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Frontiers in Endocrinology 2020The pituitary gland has the primordial ability to dynamically adapt its cell composition to changing hormonal needs of the organism throughout life. During the first... (Review)
Review
The pituitary gland has the primordial ability to dynamically adapt its cell composition to changing hormonal needs of the organism throughout life. During the first weeks after birth, an impressive growth and maturation phase is occurring in the gland during which the distinct hormonal cell populations expand. During pubertal growth and development, growth hormone (GH) levels need to peak which requires an adaptive enterprise in the GH-producing somatotrope population. At aging, pituitary function wanes which is associated with organismal decay including the somatopause in which GH levels drop. In addition to these key time points of life, the pituitary's endocrine cell landscape plastically adapts during specific (patho-)physiological conditions such as lactation (need for PRL) and stress (engagement of ACTH). Particular resilience is witnessed after physical injury in the (murine) gland, culminating in regeneration of destroyed cell populations. In many other tissues, adaptive and regenerative processes involve the local stem cells. Over the last 15 years, evidence has accumulated that the pituitary gland houses a resident stem cell compartment. Recent studies propose their involvement in at least some of the cell remodeling processes that occur in the postnatal pituitary but support is still fragmentary and not unequivocal. Many questions remain unsolved such as whether the stem cells are key players in the vivid neonatal growth phase and whether the decline in pituitary function at old age is associated with decreased stem cell fitness. Furthermore, the underlying molecular mechanisms of pituitary plasticity, in particular the stem cell-linked ones, are still largely unknown. Pituitary research heavily relies on transgenic mouse models. While having proven their value, answers to pituitary stem cell-focused questions may more diligently come from a novel powerful research model, termed organoids, which grow from pituitary stem cells and recapitulate stem cell phenotype and activation status. In this review, we describe pituitary plasticity conditions and summarize what is known on the involvement and phenotype of pituitary stem cells during these pituitary remodeling events.
Topics: Animals; Humans; Pituitary Diseases; Pituitary Gland; Stem Cells
PubMed: 33584539
DOI: 10.3389/fendo.2020.604519 -
Microscopy Research and Technique Jan 1992Various drugs and hormones influence the light microscopic and especially the electron microscopic structure of the anterior pituitary and its tumors. Many structural... (Review)
Review
Various drugs and hormones influence the light microscopic and especially the electron microscopic structure of the anterior pituitary and its tumors. Many structural effects are known only from animal experiments since specimens from human pituitaries are mostly not available. The structure of growth hormone (GH) cells is relatively stable. A massive GH cell hyperplasia is known only in rare cases with growth hormone releasing factor (GRF) excess from tumors. Prolactin cells can be stimulated by drugs, neurotransmitters, and hormones which decrease the dopamine inhibition. Adrenocorticotropic hormone (ACTH) cells are stimulated by stress, some hormones, loss of adrenals, and drugs which activate the alpha 1- and beta-receptors or inhibit the alpha 2-receptors. They are suppressed and changed into Crooke's cells by treatment with glucocorticoids. Thyroid-stimulating hormone (TSH) cells increase in number and size in states for overstimulation especially by thyrotropin releasing hormone (TRH). A decrease results from hyperthyroidism and possibly from somatostatin, L-dopa, and dopamine. Gonadotroph cells transform into castration cells in strongly hyperactive states (gonadectomy, antiandrogens, gonadotropin releasing hormone [Gn-RH]agonists, aminoglutethimide). Special types of pituitary adenomas can be treated with drugs which suppress hormone production and proliferation. Dopamine agonists and somatostatin reduce the tumor size of varying proportions of GH secreting adenomas in acromegaly. Ultrastructurally, a decrease of cytoplasmic and nuclear volume and an increase of lysosomes are found. Bromocriptine and other dopamine agonists are established in the treatment of prolactin secreting adenomas. They induce a shrinkage in many cases. Ultrastructurally, a reduction of cellular and nuclear size, an increase in number of secretory granules and of lysosomes, and a reduction of rough endoplasmic reticulum can be demonstrated.
Topics: Adenoma; Animals; Humans; Pituitary Gland; Pituitary Hormones; Pituitary Neoplasms
PubMed: 1547357
DOI: 10.1002/jemt.1070200205 -
Journal of Neuropathology and... Oct 2019Human prion diseases including sporadic Creutzfeldt-Jakob disease (sCJD), inherited prion diseases, and acquired human prion diseases are lethal neurodegenerative...
