Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 373
Filter
1.
J Clin Res Pediatr Endocrinol ; 16(1): 116-122, 2024 03 11.
Article in English | MEDLINE | ID: mdl-38054413

ABSTRACT

Monocarboxylate transporter 8 (MCT8) deficiency is a rare genetic disorder characterized by peripheral thyrotoxicosis and severe cognitive and motor disability due to cerebral hypothyroidism. 3,3',5-triiodothyroacetic acid (Triac) was shown to improve peripheral thyrotoxicosis but data on neurodevelopmental outcome are scarce. We present a case of MCT8 deficiency and the experience with Triac focusing on change in neurodevelopmental and peripheral features. A five-month-old boy was referred because of feeding difficulty, central hypotonia and global developmental delay. Despite six months of physiotherapy, physical developmental milestones did not improve, and distal muscle tone was increased. A hemizygous pathogenic variant in SLC16A2 was found and MCT8 deficiency was confirmed at 19-months. Thyroid stimulating hormone was 2.83 mIU/mL, free thyroxine 6.24 pmol/L (N=12-22) and free triiodothyronine (FT3) 15.65pmol/L (N=3.1-6.8). He had tachycardia, blood pressure and transaminases were elevated. Triac was started at 21-months. Two weeks after treatment, FT3 dramatically decreased, steady normal serum FT3 was achieved at 28-months. Assessment of neurodevelopmental milestones and signs of hyperthyroidism were evaluated at baseline, 6 months and 12 months after treatment. Signs of hyperthyroidism were improved by 6 months. Developmental composite scores of Bayley Scales of Infant Developmental 3rd Edition remained the same but important developmental milestones (head control, recognition of caregiver, response to his name) were attained, regression in the attained milestones were not observed. Initial dose, management protocol for Triac and research into its efficacy on neurodevelopmental signs in MCT8 deficiency are progressing. This case presents evidence that Triac may resolve peripheral thyrotoxicosis successfully and may slow neurodevelopmental regression, while some developmental milestones were achieved after one year of treatment.


Subject(s)
Disabled Persons , Hyperthyroidism , Mental Retardation, X-Linked , Motor Disorders , Symporters , Thyrotoxicosis , Triiodothyronine/analogs & derivatives , Male , Infant , Humans , Muscle Hypotonia/diagnosis , Muscle Hypotonia/drug therapy , Muscle Hypotonia/genetics , Mental Retardation, X-Linked/diagnosis , Muscular Atrophy/diagnosis , Muscular Atrophy/drug therapy , Muscular Atrophy/genetics , Monocarboxylic Acid Transporters/genetics , Monocarboxylic Acid Transporters/therapeutic use , Symporters/genetics , Symporters/therapeutic use
2.
J Clin Endocrinol Metab ; 107(3): e1136-e1147, 2022 02 17.
Article in English | MEDLINE | ID: mdl-34679181

ABSTRACT

CONTEXT: Patients with mutations in thyroid hormone transporter MCT8 have developmental delay and chronic thyrotoxicosis associated with being underweight and having cardiovascular dysfunction. OBJECTIVE: Our previous trial showed improvement of key clinical and biochemical features during 1-year treatment with the T3 analogue Triac, but long-term follow-up data are needed. METHODS: In this real-life retrospective cohort study, we investigated the efficacy of Triac in MCT8-deficient patients in 33 sites. The primary endpoint was change in serum T3 concentrations from baseline to last available measurement. Secondary endpoints were changes in other thyroid parameters, anthropometric parameters, heart rate, and biochemical markers of thyroid hormone action. RESULTS: From October 15, 2014 to January 1, 2021, 67 patients (median baseline age 4.6 years; range, 0.5-66) were treated up to 6 years (median 2.2 years; range, 0.2-6.2). Mean T3 concentrations decreased from 4.58 (SD 1.11) to 1.66 (0.69) nmol/L (mean decrease 2.92 nmol/L; 95% CI, 2.61-3.23; P < 0.0001; target 1.4-2.5 nmol/L). Body-weight-for-age exceeded that of untreated historical controls (mean difference 0.72 SD; 95% CI, 0.36-1.09; P = 0.0002). Heart-rate-for-age decreased (mean difference 0.64 SD; 95% CI, 0.29-0.98; P = 0.0005). SHBG concentrations decreased from 245 (99) to 209 (92) nmol/L (mean decrease 36 nmol/L; 95% CI, 16-57; P = 0.0008). Mean creatinine concentrations increased from 32 (11) to 39 (13) µmol/L (mean increase 7 µmol/L; 95% CI, 6-9; P < 0.0001). Mean creatine kinase concentrations did not significantly change. No drug-related severe adverse events were reported. CONCLUSIONS: Key features were sustainably alleviated in patients with MCT8 deficiency across all ages, highlighting the real-life potential of Triac for MCT8 deficiency.


