TSHR signaling promotes hippocampal dependent memory formation through modulating Wnt5a/ß-catenin mediated neurogenesis.

Subclinical hyperthyroidism is defined biochemically as a low or undetectable thyroid-stimulating hormone (TSH) with normal thyroid hormone levels. Low TSHR signaling is considered to associate with cognitive impairment. However, the underlying molecular mechanism by which TSHR signaling modulates memory is poorly understood. In this study, we found that Tshr-deficient in the hippocampal neurons impairs the learning and memory abilities of mice, accompanying by a decline in the number of newborn neurons. Notably, Tshr ablation in the hippocampus decreases the expression of Wnt5a, thereby inactivating the ß-catenin signaling pathway to reduce the neurogenesis. Conversely, activating of the Wnt/ß-catenin pathway by the agonist SKL2001 results in an increase in hippocampal neurogenesis, resulting in the amelioration in the deficits of memory caused by Tshr deletion. Understanding how TSHR signaling in the hippocampus regulates memory provides insights into subclinical hyperthyroidism affecting cognitive function and will suggest ways to rationally design interventions for neurocognitive disorders.

Characterizing the Interplay of Lymphocytes in Graves' Disease.

Graves' disease (GD) is a thyroid-specific autoimmune disease with a high prevalence worldwide. The disease is primarily mediated by B cells, which produce autoantibodies against the thyroid-stimulating hormone receptor (TSHR), chronically stimulating it and leading to high levels of thyroid hormones in the body. Interest in characterizing the immune response in GD has motivated many phenotyping studies. The immunophenotype of the cells involved and the interplay between them and their secreted factors are crucial to understanding disease progression and future treatment options. T cell populations are markedly distinct, including increased levels of Th17 and follicular helper T cells (Tfh), while Treg cells appear to be impaired. Some B cells subsets are autoreactive, and anti-TSHR antibodies are the key disease-causing outcome of this interplay. Though some consensus across phenotyping studies will be discussed here, there are also complexities that are yet to be resolved. A better understanding of the immunophenotype of Graves' disease can lead to improved treatment strategies and novel drug targets.

Determining Specific Thyroid Transcripts in Peripheral Blood: A Single Center Study Experience.

Thyroid carcinoma (TC) comprises a spectrum of different tumors with a wide range of biological behavior and prognosis. The techniques based on the latest trends in molecular biology may have application in diagnosis of metastatic TC. The aim of this study was to apply and analyze mRNA expression in peripheral blood of thyrotropin receptor [thyroid stimulating hormone receptor (TSHR-mRNA)] gene and thyroglobulin (Tg-mRNA) gene using 2-ΔΔCt method in differentiated TC patients and healthy individuals. Fifty-seven subjects were included in the study, consisting of 40 patients with TC and 17 healthy volunteers as a control group. Total RNA was isolated from peripheral blood and used for two-step reverse transcriptase-polymerase chain reaction (PCR). Real-time PCR was performed with appropriate primers. Relative quantification using the 2-ΔΔCt method was applied. Thyroid carcinoma patients with metastatic disease or loco-regional relapse expressed TSHR-mRNA by a 8.57-fold higher level than healthy controls. Thyroid carcinoma patients with biochemical relapse expressed TSHR-mRNA by a 14.17-fold higher level than healthy controls, while expression of Tg-mRNA was 6.6-fold higher in TC patients with metastatic disease and loco-regional relapse than healthy controls and 8.34-fold higher level compared with TC patients with excellent response to treatment. Our preliminary study showed that the TSHR gene expression might have more useful application as a biomarker compared to detection of Tg gene expression.

Mild TSH resistance: Clinical and hormonal features in childhood and adulthood.

OBJECTIVE: Mutations in TSH receptor (TSHR) are associated with TSH resistance, a genetic defect characterized by a heterogeneous phenotype ranging from severe hypothyroidism to subclinical hypothyroidism (SCH). We assessed the clinical and hormonal pattern of TSHR variants in a series of pediatric patients, and the long-term outcome of growth, biochemical measurements of metabolism, and neuropsychological functions in TSHR mutations carriers. DESIGN: Observational, retrospective study. PATIENTS: Thirty four children (age 7 days to 11 years) and 18 adult carriers of TSHR variants. MEASUREMENTS: The TSHR gene was sequenced by PCR-amplified direct sequencing in 111 pediatric patients with slight to moderate elevation of TSH and normal FT4 levels. The study focused on the: auxological and biochemical parameters, thyroid ultrasound, bone age, bone mineral density (BMD), and intellectual outcome (IQ) were collected during the long follow-up (1-15 years). RESULTS: Seventeen different TSHR variants (eight novel) were identified in 34 of the 111 pediatric patients, with a high prevalence of familial cases (27/34). Neonatal screening for congenital hypothyroidism was positive in half of the TSHR carriers. Growth, IQ, BMD, and biochemical parameters were normal in all subjects. Twenty patients received L-T4 replacement therapy, in all cases before genetic analysis. After re-evaluation, six patients resumed L-T4 therapy: they were compound heterozygous, or single heterozygous and with associated conditions at risk of thyroid impairment (SGA). No adults presented clinical features consistent with impaired thyroid function. CONCLUSIONS: Children carriers of TSHR variants, regardless of L-T4 treatment, show regular growth and neuropsychological development, with no evident biochemical and US alterations.

