SBP1 promotes tumorigenesis of thyroid cancer through TXN/NIS pathway.

BACKGROUND: As the tissue with the highest selenium content in the body, the occurrence and development of thyroid cancer are closely related to selenium and selenoproteins. Selenium-binding protein 1 (SBP1) has been repeatedly implicated in several cancers, but its role and molecular mechanisms in thyroid cancer remains largely undefined. METHODS: The expression of SBP1, sodium/iodide symporter (NIS) and thioredoxin (TXN) were analyzed in clinical samples and cell lines. Cell counting kit-8 (CCK-8) and tube formation assays were used to analyze the cell viability and tube formation of cells. Immunofluorescence was used to determine the expression of the NIS. Co-immunoprecipitation (Co-IP) assay was carried out to verify the interaction of SBP1 with TXN. The mouse xenograft experiment was performed to investigate the growth of thyroid cancer cells with SBP1 knockdown in vivo. RESULTS: SBP1 was significantly increased in human thyroid cancer tissues and cells, especially in anaplastic thyroid cancer. Overexpression of SBP1 promoted FTC-133 cell proliferation, and the culture supernatant of SBP1-overexpression FTC-133 cells promoted tube formation of human retinal microvascular endothelial cells. Knockdown of SBP1, however, inhibited cell proliferation and tube formation. Furthermore, overexpression of SBP1 inhibited cellular differentiation of differentiated thyroid cancer cell line FTC-133, as indicated by decreased expression of thyroid stimulating hormone receptors, thyroglobulin and NIS. Knockdown of SBP1, however, promoted differentiation of BHT101 cells, an anaplastic thyroid cancer cell line. Notably, TXN, a negative regulator of NIS, was found to be significantly upregulated in human thyroid cancer tissues, and it was positively regulated by SBP1. Co-IP assay implied a direct interaction of SBP1 with TXN. Additionally, TXN overexpression reversed the effect of SBP1 knockdown on BHT101 cell viability, tube formation and cell differentiation. An in vivo study found that knockdown of SBP1 promoted the expression of thyroid stimulating hormone receptors, thyroglobulin and NIS, as well as inhibited the growth and progression of thyroid cancer tumors. CONCLUSION: SBP1 promoted tumorigenesis and dedifferentiation of thyroid cancer through positively regulating TXN.

Sinomenine Hydrochloride Promotes TSHR-Dependent Redifferentiation in Papillary Thyroid Cancer.

Radioactive iodine (RAI) plays an important role in the diagnosis and treatment of papillary thyroid cancer (PTC). The curative effects of RAI therapy are not only related to radiosensitivity but also closely related to the accumulation of radionuclides in the lesion in PTC. Sinomenine hydrochloride (SH) can suppress tumor growth and increase radiosensitivity in several tumor cells, including PTC. The aim of this research was to investigate the therapeutic potential of SH on PTC cell redifferentiation. In this study, we treated BCPAP and TPC-1 cells with SH and tested the expression of thyroid differentiation-related genes. RAI uptake caused by SH-pretreatment was also evaluated. The results indicate that 4 mM SH significantly inhibited proliferation and increased the expression of the thyroid iodine-handling gene compared with the control group (p < 0.005), including the sodium/iodide symporter (NIS). Furthermore, SH also upregulated the membrane localization of NIS and RAI uptake. We further verified that upregulation of NIS was associated with the activation of the thyroid-stimulating hormone receptor (TSHR)/cyclic adenosine monophosphate (cAMP) signaling pathway. In conclusion, SH can inhibit proliferation, induce apoptosis, promote redifferentiation, and then increase the efficacy of RAI therapy in PTC cells. Thus, our results suggest that SH could be useful as an adjuvant therapy in combination with RAI therapy in PTC.

Insight Into Mouse Models of Hyperthyroidism.