Human prion diseases including sporadic Creutzfeldt-Jakob disease (sCJD), inherited prion diseases, and acquired human prion diseases are lethal neurodegenerative diseases. One of the major sources of iatrogenic Creutzfeldt-Jakob disease was human growth hormone (hGH-iCJD) derived from contaminated cadaveric pituitaries. The incidence of hGH-iCJD has decreased since changing from growth hormone extracted from human cadaveric pituitaries to recombinant pituitary hormones. However, extensive analysis on the localization and detecting of abnormal prion protein in the pituitary gland are limited. In this study, we examined 9 autopsied brains and pituitary glands from 6 patients with prion disease (3 Gerstmann-Sträussler-Scheinker disease, 2 sCJD, and 1 dura mater graft-associated CJD) and 3 individuals with nonprion diseases. Western blot analysis of pituitary samples demonstrated unique glycoforms of normal cellular prion protein with molecular weights of 30-40 kDa, which was higher than the typical 25-35 kDa prion protein in brains. Proteomic analysis also revealed prion protein approximately the molecular weight of 40 kDa in pituitary samples. Moreover, proteinase K-resistant Prion protein was frequently detected in pituitary samples of the prion diseases. Immunohistochemistry for Prion protein revealed mosaic cellular distribution preferentially in growth hormone- or prolactin-producing cells.
Topics: Aged; Aged, 80 and over; Brain; Female; Humans; Male; Middle Aged; Pituitary Gland; PrPSc Proteins; Prion Diseases; Proteomics
PubMed: 31504701
DOI: 10.1093/jnen/nlz075 -
General and Comparative Endocrinology May 2019The pituitary is a central organ of the neuro-endocrine system in fish that plays critical roles in various physiological processes, including stress response and...
The pituitary is a central organ of the neuro-endocrine system in fish that plays critical roles in various physiological processes, including stress response and behavior. Although it is known that pituitary hormones can have a direct or indirect influence stimulating or suppressing the immune responses, whether there is a local immune response in the pituitary or what is the effect of the immune stimulus on the pituitary function in fish is unknown. With the aim to understand the interaction between the immune responses and the endocrine axes at the pituitary level, particularly the Hypothalamus-Pituitary-Interrenal (HPI) axis, pituitaries of rainbow trout (Oncorhynchus mykiss) were cultured in vitro, incubated with bacterin, or bacterin plus CRH, cortisol, human recombinant IL1β, or spleen medium for 3 h, and then genes involved in pro-inflammation (il1β, il8, tnfα1, ifnγ), anti-inflammation (tgfβ1b, il10), immune modulation (mhcIIa, c3, mif) and stress response (crhbp, pomca, pomcb, gr1) were tested. Data showed that, incubation with bacterin alone and bacterin plus recombinant IL1β or CRH, as well as medium from bacterin treated spleen caused significant up-regulation of pro-inflammatory genes il1β and il8, while down-regulated the anti-inflammatory gene tgfβ1b. Besides, recombinant IL1β plus bacterin or alone caused raise of mhcIIa and tnfa, respectively. On the contrary, just a slight or even no alteration was recorded in the expression of stress response genes including crhbp, pomca, pomcb and gr1 in the in vitro cultured trout pituitary following this stimulation. These results suggest a local immune gene equipment in the pituitary of fish, and the potential for fish pituitary to develop both innate and adaptive immune responses, whereas that immune stimulation was not able to evoke a significant endocrine stress response in vitro.
Topics: Animals; Anti-Inflammatory Agents; Bacterial Vaccines; Cells, Cultured; Gene Expression Regulation; Hydrocortisone; Immunity, Active; Inflammation Mediators; Oncorhynchus mykiss; Organ Culture Techniques; Pituitary Gland; Vibrio
PubMed: 30769010
DOI: 10.1016/j.ygcen.2019.02.011 -
Endocrinology Jul 1983Recent evidence indicates that endogenous GnRH is required for maintenance of its own pituitary receptors (GnRH-R). We have measured GnRH-R in pituitaries of...
