scholarly journals Thyrotrophin receptor protein expression in normal and adenomatous human pituitary

2000 ◽  
Vol 167 (1) ◽  
pp. 7-13 ◽  
Author(s):  
M Theodoropoulou ◽  
T Arzberger ◽  
Y Gruebler ◽  
Z Korali ◽  
P Mortini ◽  
...  
Keyword(s):  
Protein Expression ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Preliminary Evidence ◽  
Positive Control ◽  
Negative Control ◽  
Receptor Protein ◽  
Human Pituitary ◽  
Thyrotrophin Releasing Hormone ◽  
Regulatory Pathways

Thyrotrophin (TSH) synthesis and secretion is under the positive control of thyrotrophin releasing hormone and under the negative control of the thyroid hormones. However, it is hypothesised that TSH has a direct effect on the regulation of its own synthesis through an intrapituitary loop mediated by pituitary TSH receptors (TSH-R). The aim of this investigation was to study the expression of TSH-R in normal human pituitary at mRNA and protein levels, and to compare the pattern of protein expression between different pituitary adenomas. Using RT-PCR we were able to detect TSH-R mRNA in the normal pituitary, and immunohistochemical studies showed TSH-R protein expression in distinct areas of the anterior pituitary. Double immunostaining with antibodies against each of the intrapituitary hormones and S100 revealed that TSH-R protein is present in thyrotrophs and folliculostellate cells. Examination of 58 pituitary adenomas, including two clinically active and two clinically inactive thyrotroph adenomas, revealed TSH-R immunopositivity in only the two clinically inactive thyrotroph adenomas. This study shows, for the first time, the presence of TSH-R protein in the normal anterior pituitary and in a subset of thyrotroph adenomas. The expression of TSH-R in the thyrotroph and folliculostellate cell subpopulations provides preliminary evidence of a role for TSH in autocrine and paracrine regulatory pathways within the anterior pituitary gland.

143 PRESENCE OF PROSTAGLANDIN F2α RECEPTOR IN IN VITRO-DERIVED MORULA AND BLASTOCYST STAGE BOVINE EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 180 ◽  
Author(s):  
F. N. Scenna ◽  
J. L. Edwards ◽  
G. M. Pighetti ◽  
F. N. Schrick
Keyword(s):  
Embryonic Development ◽  
Protein Expression ◽  
Room Temperature ◽  
Positive Control ◽  
Blastocyst Stage ◽  
Receptor Protein ◽  
Bovine Embryos ◽  
Pvdf Membrane ◽  
Receptor Mrna

Culture of in vitro and in vivo-derived embryos in medium containing prostaglandin F2� (PGF) decreased embryonic development to blastocyst stage and reduced hatching rates (Scenna et al. Prostaglandins 73, 215-226). Moreover, administration of an inhibitor of PGF synthesis at the time of embryo transfer in bovine recipients improved pregnancy rates (Schrick et al. 2001 Theriogenology 59, 335 abstr.). These findings indicate a direct negative effect of PGF on embryonic development. However, to our knowledge, no evidence of PGF receptor expression in morula or blastocyst stage bovine embryos is available in the literature. Therefore, the objective of the current study was to determine the presence of PGF receptor mRNA using real-time RT-PCR and protein expression by Western blotting in morula or blastocyst stage in vitro bovine embryos. Briefly, isolated total RNA from compact morula or blastocyst stage embryos and from bovine tongue epithelium (positive control for PGF receptor mRNA) were reverse-transcribed into cDNA. A volume from the RT reaction equivalent to 10 embryos per tube was utilized to determine transcripts for PGF receptor and Histone H2A (standard PCR control). Polymerase chain reaction was performed, and identity of PCR fragments was confirmed by ethidium-bromide-stained 2% agarose gel electrophoresis and by DNA sequencing. To determine protein expression, morula and blastocyst stage embryos were lysed in lysis buffer (10% SDS, 1 m Tris pH 7.5, 1 m NaF, 1 m DTT, 0.1 m EGTA with protease inhibitors) and stored at -20�C. Crude proteins isolated from bovine corpora lutea (positive control for PGF receptor protein), embryo samples, and prestained standards were separated by 12% SDS-PAGE under reducing conditions. Proteins were electrotransferred onto a PVDF membrane. Nonspecific binding sites in the PVDF membrane were blocked with 10% nonfat dry milk, and the blot was washed and incubated for 1 h at room temperature with a 1:1000 dilution of the primary antibody (rabbit polyclonal antibody against PGF receptor protein). Subsequently, the blot was washed and incubated for 1 h at room temperature with 1:1000 dilution of mouse anti-rabbit IgG conjugated with horseradish peroxidase. Finally, the blot was washed and revealed by chemiluminescence in a CCD camera. Results indicated that transcripts as well as the protein for PGF receptor were present in early stage bovine embryos. Identification of PGF receptor in morula and blastocyst stage bovine embryos may, in part, explain the increase in pregnancy rates after administration of a PGF synthesis inhibitor at the time of embryo transfer, which opens up the possibility to develop new strategies to prevent detrimental effects of PGF during early embryonic development.

