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First-generation somatostatin analogs (SSAs), such as octreotide (OCT), are the first line medical therapy for acromegaly. Pasireotide (PAS), a newly developed SSA, has shown promising results in the treatment of acromegaly. To compare the antisecretory effect of OCT and PAS in primary cultures of growth hormone (GH)-secreting pituitary adenomas (GH-omas). To correlate responses with the adenoma somatostatin receptor (SSTR) profile. The effect of OCT and PAS on GH (and PRL) secretion was tested in 33 GH-oma cultures. SSTR expression was evaluated in adenoma samples. Patients with acromegaly referred to the Erasmus Medical Center (Rotterdam, The Netherlands). OCT and PAS treatment for 72 hours (10 nM). GH (and PRL) concentrations in cell culture media. SSTR expression in adenoma samples. The overall effect of OCT (-36.8%) and PAS (-37.1%) on GH secretion was superimposable. We identified three adenoma groups: PAS+ (PAS more effective than OCT), n = 6; PAS = OCT, n = 22; and OCT+ (OCT more effective than PAS), n = 5. PAS+ adenomas showed lower somatostatin receptor subtype (sst)2 messenger RNA (mRNA) and sst2/sst5 mRNA ratio, compared with the other groups (P < 0.05). PAS inhibited PRL hypersecretion more than OCT (P < 0.01). Overall, OCT and PAS equally reduced GH secretion in vitro. Adenomas with lower sst2 mRNA expression and lower sst2/sst5 mRNA ratio were better responders to PAS compared with OCT. SSTR evaluation in GH-omas may become a tool for tailored SSA treatment in acromegaly.

Pituitary somatotroph adenomas result in dysregulated growth hormone (GH) hypersecretion and acromegaly; however, regulatory mechanisms that promote GH hypersecretion remain elusive. Here, we provide evidence that STAT3 directly induces somatotroph tumor cell GH. Evaluation of pituitary tumors revealed that STAT3 expression was enhanced in human GH-secreting adenomas compared with that in nonsecreting pituitary tumors. Moreover, STAT3 and GH expression were concordant in a somatotroph adenoma tissue array. Promoter and expression analysis in a GH-secreting rat cell line (GH3) revealed that STAT3 specifically binds the Gh promoter and induces transcription. Stable expression of STAT3 in GH3 cells induced expression of endogenous GH, and expression of a constitutively active STAT3 further enhanced GH production. Conversely, expression of dominant-negative STAT3 abrogated GH expression. In primary human somatotroph adenoma-derived cell cultures, STAT3 suppression with the specific inhibitor S3I-201 attenuated GH transcription and reduced GH secretion in the majority of derivative cultures. In addition, S3I-201 attenuated somatotroph tumor growth and GH secretion in a rat xenograft model. GH induced STAT3 phosphorylation and nuclear translocation, indicating a positive feedback loop between STAT3 and GH in somatotroph tumor cells. Together, these results indicate that adenoma GH hypersecretion is the result of STAT3-dependent GH induction, which in turn promotes STAT3 expression, and suggest STAT3 as a potential therapeutic target for pituitary somatotroph adenomas.

Anterior pituitary is critical for endocrine systems. Its hormonal responses to positive and negative regulators are indispensable for homeostasis. For this reason, generating human anterior pituitary tissue that retains regulatory hormonal control in vitro is an important step for the development of cell transplantation therapy for pituitary diseases. Here we achieve this by recapitulating mouse pituitary development using human embryonic stem cells. We find that anterior pituitary self-forms in vitro following the co-induction of hypothalamic and oral ectoderm. The juxtaposition of these tissues facilitated the formation of pituitary placode, which subsequently differentiated into pituitary hormone-producing cells. They responded normally to both releasing and feedback signals. In addition, after transplantation into hypopituitary mice, the in vitro -generated corticotrophs rescued physical activity levels and survival of the hosts. Thus, we report a useful methodology for the production of regulator-responsive human pituitary tissue that may benefit future studies in regenerative medicine. It is difficult to generate functional human anterior pituitary tissues in vitro . Here, Ozone et al. generate human anterior pituitary from embryonic stem cells by recapitulating in vivo development, and demonstrate this tissue secretes hormones and rescues hypopituitarism when grafted into mice.

