Endocrine Abstracts

cAMP is an ubiquitous second messenger that is implicated in the regulation of a wide variety of cell functions, including cell proliferation that is differently affected depending on the cell type. Although the effects exerted by cAMP were initially attributed to PKA activation, two exchange proteins directly activated by cAMP (Epac1/2) have been identified as cAMP targets able to mediate several cAMP effects. Aim of this study was to investigate the effect of cAMP on neuroen...

The rate of diagnosis of pituitary adenomas in the elderly is increasing, as a consequence of the improved life expectancy. The management of elderly patients affected by pituitary adenomas are still a subject of debate in literature. In particular, data on the safety of endoscopic transnasal transsphenoidal surgery (TNS) are still controversial. The primary endpoint of the present study is to assess the surgical outcome of a cohort of patients who underwent TNS for non-functi...

Treatment options for neuroendocrine tumors (NET), including everolimus, are rarely curative, as NETs frequently show resistance to medical therapy. In fact, the use of everolimus, an mTOR inhibitor, is limited by the development of resistance, probably due to the activation of Akt signalling. Metformin seems to have anticancer effects in neuroendocrine tumors (NETs). A recent retrospective study found longer progression-free-survival in diabetic pancreatic neuroendocrine tumo...

Somatostatin (SS) binds to different SS receptors (SSTR1–5) and SS analogues are the first choice medical treatment of GH-secreting pituitary adenomas (GH-omas). A subset of patients is resistant to SS, although the mechanisms involved in SS resistance are not fully understood. Recent studies identified specific protein–protein interactions as determinant in the regulation of receptor anchoring and signalling. Filamin A (FLNA) is a widely expressed cytoskeleton prote...

The two main subtypes of pseudohypoparathyroidism (PHP), PHP-Ia and -Ib, are caused by mutations in GNAS exons 1–13 and methylation defects in the imprinted GNAS cluster, respectively. PHP-Ia patients show Albright hereditary osteodystrophy (AHO) and resistance toward PTH and additional hormones, while PHP-Ib patients do not have AHO and hormone resistance is limited to PTH and TSH. Recently, methylation defects have been detected in 5 patients with PHP-Ia, indicating a m...

GH-secreting and non-functioning pituitary tumors are clinically distinct, usually benign but potentially locally aggressive lesions originating from the replication of a single mutated pituitary cell. As for the underlying genetic and epigenetic alterations, also the patterns of activation of specific signaling pathways as well as the prognostic molecular factors leading to local invasiveness are, to date, largely unknown. In this study, we used two-dimensional electrophoresi...

Pseudohypoparathyroidism (PHP) is a disorder characterized by hypocalcemia and hyperphosphatemia due to end-organ resistance to the action of PTH. The two main subtypes of PHP, PHP type Ia and Ib are caused by heterozygous loss-of-function mutations in GNAS exons 1–13, which encode Gsα, and by methylation defects in the imprinted GNAS cluster, respectively. Individuals affected with PHP-Ia typically show clinical abnormalities referred to as Albright hereditary osteo...

Somatostatin (SS) is a widely distributed polypeptide that exerts inhibitory effects on hormone secretion and cell proliferation by interacting with five different receptors (SST1-SST5), that display important differences in tissue distribution, coupling to second messengers, affinity for SS and intracellular trafficking. SS analogues currently used in the treatment of acromegaly inhibit hormone secretion and cell proliferation by binding to SST2 and 5. Beta-arrestins have bee...

Aim of this study was to evaluate the impact of rhGH treatment on glucose and lipid metabolism in in 26 patients (17M and 9F, age 47.0±11.1 years) with adult onset GH deficiency. Metabolic parameters (fasting glucose and insulin, glycated haemoglobin, lipid profile, body composition, OGTT) and indices of insulin resistance (IR) and sensitivity (IS), i.e. homeostasis model assessment (HOMA-IR and derived ISI-HOMA), quantitative insulin check index (QUICKI), ISI-composite, ...

Long-term effects of trans-naso-sphenoidal surgery (TNS) and long-acting somatostatin analogs (SSTa) on hypotalamic-pituitary-adrenal (HPA) function have been poorly investigated. Aim of the study was to evaluate over time the integrity of HPA axis in acromegalic patients with baseline preserved adrenal function and treated with one or both available treatments. We selected 23 patients (15F & 8M, age (±S.D.)=46.8±13.7 yrs) with normal (n=19)...