Endocrine Abstracts

Introduction: Besides the classical thyroid hormones T4 and T3 the endogenous thyroid hormone metabolite 3,5-diiodothyronine (3,5-T2) attracted attention during the last years due to its metabolic activity. 3,5-T2 exerts thyromimetic action on the hypothalamus-pituitary-thyroid axis and the heart as well as on energy and lipid metabolism. In previous liver transcriptome analyses of 3,5-T2-treated lean and diet-induced obese male mice, effects on hepatic lipid, steroid, xenobio...

Recent findings revealed 3,5-diiodo-L-thyronine (3,5-T2) as a metabolically active iodothyronine affecting hepatic energy and lipid metabolism. Therefore, 3,5-T2 has been proposed as a potential hypolipidemic agent for treatment of obesity and its hepatic aftermath. So far only limited data exists relating to the effects of 3,5-T2 on metabolism in euthyroid mammals maintained on high-fat diet from the day of weaning onwards. Therefore, we performed a study in wh...

The functional state of the thyroid is usually determined by thyrotropin (TSH), whose serum levels depend on circulating thyroid hormone (TH) levels. This feedback mechanism is tightly controlled in the individual and contrasts broad reference range for TSH in the general population, leading to the concept of subclinical thyroid disease. We studied a model of experimental thyrotoxicosis in humans employing an untargeted metabolome and proteome approach. This allowed us to gain...

Thyroid hormones (TH) play a pivotal role in embryonal and postnatal development in vertebrates, hence, their secretion is highly regulated. In clinical practice TSH and free T4 (fT4) are commonly used as the most reliable parameters to evaluate the TH status. But they only represent the TH receptor β driven status of the hypothalamic-pituitary-thyroid axis while organ or tissue specific TH availability may be different. This discrepancy originates in the tissue specific ...

Background: Numerous animal models have shown impressive beneficial metabolic effects of the putative thyroid hormone (TH)-derivative 3,5-diiodothyronine (3,5-T2), including the prevention of insulin resistance or the reversal of hepatic steatosis, in the absence of thyrotoxic side effects. In contrast, the endogenous fate of 3,5-T2 in humans is still unclear. Comprehensive molecular profiling holds promise to gain deeper insights in metabolic alterations associated with serum...

The thyroid gland functions in supplying thyroid hormones (TH) to the body periphery, which is enabled by cathepsin-mediated thyroglobulin proteolysis and TH translocation across membranes by the Mct8, Mct10, and Lat2 transporters. Previously, we showed that cathepsin K-deficient mice feature normal thyroid phenotypes which is, in part, due to the functional compensation through cathepsin L upregulation that is independent of the classical hypothalamus–pituitary–thyr...