Phase 3 Trial of Selpercatinib in Advanced RET-Mutant Medullary Thyroid Cancer.

BACKGROUND: Selpercatinib, a highly selective, potent RET inhibitor, has shown efficacy in advanced RET-mutant medullary thyroid cancer in a phase 1-2 trial, but its efficacy as compared with approved multikinase inhibitors is unclear. METHODS: We conducted a phase 3, randomized trial comparing selpercatinib as first-line therapy with the physician's choice of cabozantinib or vandetanib (control group). Eligible patients had progressive disease documented within 14 months before enrollment. The primary end point in the protocol-specified interim efficacy analysis was progression-free survival, assessed by blinded independent central review. Crossover to selpercatinib was permitted among patients in the control group after disease progression. Treatment failure-free survival, assessed by blinded independent central review, was a secondary, alpha-controlled end point that was to be tested only if progression-free survival was significant. Among the other secondary end points were overall response and safety. RESULTS: A total of 291 patients underwent randomization. At a median follow-up of 12 months, median progression-free survival as assessed by blinded independent central review was not reached in the selpercatinib group and was 16.8 months (95% confidence interval [CI], 12.2 to 25.1) in the control group (hazard ratio for disease progression or death, 0.28; 95% CI, 0.16 to 0.48; P<0.001). Progression-free survival at 12 months was 86.8% (95% CI, 79.8 to 91.6) in the selpercatinib group and 65.7% (95% CI, 51.9 to 76.4) in the control group. Median treatment failure-free survival as assessed by blinded independent central review was not reached in the selpercatinib group and was 13.9 months in the control group (hazard ratio for disease progression, discontinuation due to treatment-related adverse events, or death, 0.25; 95% CI, 0.15 to 0.42; P<0.001). Treatment failure-free survival at 12 months was 86.2% (95% CI, 79.1 to 91.0) in the selpercatinib group and 62.1% (95% CI, 48.9 to 72.8) in the control group. The overall response was 69.4% (95% CI, 62.4 to 75.8) in the selpercatinib group and 38.8% (95% CI, 29.1 to 49.2) in the control group. Adverse events led to a dose reduction in 38.9% of the patients in the selpercatinib group, as compared with 77.3% in the control group, and to treatment discontinuation in 4.7% and 26.8%, respectively. CONCLUSIONS: Selpercatinib treatment resulted in superior progression-free survival and treatment failure-free survival as compared with cabozantinib or vandetanib in patients with RET-mutant medullary thyroid cancer. (Funded by Loxo Oncology, a subsidiary of Eli Lilly; LIBRETTO-531 ClinicalTrials.gov number, NCT04211337.).

Use of levothyroxine for euthyroid, thyroid antibody positive women with infertility: Analyses of aggregate data from a survey of European thyroid specialists (Treatment of Hypothyroidism in Europe by Specialists: An International Survey).

OBJECTIVES: The use of levothyroxine (LT4) treatment aiming to improve fertility in euthyroid women with positive thyroid peroxidase antibodies (TPOAb) is not supported by the available evidence. The aim of the study was to document the use of LT4 by European thyroid specialists in such patients. DESIGN: The data presented derive from Treatment of Hypothyroidism in Europe by Specialists, an International Survey (THESIS), a questionnaire conducted between 2019 and 2021 to document the management of hypothyroidism by European thyroid specialists. Here, we report the aggregate results on the use of LT4 in infertile, euthyroid women with positive TPOAb. RESULTS: A total of 2316/5406 (42.8%) respondents stated that LT4 may be indicated in TPOAb positive euthyroid women with infertility. The proportion of those replying positively to this question varied widely across different countries (median 39.4, range 22.9%-83.7%). In multivariate analyses males (OR: 0.8; CI: 0.7-0.9) and respondents >60 years (OR: 0.7; 0.6-0.8) were the least inclined to consider LT4 for this indication. Conversely, respondents managing many thyroid patients ("weekly" [OR: 1.4; CI: 1.0-1.9], "daily" [OR: 1.8; CI: 1.3-2.4]) and practicing in Eastern Europe (OR: 1.5; CI: 1.3-1.9) were most likely to consider LT4. CONCLUSIONS: A remarkably high number of respondents surveyed between 2019 and 2021, would consider LT4 treatment in TPOAb positive euthyroid women with infertility. This view varied widely across countries and correlated with sex, age and workload, potentially influencing patient management. These results raise concerns about potential risks of overtreatment.