Hyperthyroidism is characterized by an increase in the synthesis and secretion of thyroid hormones in the thyroid gland, and the most common cause of overproduction of thyroid hormones is Graves' disease (GD). Long-term disease models of hyperthyroidism have been established. In general, methods to induce GD include transfection of fibroblasts, injecting plasmids or adenovirus containing thyroid stimulating hormone receptor (TSHR) or TSHR subunit, and exogenous artificial thyroid hormone supplementation. Fortunately, in mouse studies, novel treatments for GD and Graves' orbitopathy (GO) were discovered. It has been reported that prophylactic administration of TSHR A subunit protein in genetically susceptible individuals could induce immune tolerance and provide protection for the future development of GD. Biologically active monoclonal antibody against intracellular adhesion molecule-1 (ICAM-1 mAb) and siRNA targeting TSHR can also be used to treat GD. Moreover, new potential therapeutic targets have been identified in GO mouse models, and these targets could present novel therapeutic approaches. Besides, human placental mesenchymal stem cells (hPMSCs) into the orbit, fucoxanthin and icariin may be new alternative therapies that could be used in addition to the existing drugs, although further research is needed.

Current concepts regarding Graves' orbitopathy.

Graves' orbitopathy (GO) is an orbital autoimmune disorder and the main extrathyroidal manifestation of Graves' disease, the most common cause of hyperthyroidism. GO affects about 30% of Graves' patients, although fewer than 10% have severe forms requiring immunosuppressive treatments. Management of GO requires a multidisciplinary approach. Medical therapies for active moderate-to-severe forms of GO (traditionally, high-dose glucocorticoids) often provide unsatisfactory results, and subsequently surgeries are often needed to cure residual manifestations. The aim of this review is to provide an updated overview of current concepts regarding the epidemiology, pathogenesis, assessment, and treatment of GO, and to present emerging targeted therapies and therapeutic perspectives. Original articles, clinical trials, systematic reviews, and meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, Graves' orbitopathy, thyroid eye disease, glucocorticoids, orbital radiotherapy, rituximab, cyclosporine, azathioprine, teprotumumab, TSH-receptor antibody, smoking, hyperthyroidism, hypothyroidism, thyroidectomy, radioactive iodine, and antithyroid drugs. Recent studies suggest a secular trend toward a milder phenotype of GO. Standardized assessment at a thyroid eye clinic allows for a better general management plan. Treatment of active moderate-to-severe forms of GO still relies in most cases on high-dose systemic-mainly intravenous-glucocorticoids as monotherapy or in combination with other therapies-such as mycophenolate, cyclosporine, azathioprine, or orbital radiotherapy-but novel biological agents-including teprotumumab, rituximab, and tocilizumab-have achieved encouraging results.

Identification of Two Different Phenotypes of Patients with Amiodarone-Induced Thyrotoxicosis and Positive Thyrotropin Receptor Antibody Tests.

Introduction: Serum thyrotropin (TSH) receptor antibodies (TRAbs) are occasionally found in patients with amiodarone-induced thyrotoxicosis (AIT), and usually point to a diagnosis of type 1 AIT (AIT1) due to Graves' disease (GD). However, the TRAb role and function in AIT have not been clarified. Methods: A retrospective cohort study of 309 AIT patients followed at a single academic center over a 30-year period. AIT TRAb-positive patients (n = 21, 7% of all cases) constituted the study group; control groups consisted of type 2 AIT (AIT2) TRAb-negative patients (n = 233), and 100 non-AIT patients with GD. Clinical and biochemical data at diagnosis and during the course of disease were compared. Histological samples of patients who had total thyroidectomy were reviewed. Stored serum samples were used for a functional assay of TRAb class G immunoglobulins (IgGs) in Chinese hamster ovary (CHO) cells stably transfected with complementary DNA encoding for the TSH receptor. Results: TRAb-positive patients were grouped according to color flow Doppler sonography, radioactive iodine thyroid uptake, and duration of amiodarone therapy before thyrotoxicosis in type 1 (n = 9, 43%; TRAb1) or type 2 (n = 12, 57%; TRAb2) AIT. TRAb1 patients had clinical and biochemical features indistinguishable from GD controls, and were responsive to methimazole. Conversely, TRAb2 patients had clinical features similar to AIT2 controls, and were responsive to glucocorticoids, but not to methimazole. The CHO cell functional assay demonstrated that TRAb1 IgGs had a stimulatory effect on cyclic AMP production, which was absent in TRAb2 IgGs. Pathology in TRAb1 showed hyperplastic thyroid follicles and mild lymphocyte infiltration, reflecting thyroid stimulation. On the contrary, TRAb2 samples revealed follicle destruction, macrophage infiltration, and sometimes fibrosis, consistent with a destructive process. Conclusions: Almost 60% of TRAb-positive AIT patients had a destructive thyroiditis. TRAb-positive tests in AIT patients do thus not necessarily imply a diagnosis of GD and AIT1, and should be evaluated in the clinical and biochemical setting of each AIT patient and confirmed by measuring thyroid-stimulating immunoglobulins.