Subject(s)
Mental Retardation, X-Linked/drug therapy , Monocarboxylic Acid Transporters/deficiency , Muscle Hypotonia/drug therapy , Muscular Atrophy/drug therapy , Symporters/deficiency , Triiodothyronine/analogs & derivatives , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Infant , Male , Mental Retardation, X-Linked/blood , Mental Retardation, X-Linked/genetics , Middle Aged , Monocarboxylic Acid Transporters/genetics , Muscle Hypotonia/blood , Muscle Hypotonia/genetics , Muscular Atrophy/blood , Muscular Atrophy/genetics , Mutation , Retrospective Studies , Symporters/genetics , Treatment Outcome , Triiodothyronine/administration & dosage , Triiodothyronine/adverse effects , Triiodothyronine/blood , Young Adult
3.
Am J Clin Pathol ; 157(2): 156-158, 2022 02 03.
Article in English | MEDLINE | ID: mdl-34542585

ABSTRACT

OBJECTIVES: Thyroid hormone analog 3,5,3'-triiodothyroacetic acid (TRIAC) is effective in reducing the hypermetabolism in monocarboxylate transporter 8 (MCT8)-deficient individuals. Because of the structural similarity between TRIAC and 3,3',5'-triiodothyronine (T3), we sought to investigate the degree of cross-reactivity of TRIAC with various commercially available total and free T3 assays. METHODS: Varying concentrations (50-1,000 ng/dL) of TRIAC (Sigma Aldrich) were added to pooled serum and assayed for total T3 (TT3) and free T3 (FT3) on the following platforms: e602 (Roche Diagnostics), Architect (Abbott Diagnostics), Centaur (Siemens Healthcare Diagnostics), IMMULITE (Siemens Healthcare Diagnostics), DxI (Beckman Coulter), and Vitros (Ortho Clinical Diagnostics). TT3 competition assay with TRIAC was performed by adding increasing amounts of T3 to pooled serum samples that contained a constant concentration of TRIAC (250 ng/dL). RESULTS: Significant overestimation of TT3 and FT3 assays were observed across all platforms corresponding to increasing concentrations of TRIAC. The TRIAC effect at 250 ng/dL showed a constant interference of approximately 190 ng/dL TT3. CONCLUSIONS: All commercial TT3 and FT3 assays tested in this work cross-react significantly with TRIAC. Therefore, patients undergoing TRIAC therapy should have T3 hormone response monitored using alternative nonimmunoassay-based methods to avoid misinterpretation of thyroid function profiles.


Subject(s)
Thyroid Function Tests , Triiodothyronine , Humans , Immunoassay , Thyroid Gland , Triiodothyronine/analogs & derivatives
4.
Thyroid ; 32(2): 119-127, 2022 02.
Article in English | MEDLINE | ID: mdl-34806412

ABSTRACT

Background: In contrast to the thyroid hormones (TH) 3,3',5-triiodothyronine (T3) and thyroxine (T4), current literature on thyroid hormone metabolite concentrations in the hypothyroid and hyperthyroid states is inconclusive. It is unknown how thyroidectomy affects thyroid hormone metabolite concentrations and if levothyroxine (LT4) replacement therapy after thyroidectomy restores thyroid hormone metabolite concentrations in those without a thyroid gland. The treatment of patients with differentiated thyroid cancer (DTC) covers the euthyroid, hypothyroid, and (subclinical) hyperthyroid states and therefore provides a unique model to answer this. Here, we prospectively studied nine TH and its metabolites (THM) across different thyroid states in a cohort of patients treated for DTC. Also, three potentially important determinants for THM concentrations were studied. Methods: We prospectively included patients aged 18 to 80 years who were scheduled for DTC treatment at the Erasmus MC. Peripheral blood samples were obtained before surgery (euthyroid, endogenous TH production), after surgery just before radioactive iodine therapy (hypothyroid), and six months later on LT4 therapy ([subclinically] hyperthyroid, exogenous T4 supplementation). Nine THMs were quantified in serum with an established liquid chromatography/tandem mass spectrometry method. Repeated measurement analysis was used to compare the three different thyroid states with each other for each THM, while linear regression was used to determine the association between THM concentrations and age, sex, and kidney function. Results: In total, 77 patients (mean age 49 years; 65% women) were eligible for the study. 3,5-diiodothyronine and 3,3',5-triiodothyroacetic acids were below the lower limit of detection. Compared with the euthyroid state, all THMs were significantly decreased in the hypothyroid state and significantly increased in the (subclinically) hyperthyroid state, with T3 concentrations remaining within the reference interval. Higher age was associated with higher 3-monoiodothyronine (3-T1) concentrations (p < 0.001). Women had higher L-thyronine concentrations than men (p = 0.003). A better kidney function was associated with lower 3-T1 concentrations (p < 0.001). Conclusions: All THMs decrease after a thyroidectomy and increase under thyrotropin (TSH)-suppressive LT4-therapy, suggesting that formation of thyroid hormone metabolites is dependent on peripheral extrathyroidal metabolism of T4. This is also reflected by T3 concentrations that remained within the reference interval in patients receiving TSH-suppressive LT4-therapy as T3 has some thyroidal origin.


