Endocrine Abstracts

Background: Precocious puberty (PP) in girls is most frequently an idiopathic gonadotropin-releasing hormone (GnRH)-dependent PP, being thelarche the typical first sign. It is well established that increased dehydroepiandrosterone sulphate (DHEAS) levels are associated with premature adrenarche and may characterize PP too. However, its relationship with signs of hypothalamic-pituitary-gonadal (HPG) axis activation and oestrogen exposure is still to be elucidated.<p class="...

Background: Routine clinical use of arginine-vasopressin (AVP) is limited by its small molecular size and pre-analytical errors. In contrast, copeptin – a peptide of 39 amino acids co-secreted with arginine-vasopressin (AVP) - is a stable protein and its measurement represents a reliable measure of AVP concentration. The aim of this study was to analyze diagnostic role of copeptin in diagnosis of diabetes insipidus (DI) in patients treated for hypothalamic-pituitary disea...

Introduction: Pseudohypoparathyroidism (PHP) is a rare genetic disease characterized by renal resistance to parathyroid hormone (PTH), presenting with hypocalcemia, hyperphosphatemia and elevated PTH levels. We describe a PHP patient who presented with clinically significant hypercalcemia.Case description: A 46-year-old woman with a prior history of hypocalcemia presented to the emergency department with new-onset hypercalcemia, renal failure and anemia....

Pseudohypoparathyroidism type 1B (PHP-1B) is a rare, familial or sporadic, imprinting disorder due to the epigenetic dysregulation of the GNAS locus, whose main product is the α subunit of the stimulatory G protein (Gsα). Sporadic PHP-1B cases (spor-PHP-1B) display broad methylation abnormalities at multiple GNAS DMRs, but the underlying molecular mechanism is still unknown.Classically, PHP-1B patients show PTH and TSH resistance, but, in the p...

Non-functioning pituitary tumors (NFPTs), although benign in nature, frequently present local invasiveness that strongly reduces neurosurgery success. Medical therapy is still under debate, although dopamine (DA) receptor 2 (DRD2) agonists may induce tumor shrinkage in some patients. Aims of this study were: 1) to evaluate the effect of DR2D agonist BIM53097 on migration and invasion of NFPT cells, 2) to investigate the molecular mechanisms regulating the motility of these cel...

Somatostatin exerts its inhibitory effects on hormone secretion and cell proliferation via five receptors subtypes (SST1-SST5). After agonist binding, receptor residues mainly located in the carboxyl terminal (CT) and in the third intracellular loop (IC3) are phosphorylated and β-arrestins are recruited to drive SSTRs internalization.Aim of the study is to characterize the intracellular mechanisms responsible for SST2 internalization and identify th...

Several studies support the existence of multipotent stem/progenitor cells in the adult pituitary, whereas the presence of stem cell in pituitary tumors and their role in pituitary tumorigenesis are still on debate. Aim of this study was to identify and characterize stem-like cells in non-functioning pituitary adenomas (NFPAs). To this purpose primary cell cultures from 25 NFPAs were grown in culture conditions that favored stem cell growth (EGF, bFGF and B27 containing medium...

The term pseudohypoparathyroidism (PHP) defines a heterogeneous group of rare, related and deeply impairing metabolic diseases due to end-organ resistance to the actions of PTH, associated to molecular defects at the GNAS locus. Different subtypes of PHP have been described based on the existence of additional clinical features, such as resistance to other hormones acting via GPCRs and Albright’s hereditary osteodystrophy (AHO). Recently, the detection in a small subset o...

The impairment of the parathyroid hormone (PTH) signaling pathway determines a group of related and highly heterogeneous disorders associated or not with the Albright’s hereditary osteodystrophy (AHO) phenotype, classified as inactivating PTH/PTHrP signaling disorder (iPPSD). iPPSD features are rather difficult to be identified in some casesbecause manifestations are somewhat variable and some AHO characteristics are not specific to a specific disorder. Actually, besides...

The actin binding protein filamin A (FLNA) is required for somatostatin receptor 2 (SST2) and dopamine receptor 2 (DRD2) expression, intracellular localization and signaling in GH- and PRL-secreting pituitary tumors, respectively, playing a role in tumor responsiveness to somatostatin analogs and dopaminergic drugs. FLNA functions are tightly regulated by several mechanisms, including FLNA phosphorylation. It has recently been shown that in GH-secreting pituitary tumors FLNA p...