Changing the structure of PFOA and PFOS: a chemical industry strategy or a solution to avoid thyroid-disrupting effects?

BACKGROUND: The family of perfluoroalkyl and polyfluoroalkyl substances (PFAS) raised concern for their proven bioaccumulation and persistence in the environment and animals as well as for their hazardous health effects. As a result, new congeners of PFAS have rapidly replaced the so-called "old long-chain PFAS" (mainly PFOA and PFOS), currently out-of-law and banned by most countries. These compounds derive from the original structure of "old long-chain PFAS", by cutting or making little conformational changes to their structure, thus obtaining new molecules with similar industrial applications. The new congeners were designed to obtain "safer" compounds. Indeed, old-long-chain PFAS were reported to exert thyroid disruptive effects in vitro, and in vivo in animals and humans. However, shreds of evidence accumulated so far indicate that the "restyling" of the old PFAS leads to the production of compounds, not only functionally similar to the previous ones but also potentially not free of adverse health effects and bioaccumulation. Studies aimed at characterizing the effects of new-PFAS congeners on thyroid function indicate that some of these new-PFAS congeners showed similar effects. PURPOSE: The present review is aimed at providing an overview of recent data regarding the effects of novel PFAS alternatives on thyroid function. RESULTS AND CONCLUSIONS: An extensive review of current legislation and of the shreds of evidence obtained from in vitro and in vivo studies evaluating the effects of the exposure to novel PFOA and PFOS alternatives, as well as of PFAS mixture on thyroid function will be provided.

Selective anti-CXCR2 receptor blockade by AZD5069 inhibits CXCL8-mediated pro-tumorigenic activity in human thyroid cancer cells in vitro.

BACKGROUND: Thyroid cancer is the most common endocrine malignancy. Current therapies are successful, however some patients progress to therapeutically refractive disease. The immunotherapeutic potential of the CXCL8-chemokine/CXCR2-chemokine-receptor system is currently being explored in numerous human cancers. This study aimed to evaluate if the targeting of CXCR2 by its selective antagonist, AZD5069, could modulate CXCL8-mediated pro-tumorigenic effects in thyroid-cancer (TC) cells in vitro. METHODS: Normal human primary thyroid cells (NHT) and TC cell lines TPC-1 (RET/PTC), BCPAP, 8505C and 8305C (BRAFV600e) were treated with AZD5069 (100 pM-10 µM) over a time-course. Viability and proliferation were assessed by WST-1 and crystal violet assays. CXCL8 and CXCR2 mRNA were evaluated by RT-PCR. CXCL8-protein concentrations were measured in cell culture supernatants by ELISA. CXCR2 on cell surface was evaluated by flow-cytometry. Cell-migration was assessed by trans-well-migration chamber-system. RESULTS: AZD5069 exerted negligible effects on cell proliferation or viability. AZD5069 significantly reduced CXCR2, (but not CXCL8) mRNAs in all cell types. CXCR2 was reduced on the membrane of some TC cell lines. A significant reduction of the CXCL8 secretion was found in TPC-1 cells (basal-secretion) and NHT (TNFα-induced secretion). AZD5069 significantly reduced basal and CXCL8-induced migration in NHT and different TC cells. CONCLUSIONS: Our findings confirm the involvement of the CXCL8/CXCR2-axis in promoting pro-tumorigenic effects in TC cells, further demonstrating its immunotherapeutic significance in human cancer.

Cardiovascular and metabolic comorbidities in patients with thyroid nodules: the impact of incidental diagnosis.