Subject(s)
Thyroid Gland/metabolism , Thyroxine/blood , Triiodothyronine/analogs & derivatives , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Hyperthyroidism/metabolism , Hypothyroidism/metabolism , Male , Middle Aged , Prospective Studies , Thyroid Neoplasms/metabolism , Triiodothyronine/blood , Young Adult
5.
J Hematol Oncol ; 14(1): 99, 2021 06 26.
Article in English | MEDLINE | ID: mdl-34174920

ABSTRACT

The human ζ-globin gene (HBZ) is transcribed in primitive erythroid cells only during the embryonic stages of development. Reactivation of this embryonic globin synthesis would likely alleviate symptoms both in α-thalassemia and sickle-cell disease. However, the molecular mechanisms controlling ζ-globin expression have remained largely undefined. Moreover, the pharmacologic agent capable of inducing ζ-globin production is currently unavailable. Here, we show that TRIAC, a bioactive thyroid hormone metabolite, significantly induced ζ-globin gene expression during zebrafish embryogenesis. The induction of ζ-globin expression by TRIAC was also observed in human K562 erythroleukemia cell line and primary erythroid cells. Thyroid hormone receptor α (THRA) deficiency abolished the ζ-globin-inducing effect of TRIAC. Furthermore, THRA could directly bind to the distal enhancer regulatory element to regulate ζ-globin expression. Our study provides the first evidence that TRIAC acts as a potent inducer of ζ-globin expression, which might serve as a new potential therapeutic option for patients with severe α-thalassemia or sickle-cell disease.


Subject(s)
Gene Expression/drug effects , Thyroid Hormone Receptors alpha/genetics , Triiodothyronine/analogs & derivatives , Up-Regulation/drug effects , zeta-Globins/genetics , Animals , Gene Expression Regulation, Developmental/drug effects , Humans , K562 Cells , Thyroid Hormone Receptors alpha/deficiency , Triiodothyronine/pharmacology , Zebrafish/embryology , Zebrafish/genetics , Zebrafish Proteins/genetics
6.
Ann Endocrinol (Paris) ; 82(3-4): 170-172, 2021 Jun.
Article in English | MEDLINE | ID: mdl-32197712

ABSTRACT

Cellular thyroid hormone homeostasis requires adequate function of: (1) thyroid hormone transporter proteins at the plasma membrane, (2) deiodinating enzymes and (3) nuclear thyroid hormone receptors (TRs). Defects in any of these processes give rise to distinct disease entities, collectively called thyroid hormone signaling disorders. Thyroid hormone analogues hold therapeutic potential in thyroid hormone signaling disorders by bypassing defective transporters or binding to mutant TRs. This review will focus on the application of analogues in thyroid hormone signaling disorders, particularly monocarboxylate transporter (MCT)8 deficiency, and resistance to thyroid hormone due to mutations in TRß (RTHß).


Subject(s)
Thyroid Diseases/drug therapy , Triiodothyronine/analogs & derivatives , Animals , Humans , Monocarboxylic Acid Transporters/genetics , Mutation , Symporters/genetics , Thyroid Diseases/genetics , Thyroid Hormone Receptors beta/genetics , Thyroid Hormone Resistance Syndrome/drug therapy , Thyroid Hormone Resistance Syndrome/genetics , Thyroid Hormones/chemistry , Thyroid Hormones/pharmacology , Thyroid Hormones/therapeutic use , Triiodothyronine/therapeutic use
7.
Exp Clin Endocrinol Diabetes ; 128(6-07): 401-413, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32450582

ABSTRACT

Thyroid hormone metabolites (THM) with few or no iodine substituents such as 3,5-T2, the thyronamines 3-T1AM and T0AM, and their oxidation products, the thyroacetic acids (TA) formed by monoamine oxidases, have recently attracted major interest due to their metabolic actions which are in part distinct from those of the classical thyromimetic hormone T3, the major ligand of T3 receptors. This review compiles and discusses in vitro effects of 3,5-T2, TAM and TA reported for thyrocytes, pancreatic islets and hepatocytes as well as findings from in vivo studies in mouse models after single or repeated administration of pharmacological doses of these agents. Comparison of the 3,5-T2 effects on the transcriptome with not yet published proteome data in livers of obese mice on high fat diet indicate a distinct anti-steatotic effect of this THM. Furthermore, uptake, metabolism, and cellular actions via various receptors such as trace amine-associated receptors (TAAR), alpha-adrenergic, GPCR and T3 receptors are discussed. Studies on postulated pathways of biosynthesis of 3-T1AM, its effects on the HPT-axis and thyroid gland as well as insulin secretion are reviewed. 3-T1AM also acts on hepatocytes and interferes with TRPM8-dependent signaling in human cell lines related to the eye compartment. Human studies are presented which address potential biosynthesis routes of 3,5-T2 and 3-T1AM from THM precursors, especially T3. The current state of diagnostic analytics of these minor THM in human blood is portrayed comparing and critically discussing the still divergent findings based on classical immunoassay and recently developed liquid-chromatography/mass- spectrometry methods, which allow quantification of the thyronome spectrum from one single small volume serum sample. The clinical perspectives of use and potential abuse of these biologically active THM is addressed.


