Endocrine Abstracts

Background: Defective thyroid gland development occurs in 80% of congenital hypothyroidism (incidence of 1:3000–1:4000). Only <5% have been shown to be caused by molecular genetic defects in few transcription factor genes (Nkx2.1, Nkx2.5, Foxe1, Pax8, Hhex) which are known to play a role in thyroid gland development. Therefore, other genes with a critical role in early thyroid development are likely to be involved in the pathogenesis of thyroid dysgenesis.<p class...

To date only seven cases of naturally occuring inactivating mutations of the aromatase gene in men have been documented. Osteoporosis is one of the typical signs of the aromatase deficiency in male patients. We report results of estrogen therapy in patient with formerly described frameshift mutation of the CYP19 gene, ins 1058 T. Bone mineral density (BMD) was assessed during three phases of estrogen therapy. Patient was substituted by calcium and vitamin D throughout t...

Retinoic acid (RA) acts as an anti-proliferative and re-differentiation agent in the therapy of thyroid carcinoma but the molecular mechanisms by which RA mediates these effects are not well understood. We have investigated the effect of RA on the production and post-translational modification of the two ENO1 transcriptional products in the human follicular thyroid carcinoma cell line FTC-133. The single ENO1 transcript encodes a 48 kDa ENO1 with its unique N-terminal enolase ...

Endocrine cells utilise endocytosis to scavenge polypeptide hormones, and to generate signals from inactive precursors, such as release of thyroid hormones from thyroglobulin in thyrocytes, and activation of vitamin D after reabsorption of ultrafiltrated pro-vitamin D binding protein complex by renal proximal tubular cells (PTC). We have investigated the role of CLC-5, a chloride/proton antiporter expressed in apical endosomes and the apical plasma membrane of thyrocytes and P...

According to the original definition, pheromones are substances released by an individual that have definite behavioural or physiological effects on another individual of the same species. For example, male mouse urine contains a complex mixture of chemosignals, some of which, such as brevicomin and thiazole are testosterone-dependent and signal the presence of a reproductively active male. These have powerful effects as releaser pheromones to elicit aggression from other male...

Human type 2 deiodinase (hD2) regulates T3 production in placenta during trophoblast development. hD2 mRNA and protein levels are elevated only during the first trimester of gestation then becoming barely detectable. These variations are similar to those of chorionic gonadotropin (hCG), a well-known marker of early gestation secreted by the cytotrophoblast. A peculiar promoter architecture of the gene encoding the alpha subunit of hCG allows a CRE-mediated synergism between cA...

Exon 1 of the androgen receptor (AR) gene contains a variable number of CAG triplets, (CAGr)n which encode a polyglutamine stretch of variable length in the N-terminal domain of the receptor. Experimental evidence has accumulated in demonstrating that the length of this stretch influences the transcriptional activity induced by the AR and therefore modulates target organs responsiveness to androgens.The (CAGr)n is inversely associated with the transcript...

WAT and BAT are two different tissues devoted to store energy in the form of triglycerides. WAT provides the organism with fuel during intervals between meals. BAT oxidizes fatty acids to produce heat. BAT is activated by cold exposure, but it is also activated by food intake suggesting its involvement in anti-obesity mechanisms. The two tissues are contained into the adipose organ. This new concept implies that, in mammals, each fat depot contains both tissues. The relative p...

One possible route for treating type 1 diabetes is through an induced augmentation of beta cell mass. Some success has been achieved in recent years using islet grafts into the liver but at present the main limitation to the wider application of this technique is the limited supply of islets from human organ donors. To overcome this problem, alternative sources of β-cells need to be found. One approach is via transdifferentiation, or the conversion of one cell type...

The main source of vitamin D is by the conversion of 7-dehydrocholesterol in the skin to cholecalceferol upon exposure to sun’s ultraviolet B radiation. Vitamin D in diet may be supplied as cholecalceferol or as ergocalciferol, which is derived from plant sources. Vitamin D is metabolised in the liver to 25-hydroxyvitamin D (25OHD; measure of an individual’s vitamin D status) and by kidneys to 1,25-dihydroxyvitamin D, which is responsible for calcium & phosphorou...