Thyroid Inflammation and Immunity During the COVID-19 Pandemic: A Comprehensive Review and Case Study.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the development of various vaccines. Reports have emerged suggesting a possible association between SARS-CoV-2 vaccination and the onset of thyroid diseases. This review explores the clinical aspects of thyroid disorders following SARS-CoV-2 vaccination, including a case report of a patient with concomitant subacute thyroiditis (SAT) and Graves' disease (GD) with blocking thyrotropin receptor autoantibodies (TSH-R-Ab) following SARS-CoV-2 vaccination. SAT, characterized by transient inflammation of the thyroid gland, has been reported after SARS-CoV-2 vaccination. GD, an autoimmune hyperthyroidism, has also been observed post-vaccination, often with stimulating TSH-R-Ab. Graves' orbitopathy (GO) has been associated with SARS-CoV-2 vaccination in patients with a history of immune thyroid disease. The unique case underscores a very rare thyroid condition of functional hypothyroidism in possible relation to SARS-CoV-2 vaccination and the usefulness of functional analysis of TSH-R-Ab that can provide valuable insights into disease pathogenesis and help to guide treatment. This review highlights the need for continued monitoring and awareness of potential thyroid-related complications following SARS-CoV-2 vaccination.

Transition from Paediatric to Adult Care in CAH: 20 Years of Experience at a Tertiary Referral Center.

Transition medicine aims at the coordinated transfer of young patients with a chronic disease from paediatric to adult care. The present study reflects 20 years of experience in transitioning patients with congenital adrenal hyperplasia (CAH) in a single center setting. Our endocrine transition-clinic was established in 2002 and offers joint paediatric and adult consultations. Data were evaluated retrospectively from 2002 to 2005 and 2008 to present. Fifty-nine patients (29 males) were transferred. Median age was 18.4 years (17.6-23.6). Ninety percent of the patients presented with 21-hydroxlase-deficiency (21-OHD), 38 patients (23 m) with salt-wasting (sw), 7 (1 m) with simple-virilising (sv) and 8 (3 m) with the non-classic (nc) form. Rarer enzyme deficiencies were found in 6 cases: 17α-OHD (2 sisters), P450-oxidoreductase-deficiency (2 siblings), 3ß-hydroxysteroid-dehydrogenase-deficiency (1 m) and 11ß-OHD (1 female). Thirty-four patients (57.6%, 20 m) are presently still attending the adult clinic, 1 patient (1.7%, m) moved away and 24 (40.7%, 8 m) were lost to follow-up (13 sw-21-OHD, 6 sv-21-OHD, 5 nc-21-OHD). Thirty-seven patients (62.7%) attended the adult clinic for >2 years after transfer, 17 (28.8%) for >10 years. In the lost to follow-up group, median time of attendance was 16.3 months (0-195.2). Defining a successful transfer as two or more visits in the adult department after initial consultation in the transition clinic, transfer was efficient in 84.7% of the cases. A seamless transfer to adult care is essential for adolescents with CAH. It requires a continuous joint support during the transition period, remains challenging, and necessitates adequate funding.

Bone Metastases in Patients with Pancreatic NETs: Prevalence and Prognosis.

The clinical relevance of bone metastases (BM) in advanced pancreatic neuroendocrine tumors (PanNETs) is poorly described. We analyzed 314 consecutive PanNET patients treated at the European Neuroendocrine Tumour Society (ENETS) Center Essen between 2009 and 2021 in terms of the occurrence and clinical and prognostic impact of BM using hybrid imaging with 68Ga-DOTATOC PET/CT. According to UICC staging, 171/314 (54.5%) patients had stage IV PanNETs. BM was diagnosed in 62/171 (36.3%) patients. Initially, 35% of BMs were visible by pathological tracer uptake only. Skeletal-related events (SREs) were detected in 11 of the 62 patients (17.7%). Patients with antiresorptive therapy had a significantly lower rate of SRE (2/36, 5.6%) than individuals without bone-specific therapy (9/26, 34.6%) (odds ratio 9.0, p=0.0054, Fisher's exact test). The median overall survival (OS) was 82 months (53.6-110.4, 95% CI) in the stage IV PanNET cohort. The median OS was significantly lower for patients with BM (63 months; 49.9-76.0, 95% CI) than for patients with distant metastases other than BM (116 months; 87.6-144.3, 95% CI) (p=0.016, log-rank test). BM occurs in more than one-third of advanced PanNETs and is associated with an unfavorable prognosis. One in five patients experiences a persistent quality-of-life-lowering SRE. Antiresorptive therapy is associated with a more favorable risk of SREs and should be offered to all patients with BM in PanNETs.