Subject(s)
Diiodothyronines/metabolism , Hepatocytes/metabolism , Islets of Langerhans/metabolism , Thyroid Epithelial Cells/metabolism , Triiodothyronine/analogs & derivatives , Triiodothyronine/metabolism , Animals , Humans , Thyronines/metabolism
8.
Horm Mol Biol Clin Investig ; 41(1)2020 Mar 02.
Article in English | MEDLINE | ID: mdl-32114521

ABSTRACT

Background 3-Iodothyronamine (T1AM) is an endogenous messenger chemically related to thyroid hormone. Recent results indicate significant transcriptional effects of chronic T1AM administration involving the protein family of sirtuins, which regulate important metabolic pathways and tumor progression. Therefore, the aim of this work was to compare the effect of exogenous T1AM and 3,5,3'-triiodo-L-thyronine (T3) chronic treatment on mammalian sirtuin expression in hepatocellular carcinoma cells (HepG2) and in primary rat hepatocytes at micromolar concentrations. Materials and methods Sirtuin (SIRT) activity and expression were determined using a colorimetric assay and Western blot analysis, respectively, in cells treated for 24 h with 1-20 µM T1AM or T3. In addition, cell viability was evaluated by the MTTtest upon 24 h of treatment with 0.1-20 µM T1AM or T3. Results In HepG2, T1AM significantly reduced SIRT 1 (20 µM) and SIRT4 (10-20 µM) protein expression, while T3 strongly decreased the expression of SIRT1 (20 µM) and SIRT2 (any tested concentration). In primary rat hepatocytes, T3 decreased SIRT2 expression and cellular nicotinamide adenine dinucleotide (NAD) concentration, while on sirtuin activity it showed opposite effects, depending on the evaluated cell fraction. The extent of MTT staining was moderately but significantly reduced by T1AM, particularly in HepG2 cells, whereas T3 reduced cell viability only in the tumor cell line. Conclusions T1AM and T3 downregulated the expression of sirtuins, mainly SIRT1, in hepatocytes, albeit in different ways. Differences in mechanisms are only observational, and further investigations are required to highlight the potential role of T1AM and T3 in modulating sirtuin expression and, therefore, in regulating cell cycle or tumorigenesis.


Subject(s)
Sirtuin 1/metabolism , Thyronines/pharmacology , Triiodothyronine/analogs & derivatives , Animals , Cell Survival/drug effects , Cells, Cultured , Down-Regulation/drug effects , Hep G2 Cells , Humans , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Rats , Rats, Wistar , Sirtuin 1/genetics , Sirtuins/genetics , Sirtuins/metabolism , Triiodothyronine/pharmacology
9.
Thyroid ; 30(8): 1099-1105, 2020 08.
Article in English | MEDLINE | ID: mdl-32098589

ABSTRACT

The development of thyroid hormone (TH) analogues was prompted by the attempt to exploit the effects of TH on lipid metabolism, avoiding cardiac thyrotoxicosis. Analysis of the relative distribution of the α and ß subtypes of nuclear TH receptors (TRα and TRß) showed that TRα and TRß are responsible for cardiac and metabolic responses, respectively. Therefore, analogues with TRß selectivity were developed, and four different compounds have been used in clinical trials: GC-1 (sobetirome), KB-2115 (eprotirome), MB07344/VK2809, and MGL-3196 (resmetirom). Each of these compounds was able to reduce low-density lipoprotein cholesterol, but a phase 3 trial with eprotirome was interrupted because of a significant increase in liver enzymes and the contemporary report of cartilage side effects in animals. As a consequence, the other projects were terminated as well. However, in recent years, TRß agonists have raised new interest for the treatment of nonalcoholic fatty liver disease (NAFLD). After obtaining excellent results in experimental models, clinical trials have been started with MGL-3196 and VK2809, and the initial reports are encouraging. Sobetirome turned out to be effective also in experimental models of demyelinating disease. Aside TRß agonists, TH analogues include some TH metabolites that are biologically active on their own, and their synthetic analogues. 3,5,3'-triiodothyroacetic acid has already found clinical use in the treatment of some cases of TH resistance due to TRß mutations, and interesting results have recently been reported in patients with the Allan-Herndon-Dudley syndrome, a rare disease caused by mutations in the TH transporter MCT8. 3,5-diiodothyronine (T2) has been used with success in rat models of dyslipidemia and NAFLD, but the outcome of a clinical trial with a synthetic T2 analogue was disappointing. 3-iodothyronamine (T1AM) is the last entry in the group of active TH metabolites. Promising results have been obtained in animal models of neurological injury induced by ß-amyloid or by convulsive agents, but no clinical data are available so far.


Subject(s)
Thyroid Hormones/metabolism , Acetates/pharmacology , Anilides/pharmacology , Animals , Central Nervous System Diseases/blood , Clinical Trials as Topic , Diiodothyronines/blood , Drug Design , Dyslipidemias/blood , Humans , Liver Diseases/blood , Male , Mice , Mutation , Non-alcoholic Fatty Liver Disease/metabolism , Phenols/pharmacology , Pyridazines/pharmacology , Rats , Signal Transduction , Thyroid Hormone Receptors alpha/metabolism , Thyroid Hormone Receptors beta/metabolism , Thyroid Hormones/chemistry , Thyronines/blood , Triiodothyronine/analogs & derivatives , Triiodothyronine/pharmacology , Uracil/analogs & derivatives , Uracil/pharmacology
10.
J Surg Res ; 249: 91-98, 2020 05.
Article in English | MEDLINE | ID: mdl-31926401

