Expression of mRNA coding for pituitary hormones and pituitary-specific transcription factor in the pituitary gland of the rdw rat with hereditary dwarfism

1993 ◽  
Vol 138 (2) ◽  
pp. 307-313 ◽  
Author(s):  
K. Shibayama ◽  
Y. Ohyama ◽  
M. Ono ◽  
S. Furudate
Keyword(s):  
Transcription Factor ◽  
Pituitary Gland ◽  
Mouse Strains ◽  
Northern Hybridization ◽  
Pituitary Hormone ◽  
Β Subunit ◽  
Glycoprotein Hormone ◽  
Α Subunit ◽  
Specific Transcription Factor ◽  
Significant Difference

ABSTRACT The rdw rat (gene symbol: rdw) with hereditary dwarfism has been shown immunohistochemically to have subnormal numbers not only of GH- but also of prolactin- and thyrotrophin-positive cells. To characterize the dwarfism of this strain, the expression of pituitary hormone mRNAs was examined by Northern hybridization. The pituitary gland in the rdw rat expressed 30–100 times less GH and prolactin mRNAs than normal controls, whereas mRNAs for pro-opiomelanocortin and the α subunit of rat glycoprotein hormone revealed a significant increase. There was a non-significant difference in rat LH-β subunit and FSH-β subunit between normal and rdw rats. The suppressed expression of a pituitary-specific transcription factor, Pit-1, is considered to cause hereditary dwarfism in mouse strains Snell and Jackson, whose phenotypes resemble those of the rdw rat. In this study, however, no difference in mRNA expression for Pit-1 was found between rdw rats and controls. This work indicates that the rdw rat may not have the same genotype as the phenotypically similar dwarf mice, Snell, Jackson and Ames. Journal of Endocrinology (1993) 138, 307–313

scholarly journals Pituitary transcription factor Prop-1 stimulates porcine pituitary glycoprotein hormone α subunit gene expression

2006 ◽  
Vol 37 (2) ◽  
pp. 341-352 ◽  
Author(s):  
Takanobu Sato ◽  
Kousuke Kitahara ◽  
Takao Susa ◽  
Takako Kato ◽  
Yukio Kato
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Binding Sites ◽  
Gh3 Cells ◽  
Pituitary Hormone ◽  
Transcriptional Level ◽  
Β Subunit ◽  
Glycoprotein Hormone ◽  
Α Subunit

Recently, we have reported that a Prophet of Pit-1 homeodomain factor, Prop-1, is a novel transcription factor for the porcine follicle-stimulating hormone β subunit (FSHβ) gene. This study subsequently aimed to examine the role of Prop-1 in the gene expression of two other porcine gonadotropin subunits, pituitary glycoprotein hormone α subunit (αGSU), and luteinizing hormone β subunit (LHβ). A series of deletion mutants of the porcine αGSU (up to −1059 bp) and LHβ (up to −1277 bp) promoters were constructed in the reporter vector, fused with the secreted alkaline phosphatase gene (pSEAP2-Basic). Transient transfection studies using GH3 cells were carried out to estimate the activation of the porcine αGSU and LHβ promoters by Prop-1, which was found to activate the αGSU promoter of −1059/+12 bp up to 11.7-fold but not the LHβ promoter. Electrophoretic mobility shift assay and DNase I footprinting analysis revealed that Prop-1 binds to six positions, −1038/−1026, −942/−928, −495/−479, −338/−326, −153/−146, and −131/−124 bp, that comprise the A/T cluster. Oligonucleotides of six Prop-1 binding sites were directly connected to the minimum promoter of αGSU, fused in the pSEAP2-Basic vector, followed by transfecting GH3 cells to determine the cis-acting activity. Finally, we concluded that at least five Prop-1 binding sites are the cis-acting elements for αGSU gene expression. The present results revealed a notable feature of the proximal region, where three Prop-1-binding sites are close to and/or overlap the pituitary glycoprotein hormone basal element, GATA-binding element, and junctional regulatory element. To our knowledge, this is the first demonstration of the role of Prop-1 in the regulation of αGSU gene expression. These results, taken together with our previous finding that Prop-1 is a transcription factor for FSHβ gene, confirm that Prop-1 modulates the synthesis of FSH at the transcriptional level. On the other hand, the defects of Prop-1 are known to cause dwarfism and combined pituitary hormone deficiency accompanying hypogonadism. Accordingly, the present observations provide a novel view to understand the hypogonadism caused by Prop-1 defects at the molecular level through the regulatory mechanism of αGSU and FSHβ gene expressions.

scholarly journals Thyroid hormone regulation of mRNAs encoding thyrotropin β-subunit, glycoprotein α-subunit, and thyroid hormone receptors α and β in brain, pituitary gland, liver, and gonads of an adult teleost, Pimephales promelas

2009 ◽  
Vol 202 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Sean C Lema ◽  
Jon T Dickey ◽  
Irvin R Schultz ◽  
Penny Swanson
Keyword(s):  
Thyroid Hormone ◽  
Pituitary Gland ◽  
Teleost Fish ◽  
Hormone Receptors ◽  
Pimephales Promelas ◽  
Early Gene ◽  
Thyroid Hormone Receptors ◽  
Β Subunit ◽  
Glycoprotein Hormone ◽  
Α Subunit