In teleosts, growth hormone (GH) production is governed by multiple neuroendocrine factors from the hypothalamus and other regulators from the pituitary and peripheral organs. Exploring the principles followed by pituitary somatotropes when differentiating and integrating the signals from these regulators at the cellular and intracellular level is essential for understanding the endocrine regulation network of growth hormone synthesis and secretion in fish. This paper discusses recent advances in the action mechanisms of GH regulation factors, including the neuroendocrine regulators, pituitary level factors and peripheral factors, primarily involved in their receptor systems as well as in post-receptor signal transduction pathways.

PurposeThe aim of this study was to generate immortalized human anterior pituitary adenoma cells. Reliable cell models for the study of human pituitary adenomas are as yet lacking and studies performed so far used repeated passaging of freshly excised adenomas, with the attendant limitations due to limited survival in culture, early senescence, and poor reproducibility.Methods & ResultsWe devised a technique based upon repeated co-transfections of two retroviral vectors, one carrying the catalytic subunit of human telomerase, hTERT, the other SV40 large T antigen. This approach extended the lifespan of cells derived from a human growth hormone-secreting adenoma up to 18 months while retaining morphology of primary cells, growth hormone synthesis and growth hormone secretion.ConclusionsOur attempt represents the first demonstration of successful lifespan extension of human growth hormone-secreting pituitary adenoma cells via co-transfection of hTERT and SV40T and paves the way to future attempts to obtain stable cell lines.

Dysregulated growth hormone (GH) hypersecretion is usually caused by a GH-secreting pituitary adenoma and leads to acromegaly - a disorder of disproportionate skeletal, tissue, and organ growth. High GH and IGF1 levels lead to comorbidities including arthritis, facial changes, prognathism, and glucose intolerance. If the condition is untreated, enhanced mortality due to cardiovascular, cerebrovascular, and pulmonary dysfunction is associated with a 30% decrease in life span. This Review discusses acromegaly pathogenesis and management options. The latter include surgery, radiation, and use of novel medications. Somatostatin receptor (SSTR) ligands inhibit GH release, control tumor growth, and attenuate peripheral GH action, while GH receptor antagonists block GH action and effectively lower IGF1 levels. Novel peptides, including SSTR ligands, exhibiting polyreceptor subtype affinities and chimeric dopaminergic-somatostatinergic properties are currently in clinical trials. Effective control of GH and IGF1 hypersecretion and ablation or stabilization of the pituitary tumor mass lead to improved comorbidities and lowering of mortality rates for this hormonal disorder.

Pituitary dysfunction with abnormal growth hormone (GH) secretion and neurocognitive deficits are common consequences of traumatic brain injury (TBI). Recognizing the comorbidity of these symptoms is of clinical importance; however, efficacious treatment is currently lacking. A review of studies in PubMed published between January 1980 to March 2020 and ongoing clinical trials was conducted using the search terms \"growth hormone,\" \"traumatic brain injury,\" and \"gut microbiome.\" Increasing evidence has implicated the effects of TBI in promoting an interplay of ischemia, cytotoxicity, and inflammation that renders a subset of patients to develop postinjury hypopituitarism, severe fatigue, and impaired cognition and behavioral processes. Recent data have suggested an association between abnormal GH secretion and altered gut microbiome in TBI patients, thus prompting the description of a hypothesized new clinical syndrome called \"brain injury associated fatigue and altered cognition.\" Notably, these patients demonstrate distinct characteristics from those with GH deficiency from other non-TBI causes in that their symptom complex improves significantly with recombinant human GH treatment, but does not reverse the underlying mechanistic cause as symptoms typically recur upon treatment cessation. The reviewed data describe the importance of alterations of the GH/insulin-like growth factor I axis and gut microbiome after brain injury and its influence in promoting neurocognitive and behavioral deficits in a bidirectional relationship, and highlight a new clinical syndrome that may exist in a subset of TBI patients in whom recombinant human GH therapy could significantly improve symptomatology. More studies are needed to further characterize this clinical syndrome.