PURPOSE: The prevalence of thyroid nodules (TN) in the general population has increased as screening procedures are implemented and an association with metabolic and cardiovascular disorders has been reported. The aim of this study was to investigate the reason leading to the diagnosis of TN and to compare the clinical characteristics of patients diagnosed incidentally with those of patients diagnosed for thyroid-related reasons. METHODS: We designed a retrospective cross-sectional study including consecutive patients with TN from two high-volume hospital-based centers for thyroid diseases (Pavia and Messina) in Italy. Data regarding reason leading to TN diagnosis, age, sex, BMI, presence of cardio-metabolic comorbidities were collected. RESULTS: Among the 623 enrolled subjects, the US diagnosis of TN was prompted by thyroid-related reasons in 421 (67.6%, TD group) and incidental in 202 (32.4%, ID group) with a similar distribution in the two centers (p = 0.960). The ID group patients were more frequently males (38.6% vs 22.1%, p < 0.001) and significantly older (58.9 ± 13.7 vs 50.6 ± 15.5 years, p < 0.001) than the TD group ones, and had a higher rate of cardiovascular comorbidities (73.8% vs 47.5%, p < 0.001), despite having a similar BMI (27.9 ± 5.2 vs 27.8 ± 13.5, p = 0.893). CONCLUSIONS: Stratification of patients with TN according to the diagnostic procedure leading to diagnosis allows a better epidemiological characterization of this inhomogeneous and large population.

Thyroid dysfunction during gestation and gestational diabetes mellitus: a complex relationship.

PURPOSE: Gestational diabetes mellitus (GDM) and thyroid dysfunction during gestation (GTD) are the two most prevalent endocrinopathies during pregnancy. The aim of the present review is to provide an overview of the peculiar aspects of GDM and GTD, to highlight the potential interactions and clinical consequences of these two frequent clinical conditions. METHODS: A literature review regarding GDM and GTD was carried out with particular interest on meta-analyses and human studies dealing with the (i) shared risk factors between GDM and GTD, (ii) the epidemiological link between GTD and GDM, (iii) physiopathologic link between GTD and GDM, (iv) clinical consequences of GDM and GTD, and (v) post-partum implications of GDM and GTD. RESULTS: The association between GDM and GTD is common and may be explained by the insulin-resistance state due to maternal GTD, to alterations in the placentation process or to the many shared risk factors. Discrepant results of epidemiologic studies can be explained, at least in part, by the changes in diagnostic criteria and screening strategies throughout the years for both conditions. GDM and GTD impact pregnancy outcome and have post-partum long-term consequences, but more studies are needed to prove an additional adverse effect. CONCLUSIONS: Based on the epidemiological and physio-pathological link between GDM and GTD, it could be suggested that a diagnosis of GTD could lead to screen GDM and the other way round.

A first-trimester serum TSH in the 4-10 mIU/L range is associated with obstetric complications in thyroid peroxidase antibody-negative women.

PURPOSE: The impact of mild subclinical hypothyroidism on pregnancy outcomes in TPOAb-negative women is poorly explored. The aim of the present study was the evaluation in a wide cohort of TPOAb-negative pregnant women the role of subclinical hypothyroidism (SCH) on several pregnancy outcomes. METHODS: The study included women aged ≥ 18 years with a singleton pregnancy without known thyroid disease with serum TSH concentration between 0.4 and 10 mIU/L and TPOAb negative. Data about clinical and demographic features were collected. A blood sample was drown to test TSH, TPOAb, ANA and ENA concentration. The mean uterine artery pulsatility index was measured. Risk of adverse obstetric and fetal outcomes was collected. RESULTS: The cohort included 2135 pregnant women. Pregnant women with TSH 4-10 mUI/L had a significantly higher frequency of family history of thyroid diseases, and personal history of celiac disease diseases, type 1 diabetes mellitus, rheumatic disease, antinuclear antibody (ANA) and anti-extractable nuclear antigen (ENA) positive tests. The risk for pre-eclampsia and small for gestational age (SGA) was significantly higher in pregnant women with first-trimester TSH 4-10 mIU/L. A first-trimester TSH serum level greater than 4 mIU/L was associated with a significant increase in the occurrence of abnormal uterine artery pulsatility index, with a more than threefold increase in the risk of developing pre-eclampsia and with the risk of SGA. CONCLUSIONS: In TPOAb-negative pregnant women, a first-trimester serum TSH level ranging from 4 to 10 mIU/L is significantly and independently linked to an increased uterine artery pulsatility index as well as to negative pregnancy outcomes such as pre-eclampsia, SGA and gestational diabetes.

Possible added value of thyroglobulin antibody (TgAb) testing in the evaluation of thyroidal status of subjects with overweight or obesity.

