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Otolaryngologic Clinics of North America Apr 2022The pituitary gland plays a vital role in hormonal regulation. Pituitary lesions include tumors, cysts, and inflammatory processes that require multidisciplinary care... (Review)
Review
The pituitary gland plays a vital role in hormonal regulation. Pituitary lesions include tumors, cysts, and inflammatory processes that require multidisciplinary care from endocrinologists, neuro-ophthalmologists, neurosurgeons, and otolaryngologists. Treatment is typically aimed at controlling hormonal hypersecretion, decompressing the optic apparatus, and reducing tumor volume, and surgery is a common first-line approach. In this article, we provide a background on the function of the pituitary gland, common pituitary lesions, and their clinical presentations, as well as a summary of the history and physical, laboratory testing, and imaging required for the workup of a pituitary lesion.
Topics: Humans; Pituitary Gland; Pituitary Neoplasms
PubMed: 35256177
DOI: 10.1016/j.otc.2021.12.001 -
Hormones (Athens, Greece) Jun 2022Prolactin, a pituitary hormone that was discovered about 80 years ago and is primarily known for its functions in mammary gland development and lactation, is now known... (Review)
Review
Prolactin, a pituitary hormone that was discovered about 80 years ago and is primarily known for its functions in mammary gland development and lactation, is now known to participate in numerous functions across different phylogenetic groups. Fundamentally known for its secretion from lactotroph cells in adenohypophysis region of pituitary gland, newer studies have demonstrated a number of extrapituitary sites which secrete prolactin, where it acts in an autocrine, paracrine, and endocrine manner to regulate essential physiological and biochemical processes. These sites include lymphocytes, epithelial cells of lactating mammary glands, breast cancer cells of epithelial origin, and the placenta. The placenta is one of the most important organs secreting prolactin; however, its role in placental biology has not to date been reviewed comprehensively. This review elaborates upon the various facets of prolactin hormone, including prolactin production and its post-translational modifications and signaling. Major emphasis is placed on placental prolactin and its potential roles, ranging from the role of prolactin in angiogenesis, preeclampsia, maternal diabetes, and anti-apoptosis, among others.
Topics: Female; Humans; Lactation; Pituitary Gland; Placenta; Pregnancy; Prolactin; Signal Transduction
PubMed: 35545690
DOI: 10.1007/s42000-022-00373-y -
Handbook of Clinical Neurology 2021Central diabetes insipidus (CDI) occurs secondary to deficient synthesis or secretion of arginine vasopressin peptide from the hypothalamo-neurohypophyseal system (HNS).... (Review)
Review
Central diabetes insipidus (CDI) occurs secondary to deficient synthesis or secretion of arginine vasopressin peptide from the hypothalamo-neurohypophyseal system (HNS). It is characterized by polydipsia and polyuria (urine output >30mL/kg/day in adults and >2l/m/24h in children) of dilute urine (<250mOsm/L). It can result from any pathology affecting one or more components of the HNS including the hypothalamic osmoreceptors, supraoptic or paraventricular nuclei, and median eminence of the hypothalamus, infundibulum, stalk or the posterior pituitary gland. MRI is the imaging modality of choice for evaluation of the hypothalamic-pituitary axis (HPA), and a dedicated pituitary or sella protocol is essential. CT can provide complimentary diagnostic information and is also of value when MRI is contraindicated. The most common causes are benign or malignant neoplasia of the HPA (25%), surgery (20%), and head trauma (16%). No cause is identified in up to 30% of cases, classified as idiopathic CDI. Knowledge of the anatomy and physiology of the HNS is crucial when evaluating a patient with CDI. Establishing the etiology of CDI with MRI in combination with clinical and biochemical assessment facilitates appropriate targeted treatment. This chapter illustrates the wide variety of causes and imaging correlates of CDI on neuroimaging, discusses the optimal imaging protocols, and revises the detailed neuroanatomy required to interpret these studies.