Long noncoding RNA PVT1 modulates thyroid cancer cell proliferation by recruiting EZH2 and regulating thyroid-stimulating hormone receptor (TSHR).

The purposes of this study were to investigate the potential roles of long noncoding RNA (lncRNA) PVT1 in thyroid cancer cell proliferation and to explore their possible mechanisms. A total of 84 patients who were diagnosed as having thyroid cancer (papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), and anaplastic thyroid carcinoma (ATC)) in Renji Hospital were enrolled in this study. Expressions of lncRNA PVT1 in thyroid cancer tissues and cell lines (IHH-4, FTC-133, and 8505C) were analyzed using RT-polymerase chain reaction (PCR) and western blotting analysis. The effects of lncRNA PVT1 expression on thyroid cancer cell proliferation and cell cycle were analyzed using flow cytometry. Furthermore, the effects of lncRNA expression on thyroid-stimulating hormone receptor (TSHR) expression and polycomb enhancer of zeste homolog 2 (EZH2) were also analyzed using RNA immunoprecipitation (RIP) assay and chromatin immunoprecipitation (ChIP) assay, respectively. Compared to the controls, lncRNA PVT1 was significantly up-regulated in thyroid tissues, as well as in three kinds of tumor cell lines (P < 0.05). Silenced PVT1 significantly inhibited thyroid cell line IHH-4, FTC-133, and 8505C cell proliferation and arrested cell cycle at G0/G1 stage and significantly decreased cyclin D1 and TSHR expressions (P < 0.05). Moreover, lncRNA PVT1 could be enriched by EZH2, and silencing PVT1 resulted in the decreased recruitment of EZH2. This study suggested that lncRNA PVT1 may contribute to tumorigenesis of thyroid cancer through recruiting EZH2 and regulating TSHR expression.

The Impact of the D727E Polymorphism has no Significant Role in Multi Nodular Goiter.

Interactions between individual genetic and environmental factors determine the onset of the multi nodular goiter (MNG). The thyroid-stimulating hormone receptor (TSHR) gene is a convincing candidate gene in the pathogenesis of certain thyroid diseases including MNG. We investigated the codon 727 polymorphism (p.Asp727Glu, p.D727E) of the human TSHR gene using the polymerase chain reaction-restriction fragment length polymorphim (PCR-RFLP) methods in 31 Turkish patients with MNG and in 30 control subjects, aiming to evaluate the relationship between this polymorphism and MNG. After genomic DNA isolation, PCR amplification was performed using a pair of primers in exon 10 of the TSHR gene that contains the p.D727E polymorphism and digested by theNlaIII (Hin1II) restriction enzyme. We found the CC and CG genotype incidence for the patient group to be 0.71 and 0.29, respectively, and for the control group to be 0.8 and 0.2, respectively. No statistically significant difference was found between the genotype and allele distribution of both groups (p = 0.417 and p = 0.449, respectively). However, the polymorphism is significantly correlated with the low serum level of the TSH (p = 0.047). These results suggest that the p.D727E polymorphism of the TSHR gene may not contribute to the pathogenesis of nontoxic MNG diseases.

Analysis of thyroid stimulating hormone receptor gene mutation in children with hyperthyroidism / 中华内分泌代谢杂志

Objective To explore the characterization of thyroid stimulating hormone receptor(TSHR) gene mutational spectrum in children with hyperthyroidism from Guangzhou. Methods Ninety children were diagnosed with hyperthyroidism from July 2009 to July 2014 in our institute. Their median age at diagnosis was(7.5± 3.4) years, and there were 28 males and 62 females. Mutational analysis were performed by performing polymerase chain reaction (PCR) and DNA direct sequencing of exon 10 of TSHR gene. TSHR gene mutations from 50 unrelated healthy children were served as controls. The correlation between TSHR gene and hyperthyroidism in children was explored. Results A total of 3 mutations were identified in ninety children who were diagnosed with hyperthyroidism, one synonymous mutations(p.V614V), and two missense mutations( p. R707W and p. D727E). Mutation of p. V614V do not change amino acid and do not influence the structure and function of TSHR, no pathogenicity. p.R707W is a SNP associated with human cancers. The frequency of C allele of the D727E in children with hyperthyroidism was 86.7%, while 55.0% in the controls, significant different between the children with hyperthyroidism and the controls( P＜0. 01). In this study, a very high association between the D727E SNP and hyperthyroidism ( OR=18. 86, P＜0. 01) was found. Conclusion Three different mutations of TSHR gene exon 10 were identified in 90 children with hyperthyroidism, (c.1842A＞G,p.V614V、c.2119C＞T,p.R707W、c.2181G＞C,p.D727E), there were association between p.D727E and hyperthyroidism, nor p. V614V and p. R707W. Finally, p. D727E may be correlated with hyperthyroidism in children.

Poly-peptide immunogenicity of human thyroid-stimulating hormone receptor that may cause Graves' disease / 基础医学与临床

DQA1*0501.TSHR peptides of 183～198、195～210、248～263、301～320、343～362 and 357～376 could bind with high affinity to both HLA-DR3 and HLA-DQA1*0501,all of their IC50 values less than(1 ?mol/L),but they could bind to neither HLA-DR7 nor HLA-DQA1*0201 with high affinity.Conclusion Epitopes of TSHR 183～198,195～210,248～263,301～320,343～362 and 357～376 on the TSHR extracellular domain might be the auto-antigens to cause GD.