PURPOSE: An increase in serum TSH concentrations in the absence of thyroid disease, named isolated hyperthyrotropinemia, is frequently observed in subjects with obesity. It is directly associated with body mass index, and it is reversible following weight loss. Autoimmune hypothyroidism is frequently associated with obesity, it is usually progressive and needs replacement treatment with L-thyroxine. The aim of this study was to investigate the role of thyroglobulin antibodies (TgAb) to define the thyroidal status in subjects with overweight or obesity. METHODS: This is a retrospective study including 749 consecutive adult patients with overweight or obesity. Of those, 76 were excluded from the analysis due to hyperthyroidism, previous thyroidectomy or radioiodine therapy for hyperthyroidism, hemiagenesis or drug-induced hypothyroidism. Serum thyrotropin (TSH), free thyroxine (FT4), free 3,5,3'-triiodothyronine (FT3), TgAb and thyroperoxidase antibodies (TPOAb) were measured in all patients. RESULTS: Out of 673 patients, 408 did not have thyroid disease. Among patients with thyroid disease (n = 265), 130 had nodular disease with no humoral signs of thyroid autoimmunity and 135 (20%) had autoimmune thyroiditis, defined by the presence of TPOAb and/or TgAb. The prevalence of hyperthyrotropinemia, either directly measured or presumed based on L-thyroxine treatment at the time of data collection, was 63.9% in patients with both TgAb and TPOAb, 47.1% in those with isolated positivity of TPOAb, 42.8% in patients with isolated positivity of TgAb, and 14.5% in those with no detectable TgAb or TPOAb. CONCLUSIONS: Our results confirm a high prevalence of autoimmune thyroiditis (20%) in patients with obesity. TgAb may be associated with hypothyroidism in the absence of TPOAb. TgAb measurement may turn helpful to unravel a proportion of subjects that may have or may develop primary hypothyroidism requiring specific substitutive treatment.

Vitamin D and interferon-γ co-operate to increase the ACE-2 receptor expression in primary cultures of human thyroid cells.

BACKGROUND: A more severe course of COVID-19 was associated with low levels of Vitamin D (VitD). Moreover in vitro data showed that VitD up-regulates the mRNA of the Angiotensin Converting Enzyme 2 (ACE-2), the SARS-COV-2 receptor in different type of cells. ACE-2 is expressed in several type of tissues including thyroid cells, on which its mRNA was shown to be up-regulated by interferon-gamma (IFN-γ). The aim of the present study was to investigate if treatment with VitD alone or in combination with IFN-γ would increase ACE-2 both at mRNA and protein levels in primary cultures of human thyrocytes. MATERIALS AND METHODS: Primary thyroid cell cultures were treated with VitD and IFN-γ alone or in combination for 24 h. ACE-2 mRNA levels were measured by Real-time Polymerase Chain Reaction (RT-PCR). The presence of ACE-2 on thyroid cell membrane was assessed by immunocytochemistry basally and after the previous mentioned treatments. RESULTS: ACE-2 mRNA levels increased after treatment with VitD and IFN-γ alone. The combination treatment (VitD + IFN-γ) showed an additive increase of ACE-2-mRNA. Immunocytochemistry experiments showed ACE-2 protein on thyroid cells membrane. ACE-2 expression increased after treatment with VitD and IFN-γ alone and further increased by the combination treatment with VitD + IFN-γ. CONCLUSIONS: VitD would defend the body by SARS-COV2 both by regulating the host immune defense and by up-regulating of the expression of the ACE-2 receptor. The existence of a co-operation between VitD and IFN-γ demonstrated in other systems is supported also for ACE-2 up-regulation. These observations lead to an increased interest for the potential therapeutic benefits of VitD supplementation in COVID-19.

Thyroid and heart, a clinically relevant relationship.