[Regional Differences in Thyroid Function Parameters: A Comparison of European Cohort Studies]. / Regionale Unterschiede von Schilddrüsenfunktionsparametern: ein Vergleich europäischer Kohortenstudien.

AIM OF THE STUDY: The aim of the project was to investigate regional differences in thyroid stimulating hormone (TSH), and free thyroxine (fT4) concentrations and iodine status in comparable German and European cohort studies. METHODS: Sex- and age-stratified TSH, fT4, and urine iodine concentrations of thyroid-healthy participants (age group 45-75 years) of the HNR (Heinz Nixdorf Recall) Study in the Ruhr region of Germany, the southern German KORA (Cooperative Health Research in the Augsburg Region) and northeastern German SHIP (Study of Health in Pomerania) studies, as well as the Norwegian HUNT (Nord-Trøndelag Health) study (age group 40-79 years), the English EPIC (European Prospective Investigation of Cancer)-Norfolk study, and the Dutch Rotterdam study were compared. The TSH reference range for the HNR study population was calculated and compared to the KORA and SHIP studies. RESULTS: Regional differences showed a stronger influence on TSH and fT4 concentrations than sex and age of the subjects in the 45- to 75-year age group. The estimated difference in medians, as measured by the HNR study, was lowest in the SHIP study, -0.47 (95% CI: -0.53; -0.41) for men and -0.41 (-0.53; -0.41) for women. The Rotterdam study had the highest difference in medians for both men and women (men: 0.56 with 0.44; 0.68 and women: 0.62 with 0.46; 0.78). The lowest median TSH concentrations, across all age categories considered, were seen in the German cohorts. CONCLUSIONS: Comparison of thyroid function parameters and iodine in elderly subjects between six comparable cohort studies from Germany and Europe showed a significant influence of region, which exceeded the sex and age dependence of the parameters.

[Graves' orbitopathy: Current concepts for medical treatment]. / Endokrine Orbitopathie: Aktueller Stand der medikamentösen Therapie.

BACKGROUND: The therapy of severe manifestations of Graves' orbitopathy (GO) is still a challenge and requires good interdisciplinary cooperation. It is especially important to use stage-adapted anti-inflammatory therapy to avoid irreversible damage. MATERIAL AND METHODS: Discussion of the latest results of multicentre randomised therapy studies on anti-inflammatory treatments for Graves' orbitopathy, as well as new therapeutic concepts. RESULTS: Mild cases of GO can be treated with only selenium supplementation and a watchful waiting strategy. In the moderate-to-severe active form of GO, primary therapy consists of i. v. steroids (cumulative 4-5 g) in combination with orbital irradiation in patients with impaired motility. In patients with insufficient therapeutic response after 6 weeks, treatment should be switched to other immunosuppressive agents. In severe sight-threatening disease, bony orbital decompression is usually necessary. As basic research has improved our understanding of the underlying pathophysiology of GO, it has been possible to develop targeted therapies for GO. Teprotumumab, an IGF-1 receptor antibody, was effective in treating GO patients in a phase III trial and should soon be awarded approval for Europe. CONCLUSION: The current therapy concept for Graves' orbitopathy is as follows: first anti-inflammatory therapy then surgical correction of the permanent defects. This may soon be modified, due to the use of targeted therapies.

Clonidine suppression test for a reliable diagnosis of pheochromocytoma: When to use.