scholarly journals Expression of guanylyl cyclase-B (GC-B/NPR2) receptors in normal human fetal pituitaries and human pituitary adenomas implicates a role for C-type natriuretic peptide

2012 ◽  
Vol 19 (4) ◽  
pp. 497-508 ◽  
Author(s):  
Iain R Thompson ◽  
Annisa N Chand ◽  
Peter J King ◽  
Olaf Ansorge ◽  
Niki Karavitaki ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Natriuretic Peptide ◽  
Cell Lines ◽  
Expression Profile ◽  
Guanylyl Cyclase ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Pituitary Cell ◽  
Human Pituitary ◽  
Normal Human

C-type natriuretic peptide (CNP/Nppc) is expressed at high levels in the anterior pituitary of rats and mice and activates guanylyl cyclase B receptors (GC-B/Npr2) to regulate hormone secretion. Mutations in NPR2/Npr2 can cause achondroplasia, GH deficiency, and female infertility, yet the normal expression profile within the anterior pituitary remains to be established in humans. The current study examined the expression profile and transcriptional regulation of NPR2 and GC-B protein in normal human fetal pituitaries, normal adult pituitaries, and human pituitary adenomas using RT-PCR and immunohistochemistry. Transcriptional regulation of human NPR2 promoter constructs was characterized in anterior pituitary cell lines of gonadotroph, somatolactotroph, and corticotroph origin. NPR2 was detected in all human fetal and adult pituitary samples regardless of age or sex, as well as in all adenoma samples examined regardless of tumor origin. GC-B immunoreactivity was variable in normal pituitary, gonadotrophinomas, and somatotrophinomas. Maximal transcriptional regulation of the NPR2 promoter mapped to a region within −214 bp upstream of the start site in all anterior pituitary cell lines examined. Electrophoretic mobility shift assays revealed that this region contains Sp1/Sp3 response elements. These data are the first to show NPR2 expression in normal human fetal and adult pituitaries and adenomatous pituitary tissue and suggest a role for these receptors in both pituitary development and oncogenesis, introducing a new target to manipulate these processes in pituitary adenomas.

Expression of serine proteases and metalloproteinases in human pituitary adenomas and anterior pituitary lobe tissue

2003 ◽  
Vol 106 (5) ◽  
pp. 471-478 ◽  
Author(s):  
Ulrich J. Knappe ◽  
Christian Hagel ◽  
Bj�rn W. Lisboa ◽  
Waldemar Wilczak ◽  
Dieter K. L�decke ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Serine Proteases ◽  
Anterior Pituitary ◽  
Human Pituitary ◽  
Human Pituitary Adenomas

Pit-1/GHF-1 expression in pituitary adenomas: further analogy between human adenomas and rat SMtTW tumours

1993 ◽  
Vol 11 (2) ◽  
pp. 129-139 ◽  
Author(s):  
M Delhase ◽  
P Vergani ◽  
A Malur ◽  
B Velkeniers ◽  
E Teugels ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Cell Types ◽  
Cell Type ◽  
Human Pituitary ◽  
Normal Human ◽  
Cell Commitment