BACKGROUND: Thyroid disorders, both overt and subclinical, are highly prevalent conditions in the general population. Although a clear relationship between overt thyroid dysfunctions and cardiovascular complications has long been established, data regarding subclinical thyroid dysfunction are by far more controversial. PURPOSE: The present review will be aimed at providing a summary of most recent evidence coming from meta-analyses regarding the complex relationship between thyroid dysfunction and cardiovascular disease. CONCLUSIONS: The review will summarize, in the first part, the physiopathological link between thyroid hormone imbalances and the cardiovascular system. In the second part the review will outline the evidence coming from meta-analyses regarding the cardiovascular risk related with both overt and subclinical thyroid dysfunctions. Particular attention will be put towards studies showing data stratified for patient's age, TSH levels and pre-existing cardiovascular disease. Finally, an overview regarding the effects of specific therapy for subclinical thyroid diseases in terms of amelioration of cardiovascular outcomes will be included.

Skeletal health in patients with differentiated thyroid carcinoma.

Osteoporosis and fractures are important comorbidities in patients with differentiated thyroid cancer (DTC), with potential negative impact on quality of life and survival. The main determinant of skeletal fragility in DTC is the thyrotropin (TSH)-suppressive therapy, which is commonly recommended to prevent disease's recurrence, especially in patients with structural incomplete response after thyroid surgery and radio-iodine therapy. TSH-suppressive therapy can stimulate bone resorption with consequent bone loss, deterioration of bone microstructure and high risk of fragility fractures. The skeletal effects of TSH-suppressive therapy may be amplified when thyroid cancer cells localize to the skeleton inducing alterations in bone remodelling, impairment of bone structure and further increase in risk of fractures. The management of skeletal fragility in DTC may be challenging, since prediction of fractures is a matter of uncertainty and data on effectiveness and safety of bone-active agents in this clinical setting are still scanty. This review deals with pathophysiological, clinical and therapeutic aspects of skeletal fragility of patients with DTC.

The new generation PFAS C6O4 does not produce adverse effects on thyroid cells in vitro.

PURPOSE: Per- and poly-fluoroalkyl-substances (PFASs) are synthetic compounds that raised concern due to their potential adverse effects on human health. Long-chain PFAS were banned by government rules in many states, and thus, new emerging PFAS were recently introduced as substitutes. Among these, Perfluoro{acetic acid, 2-[(5-methoxy-1,3-dioxolan-4-yl)oxy]}, ammonium salt (C6O4) was recently introduced to produce a range of food contact articles and literature data about this compound are scanty. The aim of this study was to evaluate the in vitro effects of exposure to C6O4, compared with PFOA and PFOS on thyroid cells. METHODS: FRTL5 rat-thyroid cell lines and normal human thyroid cells (NHT) were incubated with increasing concentrations of C6O4 for 24, 48, 72, and 144 h to assess cell viability by WST-1. Cell viability was confirmed by AnnexinV/PI staining. Long-chain PFAS (PFOA and PFOS) were used at same concentrations as positive controls. The proliferation of cells exposed to C6O4, PFOA, and PFOS was measured by staining with crystal violet and evaluation of optical density after incubation with SDS. Changes in ROS production by FRTL5 and NHT after exposure to C6O4 at short (10, 20, and 30 min) and long-time points (24 h) were evaluated by cytofluorimetry. RESULTS: C6O4 exposure did not modify FRTL5 and NHT cell viability at any concentration and/or time points with no induction of necrosis/apoptosis. At difference, PFOS exposure reduced cell viability of FRTL5 while and NHT, while PFOA only in FRTL5. FRTL5 and NHT cell proliferation was reduced by incubation with by PFOA and PFOS, but not with C6O4. ROS production by NHT and FRTL5 cells was not modified after C6O4 exposure, at any time/concentration tested. CONCLUSIONS: The present in vitro study constitutes the first evaluation of the potential adverse effects of the new emerging PFAS C6O4 in cultured rat and human thyroid cells, suggesting its safety for thyroid cells in vitro.

Detection of SARS-COV-2 receptor ACE-2 mRNA in thyroid cells: a clue for COVID-19-related subacute thyroiditis.