OBJECTIVE: In clinical practice, false-positive results in biochemical testing for suspected pheochromocytoma/paraganglioma (PPGL) are not infrequent and may lead to unnecessary examinations. We aimed to evaluate the role of the clonidine suppression test (CST) in the era of analyses of plasma-free metanephrines for the diagnosis or exclusion of PPGL in patients with adrenal tumours and/or arterial hypertension. DESIGN AND METHODS: This single-centre, prospective trial investigated the use of CST in 60 patients with suspected PPGL associated with out-patient elevations of plasma normetanephrine (NMN) and/or metanephrine (MN), in most cases accompanied with hypertension or an adrenal mass. Measurements of plasma catecholamines and free metanephrines were performed by liquid chromatography with electrochemical detection and tandem mass spectrometry, respectively. RESULTS: Forty-six patients entered final analysis (n = 20 with PPGL and n = 26 with a nonfunctional adrenal mass and/or hypertension). CST reliably excluded false-positive baseline NMN results with a specificity of 100%. The sensitivity of CST improved from 85% to 94% when tumours with isolated MN increase (n = 3) were not considered. In patients with elevated baseline NMN (n = 24), CST correctly identified all patients without PPGL. Patients with falsely elevated baseline NMN results (n = 7, 26.9%) exhibited increases of baseline NMN up to 1.7-fold above the upper reference limit. CONCLUSION: CST qualifies as a useful diagnostic tool for differential diagnosis of borderline elevated plasma-free NMN in patients with suspected PPGL. In this context, CST helps to correctly identify all false-positive NMN screening results.

Cell-Specific Transport and Thyroid Hormone Receptor Isoform Selectivity Account for Hepatocyte-Targeted Thyromimetic Action of MGL-3196.

Thyroid hormones (THs) and TH receptor-beta (TRß) reduce hepatic triglycerides, indicating a therapeutic potential for TH analogs in liver steatosis. To avoid adverse extrahepatic, especially TRα-mediated effects such as tachycardia and bone loss, TH analogs with combined TRß and hepatocyte specificity are desired. MGL-3196 is a new TH analog that supposedly meets these criteria. Here, we characterize the thyromimetic potential of MGL-3196 in cell-based assays and address its cellular uptake requirements. We studied the contribution of liver-specific organic anion transporters (OATP)1B1 and 1B3 to MGL-3196 action. The TR isoform-specific efficacy of MGL-3196 compared with 3,5,3'-triiodothyronine (T3) was determined with luciferase assays and gene expression analysis in OATP1B1 and OATP1B3 and TRα- or TRß-expressing cells and in primary murine hepatocytes (PMHs) from wild-type and TRß knockout mice. We measured the oxygen consumption rate to compare the effects of MGL-3196 and T3 on mitochondrial respiration. We identified OATP1B1 as the primary transporter for MGL-3196. MGL-3196 had a high efficacy (90% that of T3) in activating TRß, while the activation of TRα was only 25%. The treatment of PMHs with T3 and MGL-3196 at EC50 resulted in a similar induction of Dio1 and repression of Serpina7. In HEK293 cells stably expressing OATP1B1, MGL-3196 had comparable effects on mitochondrial respiration as T3. These data indicate that MGL-3196's hepatic thyromimetic action, the basis for its therapeutic use, results from a combination of hepatocyte-specific transport by OATP1B1 and the selective activation of TRß over TRα.

Hepatobiliary Thyroid Hormone Deficiency Impacts Bile Acid Hydrophilicity and Aquaporins in Cholestatic C57BL/6J Mice.

Women are more prone to develop either hypothyroidism or cholesterol gallstones than men. However, a male predominance in cholesterol gallstones under hypothyroidism was reported. Recently, a novel pathogenic link between thyroid hormone (TH) deficiency and cholesterol gallstones has been described in male mice. Here, we investigate if TH deficiency impacts cholesterol gallstone formation in females by the same mechanism. Three-month-old C57BL/6J mice were randomly divided into a control, a TH deficient, a lithogenic, and a lithogenic + TH deficient group and diet-treated for two, four, and six weeks. Gallstone prevalence, liver function tests, bile composition, hepatic gene expression, and gallbladder aquaporin expression and localization were investigated. Cholesterol gallstones were observed in lithogenic + TH deficient but not lithogenic only female mice. Diminished hydrophilicity of primary bile acids due to decreased gene expression of hepatic detoxification phase II enzymes was observed. A sex-specific expression and localization of hepatobiliary aquaporins involved in transcellular water and glycerol permeability was observed under TH deficient and lithogenic conditions. TH deficiency promotes cholesterol gallstone formation in female C57BL/6J mice by the same mechanism as observed in males. However, cholesterol gallstone prevalence was lower in female than male C57BL/6J mice. Interestingly, the sex-specific expression and localization of hepatobiliary aquaporins could protect female C57BL/6J mice to cholestasis and could reduce biliary water transport in male C57BL/6J mice possibly contributing to the sex-dependent cholesterol gallstone prevalence under TH deficiency.

