Faculty Opinions recommendation of SOX2-expressing progenitor cells generate all of the major cell types in the adult mouse pituitary gland.

This report describes the development and validation of the rGHp-Cre transgenic mouse that allows for selective Cre-mediated recombination of loxP-modified alleles in the GH-producing cells of the anterior pituitary. Initial screening of the rGHp-Cre parental line showed Cre mRNA was specifically expressed in the anterior pituitary gland of adult Cre+/− mice and cephalic extracts of e17 Cre+/− fetuses. Heterozygote rGHp-Cre transgenic mice were crossbred with Z/AP reporter mice to generate Cre+/−,Z/AP+/− offspring. In this model system, the GH promoter-driven, Cre-mediated recombination of the Z/AP reporter leads to human placental alkaline phosphatase (hPLAP) expression that serves to mark cells that currently produce GH, in addition to cells that would have differentiated from GH cells but currently do not express the GH gene. Double immunocytochemistry of adult male and female Cre+/−,Z/AP+/− pituitary cells revealed the majority (∼99%) of GH-producing cells of the anterior pituitary also expressed hPLAP, whereas ACTH-, TSH-, and LH-producing cells were negative for hPLAP, confirming previous reports that corticotropes, thyrotropes, and gonadotropes develop independently of the somatotrope lineage. A small subset (∼10%) of the prolactin-producing cells was positive for hPLAP, consistent with previous reports showing lactotropes can arise from somatotropes during pituitary development. However, the fact that 90% of prolactin-producing cells were negative for hPLAP suggests that the majority of lactotropes in the adult mouse pituitary gland develop independently of the somatotrope lineage. In addition to developmental studies, the rGHp-Cre transgenic mouse will provide a versatile tool to study the role of a variety of genes in somatotrope function and neoplastic transformation.

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Epithelial cell integrin β1 is required for developmental angiogenesis in the pituitary gland

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1614970113 ◽

2016 ◽

Vol 113 (47) ◽

pp. 13408-13413 ◽

Cited By ~ 7

Author(s):

Kathleen M. Scully ◽

Dorota Skowronska-Krawczyk ◽

Michal Krawczyk ◽

Daria Merkurjev ◽

Havilah Taylor ◽

...

Keyword(s):

Epithelial Cells ◽

Pituitary Gland ◽

Molecular Mechanisms ◽

Cell Types ◽

Endocrine Function ◽

Vascular Density ◽

Integrin Β1 ◽

Coordinated Development ◽

Mouse Pituitary ◽

Insight Into

As a key component of the vertebrate neuroendocrine system, the pituitary gland relies on the progressive and coordinated development of distinct hormone-producing cell types and an invading vascular network. The molecular mechanisms that drive formation of the pituitary vasculature, which is necessary for regulated synthesis and secretion of hormones that maintain homeostasis, metabolism, and endocrine function, remain poorly understood. Here, we report that expression of integrin β1 in embryonic pituitary epithelial cells is required for angiogenesis in the developing mouse pituitary gland. Deletion of pituitary epithelial integrin β1 before the onset of angiogenesis resulted in failure of invading endothelial cells to recruit pericytes efficiently, whereas deletion later in embryogenesis led to decreased vascular density and lumen formation. In both cases, lack of epithelial integrin β1 was associated with a complete absence of vasculature in the pituitary gland at birth. Within pituitary epithelial cells, integrin β1 directs a large transcriptional program that includes components of the extracellular matrix and associated signaling factors that are linked to the observed non–cell-autonomous effects on angiogenesis. We conclude that epithelial integrin β1 functions as a critical and canonical regulator of developmental angiogenesis in the pituitary gland, thus providing insight into the long-standing systems biology conundrum of how vascular invasion is coordinated with tissue development.