The Role of the Microbiota in Graves' Disease and Graves' Orbitopathy.

Graves' disease (GD) is a clinical syndrome with an enlarged and overactive thyroid gland, an accelerated heart rate, Graves' orbitopathy (GO), and pretibial myxedema (PTM). GO is the most common extrathyroidal complication of GD. GD/GO has a significant negative impact on the quality of life. GD is the most common systemic autoimmune disorder, mediated by autoantibodies to the thyroid-stimulating hormone receptor (TSHR). It is generally accepted that GD/GO results from complex interactions between genetic and environmental factors that lead to the loss of immune tolerance to thyroid antigens. However, the exact mechanism is still elusive. Systematic investigations into GD/GO animal models and clinical patients have provided important new insight into these disorders during the past 4 years. These studies suggested that gut microbiota may play an essential role in the pathogenesis of GD/GO. Antibiotic vancomycin can reduce disease severity, but fecal material transfer (FMT) from GD/GO patients exaggerates the disease in GD/GO mouse models. There are significant differences in microbiota composition between GD/GO patients and healthy controls. Lactobacillus, Prevotella, and Veillonella often increase in GD patients. The commonly used therapeutic agents for GD/GO can also affect the gut microbiota. Antigenic mimicry and the imbalance of T helper 17 cells (Th17)/regulatory T cells (Tregs) are the primary mechanisms proposed for dysbiosis in GD/GO. Interventions including antibiotics, probiotics, and diet modification that modulate the gut microbiota have been actively investigated in preclinical models and, to some extent, in clinical settings, such as probiotics (Bifidobacterium longum) and selenium supplements. Future studies will reveal molecular pathways linking gut and thyroid functions and how they impact orbital autoimmunity. Microbiota-targeting therapeutics will likely be an essential strategy in managing GD/GO in the coming years.

New Therapeutic Horizons for Graves' Hyperthyroidism.

Graves' hyperthyroidism is characterized by the presence of autoantibodies that stimulate the thyroid-stimulating hormone receptor (TSHR), resulting in uncontrolled secretion of excessive thyroid hormone. Conventional treatments, including antithyroid medication, radioiodine, or surgery have remained largely unchanged for the past 70 years and either lack efficacy for many patients, or result in lifelong thyroid hormone replacement therapy, in the case of the latter 2 options. The demand for new therapeutic options, combined with greater insight into basic immunobiology, has led to the emergence of novel approaches to treat Graves' hyperthyroidism. The current therapies under investigation include biologics, small molecules, and peptide immunomodulation. There is a growing focus on TSHR-specific treatment modalities, which carry the advantage of eliciting a specific, targeted approach, with the aim of avoiding disruption of the functioning immune system. These therapies present a new opportunity to supersede the inadequate treatments currently available for some Graves' patients, offering hope of successful restoration of euthyroidism without the need for ongoing therapy. Several of these therapeutic options have the potential to translate into clinical practice in the near future. This review provides a comprehensive summary of the recent advances and various stages of development of the novel therapeutic approaches to treat Graves' hyperthyroidism.

