Endocrine Abstracts

Objectives: Hypothyroidism is successfully treated by T4 replacement. Nevertheless, T4 treatment is not always well-tolerated. Regenerative medicine using thyroid follicular cells (TFCs) constitutes a very attractive alternative therapy; however, the minimal number of TFCs that have to be fixed remains unknown.Methods: The severe hypothyroid phenotype of DUOXA-/- mice will be rescued using targeted expression of the H2O2;...

Objective: Hashimoto’s thyroiditis (HT) is not only the most frequent autoimmune thyroid disease (AITD), but it also has a significant impact on patients’ health-related quality of life (HRQoL), and it has been variably associated with differentiated thyroid carcinoma. Even though its pathogenesis is still incompletely understood, oxidative stress is believed to play an important role. Hypothyroidism related to later stages of HT can be treated with levothyroxine sub...

The thyroid hormone (TH) feedback is the principal mechanism contributing to maintain the circulating levels of thyroid hormones within the physiological limits that are required for an adequate action at the tissue level. Therefore, circulating TSH determination is considered the most accurate parameter to diagnose a disorder of thyroid function. Several defects are known to be associated with the disruption of such mechanism, but their intimate understanding is still limited...

Congenital hypothyroidism (CH) is the most common endocrine disorder in neonates, but its etiology is still poorly understood. To identify novel genes, we performed whole exome sequencing in 98 CH patients not harboring known CH candidate genes. Through bioinformatic analysis, eukaryotic translation initiation factor 4B (EIF4B) was identified as the most promising candidate gene. The EIF4B gene was inherited in an autosomal recessive model, and one patient with thyroid dysgene...

Background and objectives: Sulforaphane is one of the best studied Nrf2-activating compounds. In preclinical studies, it is usually administered either intravenously or via gavage. While these administration methods are efficacious in activating Nrf2 in target tissues, they have certain disadvantages: (i) they are invasive and thus not optimal from the perspective of the 3Rs (Replacement-Reduction-Refinement), notably regarding Refinement; (ii) their invasive nature may potent...

The growing obesity rate is not only the result of sedentary lifestyle and Western diet, but environmental exposure to endocrine disrupting chemicals (EDCs) may also contribute to this global phenomenon. Some EDCs called obesogens target central pathways regulating food intake and energy expenditure, in particular in the hypothalamus. Indeed, this brain region is the central regulator of many functions including thyroid axis and metabolism. It consists of various nuclei, each ...

Objective: The autoregulatory response of thyroid follicles to excess iodine involves different steps and processes, most notably the acute inhibition of thyroglobulin (Tg) iodination called the Wolff-Chaikoff phenomenon, and the subsequent downregulation of the sodium-iodide symporter (NIS) during the so-called escape from the Wolff-Chaikoff phenomenon. The molecular mechanisms involved in these phenomena are still incompletely understood. In previous studies, we have found p...

Background: Recent studies in France have shown a 1.4-fold increase in the incidence of congenital hypothyroidism (CH) due to gland in situ over the last four decades. CH was previously thought to follow a monogenic model. In recent years, however, evidence has emerged for a more complex genetic cause involving multiple genes and external factors. Our hypothesis is that environmental factors such as endocrine disrupting chemicals (EDCs) may lead to altered thyroid dev...

Environmental pollution is a major concern in households and ecosystems, many of which interfere with the homeostatic balance of living systems. Endocrine disruptors affect many biological pathways including thyroid axis. The identification of Thyroid Disruptor Chemicals and of their effects on organisms is a challenge for both regulators and industry. As thyroid signaling is highly conserved in vertebrates, zebrafish and amphibian embryos are alternative models for studying b...