Recent evidence indicates that endogenous GnRH is required for maintenance of its own pituitary receptors (GnRH-R). We have measured GnRH-R in pituitaries of hypogonadotrophic hypogonadal (hpg) mice, in whom hypothalamic GnRH is deficient or absent. The GnRH-R concentration in hpg male mouse pituitaries was 10.6 +/- 1 fmol/pituitary vs. 30.9 +/- 1 fmol/pituitary in normal male littermate pituitaries. Similarly, GnRH-R in female hpg mice (15.2 +/- 1.7 fmol/pituitary) were 30% those of normal random cycling females (51.4 +/- 3.5 fmol/pituitary). There was no difference in receptor affinity (Ka = 1.5-3 C 10(9) M-1) of hpg mouse pituitaries. The pituitary LH content in hpg male and female mice was very similar (range 3.4-4.8 micrograms/pituitary) representing 5% and 19% of normal male (95 +/- 7.2 micrograms/pituitary) and female (18.1 +/- 1.5 micrograms/pituitary) values, respectively. The administration of 50 ng GnRH sc 10 times daily to male hpg mice, increased GnRH-R to 80% of normal values within 3 days. Serum FSH and pituitary FSH content rose to normal male values after 7 days of GnRH injections. However, serum LH remained undetectable and pituitary LH reached only 20% of normal male levels, even after 15 days of GnRH administration. Treatment of hpg male mice with 60 ng GnRH either once daily for 6 days, or 12 times daily for 5 days, increased GnRH-R to 50% of normal male values. Twelve daily injections of GnRH elevated serum FSH to above the normal male range, whereas daily GnRH only doubled untreated hpg levels. Pituitary FSH was stimulated to 50% of normal with 12 daily injections, whereas once daily administration elevated pituitary FSH to 30% of normal values. Both pulsatile regimes depleted pituitary LH. These data demonstrate that: 1) despite absence of bioactive GnRH, GnRH-R values are only reduced to 30% of normal in hpg mouse pituitaries, suggesting that little, if any, endogenous GnRH is required for expression of GnRH receptors. 2) Pituitary GnRH-R number rapidly increase when GnRH is administered to hpg male mice indicating that, as in the rat, GnRH positively regulates its own receptor concentration. 3) The pituitary FSH and LH responses to GnRH treatment in hpg mice depends to a different extent on the frequency and duration of GnRH administration. 4) The hpg mouse provides an ideal animal model for investigating the interaction of defined regiments of exogenous GnRH and gonadal steroids on pituitary GnRH receptor and gonadotroph function.
Topics: Animals; Female; Follicle Stimulating Hormone; Gonadotropin-Releasing Hormone; Hypogonadism; Luteinizing Hormone; Male; Mice; Mice, Inbred Strains; Pituitary Gland; Receptors, Cell Surface; Receptors, LHRH
PubMed: 6305640
DOI: 10.1210/endo-113-1-55 -
International Review of Cell and... 2013This chapter reviews the functions of arginine vasotocin (AVT) and its receptors in the central nervous system (CNS) of primarily submammalian vertebrates. The V1a-type... (Review)
Review
This chapter reviews the functions of arginine vasotocin (AVT) and its receptors in the central nervous system (CNS) of primarily submammalian vertebrates. The V1a-type receptor, which is widely distributed in the CNS of birds, amphibians, and fish, is one of the most important receptors involved in the expression of social and reproductive behaviors. In mammals, the V1b receptor of arginine vasopressin, an AVT ortholog, is assumed to be involved in aggression, social memory, and stress responses. The distribution of the V1b-type receptor in the brain of submammalian vertebrates has only been reported in an amphibian species, and its putative functions are discussed in this review. The functions of V2-type receptor in the CNS are still unclear. Recent phylogenetical and pharmacological analyses have revealed that the avian VT1 receptor can be categorized as a V2b-type receptor. The distribution of this newly categorized VT1 receptor in the brain of avian species should contribute to our knowledge of the possible roles of the V2b-type receptor in the CNS of other nonmammalian vertebrates. The functions of AVT in the amphibian and avian pituitaries are also discussed, focusing on the V1b- and V1a-type receptors.
Topics: Amino Acid Sequence; Animals; Arginine Vasopressin; Molecular Sequence Data; Pituitary Gland; Receptors, Vasopressin; Vertebrates
PubMed: 23809437
DOI: 10.1016/B978-0-12-407696-9.00004-X -
Annals of the New York Academy of... Apr 2005As studied by single cell RT-PCR of pituitary hormones, we demonstrated that the pituitaries of rats and mice contain a subpopulation of cells that express two or more... (Comparative Study)
Comparative Study Review
As studied by single cell RT-PCR of pituitary hormones, we demonstrated that the pituitaries of rats and mice contain a subpopulation of cells that express two or more hormone phenotypes typically belonging to lineages that are branched separately early during embryonic development, such as glycoprotein hormone alpha-subunit (alphaGSU) mRNA + PRL mRNA, alphaGSU mRNA + POMC mRNA, and POMC mRNA + GH or PRL mRNA. GnRH in vitro selectively expands the population of cells coexpressing alphaGSU mRNA + PRL mRNA, and CRH selectively increases the proportion of cells coexpressing alphaGSU mRNA + POMC mRNA. Colocalization of alphaGSU + PRL or alphaGSU + POMC could not be detected by double immunofluorescence. This lineage promiscuity was also observed in the pituitary in vivo.