Autoimmune gastritis.

Autoimmune gastritis (AIG) is an increasingly prevalent, organ-specific, immune-mediated disorder characterized by the destruction of gastric parietal cells, leading to the loss of intrinsic factor and reduced acid output. These alterations result in malabsorption of iron, vitamin B12 (pernicious anaemia) and potentially other micronutrients. For several years, most studies have focused on pernicious anaemia only, generating confusion between the two entities. In AIG, the gastric proton pump, H+/K+ ATPase, is the major autoantigen recognized by autoreactive T cells. The T cell-dependent activation of B cells stimulates the production of anti-parietal cell antibodies, the serological hallmark of AIG. The role of Helicobacter pylori infection in activating or favouring the autoimmune process is still uncertain. Early histopathological alterations allowing a more precise and prompt recognition have recently been described. AIG is burdened by a substantial diagnostic delay as it can present with varied clinical signs including, among others, gastrointestinal symptoms and neuropsychiatric manifestations. In advanced stages, AIG might progress to neuroendocrine tumours and gastric adenocarcinoma. Management includes early detection through a proactive case-finding strategy, micronutrient supplementation and endoscopic surveillance. This Primer comprehensively describes the most important insights regarding the epidemiology, pathophysiology, diagnosis and management of AIG, focusing on the most controversial, outstanding issues and future directions.

Ameliorative effect of Aloe gel against L-T4-induced hyperthyroidism via suppression of thyrotropin receptors, inflammation and oxidative stress.

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.

A model of the cost of delaying treatment of Hashimotos thyroiditis: thyroid cancer initiation and growth.

Hashimoto's thyroiditis (HT) is an autoimmune disorder that drives the function of thyroid gland to the sequential clinical states:euthyroidism (normal condition), subclinical hypothyroidism (asymptomatic period) and overt hypothyroidism (symptomatic period). In this disease, serum thyroidstimulating hormone (TSH) levels increase monotonically, stimulating the thyroid follicular cells chronically and initiating benign (non-cancerous) thyroid nodules at various sites of the thyroid gland. This process can also encourage growth of papillary thyroid microcarcinoma. Due to prolonged TSH stimulation, thyroid nodules may grow and become clinically relevant without the administration of treatment by thyroid hormone replacement. Papillary thyroid cancer (80% of thyroid cancer) whose incidence is increasing worldwide, is associated with Hashimoto's thyroiditis. A stochastic model is developed here to produce the statistical distribution of thyroid nodule sizes and growth by taking serum TSH value as the continuous input to the model using TSH values from the output of the patientspecific deterministic model developed for the clinical progression of Hashimoto's thyroiditis.

A pilot study on the beneficial effects of additional selenium supplementation to methimazole for treating patients with Graves' disease

Background/aim: The aim of this study was to assess the effect of a combination use of methimazole (MMI) and selenium (Se) in the treatment of Graves' disease (GD). Materials and methods: A total of 103 newly diagnosed hyperthyroidism patients were randomized to MMI and MMI + Se combination groups. After treatment for 6 months, the levels of triiodothyronine (FT3), free thyroxine (FT4), thyrotropin receptor antibody (TRAb), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb) were observed. An in vitro culture model of thyroid cells was established and the protein expression and mRNA levels of TRAb, TPOAb, and TGAb were determined by western blot and RT-PCR. Results: A significant decrease in the levels of FT3, FT4, TRAb, TPOAb, and TGAb were observed in both groups along with a marked increase in TSH levels. Furthermore, the in vitro experiments showed that the protein expression and mRNA levels of TRAb, TPOAb, and TGAb decreased significantly. Also, compared to the MMI group, there was a greater improvement of these indices in the MMI + Se group. Conclusion: We suggest that the combined use of MMI and Se could improve the thyroid activity in patients, which may provide an effective therapy for the treatment of GD in clinical settings.