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Improved immunolabelling of ultrathin cryosections using antibody conjugated with 1nm gold particles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016220x ◽

1990 ◽

Vol 48 (3) ◽

pp. 928-929

Author(s):

Morten H. Nielsen ◽

Lone Bastholm

Keyword(s):

Pituitary Gland ◽

Liquid Nitrogen ◽

Electron Density ◽

Small Diameter ◽

Cytochemical Staining ◽

Gold Particles ◽

Labelling Density ◽

Ultrathin Cryosections ◽

Mouse Pituitary ◽

Electron Microscopical

During the last 5 years the diameter of the gold probes used for immuno-cytochemical staining at the electron microscopical (EM) level has been decreased. The advantage of small diameter gold probes is an overall increased labelling density. The disadvantage is a lower detectability due to the low electron density of smaller gold particles consequently an inconvenient high primary magnification needed for EM examination. Since 1 nm gold particles are barely visible by conventional EM examination the need for enlargement by silverenhancement of the gold particles has increased.In the present study of ultrathin cryosectioned material the results of immunostaining using 5 nm gold conjugated antibody and 1 nm gold conjugated antibodies are compared after silverenhancement of the 1 nm gold particles.Slices of freshly isolated mouse pituitary gland were immersion fixed for 20 min in 2 % glutaraldehyde /2 % paraformaldehyde. Blocks cryoprotected with 2.3 M sucrose were frozen in liquid nitrogen and ultra-cryosectioned on a RMC cryoultra-microtome.

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The functional significance of glycosylation of proopiomelanocortin in melanotrophs of the mouse pituitary gland

Journal of Endocrinology ◽

10.1677/joe.0.1070365 ◽

1985 ◽

Vol 107 (3) ◽

pp. 365-374 ◽

Cited By ~ 6

Author(s):

B. G. Jenks ◽

A. G. H. Ederveen ◽

J. H. M. Feyen ◽

A. P. van Overbeeke

Keyword(s):

Pituitary Gland ◽

Functional Significance ◽

Peptide Hormones ◽

Terminal Region ◽

Pars Intermedia ◽

Apparent Effect ◽

Glycoprotein Precursor ◽

Tunicamycin Treatment ◽

Mouse Pituitary

ABSTRACT Pro-opiomelanocortin (POMC) is a glycoprotein precursor for a number of neuropeptides and peptide hormones. The functional significance of the glycosylation of POMC has never been established. Using the antibiotic tunicamycin to block glycosylation of the prohormone in the mouse pars intermedia, we have compared processing of non-glycosylated prohormone with that of glycosylated prohormone in pulse-chase experiments. The peptides produced from non-glycosylated prohormone were shown to be correct cleavage products. Therefore it was concluded that, with the possible exception of peptides from the N-terminal region of the prohormone, the carbohydrate on POMC plays no role in directing cleavage or in protecting the prohormone from random proteolysis. Tunicamycin treatment retarded N-terminal acetylation of melanotrophin but had no apparent effect on acetylation of β-endorphin. The mouse pars intermedia synthesizes two forms of POMC which differ in their degree of glycosylation. Our results indicated that, during secretion, the melanotrophs make no distinction between peptides derived from the two prohormones. J. Endocr. (1985) 107, 365–374

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Comparative Analysis of the Frequency and Distribution of Stem and Progenitor Cells in the Adult Mouse Brain

Stem Cells ◽

10.1634/stemcells.2007-0919 ◽

2008 ◽

Vol 26 (4) ◽

pp. 979-987 ◽

Cited By ~ 51

Author(s):

Mohammad G. Golmohammadi ◽

Daniel G. Blackmore ◽

Beatrice Large ◽

Hassan Azari ◽

Ebrahim Esfandiary ◽

...

Keyword(s):

Comparative Analysis ◽

Progenitor Cells ◽

Mouse Brain ◽

Adult Mouse ◽

Adult Mouse Brain ◽

Stem And Progenitor Cells

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Human leukemia mutations corrupt but do not abrogate GATA-2 function

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1813015115 ◽

2018 ◽

Vol 115 (43) ◽

pp. E10109-E10118 ◽

Cited By ~ 14

Author(s):

Koichi R. Katsumura ◽

Charu Mehta ◽

Kyle J. Hewitt ◽

Alexandra A. Soukup ◽

Isabela Fraga de Andrade ◽

...

