scholarly journals 17β-Hydroxysteroid Dehydrogenase Type 1, 2, 3, and 4 Expression and Enzyme Activity in Human Anterior Pituitary Adenomas

1999 ◽  
Vol 84 (4) ◽  
pp. 1340-1345
Author(s):  
V. L. Green ◽  
V. Speirs ◽  
A. M. Landolt ◽  
P. M. Foy ◽  
S. L. Atkin
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Estrogenic Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Messenger Ribonucleic Acid ◽  
Human Anterior Pituitary

17β-Hydroxysteroid dehydrogenase (17βHSD) isoforms reversibly catalyze the final step in the formation of estradiol (E2) from estrone (E1) and the formation of testosterone from androstenedione. We have investigated 17βHSD type 1, 2, 3, and 4 gene expression and 17βHSD estrogenic activity in human anterior pituitary adenomas. 17βHSD messenger ribonucleic acid (mRNA) expression was studied by RT-PCR in 42 pituitary tumors and 3 normal pituitaries, 17βHSD activity was studied in 11 tumors and 17βHSD type 1 was immunolocalized in vitro in 6 tumors. 17βHSD type 1 gene expression was detected in 34 of 42 adenomas in all tumor subtypes; 17βHSD type 2 mRNA was detected in 18 of 42 adenomas, but not in prolactinomas; 17βHSD type 3 mRNA was detected in 12 of 42 adenomas, but not in corticotropinomas; 17βHSD type 4 was expressed in 20 of 42 adenomas by all adenoma subtypes. Reversible 17βHSD activity was found in 9 of 11 adenomas, and 17βHSD type 1 immunopositivity was cytoplasmically distributed in all 6 adenomas in vitro. All 4 17βHSD isoforms are variably expressed in human anterior pituitary adenomas, which also show 17βHSD enzyme activity, suggesting that 17βHSD may play an important role in regulating the local cellular levels of estradiol.

An in vitro microdialysis methodology to study 11β-hydroxysteroid dehydrogenase type 1 enzyme activity in liver microsomes

2007 ◽  
Vol 370 (1) ◽  
pp. 26-37 ◽  
Author(s):  
Li Sun ◽  
Julie A. Stenken ◽  
Amy Y. Yang ◽  
Jamie J. Zhao ◽  
Donald G. Musson
Keyword(s):  
Enzyme Activity ◽  
Liver Microsomes ◽  
Hydroxysteroid Dehydrogenase

scholarly journals 17β-Hydroxysteroid Dehydrogenase Type 1 and 2 Expression in the Human Fetus1

2000 ◽  
Vol 85 (1) ◽  
pp. 410-416 ◽  
Author(s):  
Junji Takeyama ◽  
Takashi Suzuki ◽  
Gen Hirasawa ◽  
Yasunari Muramatsu ◽  
Hiroshi Nagura ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Epithelial Cells ◽  
Ribonucleic Acid ◽  
Estrogenic Activity ◽  
Expression Patterns ◽  
Hydroxysteroid Dehydrogenase ◽  
Pcr Analysis ◽  
Maternal Circulation ◽  
Messenger Ribonucleic Acid

The present study investigates the expression patterns of 17β-hydroxysteroid dehydrogenase (17βHSD) isozymes in human fetal tissues to understand how estrogenic activity is regulated in the human fetus. Using enzyme assay, high 17βHSD activity was detected in the placenta and liver, and low levels of 17βHSD activity were also present in the gastrointestinal tract and kidney. After Northern blot analysis, we detected the messenger ribonucleic acid for 17βHSD type 1 (17βHSD1) only in the placenta, whereas that for 17βHSD type 2 (17βHSD2) was detected in the placenta, liver, gastrointestinal tract, and urinary tract at 20 gestational weeks. In RT-PCR analysis of the messenger ribonucleic acid transcripts, 17βHSD1 was predominantly expressed in the placenta, brain, heart, lung, and adrenal, whereas 17βHSD2 expression was predominantly detected in the liver, gastrointestinal tract, and kidney. In addition, we detected 17βHSD2 immunoreactive protein in surface epithelial cells of the stomach, absorptive epithelial cells of the small intestine and colon, hepatocytes of the liver, and interstitial cells surrounding the urinary tubules of the renal medulla. 17βHSD2 in these tissues may be functioning in the prevention of in utero exposure of the fetus to excessive estradiol from the maternal circulation and amniotic fluids.