PURPOSE: SARS-COV-2 is a pathogenic agent belonging to the coronavirus family, responsible for the current global world pandemic. Angiotensin-converting enzyme 2 (ACE-2) is the receptor for cellular entry of SARS-CoV-2. ACE-2 is a type I transmembrane metallo-carboxypeptidase involved in the Renin-Angiotensin pathway. By analyzing two independent databases, ACE-2 was identified in several human tissues including the thyroid. Although some cases of COVID-19-related subacute thyroiditis were recently described, direct proof for the expression of the ACE-2 mRNA in thyroid cells is still lacking. Aim of the present study was to investigate by RT-PCR whether the mRNA encoding for ACE-2 is present in human thyroid cells. METHODS: RT-PCR was performed on in vitro ex vivo study on thyroid tissue samples (15 patients undergoing thyroidectomy for benign thyroid nodules) and primary thyroid cell cultures. RESULTS: The ACE-2 mRNA was detected in all surgical thyroid tissue samples (n = 15). Compared with two reporter genes (GAPDH: 0.052 ± 0.0026 Cycles-1; ß-actin: 0.044 ± 0.0025 Cycles-1; ACE-2: 0.035 ± 0.0024 Cycles-1), the mean level of transcript expression for ACE-2 mRNA was abundant. The expression of ACE-2 mRNA in follicular cells was confirmed by analyzing primary cultures of thyroid cells, which expressed the ACE-2 mRNA at levels similar to tissues. CONCLUSIONS: The results of the present study demonstrate that the mRNA encoding for the ACE-2 receptor is expressed in thyroid follicular cells, making them a potential target for SARS-COV-2 entry. Future clinical studies in patients with COVID-19 will be required for increase our understanding of the thyroid repercussions of SARS-CoV-2 infection.

Laser photocoagulation therapy for thyroid nodules: long-term outcome and predictors of efficacy.

PURPOSE: The aim of the present study was to retrospectively evaluate the efficacy of interstitial laser photocoagulation (ILP) ablation of thyroid nodules during a 6-year follow-up period and to identify possible predictors of the final outcome. METHODS: Forty-three outpatients (38 women) were assigned to ILP therapy. The study group included euthyroid patients with benign thyroid nodules. Thyroid size, nodule volume and features, and autoimmune test were collected at baseline. Patients underwent US control after the ILP procedure and 1 month, 6 months, 12 months later and then annually. RESULTS: During the follow-up, two distinct groups of patients emerged: the responders (N = 33) and the non-responder (N = 10) ones to ILP. In the responder group, the nodule volume significantly decreased during the follow-up, but a trend toward a slight increase in nodule volume was recorded up to the end of follow-up. No significant decrease in nodule volume was observed in the non-responder group. Neither baseline clinical nor demographic features were significantly different between responders and non-responders groups. In the whole group of patients, the energy delivered per mL of nodule tissue was significantly correlated with the percent volume decrease at the end of follow-up. CONCLUSIONS: Interstitial laser photocoagulation is a safe technique able to reduce byabout 50% the volume of benign thyroid nodules in the majority of treated patients. However, due to the great variability of results, an active follow-up is required. The only independent predictor of ILP outcome is the energy delivered per mL of nodule tissue.

The clinical phenotype of Graves' disease occurring as an isolated condition or in association with other autoimmune diseases.

PURPOSE: Graves' disease (GD) can present as an isolated disease (iGD) or in association with other autoimmune diseases (aGD). The aim of this study, performed in two Endocrine referral centers settled in different geographical areas of Italy, was to compare the anthropometric, clinical, and biochemical phenotype of iGD patients with that of the aGD ones. METHODS: Clinical history, physical examination data, serum levels of TSH, FT4, FT3, thyroglobulin (TgAb), thyroid-peroxidase (TPOAb) and TSH-receptor (TRAb) antibody, presence of Graves' orbitopathy (GO), and thyroid ultrasound examination at disease diagnosis were recorded. RESULTS: 68 aGD and 136 iGD patients were consecutively recruited. At diagnosis, aGD and iGD patients did not differ for F/M ratio, age at presentation, thyroid function parameters, serum levels of TRAb, TgAb, TPOAb, presence of GO, and thyroid volume. The serum levels of TRAb were strongly correlated with the circulating concentrations of both FT3 (ρ = 0.667; p < 0.0001) and FT4 (ρ = 0.628; p < 0.001) in iGD patient, but not in the aGD ones (FT3: ρ = 0.231; p = 0.058; FT4: ρ = 0.096; p = 0.435). Compared with iGD patients, the aGD ones displayed a higher rate of transition from the previous hypothyroidism to hyperthyroidism (χ2 = 6.375; p = 0.012). CONCLUSION: Despite similar anthropometric, clinical, and biochemical features at diagnosis, aGD patients display a higher rate of transition from a thyroid functional status to the other as compared with iGD patients.