Cardioprotection by Hypothyroidism Is Not Mediated by Favorable Hemodynamics-Role of Canonical Thyroid Hormone Receptor Alpha Signaling.

Hypothyroidism has been shown to reduce infarct size in rats, but the underlying mechanisms are unclear. We used isolated pressure-constant perfused hearts of control, hypothyroid and hyperthyroid mice and measured infarct size, functional parameters and phosphorylation of key molecules in cardioprotective signaling with matched heart rate. Compared with controls, hypothyroidism was cardioprotective, while hyperthyroidism was detrimental with enlarged infarct size. Next, we asked how thyroid hormone receptor α (TRα) affects ischemia/reperfusion (IR) injury. Thus, canonical and noncanonical TRα signaling was investigated in the hearts of (i) mice lacking TRα (TRα0), (ii) with a mutation in TRα DNA-binding domain (TRαGS) and (iii) in hyperthyroid TRα0 (TRα0hyper) and TRαGS mice (TRαGShyper). TRα0 mouse hearts were protected against IR injury. Furthermore, infarct size was reduced in the hearts of TRαGS mice that lack canonical TRα signaling but maintain noncanonical TRα action. Hyperthyroidism did not increase infarct size in TRα0 and TRαGS mouse hearts. These cardioprotective effects were not associated with increased phosphorylation of key proteins of RISK, SAFE and eNOS pathways. In summary, chronic hypothyroidism and the lack of canonical TRα signaling are cardioprotective in IR injury and protection is not due to favorable changes in hemodynamics.

Sunitinib-Induced Hypothyroidism and Survival in Pancreatic Neuroendocrine Tumors.

Sunitinib has been approved for the treatment of pancreatic neuroendocrine tumors, renal-cell carcinoma, and gastrointestinal stromal tumors. The elevation of thyroid-stimulating hormone serum levels is a common side effect. Studies suggest a correlation between sunitinib-induced hypothyroidism and treatment outcome in patients with renal-cell carcinoma and gastrointestinal stromal tumors. This study assessed whether sunitinib-induced hypothyroidism is a predictive marker of the objective response rate, progression-free survival, and overall survival in pancreatic neuroendocrine tumor patients. Twenty-nine patients treated with sunitinib for advanced pancreatic neuroendocrine tumors were included. The incidence of sunitinib-induced hypothyroidism was 33%. The median progression-free survival of patients who developed hypothyroidism was 16 months (95% confidence interval: 6.2-25.8 months) as compared with six months among euthyroid patients (95% confidence interval: 0.1-12.2 months) (p=0.02). The median overall survival was 77 months (95% confidence interval: 31.4-122.6 months) in hypothyroid patients but 12 months (95% confidence interval: 5.9-18.1 months) in subjects with euthyroidism (p=0.001). The median overall survival from the time of initial diagnosis ranged from 247 months in patients with hypothyroidism to 65 months in euthyroid subjects (p=0.015). Elevated thyroid-stimulating hormone levels are a prognostic biomarker of improved outcomes of sunitinib therapy in pancreatic neuroendocrine tumor patients.

Distinct Late-Night Salivary Cortisol Cut-Off Values for the Diagnosis of Hypercortisolism.