ABSTRACT Adenomas can develop from each cell type of the anterior pituitary. In the normal pituitary, three of these cell types, the GH-, prolactin- and TSH-secreting cells, express the transcription factor Pit-1/GHF-1 which is responsible for prolactin and GH (and probably TSH) cell commitment, differentiation, probably proliferation and gene expression. We have analysed the expression of Pit-1/GHF-1 in a panel of human pituitary adenomas. All GH-, prolactin- and TSH-expressing adenomas studied expressed the Pit-1/GHF-1 factor, as demonstrated by in-situ hybridization and immunocytochemistry. The expression was higher in adenomas than in normal human pituitary. In contrast, ACTH- and LH—FSH-secreting and non-secreting adenomas were negative. Seven transplants of the spontaneous rat prolactinoma SMtTW were also investigated and all were found to be positive. This further stresses the analogy between these tumours and human prolactinomas. Taken together, the data confirm that Pit-1/GHF-1 expression is restricted to GH-, prolactin- and TSH-expressing cells, and the increased expression in adenomas is compatible with a role of Pit-1/GHF-1 in cell proliferation.

scholarly journals Expression of 5'-deiodinase enzymes in normal pituitaries and in various human pituitary adenomas

2002 ◽  
pp. 263-268 ◽  
Author(s):  
A Baur ◽  
M Buchfelder ◽  
J Kohrle
Keyword(s):  
Thyroid Hormone ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Potent Inhibitor ◽  
Feedback Regulation ◽  
Cellular Distribution ◽  
Limited Information ◽  
Human Pituitary ◽  
Normal Tissues ◽  
Human Anterior Pituitary

OBJECTIVE: Local 5'-deiodination of l-thyroxine (T(4)) to active thyroid hormone 3,3',5-tri-iodothyronine (T(3)) catalyzed by the two 5'-deiodinase enzymes (D1 and D2) regulates various T(3)-dependent functions in the anterior pituitary and has been well studied in rodents. Only limited information about deiodinase expression and its cellular distribution in human anterior pituitaries is available. DESIGN: We examined 5'-deiodinase enzyme activities in pituitary adenomas (18 non-functioning, seven TSH-producing, one GH- and TSH-producing, five GH-producing, eight prolactin (PRL)-producing, two adenomas each from patients with Cushing's disease and Nelson's syndrome) and three normal anterior pituitaries. METHODS: Activities were measured as release of (125)I(-) from tyrosyl-ring labeled reverse T(3) with or without propylthiouracil, a potent inhibitor of D1 which does not influence D2 activities. RESULTS: Most of the adenomas and normal tissues expressed both isoenzymes, with D2 activity higher than D1. In a few tissues D1 activity was higher than D2 and some tissues did not express D1 activity at all. Highest activities of both enzymes were found in TSH- and PRL-producing adenomas but absolute activities and the D1/D2 ratio were variable in the same kind of tumor in different patients. CONCLUSION: The finding that all examined tissues expressed 5'-deiodinase activity, most of them expressing both isoenzymes, implies that both enzymes are still active in tumors and that local deiodination is important for the function and feedback regulation of human anterior pituitary.

scholarly journals Reduced expression levels of the cell-cycle inhibitor p27Kip1 in human pituitary adenomas

1999 ◽  
pp. 250-255 ◽  
Author(s):  
CM Bamberger ◽  
M Fehn ◽  
AM Bamberger ◽  
DK Ludecke ◽  
FU Beil ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Cellular Proliferation ◽  
Cell Types ◽  
Null Cell ◽  
Human Pituitary ◽  
Expression Levels ◽  
Cell Cycle Inhibitor ◽  
Null Cell Adenomas