Keyword(s):

Dna Binding ◽

Progenitor Cells ◽

Zinc Finger ◽

Erythroid Differentiation ◽

Cell Types ◽

Myeloid Differentiation ◽

Human Leukemia ◽

Hematopoietic Stem ◽

Amino Terminal ◽

Disease Mutations

By inducing the generation and function of hematopoietic stem and progenitor cells, the master regulator of hematopoiesis GATA-2 controls the production of all blood cell types. Heterozygous GATA2 mutations cause immunodeficiency, myelodysplastic syndrome, and acute myeloid leukemia. GATA2 disease mutations commonly disrupt amino acid residues that mediate DNA binding or cis-elements within a vital GATA2 intronic enhancer, suggesting a haploinsufficiency mechanism of pathogenesis. Mutations also occur in GATA2 coding regions distinct from the DNA-binding carboxyl-terminal zinc finger (C-finger), including the amino-terminal zinc finger (N-finger), and N-finger function is not established. Whether distinct mutations differentially impact GATA-2 mechanisms is unknown. Here, we demonstrate that N-finger mutations decreased GATA-2 chromatin occupancy and attenuated target gene regulation. We developed a genetic complementation assay to quantify GATA-2 function in myeloid progenitor cells from Gata2 −77 enhancer-mutant mice. GATA-2 complementation increased erythroid and myeloid differentiation. While GATA-2 disease mutants were not competent to induce erythroid differentiation of Lin−Kit+ myeloid progenitors, unexpectedly, they promoted myeloid differentiation and proliferation. As the myelopoiesis-promoting activity of GATA-2 mutants exceeded that of GATA-2, GATA2 disease mutations are not strictly inhibitory. Thus, we propose that the haploinsufficiency paradigm does not fully explain GATA-2–linked pathogenesis, and an amalgamation of qualitative and quantitative defects instigated by GATA2 mutations underlies the complex phenotypes of GATA-2–dependent pathologies.

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IGF-I regulates pro-opiomelanocortin and GH gene expression in the mouse pituitary gland

Journal of Endocrinology ◽

10.1677/joe.0.1780071 ◽

2003 ◽

Vol 178 (1) ◽

pp. 71-82 ◽

Cited By ~ 10

Author(s):

J Honda ◽

Y Manabe ◽

R Matsumura ◽

S Takeuchi ◽

S Takahashi

Keyword(s):

Pituitary Gland ◽

Anterior Pituitary ◽

Northern Blotting ◽

Pituitary Cells ◽

Mrna Levels ◽

Gh Treatment ◽

Gh Receptor ◽

Pomc Mrna ◽

Igf I ◽

Mouse Pituitary

IGF-I is expressed in somatotrophs, and IGF-I receptors are expressed in most somatotrophs and some corticotrophs in the mouse pituitary gland. Our recent study demonstrated that IGF-I stimulates the proliferation of corticotrophs in the mouse pituitary. These results suggested that somatotrophs regulate corticotrophic functions as well as somatotrophic functions by the mediation of IGF-I molecules. The present study aimed to clarify factors regulating pituitary IGF-I expression and also the roles exerted by IGF-I within the mouse anterior pituitary gland. Mouse anterior pituitary cells were isolated and cultured under serum-free conditions. GH (0.5 or 1 microg/ml), ACTH (10(-8) or 10(-7) M), GH-releasing hormone (GHRH; 10(-8) or 10(-7) M), dexamethasone (DEX; 10(-8) or 10(-7) M) and estradiol-17beta (e2; 10(-11) or 10(-9) M) were given for 24 h. IGF-I mRNA levels were measured using competitive RT-PCR, and GH and pro-opiomelanocortin (POMC) mRNA levels were measured using Northern blotting analysis. GH treatment significantly increased IGF-I mRNA levels (1.5- or 2.1-fold). ACTH treatment did not alter GH and IGF-I mRNA levels. IGF-I treatment decreased GH mRNA levels (0.7- or 0.5-fold), but increased POMC mRNA levels (1.8-fold). GH treatment (4 or 8 microg/ml) for 4 days increased POMC mRNA levels. GHRH treatment increased GH mRNA levels (1.3-fold), but not IGF-I mRNA levels. DEX treatment significantly decreased IGF-I mRNA levels (0.8-fold). e2 treatment did not affect IGF-I mRNA levels. GH receptor mRNA, probably with GH-binding protein mRNA, was detected in somatotrophs, and some mammotrophs and gonadotrophs by in situ hybridization using GH receptor cDNA as a probe. These results suggested that IGF-I expression in somatotrophs is regulated by pituitary GH, and that IGF-I suppresses GH expression and stimulates POMC expression at the transcription level. Pituitary IGF-I produced in somatotrophs is probably involved in the regulation of somatotroph and corticotroph functions.

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