POSITIVE THYROTROPIN RECEPTOR ANTIBODIES IN PATIENTS WITH TRANSIENT THYROTOXICOSIS.

OBJECTIVE: Thyrotropin (TSH) receptor antibody (TRAb) testing is considered accurate for the diagnosis of Graves disease (GD) and has been identified rarely in thyrotoxic patients without GD. We describe 4 patients with transient thyrotoxicosis and positive TRAb to highlight this clinical possibility. METHODS: Patient demographics, symptoms, laboratory findings, and time to resolution of thyrotoxicosis are summarized. TRAb testing was performed by either a third-generation thyrotropin-binding inhibitory immunoglobulin (TBII) competitive-binding assay or a thyroid-stimulating immunoglobulin (TSI) bioassay from either Mayo Clinic Laboratory or Quest Diagnostics. RESULTS: Four patients with transient thyrotoxicosis and positive TRAb testing were identified. Of these, three were female, and the median age was 44 years (range, 25 to 49 years). Median symptom duration at evaluation was 6.5 weeks (range, 3 to 12 weeks). No patient had any clinical manifestations unique to GD or exposure to biotin, thyroid hormone, supplements, iodine, or relevant medications. The TSH was <0.1 mIU/L in all patients. Three patients had a positive TSI, which was elevated less than twice the upper limit of the reference range in all cases, and 1 patient had a strongly positive TBII. None of the patients were treated with thionamides or radioactive iodine. Spontaneous resolution occurred in all patients at a median of 5.5 weeks (range, 2 to 14.4 weeks). CONCLUSION: These cases demonstrate that TSI or TBII may be present in thyrotoxic patients with transient thyrotoxicosis. For clinically stable patients presenting without pathognomonic evidence of GD, mildly elevated TRAb results may require cautious interpretation, and alterative diagnostic testing or close monitoring should be considered. ABBREVIATIONS: cAMP = cyclic adenosine monophosphate; FT4 = free thyroxine; GD = Graves disease; TBII = thyrotropin-binding inhibitory immunoglobulin (also known as TBI); TRAb = thyrotropin receptor antibody; TSH = thyrotropin; TSHR = thyrotropin receptor; TSI = thyroid-stimulating immunoglobulin; TT3 = total triiodothyronine; TT4 = total thyroxine.

Serum Trace Elements Profile in Graves' Disease Patients with or without Orbitopathy in Northeast China.

OBJECTIVE: The purpose of the present study was to investigate serum trace elements in Graves' disease (GD) patients with or without orbitopathy in Northeast China. METHODS: Patients with newly diagnosed Graves' disease (HyGD) (n = 66), GD patients with euthyroid status or subclinical thyroidism after treatment (EUGD) (n = 55), GO patients with euthyroid status or subclinical thyroidism after treatment (GO) (n = 57), and normal controls (NC) (n = 66) were enrolled in this study. Serum trace elements were measured with ICP-MS. RESULTS: Serum selenium (Se) levels in EUGD group (median: 7.53 µg/dL), HyGD group (median: 6.76 µg/dL), and GO group (median: 7.40 µg/dL) were significantly lower than those in NC group (median: 9.20 µg/dL, all P < 0.01). Serum copper (Cu) levels in GO group (median: 95.93 µg/dL) were significantly lower than those in the NC group (median: 113.59 µg/dL, P = 0.015). After being adjusted for multivariables, thyroid-specific antibodies grade was associated with low Se levels. Hyperthyroidism and thyroid-specific antibodies grade were associated with high Cu levels. In addition, orbitopathy was associated with low Cu levels. CONCLUSIONS: Thyroid autoimmunity was associated with low Se levels. Hyperthyroidism and thyroid autoimmunity may be associated with relatively high serum Cu levels. Alternatively, ophthalmopathy may be related to low serum Cu levels.