Due to high morbidity and mortality of untreated hypercortisolism, a prompt diagnosis is essential. Measurement of late-night salivary cortisol provides a simple and non-invasive method. However, thresholds and reference ranges differ among studies. The goal of this study was to define a threshold of late-night salivary cortisol for the diagnosis of hypercortisolism based on the used assay. Moreover, the influence of different aetiologies of hypercortisolism and individual comorbidities were investigated. Prospective analyses of 217 patients, including 36 patients with proven hypercortisolism were carried out. A sum of 149 patients with suspicion of hypercortisolism but negative endocrine testing and 32 patients with hypercortisolism in remission served as control group. Late-night salivary cortisol was measured using an automated chemiluminescence immunoassay. Cut-off values were calculated by ROC analysis. The calculated cut-off value for the diagnosis of hypercortisolism was 10.1 nmol/l (sensitivity 94%; specificity 84%). Only slightly lower thresholds were obtained in patients with suspected hypercortisolism due to weight gain/obesity (9.1 nmol/l), hypertension or adrenal tumours (both 9.8 nmol/l) or pituitary adenomas (9.5 nmol/l). The late-night salivary cortisol threshold to distinguish between Cushing's disease and Cushing's disease in remission was 9.2 nmol/l. The cut-off value for the diagnosis of ectopic ACTH-production was 109.0 nmol/l (sensitivity 50%, specificity 92%). Late-night salivary cortisol is a convenient and reliable parameter for the diagnosis of hypercortisolism. Except for ectopic ACTH-production, thresholds considering different indications for evaluation of hypercortisolism were only slightly different. Therefore, they might only be useful if late-night salivary cortisol results near the established cut-off value are present.

Licogliflozin versus placebo in women with polycystic ovary syndrome: A randomized, double-blind, phase 2 trial.

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism and insulin resistance. The dual sodium-glucose co-transporter 1/2 inhibitor (SGLT1/2i) licogliflozin (LIK066) ameliorates hyperinsulinism in patients with diabetes and obesity. This study examines the effect of licogliflozin on androgens in women with PCOS. In a multicentre, randomized, placebo-controlled, double-blind, 2-week trial, patients with PCOS received licogliflozin 50 mg or placebo three times a day (TID). Changes in free testosterone (FT), other androgens and variables of insulin resistance were analysed. Concentration of FT did not change (TRLIK066 :TRPCB [FT]: 0.88; 90% CI: 0.70-1.11; P = .353). Licogliflozin reduced androstendione (A4) by 19% (TRLIK066 :TRPCB [A4]: 0.81; 90% CI: 0.68-0.99; P = .089) and dehydroepiandrosteron sulphate (DHEAS) by 24% (TRLIK066 :TRPCB [DHEAS]: 0.76; 90% CI: 0.65-0.89; P = .008). Hyperinsulinaemia was reduced by 70% by licogliflozin (highest insulin concentration [MAXI]; TRLIK066 :TRPCB [MAXI]: 0·26; 90% CI:0.20-0.34; P < .001 and area under the curve insulin [AUCI]; TRLIK066 :TRPCB [AUCI]: 0.32; 90% CI: 0.25-0.41; P < .001). Diarrhoea and nausea occurred as common adverse events. Dual inhibition of SGLT1/2 ameliorates hyperinsulinaemia and hyperandrogenaemia in women with PCOS. Licogliflozin may represent a promising novel treatment option for PCOS.

Graves' Orbitopathy: Current Concepts for Medical Treatment. / Endokrine Orbitopathie: aktueller Stand der medikamentösen Therapie.

BACKGROUND: The therapy of severe manifestations of Graves' orbitopathy (GO) is still a challenge and requires good interdisciplinary cooperation. It is especially important to use stage-adapted anti-inflammatory therapy to avoid irreversible damage. MATERIAL AND METHODS: Discussion of the latest results of multicentre randomised therapy studies on anti-inflammatory treatments for Graves' orbitopathy, as well as new therapeutic concepts. RESULTS: Mild cases of GO can be treated with only selenium supplementation and a watchful waiting strategy. In the moderate-to-severe active form of GO, primary therapy consists of i. v. steroids (cumulative 4 - 5 g) in combination with orbital irradiation in patients with impaired motility. In patients with insufficient therapeutic response after 6 weeks, treatment should be switched to other immunosuppressive agents. In severe sight-threatening disease, bony orbital decompression is usually necessary. As basic research has improved our understanding of the underlying pathophysiology of GO, it has been possible to develop targeted therapies for GO. Teprotumumab, an IGF-1 receptor antibody, was effective in treating GO patients in a phase III trial and should soon be awarded approval for Europe. CONCLUSION: The current therapy concept for Graves' orbitopathy is as follows: first anti-inflammatory therapy then surgical correction of the permanent defects. This may soon be modified, due to the use of targeted therapies.