scholarly journals Regulation of 11beta-hydroxysteroid dehydrogenase type 1 gene expression by LH and interleukin-1beta in cultured rat granulosa cells

1999 ◽  
Vol 163 (3) ◽  
pp. 417-423 ◽  
Author(s):  
M Tetsuka ◽  
LC Haines ◽  
M Milne ◽  
GE Simpson ◽  
SG Hillier
Keyword(s):  
Gene Expression ◽  
Mrna Expression ◽  
Granulosa Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Releasing Hormone ◽  
Cell Monolayers ◽  
Interleukin 1Beta ◽  
Lh Releasing Hormone

Granulosa cells from preovulatory follicles show increased expression of 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) at the time of ovulation. As ovulation may be an inflammatory process, this may be a mechanism of local enhancement of the activity of anti-inflammatory glucocorticoids. In this study, we examined direct effects of LH, the proinflammatory cytokine, interleukin-1beta (IL-1beta), and pharmacological activators of protein kinase A (PKA) (forskolin and dibutyryl (db) cAMP) and PKC (LH-releasing hormone and phorbol 12-myristate 13-acetate (PMA)) signalling on the expression of 11betaHSD1 mRNA in vitro. Granulosa cells from immature female rat ovaries were cultured (pretreatment) in serum-free medium 199 containing recombinant human (rh) FSH (1 ng/ml) for 48 h to induce responsiveness to LH. Cell monolayers were then washed and cultured (test treatment) for a further 12 h in the presence of rhLH (0-100 ng/ml), IL-1beta (0-50 ng/ml), or both. Total RNA was extracted from granulosa cell monolayers and taken for quantitative ribonuclease protection analysis of 11betaHSD1 mRNA. The low level of 11betaHSD1 mRNA detectable in unstimulated (control) cultures was increased approximately twofold by the 48-h pretreatment with rhFSH. Subsequent exposure to rhLH (1-100 ng/ml) for a further 12 h dose-dependently increased 11betaHSD1 mRNA expression by an additional two- to threefold. Forskolin (10 microM), db-cAMP (2 mM), LH-releasing hormone (LHRH; 1 microM) and PMA (200 nM) were also stimulatory. IL-1beta (0.05-50 ng/ml) stimulated 11betaHSD1 mRNA expression in a dose-related manner, both in the absence and in the presence of rhLH (3 ng/ml). The interaction between IL-1beta (5 ng/ml) and rhLH (3 ng/ml) was additive. Co-treatment with a 50-fold excess of IL-1 receptor antagonist fully reversed the action of IL-1beta. We conclude that 11betaHSD1 mRNA expression in functionally mature granulosa cells is directly stimulated by gonadotrophins and IL-1beta in vitro, potentially involving post-receptor signalling via PKA- and PKC-mediated pathways. Thus both LH and IL-1beta may serve physiological roles in the upregulation of 11betaHSD1 gene expression by granulosa cells in ovulatory follicles.

A comparison of proliferation indices in human anterior pituitary adenomas using formalin-fixed tissue and in vitro cell culture

1997 ◽  
Vol 87 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Stephen L. Atkin ◽  
Victoria L. Green ◽  
Leslie J. Hipkin ◽  
Alex M. Landolt ◽  
Patrick M. Foy ◽  
...  
Keyword(s):  
Cell Culture ◽  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Labeling Index ◽  
Ki 67 ◽  
Histological Sections ◽  
Human Anterior Pituitary ◽  
Proliferative Indices