ABSTRACT

BACKGROUND: Tibia fractures are common after trauma. Prior studies have shown that delays in treatment are associated with poor outcomes. A subpopulation of our patients are transported from Mexico, adding barriers to prompt care. We hypothesized that patients with tibia fractures crossing from Mexico would have delays in treatment and subsequently worse outcomes. METHODS: The trauma registry of an American College of Surgeons-verified level 1 trauma center was retrospectively reviewed for all tibia fractures admitted from 2010 to 2015. Data collection included demographics, country of injury, characterization of injuries, interventions, complications, and outcomes. Patients were subdivided into those injured in the United States and in Mexico, and the two groups were compared. RESULTS: A total of 498 patients were identified, 440 from the United States and 58 from Mexico. Mexico patients were more severely injured overall, with higher injury severity scores and a higher percentage of patients with abbreviated injury scale scores ≥3 for both head and chest regions. Mexico patients had longer times from injury to admission, as well as increased times to both debridement of open fractures and operative fixation after admission. On subgroup analysis of patients with isolated tibia fractures (other system abbreviated injury scale < 3), times from arrival to treatment and injury severity score were no longer statistically different. CONCLUSIONS: Patients crossing the border from Mexico with tibia fractures have delays in time to admission and from admission to operative management, although this is primarily due to other severe injuries. Ongoing systems development is required to minimize delays in care and optimize outcomes.


Subject(s)
Fractures, Open/surgery , Tibial Fractures/surgery , Time-to-Treatment/statistics & numerical data , Transportation of Patients/statistics & numerical data , Adult , Debridement/statistics & numerical data , Female , Fracture Fixation/statistics & numerical data , Fractures, Open/diagnosis , Humans , Injury Severity Score , Male , Mexico , Middle Aged , Patient Admission/statistics & numerical data , Registries/statistics & numerical data , Retrospective Studies , Tibial Fractures/diagnosis , Trauma Centers/statistics & numerical data , Triiodothyronine/analogs & derivatives , United States , Young Adult
11.
PLoS One ; 14(12): e0226017, 2019.
Article in English | MEDLINE | ID: mdl-31809508

ABSTRACT

Patients lacking the thyroid hormone (TH) transporter MCT8 present abnormal serum levels of TH: low thyroxine and high triiodothyronine. They also have severe neurodevelopmental defects resulting from cerebral hypothyroidism, most likely due to impaired TH transport across the brain barriers. The use of TH analogs, such as triiodothyroacetic acid (TRIAC), that can potentially access the brain in the absence of MCT8 and restore at least a subset of cerebral TH actions could improve the neurological defects in these patients. We hypothesized that direct administration of TRIAC into the brain by intracerebroventricular delivery to mice lacking MCT8 could bypass the restriction at the brain barriers and mediate TH action without causing hypermetabolism. We found that intracerebroventricular administration of therapeutic doses of TRIAC does not increase further plasma triiodothyronine or further decrease plasma thyroxine levels and does not alter TH content in the cerebral cortex. Although TRIAC content increased in the brain, it did not induce TH-mediated actions on selected target genes. Our data suggest that intracerebroventricular delivery of TRIAC has the ability to target the brain in the absence of MCT8 and should be further investigated to address its potential therapeutic use in MCT8 deficiency.


Subject(s)
Cerebral Cortex/metabolism , Monocarboxylic Acid Transporters/genetics , Symporters/genetics , Thyroid Hormones/metabolism , Triiodothyronine/analogs & derivatives , Animals , Female , Infusions, Intraventricular , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Monocarboxylic Acid Transporters/deficiency , Symporters/deficiency , Thyroid Hormones/chemistry , Thyroxine/blood , Triiodothyronine/administration & dosage , Triiodothyronine/blood
13.
Lancet Diabetes Endocrinol ; 7(9): 695-706, 2019 09.
Article in English | MEDLINE | ID: mdl-31377265