Function of Cathepsin K in the Central Nervous System of Male Mice is Independent of Its Role in the Thyroid Gland.

Cathepsin K deficiency in male mice (Ctsk-/-) results in decreased numbers of hippocampal astrocytes and altered neuronal patterning as well as learning and memory deficits. Additionally, cathepsin K carries essential roles in the thyroid gland where it contributes to the liberation of thyroid hormones (TH). Because TH are essential for brain development, in particular for the cerebellum, we investigated whether cathepsin K's function in the thyroid is directly linked to the brain phenotype of Ctsk-/- mice. Serum levels of thyroid stimulating hormone, brain concentrations of free TH, and deiodinase 2 (Dio2) activity in brain parenchyma as well as cerebellar development were comparable in Ctsk-/- and WT animals, suggesting regular thyroid states and TH metabolism. Despite unaltered transcript levels, protein expression of two TH transporters was enhanced in specific brain regions in Ctsk-/- mice, suggesting altered TH supply to these regions. Thyrotropin releasing hormone (Trh) mRNA levels were enhanced threefold in the hippocampus of Ctsk-/- mice. In the striatum of Ctsk-/- mice the mRNA for Dio2 and hairless were approximately 1.3-fold enhanced, while mRNA levels for monocarboxylate transporter 8 and Trh were reduced to 60% and 40%, respectively, pointing to altered striatal physiology. We conclude that the role of cathepsin K in the thyroid gland is not directly associated with its function in the central nervous system (CNS) of mice. Future studies will show whether the brain region-specific alterations in Trh mRNA may eventually result in altered neuroprotection that could explain the neurobehavioral defects of Ctsk-/- mice.

Effect of vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients: results of a randomized controlled trial.

PURPOSE: While observational studies revealed inverse associations between serum vitamin D levels [25(OH)D] and depression, randomized controlled trials (RCT) in children and adolescents are lacking. This RCT examined the effect of an untreated vitamin D deficiency compared to an immediate vitamin D3 supplementation on depression scores in children and adolescents during standard day and in-patient psychiatric treatment. METHODS: Patients with vitamin D deficiency [25(OH)D ≤ 30 nmol/l] and at least mild depression [Beck Depression Inventory II (BDI-II) > 13] (n = 113) were 1:1 randomized into verum (VG; 2640 IU vitamin D3/d) or placebo group (PG) in a double-blind manner. During the intervention period of 28 days, both groups additionally received treatment as usual. BDI-II scores were assessed as primary outcome, DISYPS-II (Diagnostic System for Mental Disorders in Childhood and Adolescence, Self- and Parent Rating) and serum total 25(OH)D were secondary outcomes. RESULTS: At admission, 49.3% of the screened patients (n = 280) had vitamin D deficiency. Although the intervention led to a higher increase of 25(OH)D levels in the VG than in the PG (treatment difference: + 14 ng/ml; 95% CI 4.86-23.77; p = 0.003), the change in BDI-II scores did not differ (+ 1.3; 95% CI - 2.22 to 4.81; p = 0.466). In contrast, DISYPS parental ratings revealed pronounced improvements of depressive symptoms in the VG (- 0.68; 95% CI - 1.23 to - 0.13; p = 0.016). CONCLUSION: Whereas this study failed to show a vitamin D supplementation effect on self-rated depression in adolescent in- or daycare patients, parents reported less depressive symptoms in VG at the end of our study. Future trials should consider clinician-rated depressive symptoms as primary outcome. TRIAL REGISTRATION: "German Clinical Trials Register" ( https://www.drks.de ), registration number: DRKS00009758.

Noncanonical thyroid hormone signaling mediates cardiometabolic effects in vivo.