Compared with classic Hashimoto's thyroiditis, chronic autoimmune serum-negative thyroiditis requires a lower substitution dose of L-thyroxine to correct hypothyroidism.

PURPOSE: Serum-negative-chronic-autoimmune-thyroiditis (SN-CAT) is considered a milder variant of classic Hashimoto's thyroiditis (CHT). However, its prevalence remains unknown and it is still unclear whether SN-CAT behaves differently in terms of L-thyroxine (LT4) substitution treatment of hypothyroidism. Aims of this study were to estimate the prevalence of SN-CAT in a large series of hypothyroid patients and to compare LT4 requirements in hypothyroid patients with SN-CAT and CHT. METHODS: Five-hundred-eighty-one consecutive patients with primary-autoimmune-hypothyroidism were enrolled in a cross-sectional study. LT4 requirements and thyroid-volume changes were longitudinally evaluated in 49 hypothyroid patients with SN-CAT and in 98 sex and age-matched hypothyroid patients with CHT. RESULTS: In our series the prevalence of SN-CAT was 20.8%. At diagnosis, patients in the CHT and SN-CAT groups had similar male/female ratio, age and BMI, while serum TSH and thyroid-volume were significantly greater in the CHT group. In the longitudinal study, during a follow-up of 8.9 ± 4.6 years, 8 out of 49 (16.3%) SN-CAT patients developed positive tests for of circulating TPO-Ab and/or Tg-Ab. Thyroid-volume significantly decreased in CHT patients, but not in those with SN-CAT. The maximum daily substitution dose of LT4 was smaller in SN-CAT patients as compared with the CHT ones. Multivariate analysis showed that age, BMI, basal TSH and thyroid antibody status independently and significantly predicted the maximum daily substitution dose of LT4. CONCLUSIONS: SN-CAT accounts for a significant proportion of patients with autoimmune hypothyroidism. Compared with hypothyroid patients diagnosed with CHT, the SN-CAT ones require smaller doses of LT4 to correct their hypothyroidism.

Features and outcome of differentiated thyroid carcinoma associated with Graves' disease: results of a large, retrospective, multicenter study.

BACKGROUND: Whether differentiated thyroid cancer (DTC) occurring concomitantly with Graves' disease (GD) is more aggressive and bound to a less favorable outcome is controversial. OBJECTIVE: Aim of this multicenter retrospective study was to compare baseline features and outcome of DTC patients with GD (DTC/GD+) or without GD (DTC/GD-). PATIENTS: Enrolled in this study were 579 patients referred to five endocrine units (Cagliari, Pavia, Pisa, Siena, and Varese) between 2005 and 2014: 193 patients had DTC/GD+ , 386 DTC/GD-. Patients were matched for age, gender and tumor size. They underwent surgery because of malignancy, large goiter size, or relapse of hyperthyroidism in GD. RESULTS: Baseline DTC features (histology, lymph node metastases, extrathyroidal extension) did not differ in the two groups, except for multifocality which was significantly more frequent in DTC/GD+ (27.5% vs. 7.5%, p < 0.0001). At the end of follow-up (median 7.5 years), 86% of DTC/GD+ and 89.6% DTC/GD- patients were free of disease. Patients with persistent or recurrent disease (PRD) had "biochemical disease" in the majority of cases. Microcarcinomas were more frequent in the DTC/GD+ group (60% vs. 37%, p < 0.0001) and had an excellent outcome, with no difference in PRD between groups. However, in carcinomas ≥ 1 cm, PRD was significantly more common in DTC/GD+ (24.4% vs. 11.5%; p = 0.005). In the whole group, univariate and multivariate analyses showed that GD+ , lymph node involvement, extrathyroidal invasion, multifocality and tall cell histotype were associated with a worse outcome. Female gender and microcarcinomas were favorable features. No association was found between baseline TSH-receptor antibody levels and outcome. Graves' orbitopathy (GO) seemed to be associated with a better outcome of DTC, possibly because patients with GO may early undergo surgery for hyperthyroidism. CONCLUSIONS: GD may be associated with a worse outcome of coexisting DTC only if cancer is ≥ 1 cm, whereas clinical outcome of microcarcinomas is not related to the presence/absence of GD.