Topics: Adult; Child; Diabetes Insipidus; Diabetes Insipidus, Neurogenic; Diabetes Mellitus; Humans; Magnetic Resonance Imaging; Neuroimaging; Pituitary Gland; Pituitary Gland, Posterior
PubMed: 34238459
DOI: 10.1016/B978-0-12-820683-6.00016-6 -
Frontiers in Endocrinology 2022The thyroid-stimulating hormone receptor (TSH-R) is predominantly expressed in the basolateral membrane of thyrocytes, where it stimulates almost every aspect of their... (Review)
Review
The thyroid-stimulating hormone receptor (TSH-R) is predominantly expressed in the basolateral membrane of thyrocytes, where it stimulates almost every aspect of their metabolism. Several extrathyroidal locations of the receptor have been found including: the pituitary, the hypothalamus, and other areas of the central nervous system; the periorbital tissue; the skin; the kidney; the adrenal; the liver; the immune system cells; blood cells and vascular tissues; the adipose tissue; the cardiac and skeletal muscles, and the bone. Although the functionality of the receptor has been demonstrated in most of these tissues, its physiological importance is still a matter of debate. A contribution to several pathological processes is evident in some cases, as is the case of Grave's disease in its multiple presentations. Conversely, in the context of other thyroid abnormalities, the contribution of the TSH-R and its ligand is still a matter of debate. This article reviews the several different sites of expression of the TSH-R and its potential role in both physiological and pathological processes.
Topics: Graves Disease; Humans; Immune System; Pituitary Gland; Receptors, Thyrotropin; Thyrotropin
PubMed: 35903283
DOI: 10.3389/fendo.2022.944715 -
Journal of Neuroendocrinology Nov 2021Anterior pituitary folliculostellate (FS) cells, first described almost 50 years ago, have a wide range of functions with respect to supporting and coordinating... (Review)
Review
Anterior pituitary folliculostellate (FS) cells, first described almost 50 years ago, have a wide range of functions with respect to supporting and coordinating endocrine cell function, in particular through paracrine and gap junction-mediated signalling. Our previous studies identified the morphological organisation of FS cells, which mediates coordinated calcium activity throughout the homotypic FS network and allows signalling across the whole pituitary gland. It is also clear that FS cells can modify endocrine output and feedback on pituitary axes over a range of timescales. Recently, several studies have defined FS cells as a source of anterior pituitary endocrine cell renewal, which has resulted in a renaming of FS cells as "Sox2+ve stem cells". Here, we highlight the broader potential of the FS cell population in fine-tuning and coordinating pituitary axes function. In addition, we identify a need for: the definition of the possible subtypes of FS cell and their relationship with the stem cell population; the potential role of FS cells in pulsatile hormone secretion and coordination of heterotypic cell networks; and the roles that FS cells may play in both early-life programming of pituitary axes and in memory, or anticipation, of demand. Further studies of FS cells may demonstrate the fundamental importance of this cell type and its potential as a therapeutic target to correct pituitary gland dysfunction, one of which is stem cell therapy. Clearly, a thorough understanding of all of these interactions and relationships of FS and endocrine cells is required whatever therapeutic use is suggested by their various roles.
Topics: Cells, Cultured; Endocrine Cells; Gap Junctions; Pituitary Gland; Pituitary Gland, Anterior; Pituitary Hormones, Anterior
PubMed: 34734454
DOI: 10.1111/jne.13053 -
Frontiers of Medicine Feb 2023A long-held belief is that pituitary hormones bind to their cognate receptors in classical target glands to actuate their manifold functions. However, a number of... (Review)
Review
A long-held belief is that pituitary hormones bind to their cognate receptors in classical target glands to actuate their manifold functions. However, a number of studies have shown that multiple types of pituitary hormone receptors are widely expressed in non-classical target organs. Each pituitary gland-derived hormone exhibits a wide range of nonconventional biological effects in these non-classical target organs. Herein, the extra biological functions of pituitary hormones, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, adrenocorticotrophic hormone, and prolactin when they act on non-classical organs were summarized, defined by the novel concept of an "atypical pituitary hormone-target tissue axis." This novel proposal explains the pathomechanisms of abnormal glucose and lipid metabolism, obesity, hypertension, fatty liver, and atherosclerosis while offering a more comprehensive and systematic insights into the coordinated regulation of environmental factors, genetic factors, and neuroendocrine hormones on human biological functions. The continued exploration of the physiology of the "atypical pituitary hormone-target tissue axis" could enable the identification of novel therapeutic targets for metabolic diseases.