ABSTRACT

BACKGROUND: Deficiency of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) causes severe intellectual and motor disability and high serum tri-iodothyronine (T3) concentrations (Allan-Herndon-Dudley syndrome). This chronic thyrotoxicosis leads to progressive deterioration in bodyweight, tachycardia, and muscle wasting, predisposing affected individuals to substantial morbidity and mortality. Treatment that safely alleviates peripheral thyrotoxicosis and reverses cerebral hypothyroidism is not yet available. We aimed to investigate the effects of treatment with the T3 analogue Triac (3,3',5-tri-iodothyroacetic acid, or tiratricol), in patients with MCT8 deficiency. METHODS: In this investigator-initiated, multicentre, open-label, single-arm, phase 2, pragmatic trial, we investigated the effectiveness and safety of oral Triac in male paediatric and adult patients with MCT8 deficiency in eight countries in Europe and one site in South Africa. Triac was administered in a predefined escalating dose schedule-after the initial dose of once-daily 350 µg Triac, the daily dose was increased progressively in 350 µg increments, with the goal of attaining serum total T3 concentrations within the target range of 1·4-2·5 nmol/L. We assessed changes in several clinical and biochemical signs of hyperthyroidism between baseline and 12 months of treatment. The prespecified primary endpoint was the change in serum T3 concentrations from baseline to month 12. The co-primary endpoints were changes in concentrations of serum thyroid-stimulating hormone (TSH), free and total thyroxine (T4), and total reverse T3 from baseline to month 12. These analyses were done in patients who received at least one dose of Triac and had at least one post-baseline evaluation of serum throid function. This trial is registered with ClinicalTrials.gov, number NCT02060474. FINDINGS: Between Oct 15, 2014, and June 1, 2017, we screened 50 patients, all of whom were eligible. Of these patients, four (8%) patients decided not to participate because of travel commitments. 46 (92%) patients were therefore enrolled in the trial to receive Triac (median age 7·1 years [range 0·8-66·8]). 45 (98%) participants received Triac and had at least one follow-up measurement of thyroid function and thus were included in the analyses of the primary endpoints. Of these 45 patients, five did not complete the trial (two patients withdrew [travel burden, severe pre-existing comorbidity], one was lost to follow-up, one developed of Graves disease, and one died of sepsis). Patients required a mean dose of 38.3 µg/kg of bodyweight (range 6·4-84·3) to attain T3 concentrations within the target range. Serum T3 concentration decreased from 4·97 nmol/L (SD 1·55) at baseline to 1·82 nmol/L (0·69) at month 12 (mean decrease 3·15 nmol/L, 95% CI 2·68-3·62; p<0·0001), while serum TSH concentrations decreased from 2·91 mU/L (SD 1·68) to 1·02 mU/L (1·14; mean decrease 1·89 mU/L, 1·39-2·39; p<0·0001) and serum free T4 concentrations decreased from 9·5 pmol/L (SD 2·5) to 3·4 (1·6; mean decrease 6·1 pmol/L (5·4-6·8; p<0·0001). Additionally, serum total T4 concentrations decreased by 31·6 nmol/L (28·0-35·2; p<0·0001) and reverse T3 by 0·08 nmol/L (0·05-0·10; p<0·0001). Seven treatment-related adverse events (transiently increased perspiration or irritability) occurred in six (13%) patients. 26 serious adverse events that were considered unrelated to treatment occurred in 18 (39%) patients (mostly hospital admissions because of infections). One patient died from pulmonary sepsis leading to multi-organ failure, which was unrelated to Triac treatment. INTERPRETATION: Key features of peripheral thyrotoxicosis were alleviated in paediatric and adult patients with MCT8 deficiency who were treated with Triac. Triac seems a reasonable treatment strategy to ameliorate the consequences of untreated peripheral thyrotoxicosis in patients with MCT8 deficiency. FUNDING: Dutch Scientific Organization, Sherman Foundation, NeMO Foundation, Wellcome Trust, UK National Institute for Health Research Cambridge Biomedical Centre, Toulouse University Hospital, and Una Vita Rara ONLUS.


Subject(s)
Membrane Transport Proteins/administration & dosage , Mental Retardation, X-Linked/drug therapy , Muscle Hypotonia/drug therapy , Muscular Atrophy/drug therapy , Triiodothyronine/analogs & derivatives , Adolescent , Child , Child, Preschool , Europe , Follow-Up Studies , Guidelines as Topic , Humans , Infant , Male , Membrane Transport Proteins/pharmacology , Mental Retardation, X-Linked/physiopathology , Muscle Hypotonia/physiopathology , Muscular Atrophy/physiopathology , Patient Safety , South Africa , Triiodothyronine/administration & dosage , Triiodothyronine/pharmacology , Young Adult
14.
Endocrine ; 66(1): 95-104, 2019 10.
Article in English | MEDLINE | ID: mdl-31327156

ABSTRACT

The field of thyroid hormone signaling has grown more complex in recent years. In particular, it has been suggested that some thyroid hormone derivatives, tentatively named "novel thyroid hormones" or "active thyroid hormone metabolites", may act as independent chemical messengers. They include 3,5-diiodothyronine (T2), 3-iodothyronamine (T1AM), and several iodothyroacetic acids, i.e., 3,5,3',5'-thyroacetic acid (TA4), 3,5,3'-thyroacetic acid (TA3), and 3-thyroacetic acid (TA1). We summarize the present knowledge on these compounds, namely their biosynthetic pathways, endogenous levels, molecular targets, and the functional effects elicited in experimental preparations or intact animals after exogenous administration. Their physiological and pathophysiological role is discussed, and potential therapeutic applications are outlined. The requirements needed to qualify these substances as chemical messengers must still be validated, although promising evidence has been collected. At present, the best candidate to the role of independent chemical messenger appears to be T1AM, and its most interesting effects concern metabolism and brain function. The responses elicited in experimental animals have suggested potential therapeutic applications. TA3 has an established role in thyroid hormone resistance syndromes, and is under investigation in Allen-Herndon-Dudley syndrome. Other potential targets are represented by obesity and dyslipidemia (for T2 and T1AM); dementia and degenerative brain disease (for T1AM and TA1); cancer (for T1AM and TA4). Another intriguing and unexplored question is the potential relevance of these metabolites in the clinical picture of hypothyroidism and in the response to replacement therapy.