✓ The authors compared detection methods for cell proliferation in human anterior pituitary adenomas using histological sections and dispersed cell culture. After tumor cells had been grown for 4 days in dispersed culture, bromodeoxyuridine (BUdR), proliferating cell nuclear antigen (PCNA), and Ki-67 were compared by double immunostaining and contrasted with single staining of PCNA and Ki-67 indices in the corresponding histological sections from 12 human pituitary adenomas. In vitro, the BUdR labeling index was positive in six of 12 tumors (range < 0.1–5.1%), 10 of 12 tumors were PCNA-positive (range < 0.1–100%), and Ki-67 was positive in 10 of 12 adenomas (range < 0.1–8%). In vitro, BUdR and Ki-67 gave similar proliferative indices for 10 of 12 adenomas. In vivo, the PCNA labeling index was positive in 12 of 12 adenomas (range 0.9–95%) and Ki-67 was positive in 11 of 12 adenomas (range < 0.1–2%). Tumors with a labeling index less than 0.1% were considered to be negative for proliferation. High PCNA values were found in vitro and in vivo, whereas Ki-67 labeling indices were similar in vitro and in vivo for nine of 12 adenomas. It is concluded that Ki-67 proliferative indices in vivo reflect those found in vitro, at least after 4 days in dispersed culture, but that PCNA overestimates pituitary adenoma proliferation in histological sections as well as in dispersed culture.

Dispersed Human Anterior Pituitary Adenomas Preferentially Attach to Poly-L-Lysine Coated Wells

1991 ◽  
Vol 81 (s25) ◽  
pp. 29P-30P
Author(s):  
SL Atkin ◽  
AM Landolt ◽  
RV Jeffreys ◽  
White MC
Keyword(s):  
Pituitary Adenomas ◽  
Anterior Pituitary ◽  
Human Anterior Pituitary

scholarly journals Differential Effects of Gonadotropin-Releasing Hormone (GnRH) Pulse Frequency on Gonadotropin Subunit and GnRH Receptor Messenger Ribonucleic Acid Levels in Vitro*

Endocrinology ◽  
1997 ◽  
Vol 138 (3) ◽  
pp. 1224-1231 ◽  
Author(s):  
Ursula B. Kaiser ◽  
Andrzej Jakubowiak ◽  
Anna Steinberger ◽  
William W. Chin
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Pulse Frequency ◽  
Gnrh Receptor ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Subunit Gene ◽  
Differential Effects ◽  
Messenger Ribonucleic Acid

Abstract The hypothalamic hormone, GnRH, is released and transported to the anterior pituitary in a pulsatile manner, where it binds to specific high-affinity receptors and regulates gonadotropin biosynthesis and secretion. The frequency of GnRH pulses changes under various physiological conditions, and varying GnRH pulse frequencies have been shown to regulate differentially the secretion of LH and FSH and the expression of the gonadotropin α, LHβ, and FSHβ subunit genes in vivo. We demonstrate differential effects of varying GnRH pulse frequency in vitro in superfused primary monolayer cultures of rat pituitary cells. Cells were treated with 10 nm GnRH pulses for 24 h at a frequency of every 0.5, 1, 2, or 4 h. α, LHβ, and FSHβ messenger RNA (mRNA) levels were increased by GnRH at all pulse frequencies. α and LHβ mRNA levels and LH secretion were stimulated to the greatest extent at a GnRH pulse frequency of every 30 min, whereas FSHβ mRNA levels and FSH secretion were stimulated maximally at a lower GnRH pulse frequency, every 2 h. GnRH receptor (GnRHR) mRNA levels also were increased by GnRH at all pulse frequencies and were stimulated maximally at a GnRH pulse frequency of every 30 min. Similar results were obtained when the dose of each pulse of GnRH was adjusted to maintain a constant total cumulative dose of GnRH over 24 h. These data show that gonadotropin subunit gene expression is regulated differentially by varying GnRH pulse frequencies in vitro, suggesting that the differential effects of varying GnRH pulse frequencies on gonadotropin subunit gene expression occur directly at the level of the pituitary. The pattern of regulation of GnRHR mRNA levels correlated with that of α and LHβ but was different from that of FSHβ. This suggests that α and LHβ mRNA levels are maximally stimulated when GnRHR levels are relatively high, whereas FSHβ mRNA levels are maximally stimulated at lower levels of GnRHR expression, and that the mechanism for differential regulation of the gonadotropins by varying pulse frequencies of GnRH may involve levels of GnRHR. Furthermore, these data suggest that the mechanisms whereby varying GnRH pulse frequencies stimulate α, LHβ, and GnRHR gene expression are similar, whereas the stimulation of FSHβ mRNA levels may be different.

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