Effect of long- and short-chain perfluorinated compounds on cultured thyroid cells viability and response to TSH.

PURPOSE: Perfluorinated chemicals are widespread pollutants persistent in the environment with links to some major health issues. The two main compounds, perfluoro-octanoic acid (PFOA) and perfluoro-alkyl sulphonate (PFOS), were recently classified as carcinogenetic and thus their use has been restricted. Short-chain PFCs were recently developed as an alternative, but no data regarding the possible endocrine toxicities of these compounds are available. Aim of this study was to investigate whether short-chain PFCs could jeopardize thyroid cell viability and/or interfere with the functional effect TSH. METHODS: Fisher rat thyroid line-5 (FRTL-5) was treated with increasing concentrations of PFOA, PFOS, perfluorobutanesulfonic acid (PFBS), perfluorobutanoic acid (PFBA), pentafluoropropionic anhydride (PFPA), perfluoropentanoic acid (PFPeA) to evaluate modifications in cell viability and TSH-stimulated cAMP production. RESULTS: Neither long nor short-chain PFCs affected cell viability (apart from PFOS 100 µM), or interfered with cAMP production. CONCLUSIONS: The results of the present study demonstrate for the first time that short-chain PFCs have no acute cytotoxic effect on thyroid cells in vitro and that cAMP production is not modulated by any of the tested PFCs.

The AMPK-activator AICAR in thyroid cancer: effects on CXCL8 secretion and on CXCL8-induced neoplastic cell migration.

PURPOSE: The AMPK-activator AICAR recently raised great interest for its anti-cancer properties. With specific regard to thyroid cancer, AICAR reduces cancer cell growth, invasion and metastasis. CXCL8, a chemokine with several recognized tumorigenic effects, is abundantly secreted in thyroid cancer microenvironment. The aim of this study was to investigate if AICAR could inhibit the basal and the TNFα-induced CXCL8 secretion in normal human thyroid cells (NHT) and in thyroid cancer cell lines TPC-1 and BCPAP (RET/PTC and BRAFV600e mutated, respectively). METHODS: The effect of AICAR on basal and CXCL8-induced cell migration was assessed. Cells were incubated with AICAR (0.05, 0.5, 1, 2 mM) alone or in combination with TNF-α (10 ng/ml) for 24 h. CXCL8 concentrations were measured in cell supernatants. Transwell migration assays were performed in NHT, TPC-1 and BCPAP, basally and after treatment with AICAR (2 mM) and rh-CXCL8 (50 ng/ml) alone or in combination. RESULTS: AICAR dose dependently inhibited the basal secretion of CXCL8 in TPC-1 (F = 4.26; p < 0.007) and BCPAP (F = 6.75; p < 0.0001) but not in NHT. TNFα-induced CXCL8 secretion was dose dependently reduced by AICAR in NHT (F = 9.99; p < 0.0001), TPC-1 (F = 9.25; p < 0.0001) and BCPAP (F = 6.82; p < 0.0001). AICAR significantly reduced the basal migration of TPC-1 and BCPAP but not of NHT. CONCLUSIONS: CXCL8-induced cell migration was inhibited in NHT, TPC-1 and BCPAP. This is the first demonstration of the inhibition of CXCL8 secretion exerted by AICAR in TPC-1 and BCPAP indicating that the anti-cancer properties of AICAR are, at least in part, mediated by its ability to reduce the pro-tumorigenic effects of CXCL8.