Thyroid hormones (THs) regulate growth, morphological development, and migratory behaviors in teleost fish, yet little is known about the transcriptional dynamics of gene targets for THs in these taxa. Here, we characterized TH regulation of mRNAs encoding thyrotropin subunits and thyroid hormone receptors (TRs) in an adult teleost fish model, the fathead minnow (Pimephales promelas). Breeding pairs of adult minnows were fed diets containing 3,5,3′-triiodo-l-thyronine (T3) or the goitrogen methimazole for 10 days. In males and females, dietary intake of exogenous T3 elevated circulating total T3, while methimazole depressed plasma levels of total thyroxine (T4). In both sexes, this methimazole-induced reduction in T4 led to elevated mRNA abundance for thyrotropin β-subunit (tshβ) in the pituitary gland. Fish treated with T3 had elevated transcript levels for TR isoforms α and β (trα and trβ) in the liver and brain, but reduced levels of brain mRNA for the immediate-early gene basic transcription factor-binding protein (bteb). In the ovary and testis, exogenous T3 elevated gene transcripts for tshβ, glycoprotein hormone α-subunit (gphα), and trβ, while not affecting trα levels. Taken together, these results demonstrate negative feedback of T4 on pituitary tshβ, identify trα and trβ as T3-autoinduced genes in the brain and liver, and provide new evidence that tshβ, gphα, and trβ are THs regulated in the gonad of teleosts. Adult teleost models are increasingly used to evaluate the endocrine-disrupting effects of chemical contaminants, and our results provide a systemic assessment of TH-responsive genes during that life stage.

scholarly journals Activation of the Thyroid-Stimulating Hormone β-Subunit Gene by LIM Homeodomain Transcription Factor Lhx2

Endocrinology ◽  
2007 ◽  
Vol 148 (7) ◽  
pp. 3468-3476 ◽  
Author(s):  
Kee K. Kim ◽  
Seok B. Song ◽  
Kwang I. Kang ◽  
Myungchull Rhee ◽  
Kyoon Eon Kim
Keyword(s):  
Transcription Factor ◽  
Reporter Gene ◽  
Thyroid Stimulating Hormone ◽  
Β Subunit ◽  
Subunit Gene ◽  
Mobility Shift ◽  
Glycoprotein Hormone ◽  
Α Subunit ◽  
Homeodomain Transcription Factor ◽  
Lim Homeodomain

Although there is evidence that the LIM homeodomain transcription factor, Lhx2, can stimulate transcription of the glycoprotein hormone α-subunit gene, the role of Lhx2 in regulating TSH β-subunit has not been established. In the present studies, the ability of Lhx2 to regulate transcription of the TSH β-subunit gene was examined. In the thyrotrope-derived TαT1 cell line, Lhx2 expression was found to be induced by treatment with either TRH or cAMP, consistent with the possibility that Lhx2 may play a role in mediating the ability of this signaling pathway to stimulate TSH gene expression. Transient, forced overexpression of Lhx2 stimulated activity of a TSH β-subunit reporter gene. Deletion studies provided evidence that the −177 to −79 region of the TSH β-subunit promoter was necessary for stimulation of reporter gene activity by Lhx2. A gel mobility shift assay provided the evidence that Lhx2 can bind to this region of DNA. DNase I footprinting studies demonstrated that two distinct regions of the TSHβ promoter, −118 to −108 and −86 to −68, are protected by Lhx2 from nuclease digestion. These regions contain repeats of the sequence, 5′-(G/T)CAAT(T/A)-3′. Mutation of this sequence, especially in the −86 to −68 region, substantially decreased Lhx2 responsiveness of the TSH β-subunit reporter gene. In addition, a DNA fragment containing the −177 to −79 region of the TSHβ promoter was found to confer Lhx2 responsiveness to a minimal promoter. These results provide multiple lines of evidence consistent with a role for Lhx2 in modulating expression of the TSH β-subunit gene.

scholarly journals Evaluation of pituitary imaging in patients with PROP-1 gene mutation

Medicina ◽  
2009 ◽  
Vol 45 (9) ◽  
pp. 693 ◽  
Author(s):  
Natalija Tkačenko ◽  
Danutė Lašienė ◽  
Silvija Jakštienė ◽  
Algidas Basevičius ◽  
Rasa Verkauskienė
Keyword(s):  
Transcription Factor ◽  
Pituitary Gland ◽  
Gene Mutation ◽  
Anterior Pituitary ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Imaging Studies ◽  
Pituitary Hyperplasia ◽  
Pituitary Hypoplasia ◽  
Genetically Determined

The most common genetically determined cause of multiple pituitary hormone deficiency is PROP-1 gene mutation. PROP-1 is a transcription factor involved in the development of pituitary gland and affects hormonal synthesis of anterior pituitary. The aim of our study was to evaluate radiological aspects of the pituitary region in patients with PROP-1 gene mutation. Pituitary imaging studies were performed in 12 patients with a confirmed PROP-1 gene mutation. Pituitary hyperplasia was found in 5 (42%) and pituitary hypoplasia in 4 (33%) patients. Changes in pituitary size were not associated with the type of PROP-1 gene mutation.

