor for thyroid carcinoma. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Iodine is a key ingredient in the synthesis of thyroid hormones and also a major factor in the regulation of thyroid function. A local reduction of iodine content in follicular lumen leads to overexpression of local thyroid-stimulating hormone receptor (TSHr), which in turn excessively stimulates the regional thyroid tissue, and result in the formation of nodular goiter. In this study, we investigated the relationship between iodine content and sodium iodide symporter (NIS) expression by using the clinical specimens from patients with nodular goiter and explored the pathogenesis triggered by iodine deficiency in nodular goiter. In total, 28 patients were clinically histopathologically confirmed to have nodular goiter and the corresponding adjacent normal thyroid specimens were harvested simultaneously. Western blot and immunohistochemistry were performed to assay NIS expression and localization in thyrocytes of both nodular goiter and adjacent normal thyroid tissues. NIS expression mediated by iodine in follicular lumen was confirmed by follicular model in vitro. Meanwhile, radioscan with iodine-131were conducted on both nodular goiter and adjacent normal thyroid. Our data showed that NIS expression in nodular goiter was significantly higher than that in adjacent normal tissues, which was associated with low iodine in the follicular lumen. Abnormal localization of NIS and lower amount of radioactive iodine-131 were also found in nodular goiter. Our data implied that low iodine in the follicular lumen caused by cytoplasm mis-localization of NIS may induce nodular goiter. [ABSTRACT FROM AUTHOR]

Ancient DNA provides an opportunity to infer the drivers of natural selection by linking allele frequency changes to temporal shifts in environment or cultural practices. However, analyses have often been hampered by uneven sampling and uncertainties in sample dating, as well as being confounded by demographic processes. Here, we present a Bayesian statistical framework for quantifying the timing and strength of selection using ancient DNA that explicitly addresses these challenges. We applied this method to time series data for two loci: TSHR and BCDO2, both hypothesised to have undergone strong and recent selection in domestic chickens. The derived variant in TSHR, associated with reduced aggression to conspecifics and faster onset of egg laying, shows strong selection beginning around 1,100 years ago, coincident with archaeological evidence for intensified chicken production and documented changes in egg and chicken consumption. To our knowledge, this is the first example of preindustrial domesticate trait selection in response to a historically attested cultural shift in food preference. For BCDO2, we find support for selection, but demonstrate that the recent rise in allele frequency could also have been driven by gene flow fromimported Asian chickens duringmore recent breed formations. Our findings highlight that traits found ubiquitously in modern domestic species may not necessarily have originated during the early stages of domestication. In addition, our results demonstrate the importance of precise estimation of allele frequency trajectories through time for understanding the drivers of selection. [ABSTRACT FROM AUTHOR]

Resistance to thyrotropin (RTSH) is broadly defined as reduced sensitivity of thyroid follicle cells to stimulation by biologically active TSH due to genetic defects. Affected individuals have elevated serum TSH in the absence of goiter, with the severity ranging from nongoitrous isolated hyperthyrotropinemia to severe congenital hypothyroidism with thyroid hypoplasia. Conceptually, defects leading to RTSH impair both aspects of TSH-mediated action, namely thyroid hormone synthesis and gland growth. These include inactivating mutations in the genes encoding the TSH receptor and the PAX8 transcription factor. A common third cause has been genetically mapped to a locus on chromosome 15, but the underlying pathophysiology has not yet been elucidated. This review provides a succinct overview of currently defined causes of nonsyndromic RTSH, their differential diagnoses (autoimmune; partial iodine organification defects; syndromic forms of RTSH) and implications for the clinical approach to patients with RTSH. [ABSTRACT FROM AUTHOR]

Recent advances in mouse genomics have revealed considerable variation in the form of single-nucleotide polymorphisms (SNPs) among common inbred strains. This has made it possible to characterize closely related strains and to identify genes that differ; such genes may be causal for quantitative phenotypes. The mouse strains DBA/1J and DBA/2J differ by just 5.6% at the SNP level. These strains exhibit differences in a number of metabolic and lipid phenotypes, such as plasma levels of triglycerides (TGs) and HDL. A cross between these strains revealed multiple quantitative trait loci (QTLs) in 294 progeny. We identified significant TG QTLs on chromosomes (Chrs) 1, 2, 3, 4, 8, 9, 10, 11, 12, 13, 14, 16, and 19, and significant HDL QTLs on Chrs 3, 9, and 16. Some QTLs mapped to chromosomes with limited variability between the two strains, thus facilitating the identification of candidate genes. We suggest that Tshr is the QTL gene for Chr 12 TG and HDL levels and that Ihh may account for the TG QTL on Chr 1. This cross highlights the advantage of crossing closely related strains for subsequent identification of QTL genes.