Topics: Humans; Pituitary Hormones; Luteinizing Hormone; Follicle Stimulating Hormone; Prolactin; Pituitary Gland
PubMed: 36849623
DOI: 10.1007/s11684-022-0973-7 -
Neurosurgery Apr 2021The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the... (Review)
Review
The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the pituitary neuroendocrine tumors (PitNETs). Immunohistochemistry assay staining for pituitary hormones is the core tool for classifying PitNETs, resulting in the diagnosis of somatotroph PitNETs, lactotroph PitNETs, and so on. For cases showing no hormonal expression, the updated WHO classification system now considers the assessment of several transcription factors: PIT-1 (pituitary-specific POU-class homeodomain transcription factor); T-PIT (T-box family member TBX19); and SF-1 (steroidogenic factor regulating gonadotroph cell differentiation) before rendering a diagnosis of null cell adenoma. Other tumors and disease processes of this site often mimic PitNETs radiographically and sometimes even clinically (ie, compression of the optic chiasm). These potpourri of processes include germ cell neoplasms (especially germinomas), tumors that originate from Rathke's pouch (craniopharyngiomas, Rathke's cleft cyst), tumors that originate from the posterior lobe of the pituitary (pituicytoma, spindle cell oncocytoma, granular cell tumor), and tumors that originate from the meninges (especially meningiomas). In addition to neoplasms, several described inflammatory and related conditions exist that need to be distinguished from PitNETs. These include lymphocytic hypophysitis and Langerhans cell histiocytosis, a neoplastic disorder of histiocytes. In this review, we aim to briefly describe the main pituitary and sellar lesions, with emphasis on the most common tumors, the PitNETs.
Topics: Adenoma; Adolescent; Adult; Child; Female; Humans; Male; Middle Aged; Pituitary Gland; Pituitary Neoplasms; Young Adult
PubMed: 33476394
DOI: 10.1093/neuros/nyaa548 -
Handbook of Clinical Neurology 2021Neuroendocrine manifestations are common in Erdheim-Chester disease (ECD) patients. ECD is a rare non-Langerhans form of histiocytosis with multisystemic infiltration.... (Review)
Review
Neuroendocrine manifestations are common in Erdheim-Chester disease (ECD) patients. ECD is a rare non-Langerhans form of histiocytosis with multisystemic infiltration. The involvement of the hypothalamo-pituitary axis is common and central diabetes insipidus (CDI) is one of the most common endocrine manifestations in ECD patients. CDI is the first manifestation of ECD in 25%-48% of the cases. Suprasellar region extension, due to the infiltration of ECD lesions, can cause neurologic manifestations by mass effects, such as headache, visual disturbance, and cranial nerve palsies. Recent studies have revealed that disorders affecting anterior pituitary hormones are common in ECD patients. Secondary adrenal insufficiency, secondary hypothyroidism, (adult) growth hormone deficiency, hypogonadotropic hypogonadism, hyperprolactinemia, and hypoprolactinemia can develop as the neuroendocrine manifestations of ECD. Since the symptoms of anterior pituitary hormone deficiencies tend to be nonspecific, the diagnosis of anterior pituitary hormone dysfunctions can be delayed. Some anterior pituitary dysfunctions such as adrenocorticotropic hormone and/or thyroid-stimulating hormone deficiencies can be life-threatening without adequate hormone supplementation therapies. An endocrinological evaluation of the function of the pituitary gland should be performed at the initial diagnosis of ECD. It is important to recognize that endocrine dysfunctions can develop later during the follow-up of ECD.