158 PRODUCTION OF RECOMBINANT LH FOR USE IN TIGER (TIGRIS ALTAICA) ASSISTED REPRODUCTION:A PRELIMINARY REPORT

2008 ◽  
Vol 20 (1) ◽  
pp. 159
Author(s):  
J. T. Aaltonen ◽  
E. Bedows ◽  
K. A. Estes ◽  
V. Y. Butnev ◽  
G. Bousfield ◽  
...  
Keyword(s):  
Leydig Cell ◽  
Chinese Hamster ◽  
Granulosa Cell Tumor ◽  
Methionine Sulfoximine ◽  
Β Subunit ◽  
Wild Type ◽  
Glycoprotein Hormone ◽  
Α Subunit ◽  
Cell Assay ◽  
Cell Assays

Genetically, porcine LH is the closest commercially available gonadotropin analog to tiger LH (93% homologous); however, its use may lead to possible autoimmune reactions, lessening ovarian responses in stimulated tigresses over time (Crichton et al. 2005 Biol. Reprod. 68, 105–113). To overcome this problem for use in assisted reproduction, we produced recombinant tiger LH (tLH), and tested the bioactivity of several tLH constructs using heterologous (rat) and homologous (cat) Leydig cell assays. To clone tLH, mRNA was isolated from an Amur tiger pituitary by TRIzol extraction (Invitrogen, Carlsbad, CA). DNA was synthesized from the mRNA using reverse transcriptase (Stratagene, La Jolla, CA) and PCR was performed using tiger-specific primers for glycoprotein hormone α subunit or LH β subunit. The α subunit was cloned into the double-expression vector pIRES (Invitrogen). The tLH β subunit was cloned into the second site of pIRES and also into the plasmid pGS. Chinese hamster ovary (CHO) K1 and human granulosa cell tumor (COV 434) cells were transfected with plasmid DNA by calcium-phosphate precipitation: (1) pIRES containing α and pGS containing LH β, or (2) pIRES containing α and LH β. Cells were grown in selection media (250 µg mL–1 geneticine for pIRES, or 25 µm methionine sulfoximine for pGS). Media was collected and clarified at 1500g for 30 min. An immature rat Leydig cell assay protocol (Bousfield et al. 2001 Biol. Reprod. 64, 136–147) detected biological activity (testosterone production) by RIA. Of 14 tLH constructs created, 1 wild-type construct (LH WTCHO8) had LH activity 3 times greater than any other. A domestic kitten Leydig cell assay was performed in order to assess comparative sensitivities and specificities. Domestic kitten testicles, obtained from a local spay clinic, were disassociated with collagenase (225 U mg–1, Worthington Biochemical, Lakewood, NJ); however, the cells were more difficult to disperse than rat testicles, leading to low Leydig cell yields as determined histologically. Modification of the Leydig cell collagenase protocol for the cat was achieved by increasing the temperature and surface area, and agitating the minced tissue in medium on a stir plate. Samples of the 14 tLH constructs were run in parallel using rat and cat Leydig cell assays. Although rat Leydig cell testosterone concentrations (3.4 ng mL–1) were nearly 10-fold greater, the same trend for the different constructs was found in the cat Leydig cells with the same wild-type construct (LH WTCHO8, 0.37 ng mL–1) having greater LH activity than any other. The lower testosterone concentrations in the cat bioassay may be explained by insufficient Leydig cell numbers, age (sensitivity), damaging effect(s) of collagenase, or felid specificity. Still, these results lend validity to the use of the heterologous rat Leydig cell bioassay for recombinant tiger LH.

FSH in therapy: physiological basis, new preparations and clinical use

1995 ◽  
Vol 4 (3) ◽  
pp. 163-177 ◽  
Author(s):  
Manuela Simoni ◽  
Eberhard Nieschlag
Keyword(s):  
Follicle Stimulating Hormone ◽  
Thyroid Stimulating Hormone ◽  
Clinical Use ◽  
Β Subunit ◽  
Glycoprotein Hormone ◽  
Physiological Basis ◽  
Α Subunit ◽  
And Function ◽  
Polypeptide Chains ◽  
Stimulating Hormone

Follicle stimulating hormone (FSH) is a glycoprotein hormone secreted by the pituitary gland that, together with luteinizing hormone (LH), controls development, maturation and function of the gonad. Like the related hormones, LH, thyroid stimulating hormone (TSH) and human chorionic gonadotropin (hCG), FSH consists of two polypeptide chains, α and β, bearing carbohydrate moietiesN-linked to asparagine (Asn) residues. The α subunit is common to all members of the glycoprotein hormone family, whereas the β subunit, although structurally very similar, differs in each hormone and confers specificity of action.

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