Hashimoto's thyroiditis (HT) and Graves' disease (GD) are prevalent autoimmune disorders, representing opposite ends of the clinical spectrum of autoimmune thyroid diseases (AITD). The pathogenesis involves a complex interplay between environment and genes. Specific susceptibility genes have been discovered that predispose to AITD, including thyroid-specific and immune-regulatory genes. Growing evidence has revealed that genetic and epigenetic variants can alter autoantigen presentation during the development of immune tolerance, can enhance self-peptide binding to MHC (major histocompatibility complex), and can amplify stimulation of T- and B-cells. These gene-driven mechanistic discoveries lay the groundwork for novel treatment targets. This review summarizes recent advances in our understanding of key AITD susceptibility genes (Tg 1 1 All genes were underlined to indicate italicization. , TSHR , HLA-DR3 , and CD40) and their translational therapeutic potential. [ABSTRACT FROM AUTHOR]

Objectives: We investigated the clinical significance of thyroid-stimulating hormone receptor (TSHR) mutations detected in thyroid fine needle aspiration (FNA) specimens., Methods: The pathology archives at our institution were reviewed between 2018 and 2021 for indeterminate (Bethesda category III and IV) specimens with Thyroseq® analysis showing TSHR mutations., Results: A total of 2184 cases diagnosed as atypia/follicular lesion of undetermined significance (AUS/FLUS), and 2625 diagnosed as follicular neoplasm/suspicious for follicular neoplasm (FN/SFN) were identified. A total of 1735 AUS/FLUS and 2339 SFN/FN underwent Thyroseq® analysis; 69 showed TSHR mutations (1.6%, 59 female, 10 male, average age: 55 years). Ten cases showed oncocytic features. Twelve patients underwent radionuclide scans within 1 year of FNA:11 were hyperfunctioning. Nodule size and TSH levels were weakly correlated. Twenty-two different TSHR mutations were identified (most common: M453T). A second mutation was found in five cases (EZH1 n = 2, and EIF1AX n = 3). The expression of sodium-iodide transporter (NIS) mRNA was in the range of 0.01%-62.43% out of all sequencing reads, and was elevated in 49 (71%) cases. Surgical pathology follow-up was available in five cases (all benign except one). On follow-up available for 38 cases (mean: 24 months; range: 7-47 months), 34 (89.5%) nodules remained stable and 3 (8%) increased in size., Conclusions: TSHR mutations in thyroid FNA samples classified as indeterminate are rare, generally benign, and commonly associated with autonomy on scan if performed., (© 2023 Wiley Periodicals LLC.)

Background: Graves' disease (GD) and Hashimoto's disease (HD) are autoimmune thyroid disorders distinguished by the presence or absence of antithyrotropin receptor (TSHR) antibodies (TRAb). TSHR gene polymorphisms determine the amount of TSHR expressed, which may in turn influence TRAb production. The FANTOM5 project identified six GD-associated single nucleotide polymorphisms (SNPs) within the enhancer regions of the TSHR and unknown genes. This study examined the association of 11 TSHR and unknown gene polymorphisms, five of which are located in TSHR enhancer regions, with the development and prognosis of GD and HD. Methods: SNPs of the TSHR and unknown genes were genotyped in 180 GD patients, including 62 patients with intractable GD and 48 patients with GD in remission; 151 HD patients, including 65 patients with severe HD and 40 patients with mild HD; and 111 healthy controls. Results: The rs4411444 GG genotype and G allele, the rs2300519 AA genotype, and the rs179247 AA genotype and A allele were more frequent in GD patients than they were in controls. These same genotypes and alleles, in addition to the rs2300519A allele and rs4903961 GG genotype and G allele, were more frequent in patients with intractable GD than they were in controls and patients with GD in remission. Interestingly, the rs2300519 TT genotype and T allele, rs4903961 CC genotype and C allele, and rs179247 GG genotype, all of which are minor genotypes and alleles among the evaluated SNPs, were more frequent in HD patients than they were in controls, but there were no differences in the frequencies of these genotypes and alleles between patients with severe HD and mild HD. Among the evaluated SNPs, the rs4411444 GG genotype and the rs4903961 C allele in the enhancer regions of the TSHR gene were most strongly associated with the development of GD, especially intractable disease, and that of HD, respectively. Conclusions: Among the evaluated TSHR gene SNPs, the rs4411444 GG genotype and the rs4903961 C allele in the enhancer regions of the TSHR gene were most strongly associated with the development of GD, especially intractable disease, and that of HD, respectively. [ABSTRACT FROM AUTHOR]