Subject(s)
Diiodothyronines/metabolism , Thyronines/metabolism , Thyroxine/analogs & derivatives , Triiodothyronine/analogs & derivatives , Animals , Humans , Thyroxine/metabolism , Triiodothyronine/metabolism
15.
Mol Cell Endocrinol ; 493: 110448, 2019 08 01.
Article in English | MEDLINE | ID: mdl-31100496

ABSTRACT

Thyroid hormone receptors (TRs) are ligand-dependent transcription factors that activate or repress gene transcription, resulting in the regulation of numerous physiological programs. While 3,3',5-L-triiodothyronine is the TR cognate ligand, these receptors can also be activated by various alternative ligands, including endogenous and synthetic molecules capable of inducing diverse active receptor conformations that influence thyroid hormone-dependent signaling pathways. This review mainly discusses current knowledge on 3,5-diiodo-L-thyronine and 3,5,3'-triiodothyroacetic acid, two endogenous molecules that bind to TRs and regulate gene expression; and the molecular interactions between TRs and ligands, like synthetic thyromimetics developed to target specific TR isoforms for tissue-specific regulation of thyroid-related disorders, or endocrine disruptors that have allowed the design of new analogues and revealed essential amino acids for thyroid hormone binding.


Subject(s)
Diiodothyronines/metabolism , Receptors, Thyroid Hormone/metabolism , Thyronines/chemical synthesis , Triiodothyronine/analogs & derivatives , Animals , Biological Mimicry , Diiodothyronines/chemistry , Drug Design , Gene Expression Regulation , Humans , Ligands , Organ Specificity , Receptors, Thyroid Hormone/chemistry , Signal Transduction/drug effects , Thyronines/chemistry , Thyronines/pharmacology , Triiodothyronine/chemistry , Triiodothyronine/metabolism
16.
Anim Sci J ; 90(2): 264-270, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30556247

ABSTRACT

This study was designed to reveal the role of posttransportation grazing on the physiological condition and meat quality traits of Black Bengal goats. Twenty-four castrated male Black Bengal goats were divided into a control (untransported) group and three treated groups: Walking and Transportation with Human Interference group (WTHI) (30 min walking before 6 hr transport and then 30 min walking with human interference), posttransportation grazing for 48 hr (PTG1), and posttransportation grazing for 72 hr (PTG2). The WTHI and PTG1 groups had a significant reduction in their blood concentrations of tri-iodothyronine (T3 ) and thyroxine (T4 ), and a significantly higher neutrophil and lymphocyte (N:L) ratio compared with those of the control group. Blood concentrations of T3 and T4 and the N:L ratio of PTG2 returned to the control level after 72 hr of grazing. The final pH and water-holding capacity values of meat were significantly higher in the WTHI group than in the control group, but those in the PTG2 group returned to the control level after 72 hr of grazing. These results demonstrate that posttransportation grazing for 72 hr is effective for recovering from damage induced by transportation stress.


Subject(s)
Food Quality , Goats/metabolism , Goats/physiology , Herbivory/physiology , Meat , Stress, Physiological/physiology , Transportation , Animals , Body Water , Hydrogen-Ion Concentration , Lymphocytes , Male , Meat/analysis , Neutrophils , Thyroxine/blood , Time Factors , Triiodothyronine/analogs & derivatives , Triiodothyronine/blood , Walking
17.
Arch Pharm Res ; 41(10): 995-1008, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30099678

ABSTRACT

Drug repositioning is a strategy that explores new pharmaceutical applications of previously launched or failed drugs, and is advantageous since it saves capital and time. In this study, we examined the inhibition of TLR2 signaling by drug candidates. HEK-Blue™-hTLR2 cells were pretreated with drugs and stimulated using the TLR2 ligand, Pam3CSK4. Among the drugs that inhibited TLR2 signaling, we selected TRIAC, which is yet to be patented. Pretreatment with TRIAC decreased the TLR2 level and the phosphorylation of Akt and MAPKs in HEK-Blue™-hTLR2 cells. Since TLR2 is overexpressed in patients with acute hepatitis, we confirmed that TRIAC alleviates necrosis in a mouse model of Con A-induced acute hepatitis. The serum AST and ALT levels are indicators of liver damage, and are increased in Con A-induced hepatitis. Additionally, TLR2 and inflammatory cytokine levels are increased following administration of Con A and lead to liver damage. TRIAC decreased the serum levels of AST and ALT, and reduced liver tissue necrosis in mice with Con A-induced acute fulminant liver damage, by reducing the levels of inflammatory cytokines. In conclusion, TRIAC alleviates inflammation in mouse models of Con A-induced hepatitis by inhibiting the phosphorylation of Akt and MAPKs, the sub-mechanisms underlying TLR2 signaling.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Toll-Like Receptor 2/metabolism , Triiodothyronine/analogs & derivatives , Animals , Cells, Cultured , Humans , Inflammation/drug therapy , Male , Mice , Mice, Inbred BALB C , Signal Transduction/drug effects , Triiodothyronine/pharmacology
18.
Sci Rep ; 7(1): 15307, 2017 11 10.
Article in English | MEDLINE | ID: mdl-29127322