Variable Effects of Dietary Selenium in Mice That Spontaneously Develop a Spectrum of Thyroid Autoantibodies.

Selenium (Se) is a critical element in thyroid function, and variable dietary Se intake influences immunity. Consequently, dietary Se could influence development of thyroid autoimmunity and provide an adjunct to treat autoimmune thyroid dysfunction. Nonobese diabetic (NOD).H2h4 mice spontaneously develop autoantibodies to thyroglobulin (Tg) and thyroid peroxidase (TPO). This mouse strain expressing a human thyroid-stimulating hormone receptor (TSHR) A-subunit transgene in the thyroid also develops pathogenic TSHR autoantibodies. In this report, we investigated whether dietary Se influences these immune processes. Male and female wild-type and transgenic NOD.H2h4 mice were maintained on normal-, low-, or high-Se (0.1, 0, or 1.0 mg/kg) rodent diets. After 4 months, Se serum levels were extremely low or significantly increased on 0 or 1.0 mg/kg Se, respectively. Varying Se intake affected Tg antibody (TgAb) levels after 2 (but not 4) months; conversely, TPO antibody (TPOAb) levels were altered by dietary Se after 4 (but not 2) months. These data correspond to the earlier development of TgAb than TPOAb in NOD.H2h4 mice. In males, TgAb levels were enhanced by high Se and in females by low Se intake. Se intake had no effect on pathogenic TSHR autoantibodies in TSHR transgenic NOD.H2h4 females. In conclusion, in susceptible NOD.H2h4 mice, we found no evidence that a higher dietary Se intake ameliorates thyroid autoimmunity by reducing autoantibodies to Tg, TPO, or the TSHR. Instead, our finding that low dietary Se potentiates the development of autoantibodies to Tg and TPO in females is consistent with reports in humans of an increased prevalence of autoimmune thyroiditis in low-Se regions.

A Case of Acute Cerebral Infarction and Thyroid Storm Associated with Moyamoya Disease

Coexistence of moyamoya disease and Graves' disease is rare. A 41-year-old woman presented with symptoms of left-sided hemiparesis and dysarthria. Magnetic resonance imaging and angiography revealed acute infarction of the right thalamus and occipital lobe with complete obstruction of the distal internal carotid arteries and obstruction of the right P2. Free thyroxine, thyroid-stimulating hormone (TSH), and TSH receptor antibody levels were 79.33 pmol/L, 0.007 uIU/mL, and 151.5 u/L, respectively. She received antiplatelet therapy and standard antithyroid drug dose. After admission, seizure and unexplained fever occurred. The thyroid storm score (Burch and Wartofsky scale) was 90 points. After intensive treatment, mental status and thyrotoxicosis-related symptoms ameliorated and vital signs stabilized. We describe a case of thyroid storm following cerebrovascular ischemic events in a Korean woman with moyamoya disease and Graves' disease. Thyroid storm combined with cerebrovascular events can lead to severe morbidity and mortality. Prompt recognition and strict management are crucial.

Presence of TSH receptors in discrete areas of the hypothalamus and caudal brainstem with relevance for feeding controls-Support for functional significance.

AIMS: Previous studies have shown that brain-derived thyroid-stimulating hormone (TSH) and its receptor (TSHr) are present in hypothalamic extracts. No studies investigating both the anatomical location and functional significance of putative TSHr proteins in specific central nervous system (CNS) nuclei involved in feeding controls have yet been conducted. The aim was thus to determine whether TSHr are present in nuclei associated with feeding behavior, and if such receptors may be functional. METHODS: Brain tissue from adult rats was analyzed for gene expression and receptor protein expression was investigated with immunohistochemistry and western blotting. To investigate whether putative TSHr may be functional, we evaluated food intake of rats given intraparenchymal nanoinjections of TSH into the nucleus of the solitary tract (NTS). RESULTS: RT-qPCR confirmed previous reports that TSHr mRNA is expressed in CNS tissues of the adult rat. Immunohistochemistry showed TSHr-immunoreactivity in the arcuate, the ventromedial, the dorsomedial, and the paraventricular hypothalamic nuclei. We also found TSHr-ir in the dorsal hindbrain to be localized to the area postrema, NTS, dorsal motor nucleus of the vagus, and the hypoglossal motor nucleus. Further protein analysis with western blotting showed 120kDa TSHr-ir proteins present in the hypothalamus and brainstem. Injections of TSH into the NTS reduced food intake similar to the positive control, urocortin. CONCLUSIONS: These data suggest that functional TSHr are present in the caudal brainstem and hypothalamic nuclei of relevance for feeding control as a possibly uncleaved holoreceptor, and highlights a hindbrain component to central TSH inhibition of food intake.