Although TSH has been suggested to be a proliferative agent for thyrocytes, the effect of TSH on human thyroid cells remains controversial. In particular, most of the reported studies relied primarily on changes in DNA synthesis but have not included measurement of the number of cells. We argue that only a direct count of cell number, demonstrating classical exponential expansion, serves as a valid measurement of proliferation. Thus, although some data support TSH as a proliferative agent, most do not provide conclusive evidence. To generate conclusive evidence with regard to a proliferative effect of TSH in human thyrocytes, we performed various experiments using primary cultures of human thyrocytes. In contrast to previous reports, TSH [±insulin-like growth factor 1 (IGF-1)] did not induce proliferation of thyrocytes under a variety of different conditions. However, TSH/IGF-1 cotreatment did upregulate thyroid-specific gene expression including thyroglobulin (TG) and TSHR in a manner consistent with cellular differentiation. Evidence for a proliferative effect of TSH has been used to inform the American Thyroid Association's guidelines for the management of thyroid cancer patients, which include TSH suppression. While these recommendations are admittedly based on lowto moderate-quality evidence, TSH suppression is still widely used. We present data that question the consensus view that TSH promotes proliferation of human thyrocytes (upon which the American Thyroid Association's guidelines are based) and suggest that additional studies, including randomized controlled trials, are warranted to address this important clinical question. [ABSTRACT FROM AUTHOR]

Background: Major regulation of thyroid gland function is mediated by thyrotropin (TSH) activating the TSH receptor (TSHR) and inducing upregulation of genes involved in thyroid hormone synthesis. Evidence suggests that the insulin-like growth factor 1 (IGF-1) receptor (IGF-1R) may play a role in regulating TSHR functional effects. This study examined the potential role of TSHR/IGF-1R crosstalk in primary cultures of human thyrocytes. Results: TSH/IGF-1 co-treatment elicited additive effects on thyroglobulin ( TG), thyroperoxidase ( TPO), and deiodinase type 2 ( DIO2) mRNA levels but synergistic effects on sodium-iodide symporter ( NIS) mRNA. Similar cooperativity was seen on the level of TG protein secretion (additive) and NIS protein expression (synergistic). The IGF-1R tyrosine kinase inhibitor linsitinib inhibited TSH-stimulated upregulation of NIS but not TG, indicating that NIS regulation is in part IGF-1R dependent and occurs via receptor crosstalk. Cooperativity was not seen at the level of cAMP/protein kinase A (PKA) signaling, IGF-1R phosphorylation, or Akt activation. However, TSH and IGF-1 synergistically activated ERK1/2. Pharmacological inhibition of ERK1/2 by the MEK1/2 inhibitor U0126 and of Akt by MK-2206 virtually abolished NIS stimulation by TSH and the synergistic effect of IGF-1. Conclusion: As linsitinib inhibited upregulation of NIS stimulated by TSH alone, it is concluded that crosstalk between TSHR and IGF-1R, without agonist activation of IGF-1R, plays a role in NIS regulation in human thyrocytes via a mechanism involving ERK1/2 and/or Akt. Fully understanding the nature of this crosstalk has clinical implications for the treatment of thyroid diseases, including thyroid cancer. [ABSTRACT FROM AUTHOR]

Myo-inositol and phosphatidylinositol(s) play a pivotal function in many metabolic pathways that, if impaired, impact unfavorably on human health. This review analyzes several experimental and clinical investigations regarding the involvement of this class of molecules in physiological and pathological situations, with a major focus on thyroid. Central issues are the relationship between phosphatidylinositol and thyrotropin (TSH) signaling on one hand, and phosphatydylinositol and autoimmunity on the other hand. Other issues are the consequences of malfunction of some receptors, such as those ones for TSH (TSHR), insulin (IR) and insulin-like growth factor-1 (IGF-1R), or the connection between serum TSH concentrations and insulin resistance. Also covered are insulin resistance, metabolic syndrome and their allied disorders (diabetes, polycystic ovary syndrome [PCOS]), autoimmunity and certain malignancies, with their reciprocal links. Myoinositol has promising therapeutic potential. Appreciation of the inositol pathways involved in certain disorders, as mentioned in this review, may stimulate researchers to envisage additional therapeutic applications. [ABSTRACT FROM AUTHOR]