Topics: Animals; Cell Lineage; Combinatorial Chemistry Techniques; Gene Expression Regulation; Mice; Phenotype; Pituitary Gland; Pituitary Hormones; Rats
PubMed: 15891010
DOI: 10.1196/annals.1327.010 -
Anatomical Science International Mar 2021Corticotrophs produce a hormone that stimulates the adrenal gland cortex to secrete glucocorticoids, which in turn have effects on carbohydrate and protein metabolism....
Corticotrophs produce a hormone that stimulates the adrenal gland cortex to secrete glucocorticoids, which in turn have effects on carbohydrate and protein metabolism. Quantification, morphological characteristics, and distribution of corticotrophs in the anterior pituitary and changes in the number and shape of the cells during aging have been examined using immunohistochemical and morphometric methods. The material consisted of 14 anterior pituitaries taken from cadavers at routine autopsy. The tissue was processed by standard histological procedure and the obtained slices were stained by the monoclonal anti-ACTH antibody for corticotrophs identification. Digital images of stained histological sections were analyzed using the morphometric method with the Image J system. The volume density of ACTH positive cells was determined. The cases were classified into three age groups. One-way ANOVA showed that the volume density of the corticotrophs was significantly higher in the second and third group in relation to the first group. The difference in the volume densities of the corticotrophs between the genders was not significant. Morphometric and statistical analyses demonstrated a significant positive correlation between the corticotrophs volume densities and the age of the evaluated cases. Linear regression showed that age significantly predicts corticotrophs volume density. Corticotrophs significantly increase during the life span.
Topics: Adrenocorticotropic Hormone; Adult; Aged; Aged, 80 and over; Aging; Cell Shape; Female; Humans; Immunohistochemistry; Male; Middle Aged; Pituitary Gland, Anterior
PubMed: 33098535
DOI: 10.1007/s12565-020-00583-7 -
Theriogenology Feb 2023The activity of the pituitary gland determines the success of female reproduction. The knowledge regarding the reproductive-status-related changes in the transcriptome...
The activity of the pituitary gland determines the success of female reproduction. The knowledge regarding the reproductive-status-related changes in the transcriptome of the porcine pituitary is limited. This study aimed to determine and compare the transcriptome profile of the pituitary gland collected from pigs during maternal recognition of pregnancy, i.e. on days 12-13 of pregnancy and during the respective days of the estrous cycle. Analysis indicated 482 differentially expressed genes (DEGs) with an FC > 1.5 (P < 0.05) in the pituitary of pregnant vs. estrous-cyclic pigs. Among them, 68 were up-regulated and 414 were down-regulated. The evaluated DEGs were annotated into 39 gene ontology (GO) biological process terms, 13 GO cellular component terms, and 10 GO molecular function terms. Among the evaluated DEGs were selected genes coding for proteins potentially involved in the regulation of early pregnancy in pigs and used for gene interaction analysis and validation of microarray results. An analysis of the relationships among DEGs in pituitaries collected during maternal recognition of pregnancy showed that some of them are connected with, for example, TGFβ signaling pathway, PRL synthesis, adipocytokines pathway and immune response during maternal recognition of pregnancy. These findings expand the knowledge regarding the molecular mechanisms appearing in the porcine pituitary during the maternal recognition period of pregnancy.
Topics: Pregnancy; Female; Swine; Animals; Transcriptome; Pituitary Gland, Anterior; Reproduction; Pituitary Gland; Estrous Cycle
PubMed: 36542881
DOI: 10.1016/j.theriogenology.2022.11.039 -
Scientific Reports Apr 2016The folliculostellate cells of the mammalian pituitary are non-endocrine cells that are implicated in long-distance communication and paracrine signaling, but to date,...
The folliculostellate cells of the mammalian pituitary are non-endocrine cells that are implicated in long-distance communication and paracrine signaling, but to date, these cells have yet to be characterized in teleosts. We found that the stellate cells of the teleost pituitary share many common attributes with mammalian folliculostellate cells. By labeling of stellate cells in live preparations of tilapia pituitaries we investigated their distribution, association with other endocrine cells and their anatomical and functional coupling. In the pars intermedia, stellate cells were arranged around neuronal bundles and their processes extended into the pars distalis. Within the pars distalis, stellate cells formed close associations with FSH cells and, to a lesser degree, with GH and LH cells, suggesting differential paracrine regulation of the two gonadotrope populations. The production of follistatin by stellate cells further corroborates the notion of a paracrine role on FSH release. We also found stellate cells to form gap junctions that enabled dye transfer to neighboring stellate cells, implicating that these cells form a large-scale network that connects distant parts of the pituitary. Our findings represent the first wide-scale study of stellate cells in teleosts and provide valuable information regarding their functional roles in pituitary function.
Topics: Animals; Follistatin; Gap Junctions; Paracrine Communication; Pituitary Gland; Tilapia
PubMed: 27086978
DOI: 10.1038/srep24426