Engineering Multi-Walled Carbon Nanotube Therapeutic Bionanofluids to Selectively Target Papillary Thyroid Cancer Cells.

BACKGROUND: The incidence of papillary thyroid carcinoma (PTC) has risen steadily over the past few decades as well as the recurrence rates. It has been proposed that targeted ablative physical therapy could be a therapeutic modality in thyroid cancer. Targeted bio-affinity functionalized multi-walled carbon nanotubes (BioNanofluid) act locally, to efficiently convert external light energy to heat thereby specifically killing cancer cells. This may represent a promising new cancer therapeutic modality, advancing beyond conventional laser ablation and other nanoparticle approaches. METHODS: Thyroid Stimulating Hormone Receptor (TSHR) was selected as a target for PTC cells, due to its wide expression. Either TSHR antibodies or Thyrogen or purified TSH (Thyrotropin) were chemically conjugated to our functionalized Bionanofluid. A diode laser system (532 nm) was used to illuminate a PTC cell line for set exposure times. Cell death was assessed using Trypan Blue staining. RESULTS: TSHR-targeted BioNanofluids were capable of selectively ablating BCPAP, a TSHR-positive PTC cell line, while not TSHR-null NSC-34 cells. We determined that a 2:1 BCPAP cell:α-TSHR-BioNanofluid conjugate ratio and a 30 second laser exposure killed approximately 60% of the BCPAP cells, while 65% and >70% of cells were ablated using Thyrotropin- and Thyrogen-BioNanofluid conjugates, respectively. Furthermore, minimal non-targeted killing was observed using selective controls. CONCLUSION: A BioNanofluid platform offering a potential therapeutic path for papillary thyroid cancer has been investigated, with our in vitro results suggesting the development of a potent and rapid method of selective cancer cell killing. Therefore, BioNanofluid treatment emphasizes the need for new technology to treat patients with local recurrence and metastatic disease who are currently undergoing either re-operative neck explorations, repeated administration of radioactive iodine and as a last resort external beam radiation or chemotherapy, with fewer side effects and improved quality of life.

[Effect of Jiakangning Capsule on Thyroid Function and Akt/mTOR Signal Pathway of Graves' Disease Mice: an Experimental Study].