Topics: Adult; Erdheim-Chester Disease; Humans; Hypopituitarism; Hypothyroidism; Pituitary Diseases; Pituitary Gland
PubMed: 34238453
DOI: 10.1016/B978-0-12-820683-6.00010-5 -
Frontiers in Endocrinology 2022The pituitary is a master gland responsible for the modulation of critical endocrine functions. Pituitary neuroendocrine tumours (PitNETs) display a considerable... (Review)
Review
The pituitary is a master gland responsible for the modulation of critical endocrine functions. Pituitary neuroendocrine tumours (PitNETs) display a considerable prevalence of 1/1106, frequently observed as benign solid tumours. PitNETs still represent a cause of important morbidity, due to hormonal systemic deregulation, with surgical, radiological or chronic treatment required for illness management. The apparent scarceness, uncommon behaviour and molecular features of PitNETs have resulted in a relatively slow progress in depicting their pathogenesis. An appropriate interpretation of different phenotypes or cellular outcomes during tumour growth is desirable, since histopathological characterization still remains the main option for prognosis elucidation. Improved knowledge obtained in recent decades about pituitary tumorigenesis has revealed that this process involves several cellular routes in addition to proliferation and death, with its modulation depending on many signalling pathways rather than being the result of abnormalities of a unique proliferation pathway, as sometimes presented. PitNETs can display intrinsic heterogeneity and cell subpopulations with diverse biological, genetic and epigenetic particularities, including tumorigenic potential. Hence, to obtain a better understanding of PitNET growth new approaches are required and the systematization of the available data, with the role of cell death programs, autophagy, stem cells, cellular senescence, mitochondrial function, metabolic reprogramming still being emerging fields in pituitary research. We envisage that through the combination of molecular, genetic and epigenetic data, together with the improved morphological, biochemical, physiological and metabolically knowledge on pituitary neoplastic potential accumulated in recent decades, tumour classification schemes will become more accurate regarding tumour origin, behaviour and plausible clinical results.
Topics: Cellular Senescence; Humans; Neuroendocrine Tumors; Pituitary Gland; Pituitary Neoplasms; Signal Transduction
PubMed: 35837315
DOI: 10.3389/fendo.2022.924942 -
Cellular and Molecular Life Sciences :... Mar 2021The pituitary plays a pivotal role in maintaining systemic homeostasis by secreting several hormones. During fetal development, the pituitary develops from the oral... (Review)
Review
The pituitary plays a pivotal role in maintaining systemic homeostasis by secreting several hormones. During fetal development, the pituitary develops from the oral ectoderm in contact with the adjacent hypothalamus. This process is regulated by the fine-tuned expression of transcription and growth factors. Impairments of this process result in congenital pituitary hypoplasia leading to dysfunction of the pituitary. Although animal models such as knockout mice have helped to clarify these underlying mechanisms, the developmental processes of the human pituitary gland and the mechanisms of human pituitary disorders have not been fully understood. This is because, at least in part, of the lack of a human pituitary developmental model. Recently, methods for in vitro induction of the pituitary gland from human pluripotent stem cells were developed. These models can be utilized not only for regenerative medicine but also for human pituitary studies on developmental biology and for modeling of pituitary disorders, such as hypopituitarism and pituitary tumors. In this review, we provide an overview of recent progress in the applications of pluripotent stem cells for pituitary research and discuss further perspectives for pituitary studies.
Topics: Animals; Cell Culture Techniques; Cell Differentiation; Cells, Cultured; Humans; Induced Pluripotent Stem Cells; Pituitary Diseases; Pituitary Gland; Pluripotent Stem Cells; Regenerative Medicine
PubMed: 33206204
DOI: 10.1007/s00018-020-03692-8