Thyroid hormone (TH) and TH receptors (TRs) α and ß act by binding to TH response elements (TREs) in regulatory regions of target genes. This nuclear signaling is established as the canonical or type 1 pathway for TH action. Nevertheless, TRs also rapidly activate intracellular second-messenger signaling pathways independently of gene expression (noncanonical or type 3 TR signaling). To test the physiological relevance of noncanonical TR signaling, we generated knockin mice with a mutation in the TR DNA-binding domain that abrogates binding to DNA and leads to complete loss of canonical TH action. We show that several important physiological TH effects are preserved despite the disruption of DNA binding of TRα and TRß, most notably heart rate, body temperature, blood glucose, and triglyceride concentration, all of which were regulated by noncanonical TR signaling. Additionally, we confirm that TRE-binding-defective TRß leads to disruption of the hypothalamic-pituitary-thyroid axis with resistance to TH, while mutation of TRα causes a severe delay in skeletal development, thus demonstrating tissue- and TR isoform-specific canonical signaling. These findings provide in vivo evidence that noncanonical TR signaling exerts physiologically important cardiometabolic effects that are distinct from canonical actions. These data challenge the current paradigm that in vivo physiological TH action is mediated exclusively via regulation of gene transcription at the nuclear level.

Procathepsin V Is Secreted in a TSH Regulated Manner from Human Thyroid Epithelial Cells and Is Accessible to an Activity-Based Probe.

The significance of cysteine cathepsins for the liberation of thyroid hormones from the precursor thyroglobulin was previously shown by in vivo and in vitro studies. Cathepsin L is most important for thyroglobulin processing in mice. The present study aims at specifying the possible contribution of its closest relative, cysteine cathepsin L2/V, to thyroid function. Immunofluorescence analysis on normal human thyroid tissue revealed its predominant localization at the apical plasma membrane of thyrocytes and within the follicle lumen, indicating the secretion of cathepsin V and extracellular tasks rather than its acting within endo-lysosomes. To explore the trafficking pathways of cathepsin V in more detail, a chimeric protein consisting of human cathepsin V tagged with green fluorescent protein (GFP) was stably expressed in the Nthy-ori 3-1 thyroid epithelial cell line. Colocalization studies with compartment-specific markers and analyses of post-translational modifications revealed that the chimeric protein was sorted into the lumen of the endoplasmic reticulum and subsequently transported to the Golgi apparatus, while being N-glycosylated. Immunoblotting showed that the chimeric protein reached endo-lysosomes and it became secreted from the transduced cells. Astonishingly, thyroid stimulating hormone (TSH)-induced secretion of GFP-tagged cathepsin V occurred as the proform, suggesting that TSH upregulates its transport to the plasma membrane before it reaches endo-lysosomes for maturation. The proform of cathepsin V was found to be reactive with the activity-based probe DCG-04, suggesting that it possesses catalytic activity. We propose that TSH-stimulated secretion of procathepsin V is the default pathway in the thyroid to enable its contribution to thyroglobulin processing by extracellular means.

MicroRNA-183 and microRNA-96 are associated with autoimmune responses by regulating T cell activation.

MircoRNAs (miRs) are small molecules that regulate gene expression at the posttranscriptional level. They have been proposed to be involved in the regulation of several immune responses including autoimmunity. Here, we identified miR-183 and miR-96 to be highly expressed in CD4+ T cells from peripheral blood of Graves' orbitopathy (GO) patients as well as in human and murine T cells upon activation in vitro. By using Luciferase-based binding assays, we identified EGR-1 as target for miR-183 and miR-96. Overexpression of miR-183 and miR-96 in murine CD4+ T cells by retroviral gene transfer resulted in decreased EGR-1 and PTEN expression, elevated Akt phosphorylation and enhanced proliferation. In contrast, treatment of murine CD4+ T cells with specific antagomiRs increased EGR-1 and PTEN expression and interfered with the proliferative activity upon stimulation in vitro. Strikingly, adoptive transfer of miR-183 and miR-96 overexpressing antigen-specific T cells into INS-HA/Rag2KO mice accelerated the development of autoimmune diabetes, whereas transfer of antagomiR-treated cells delayed the disease onset. These results indicate that miR-183 and miR-96 have the ability to regulate the strength of T cell activation and thereby the development and severity of T cell-dependent autoimmune diseases.