Painful Hashimoto's thyroiditis: myth or reality?

Neck pain is a common complain, being in most cases due to non-thyroidal causes. However, a minority of patients suffer from painful thyroid diseases. Among them, sub-acute thyroiditis (SAT) is the most frequent one. Rare thyroid-related causes of neck pain include hemorrhage within a thyroid nodule as well as Riedel's thyroiditis and suppurative thyroiditis. In the last 30 years, a few cases of a painful variant of Hashimoto's thyroiditis (HT) have been described. Biochemical, ultrasound, and histologic features were clearly suggestive for HT in all of the published cases and definitely ruled out the diagnosis of SAT. While sound descriptions of painful HT are present in the literature, it is important to emphasize that only 20 cases were reported from the year 2000 until now. The condition, however, is clinically relevant because neck pain was reported to be refractory both to steroids and to other analgesic drugs, being thyroidectomy the only effective treatment for pain relief in these patients. This short review analyzes currently available data supporting a role for HT as a rare cause of neck pain.

Thyroid disruption by perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA).

BACKGROUND: Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are two fluorinated compounds widely used in industry because of their useful chemical characteristics. They were identified as endocrine disruptors due to their ability to interfere with thyroid function. The resistance of PFOA and PFOS to environmental degradation, their bio-accumulation in food chains, and their long half-life raised concern in the scientific community, and several studies were performed with the aim to establish the real dangerousness of these compounds for the human health. PURPOSE: The present review will focus on the effects of PFOA and PFOS on the thyroid gland taking into account in vitro experiments, animal studies, and human data. PFOS and PFOA reduce the circulating levels of thyroid hormones in diet-exposed animals, mainly by increasing their metabolic clearance rate. CONCLUSIONS: An accumulation of PFOS and PFOA was documented in thyroid cells, and a cytotoxic effect was observed after exposure to extremely high concentrations of these compounds. In environmentally exposed communities and in the general population, the most consistent effect of exposure to PFOA, and to a less extent to PFOS, is the occurrence of hypothyroidism. Women and children appear to be more at risk of developing mild thyroid failure. Pregnant women with circulating thyroid antibodies might be at risk of developing subclinical hypothyroidism, mainly when exposed at high doses of PFOS. The relative risks for thyroid cancer in people exposed to PFOA and PFOS were low and based on a few cases. Moreover, there was no consistent finding across all or even most studies.

Influence of short-term selenium supplementation on the natural course of Hashimoto's thyroiditis: clinical results of a blinded placebo-controlled randomized prospective trial.

BACKGROUND: The real efficacy of selenium supplementation in Hashimoto's thyroiditis (HT) is still an unresolved issue. OBJECTIVES: We studied the short-term effect of L-selenomethionine on the thyroid function in euthyroid patients with HT. Our primary outcome measures were TSH, thyroid hormones, thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb) levels and thyroid echogenicity after 6 months of L-selenomethionine treatment. The secondary outcome measure was serum CXCL10 levels. METHODS: In a placebo-controlled randomized prospective study, we have enrolled untreated euthyroid patients with HT. Seventy-six patients were randomly assigned to receive L-selenomethionine 166 µg/die (SE n = 38) or placebo (controls n = 38) for 6 months. TSH, free T4 (FT4), free T3 (FT3), TPOAb and CXCL10 serum levels were assayed at time 0, after 3 and 6 months. An ultrasound examination of the left and right thyroid lobe in transverse and longitudinal sections was performed. A rectangular region, the region of interest, was selected for analysis. RESULTS: TSH, FT4, FT3, TPOAb, thyroid echogenicity and CXCL10 were not statistically different between SE and control groups at time 0, after 3 and 6 months. In the SE group, FT4 levels were significantly decreased (P < 0.03) after 3 months, while FT3 increased (P < 0.04) after 3 and 6 months versus baseline values. In the control group, the FT3 decreased after 3 and 6 months (P < 0.02) compared to baseline. CONCLUSION: The short-term L-selenomethionine supplementation has a limited impact on the natural course in euthyroid HT. Our results tip the balance toward the ineffectiveness of short-term L-selenomethionine supplementation in HT.