The molecular mechanisms leading to increased cellular proliferation rates and, thus, tumor formation in the anterior pituitary gland are poorly understood. The cyclin-dependent kinase inhibitor p27Kip1 is a key molecule regulating the G1 phase of the cell cycle in many cell types. Furthermore, it was shown that p27 knock-out mice develop pro-opiomelanocortin-positive pituitary tumors. In an effort to clarify the role of p27 in the normal and tumorous human pituitary, we studied the expression of p27 by immunohistochemistry, using a highly specific mouse monoclonal anti-human p27 antibody. Normal pituitaries and 54 pituitary adenomas (twelve somatotrope adenomas, nine prolactinomas, twelve corticotrope adenomas, three TSH-producing tumors, six gonadotrope adenomas, six null cell adenomas, and six oncocytomas) were analyzed. p27 expression was determined semiquantitatively with regard to both the percentage of positive cells and the intensity of the staining. Normal human pituitaries showed strong expression of p27 in most nuclei. In contrast, the levels of p27 were reduced in the majority of the tumors analyzed. Twenty-two tumors (six somatotrope adenomas, five prolactinomas, four corticotrope adenomas, two TSH-producing tumors, two gonadotrope adenomas, and three null cell adenomas) were completely p27-negative. In 18 tumors, p27 expression was found in < or = 10% of the cells. In the other ten tumors, 11-80% of the cells were p27-positive. In summary, we were able to demonstrate reduced expression levels of the cell-cycle inhibitor p27 in tumors derived from all pituitary cell types. Our data indicate that p27 may be an important regulator of cellular proliferation in the anterior pituitary, the underexpression of which could play a role in pituitary tumorigenesis.

Apoptosis and p53 suppressor gene protein expression in human anterior pituitary adenomas

1997 ◽  
Vol 136 (4) ◽  
pp. 382-387 ◽  
Author(s):  
Victoria L Green ◽  
Michael C White ◽  
Leslie J Hipkin ◽  
Richard V Jeffreys ◽  
Patrick M Foy ◽  
...  
Keyword(s):  
Protein Expression ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
P53 Protein ◽  
Tumour Size ◽  
Suppressor Gene ◽  
Tumour Suppressor ◽  
Tumour Type ◽  
P53 Protein Expression ◽  
Human Anterior Pituitary

Abstract Human anterior pituitary adenomas proliferate and express the p53 tumour suppressor gene protein, but it is not known if apoptosis (programmed cell death) occurs. Therefore, the detection of apoptosis was undertaken in tumorous human anterior pituitary tissue and compared with p53 protein expression, tumour type and tumour size. Apoptosis (detected by the in situ end labelling technique) and p53 suppressor gene protein (detected by DO. 1-antibody immunocytochemistry) were determined in formalin-fixed and paraffin-embedded tissue from 37 human pituitary adenomas (2 macroprolactinomas, 9 somatotrophinomas and 26 non-functioning adenomas). Two normal anterior pituitaries were also included in this study. Pre-operative tumour size was scored 1 to 4 from magnetic resonance imaging radiology. Apoptosis was found in 7 of 29 tumours (24%), 11% of somatotrophinomas and 33% of non-functioning adenomas, although this difference was not significant. The p53 tumour suppressor protein was found in 7 of 31 tumours (23%), 33% of somatotrophinomas and 19% of nonfunctioning adenomas. Apoptosis and p53 protein expression were not found in normal anterior pituitary. In conclusion, apoptosis occurs in human anterior pituitary adenomas, but no significant association was found between apoptosis and p53 protein expression, tumour type or tumour size. European Journal of Endocrinology 136 382–387

Fine Structural Classification of Chromophobe Adenomas of the Human Pituitary Gland

1975 ◽  
Vol 33 ◽  
pp. 378-379
Author(s):  
K. Kovacs ◽  
E. Horvath
Keyword(s):  
Pituitary Adenomas ◽  
Secretory Activity ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Human Pituitary ◽  
Cytoplasmic Staining ◽  
Human Pituitary Gland ◽  
Microscopic Features

Chromophobe pituitary adenomas arise from adenohypophysial cells and fail to exhibit cytoplasmic staining with conventional acid or basic dyes by light microscopy. The aim of the present work was to study the electron microscopic features of these tumors, to separate them into distinct entities and to correlate their fine structural appearances with secretory activity.Among 48 surgically removed various pituitary adenomas 30 tumors were found which, based on the tinctorial characteristics of the cytoplasm, corresponded to chromophobe adenomas. For electron microscopic investigation pieces of these tumors were fixed in 2.5 per cent glutaraldehyde in Sorensen's buffer, post fixed in 1 per cent osmium tetroxide in Millonig's buffer, dehydrated in graded ethanol and embedded in Epon 812. Ultrathin sections were stained with uranyl acetate and lead citrate.By electron microscopy it was possible to separate chromophobe adenomas into 3 distinct entities: 1) adenomas consisting of sparsely granulated growth hormone cells (7 cases).

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