Introduction: Thyroid eye disease or Graves’ orbitopathy (GO) is an autoimmune condition most common in people with hyperthyroid Graves’ disease. Severe GO may cause blindness and all patients have reduced quality of life and effective treatments are lacking. This has driven efforts to identify novel therapeutic options resulting in progress in our understanding of the tissue remodeling processes underpinning GO. Areas covered: We have described clinical aspects including signs and symptoms, risk factors and current treatments. We have summarized GO pathogenesis including target autoantigens, regulation of tissue remodeling and tolerance mechanisms. Finally we reflect on the possible role of the microbiome in autoimmunity. References cited were selected from pubmed using the search terms ‘Graves’ orbitopathy’ ‘thyroid eye disease.’ Expert commentary: Currently the results of two clinical trials, using completely novel treatments for thyroid eye disease (TED)/GO, are awaited. The trials are the result of progress made in understanding some aspects of the pathogenesis of TED/GO (end stages of disease) mainly derived using in vitro models. However, we remain largely ignorant of the triggers that initiate and maintain the autoimmune response; studies using in vivo models are likely to shed light on the mechanisms leading to loss of tolerance. [ABSTRACT FROM PUBLISHER]

In Graves' disease (GD), a combination of genetic, epigenetic and environmental factors causes an autoimmune response to the thyroid gland, characterized by lymphocytic infiltrations and autoantibodies targeting the thyroid stimulating hormone receptor (TSHR) and other thyroid antigens. To identify the epigenetic changes involved in GD, we performed a genome-wide analysis of DNA methylation and enrichment of H3K4me3 and H3K27ac histone marks in sorted CD4+ and CD8+ T cells. We found 365 and 3322 differentially methylated CpG sites in CD4+ and CD8+ T cells, respectively. Among the hypermethylated CpG sites, we specifically found enrichment of genes involved in T cell signaling ( CD247, LCK, ZAP70, CD3D, CD3E, CD3G, CTLA4 and CD8A ) and decreased expression of CD3 gene family members. The hypermethylation was accompanied with decreased levels of H3K4me3 and H3K27ac marks at several T cell signaling genes in ChIP-seq analysis. In addition, we found hypermethylation of the TSHR gene first intron, where several GD-associated polymorphisms are located. Our results demonstrate an involvement of dysregulated DNA methylation and histone modifications at T cell signaling genes in GD patients. [ABSTRACT FROM AUTHOR]

Clear cell follicular carcinoma is a rare type of thyroid cancer and some with aggressive biological behavior. The cytoplasmic clearing of the neoplastic cells has been attributed to the accumulation of various substances, such as glycogen, lipid, mucin, and thyroglobulin, or distension of mitochondria or endoplasmic reticulum. However, the molecular mechanisms responsible for the characteristic appearance of the cell cytoplasm and the biological behavior remain unknown. We report here a case of aggressive clear cell follicular carcinoma of the thyroid with molecular profile using targeted next generation sequencing (NGS) that presented as a metastatic tumor in a woman with a history of breast carcinoma. The NGS data revealed the coexisting of a well-characterized loss-of-function TP53 R248Q mutation and a putative gain-of-function mutation of TSHR L272V, which was suggested by the overexpression of thyroglobulin and SLC5A5 ( NIS) genes in this tumor. TP53 mutations are usually related with dedifferentiation, progression, and metastasis of thyroid carcinomas. Identification of TP53 R248Q in this tumor correlated with its aggressive clinical behavior. Gain-of-function mutation of TSHR can overstimulate the thyroid follicular cells as the elevated level of TSH does and might have contributed to the development of clear cell morphology in this tumor. This report represents the first case of clear cell follicular carcinoma of the thyroid with NGS analysis and more molecular characterization is needed to elucidate the pathogenesis and provide more prognosis-relevant information for this uncommon variant of thyroid carcinomas. [ABSTRACT FROM AUTHOR]