ABSTRACT

The sodium taurocholate co-transporting polypeptide (NTCP, SLC10A1) is the main hepatic transporter of conjugated bile acids, and the entry receptor for hepatitis B virus (HBV) and hepatitis delta virus (HDV). Myrcludex B, a synthetic peptide mimicking the NTCP-binding domain of HBV, effectively blocks HBV and HDV infection. In addition, Myrcludex B inhibits NTCP-mediated bile acid uptake, suggesting that also other NTCP inhibitors could potentially be a novel treatment of HBV/HDV infection. This study aims to identify clinically-applied compounds intervening with NTCP-mediated bile acid transport and HBV/HDV infection. 1280 FDA/EMA-approved drugs were screened to identify compounds that reduce uptake of taurocholic acid and lower Myrcludex B-binding in U2OS cells stably expressing human NTCP. HBV/HDV viral entry inhibition was studied in HepaRG cells. The four most potent inhibitors of human NTCP were rosiglitazone (IC50 5.1 µM), zafirlukast (IC50 6.5 µM), TRIAC (IC50 6.9 µM), and sulfasalazine (IC50 9.6 µM). Chicago sky blue 6B (IC50 7.1 µM) inhibited both NTCP and ASBT, a distinct though related bile acid transporter. Rosiglitazone, zafirlukast, TRIAC, sulfasalazine, and chicago sky blue 6B reduced HBV/HDV infection in HepaRG cells in a dose-dependent manner. Five out of 1280 clinically approved drugs were identified that inhibit NTCP-mediated bile acid uptake and HBV/HDV infection in vitro.


Subject(s)
Antiviral Agents/pharmacology , Hepatitis B virus/metabolism , Hepatitis B , Hepatitis D , Hepatitis Delta Virus/metabolism , Organic Anion Transporters, Sodium-Dependent/antagonists & inhibitors , Symporters/antagonists & inhibitors , Virus Internalization/drug effects , Animals , Dogs , Hepatitis B/drug therapy , Hepatitis B/metabolism , Hepatitis B/pathology , Hepatitis D/drug therapy , Hepatitis D/metabolism , Hepatitis D/pathology , Humans , Indoles , Lipopeptides/pharmacology , Madin Darby Canine Kidney Cells , Organic Anion Transporters, Sodium-Dependent/genetics , Organic Anion Transporters, Sodium-Dependent/metabolism , Phenylcarbamates , Rosiglitazone/pharmacology , Sulfasalazine/pharmacology , Sulfonamides , Symporters/genetics , Symporters/metabolism , Tosyl Compounds/pharmacology , Triiodothyronine/analogs & derivatives , Triiodothyronine/pharmacology , Trypan Blue/pharmacology
19.
J Endocrinol ; 234(2): R99-R121, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28576869

ABSTRACT

Thyroid hormone (TH) is crucial for development and metabolism of many tissues. The physiological relevance and therapeutic potential of TH analogs have gained attention in the field for many years. In particular, the relevance and use of 3,3',5-triiodothyroacetic acid (Triac, TA3) has been explored over the last decades. Although TA3 closely resembles the bioactive hormone T3, differences in transmembrane transport and receptor isoform-specific transcriptional activation potency exist. For these reasons, the application of TA3 as a treatment for resistance to TH (RTH) syndromes, especially MCT8 deficiency, is topic of ongoing research. This review is a summary of all currently available literature about the formation, metabolism, action and therapeutic applications of TA3.


Subject(s)
Triiodothyronine/analogs & derivatives , Animals , Basal Metabolism/physiology , Biological Transport/physiology , Humans , Hypothalamo-Hypophyseal System/physiology , Receptors, Thyroid Hormone/metabolism , Thyroid Gland/physiology , Triiodothyronine/metabolism , Triiodothyronine/pharmacology
20.
Nan Fang Yi Ke Da Xue Xue Bao ; 37(3): 296-300, 2017 03 20.
Article in Chinese | MEDLINE | ID: mdl-28377342

ABSTRACT

OBJECTIVE: To compared the efficacy of drug-coated balloon and common balloon for treatment of superficial femoral artery and popliteal artery occlusive disease. METHODS: Forty-six patients were admitted for ipsilateral single or multiple superficial femoral artery and/or popliteal artery lesions (between 3 and 15 cm stenosis or occlusion), Rutherford grades 2 to 5, with or without other accompanying diseases in the Department of Interventional Vascular Therapy of the First Hospital of Nanjing between September, 2015 and December, 2016. The patients were randomly assigned into drug-coated balloon (DCB) group (n=23) and common balloon (CB) group (n=23). None of the patients had stent restenosis, aneurysms, acute thrombosis, pregnancy, life expectancy less than 1 year, or below-the-knee artery occlusion. The late lumen loss (LLL), improvement of the ankle brachial index (ABI), improvement of Rutherford grade, incidence of restenosis, thrombosis rate and amputation rate were compared between the two groups at 6 months after treatment. RESULTS: The two groups of patients were comparable for general conditions, risk factors, and characteristics of the compromised vessels (P>0.05). Six months after treatment, the patients in DCB group showed significantly smaller LLL, more obvious improvement of the ABI and Rutherford grade, and lower restenosis rate and thrombosis rate than those in CB group (P<0.05). The amputation rates were similar between the two groups (P>0.05). CONCLUSIONS: DCB shows obvious advantages over common balloon for treatment of superficial artery and popliteal artery arteriosclerosis obliterans in that it more effectively reduces LLL, restenosis rate and thrombosis rate and improves the ABI and Rutherford grade at 6 months after the treatment.


Subject(s)
Angioplasty, Balloon , Arteriosclerosis Obliterans/therapy , Constriction, Pathologic , Femoral Artery/pathology , Humans , Popliteal Artery/pathology , Prospective Studies , Treatment Outcome , Triiodothyronine/analogs & derivatives , Vascular Patency
SELECTION OF CITATIONS
SEARCH DETAIL
...