OBJECTIVE: To observe the improvement of thyroid function and changes of Akt, p-Akt, mammalian target of rapamycin (mTOR), and para-mTOR (p-mTOR) expression in Graves' disease (GD) mice after intervened by Jiakangning Capsule (JC), and to explore possible mechanism for JC in treating GD. METHODS: GD model was established by immunizing female BALB/c mice with thyroid stimulating hormone receptor A subunit (Ad-TSHRα-289). Totally 70 successfully modeled mice were divided into the model group (n =20), the JC intervened group (n =25), the Methimazole Tablet intervened group (n =25) according to random digit table. A normal control group (n =15) and a vehicle control group (n =20, injected with Ad-null) were also set up. Mice in the JC intervened group were administered with JC suspension at the daily dose of 1. 5 g/kg by gastrogavag. Mice in the Methimazole intervened group were administered with Methimazole suspension at the daily dose of 2. 5 g/kg by gastrogavage. Equal volume of normal saline was administered to mice in the rest 3 groups by gastrogavage. All intervention lasted for 5 weeks. Six mice were selected from each group to observe pathological changes of thyroid tissues. Serum levels of thyroxine (T4), triiodothyronine (T3), thyroid stimulating hormone (TSH), and thyrotropin receptor antibody (TRAb) were analyzed by radioimmunoassay. Expression levels of Akt, p-Akt, mTOR, and p-mTOR in thyroid tissues were etermined by Western blot. RESULTS: (1) The thyroid gland in the GD model group showed proliferative changes, with enlarged follicles of various sizes. Interstitial stroma was filled with blood vessels. Structures of thyroid tissues in the JC intervened group and the Methimazole intervened group were significantly restored, and follicular hyperplasia was relieved. (2) Compared with the normal control group and the vehicle control group, levels of TRAb, T4, and T3 increased; ratios of P-Akt/ß-actin, p-Akt/Akt, p-mTOR/ß-actin, and p-mTOR/mTOR also increased in the model group (all P <0. 01). Compared with the model group, levels of TRAb, T4, and T3 decreased in the JC intervened group and the Methimazole intervened group (P <0. 01); ratios of p-mTOR/ß-actin and pmTOR/mTOR decreased in the JC intervened group (P <0.01); ratios of P-Akt/ß-actin, p-Akt/Akt, p-mTOR/ß-actin, and p-mTOR/mTOR decreased in the Methimazole intervened group (P <0. 05, P <0. 01). Conclusion JC could reduce thyroid hormonc levels of GD mice and lower expression levels of mTOR, and its mechanism for improving thyroid function of GD mice might be associated with this influence.

New small molecule agonists to the thyrotropin receptor.

BACKGROUND: Novel small molecular ligands (SMLs) to the thyrotropin receptor (TSHR) have potential as improved molecular probes and as therapeutic agents for the treatment of thyroid dysfunction and thyroid cancer. METHODS: To identify novel SMLs to the TSHR, we developed a transcription-based luciferase-cAMP high-throughput screening system and we screened 48,224 compounds from a 100K library in duplicate. RESULTS: We obtained 62 hits using the cut-off criteria of the mean±three standard deviations above the baseline. Twenty molecules with the greatest activity were rescreened against the parent CHO-luciferase cell for nonspecific activation, and we selected two molecules (MS437 and MS438) with the highest potency for further study. These lead molecules demonstrated no detectible cross-reactivity with homologous receptors when tested against luteinizing hormone (LH)/human chorionic gonadotropin receptor and follicle stimulating hormone receptor-expressing cells. Molecule MS437 had a TSHR-stimulating potency with an EC50 of 13×10(-8) M, and molecule MS438 had an EC50 of 5.3×10(-8) M. The ability of these small molecule agonists to bind to the transmembrane domain of the receptor and initiate signal transduction was suggested by their activation of a chimeric receptor consisting of an LHR ectodomain and a TSHR transmembrane. Molecular modeling demonstrated that these molecules bound to residues S505 and E506 for MS438 and T501 for MS437 in the intrahelical region of transmembrane helix 3. We also examined the G protein activating ability of these molecules using CHO cells co-expressing TSHRs transfected with luciferase reporter vectors in order to measure Gsα, Gßγ, Gαq, and Gα12 activation quantitatively. The MS437 and MS438 molecules showed potent activation of Gsα, Gαq, and Gα12 similar to TSH, but neither the small molecule agonists nor TSH showed activation of the Gßγ pathway. The small molecules MS437 and MS438 also showed upregulation of thyroglobulin (Tg), sodium iodine symporter (NIS), and TSHR gene expression. CONCLUSIONS: Pharmacokinetic analysis of MS437 and MS438 indicated their pharmacotherapeutic potential, and their intraperitoneal administration to normal female mice resulted in significantly increased serum thyroxine levels, which could be maintained by repeated treatments. These molecules can therefore serve as lead molecules for further development of powerful TSH agonists.