Purpose β-thalassemia major (βTM) frequently leads to endocrinological complications of chronic transfusion-induced iron overload, including growth hormone deficiency (GHD). With contrasting data on GHD in adult βTM populations, our study aimed to reevaluate the diagnosis of GHD using multiple tests and its progression over time. Methods Two experimental studies were conducted in adult βTM patients to assess GH secretory status. The first study reevaluated GH secretion after two years using a GHRH plus arginine test performed initially and during follow-up. The second study applied a glucagon stimulation test to those initially diagnosed with severe GHD, comparing the results with those of a GHRH plus arginine test. Results The first study involved 80 patients: 67 patients had normal GH secretion at the first test, confirmed in 57 of them. Of the 13 initially diagnosed with GHD, only 3 were confirmed at the second test. The second study included 91 patients: 18 of the initially identified as having severe GHD, were tested with another challenge, but only 6 confirmed severe GHD, suggesting a possible risk of overdiagnosis in initial evaluations. Conclusions The marked variability in GHD diagnoses among adult patients with βTM highlights the need for multiple diagnostic tests to improve accuracy and avoid unnecessary interventions. Our findings highlight the importance of reassessing GH secretory reserves with multiple tests at multiple time points, supporting a cautious approach to hormone replacement therapy, suggesting to start it only when clearly indicated.

OBJECTIVE: To evaluate the therapeutic trends and long-term outcome of treatment modalities for acromegaly in our center over a 40-year period. Design: We retrospectively studied 321 acromegalic patients (145 males/176 females) diagnosed and treated from the 1970s until September 2013. Patients were divided into two subgroups: group A consisted of 166 patients diagnosed before 1990 and group B of 155 patients diagnosed after 1990. Outcome was assessed with GH (random and/or post OGTT) and IGF1 measurements. RESULTS: More group A than group B patients were submitted to radiotherapy (57.8% vs 16.8% patients, respectively, p <0.001). In contrast, more patients of group B were offered surgery (70.3% vs 42.1% in group A, p <0.001) and/or medical treatment (70.3% vs 23.4% in group A, p <0.001). At latest follow-up, 68.4 % of patients in group B achieved GH <2.5 µg/l after treatment vs 39.8% in group A, p=0.001, 46.9% of patients in group B achieved GH <1 µg/l vs 20.3% in group A, p=0.001 and 47.1% of patients in group B achieved during OGTT GH nadir <0.4 µg/l vs 18.6% in group A, p=0.001. CONCLUSIONS: Transsphenoidal resection and medical treatment resulted in improved outcome in acromegalic patients treated over the last 20 years. However, the disease still remains uncontrolled in a considerable number of patients.

Betaine is a methyl derivative of glycine first isolated from sugar beets. Betaine consumed from food sources and through dietary supplements presents similar bioavailability and is metabolized to di-methylglycine and sarcosine in the liver. The ergogenic and clinical effects of betaine have been investigated with doses ranging from 500 to 9,000 mg/day. Some studies using animal models and human subjects suggest that betaine supplementation could promote adiposity reductions and/or lean mass gains. Moreover, previous investigations report positive effects of betaine on sports performance in both endurance- and resistance-type exercise, despite some conflicting results. The mechanisms underlying these effects are poorly understood, but could involve the stimulation of lipolysis and inhibition of lipogenesis via gene expression and subsequent activity of lipolytic-/lipogenic-related proteins, stimulation of autocrine/endocrine IGF-1 release and insulin receptor signaling pathways, stimulation of growth hormone secretion, increased creatine synthesis, increases in protein synthesis via intracellular hyper-hydration, as well as exerting psychological effects such as attenuating sensations of fatigue. However, the exact mechanisms behind betaine action and the long-term effects of supplementation on humans remain to be elucidated. This review aims to describe evidence for the use of betaine as an ergogenic and esthetic aid, and discuss the potential mechanisms underlying these effects.