A synthetic peptide derived from mouse pituitary calcitonin cDNA sequence exhibits potent inhibition of prolactin secretion and prolactin mRNA abundance in primary mouse pituitary cells

GnRH agonists (GnRHa) are increasingly used for fertility preservation in women undergoing gonadotoxic chemotherapy. However, the protective mechanisms of action for these compounds have not yet been elucidated. In this study, we aimed to determine whether GnRHa have a direct effect on ovarian granulosa cells. GnRH receptor (GnRHR) expression was determined in mouse somatic and gonadal tissues including granulosa/cumulus cells and oocytes using quantitative RT-PCR and immunohistochemistry. Granulosa cells were isolated from mouse ovaries primed with pregnant mare serum gonadotropin. Response to GnRHa in cultured granulosa cells was assessed by determining the increase of intracellular cAMP and by assessing phosphorylation of downstream mediators of GnRH signaling: ERK and p38. To measure intracellular cAMP in our system, the cells were transfected with a cAMP-responsive luciferase reporter plasmid and stimulated with GnRHa. For all experiments, pituitary tissue and/or the αT3–1 mouse pituitary cell line were used as controls. GnRHR mRNA and protein were detected in mouse ovaries, granulosa/cumulus cells, and oocytes. After GnRHa stimulation at various time intervals, we were unable to detect a cAMP increase or activation of the ERK or p38 signaling pathway in cultured primary mouse granulosa cells, whereas activation was detected in the control αT3–1 mouse pituitary cells. In this study, we have not detected activation of the canonical GnRH signaling pathways in mouse ovarian somatic cells. Our findings suggest that the mechanism of action of GnRHa in the ovary is either below the detection level of our experimental design or is different from that in the pituitary.

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Proton Sensitivity of Corticotropin-Releasing Hormone Receptor 1 Signaling to Proopiomelanocortin in Male Mice

Endocrinology ◽

10.1210/en.2018-00920 ◽

2018 ◽

Vol 160 (2) ◽

pp. 276-291 ◽

Cited By ~ 3

Author(s):

Hiraku Kameda ◽

Masaaki Yamamoto ◽

Yukiko Tone ◽

Masahide Tone ◽

Shlomo Melmed

Keyword(s):

Ligand Binding ◽

Low Ph ◽

Pituitary Cells ◽

Dependent Protein Kinase ◽

Ectopic Acth ◽

Primary Mouse ◽

Dependent Protein ◽

Acidic Conditions ◽

Mouse Pituitary ◽

The Impact

Abstract Because an acidic cellular microenvironment is engendered by inflammation and may determine cell differentiation, we elucidated the impact of acidic conditions on induction of proopiomelanocortin (POMC) expression. Here, we demonstrate mechanisms for proton sensitivity of CRH receptor 1 (CRHR1) signaling to POMC and ACTH production. Low pH (6.8) resulted in doubling of POMC expression and ACTH production in pituitary cell line AtT-20 and in primary mouse pituitary cells. Using CRISPR knockout, we show that CRHR1 is necessary for acid-induced POMC expression, and this induction is mediated by CRHR1 histidine residues and calmodulin-dependent protein kinase II in both pituitary corticotroph cells and in nonpituitary cell lines expressing ectopic ACTH. In contrast, CRH ligand binding affinity to CRHR1 was decreased with acidic pH, implying that proton-induced POMC expression prevails in acidic conditions independently of CRH ligand binding. The results indicate that proton-induced CRHR1 signaling regulates ACTH production in response to an acidic microenvironment.

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Suppression of prolactin release and mRNA accumulation by two novel dopamine agonist agents

Acta Endocrinologica ◽

10.1530/acta.0.1200672 ◽

1989 ◽

Vol 120 (5) ◽

pp. 672-676 ◽

Cited By ~ 2

Author(s):

Julian R. E. Davis ◽

Maria E. Vidal ◽

Elizabeth M. Wilson ◽

Michael C. Sheppard

Keyword(s):

Dopamine Agonist ◽

Control Release ◽

Prolactin Secretion ◽

Pituitary Cells ◽

Mrna Levels ◽

Hormone Release ◽

Prolactin Release ◽

Mrna Accumulation ◽

Prolactin Synthesis ◽

Prolactin Mrna

Abstract. Two novel dopamine agonist drugs, CV 205–502 and CQP 201–403, have been investigated to compare their effects on prolactin secretion and prolactin mRNA accumulation in cultured rat pituitary cells. Both drugs gave dose-dependent suppression of prolactin release over a 24 h incubation period: when each drug was used at 100 nmol/l CV 205–502 and CQP 201–403 induced suppression to 8.9 ± 1.7 and 10.2 ± 1.8% of control release, respectively, compared to 26.7 ± 4.8% of control with 100 nmol/l bromocriptine. There was no consistent effect on growth hormone release. Cytoplasmic accumulation of prolactin mRNA was also inhibited by both drugs at this concentration, to 50.2 ± 5.5% of control values by CV 205–502 and to 67.4 ± 8% of control by CQP 201–403, and to a similar extent by 100 nmol/l bromocriptine (50.6 ± 9.1% of control). None of the drugs had any significant effect on GH mRNA levels. These data suggest that the agents exert their effect at a pretranslational stage of prolactin synthesis, as well as at the level of hormone release.

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Modulation of prolactin secretion by contraceptive progestins in cultured rat pituitary cells in vitro

Acta Endocrinologica ◽

10.1530/acta.0.117s188 ◽

1988 ◽

Vol 117 (4_Suppl) ◽

pp. S188-S189

Author(s):

L. KIESEL ◽

T. RABE ◽

D. SCHOLZ ◽

V. KIRSCHNER ◽

B. RUNNEBAUM

Keyword(s):

Prolactin Secretion ◽

Pituitary Cells ◽

Rat Pituitary ◽

Rat Pituitary Cells

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Effect of tunicamycin on the synthesis, processing, and secretion of pro-opiomelanocortin peptides in mouse pituitary cells.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)33993-0 ◽

1982 ◽

Vol 257 (17) ◽

pp. 10128-10135 ◽

Cited By ~ 5

Author(s):

M L Budarf ◽

E Herbert

Keyword(s):

Pituitary Cells ◽

Mouse Pituitary

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Thyrotropin-releasing hormone stimulates rapid loss of phosphatidylinositol and its conversion to 1,2-diacylglycerol and phosphatidic acid in rat mammotropic pituitary cells. Association with calcium mobilization and prolactin secretion.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)33245-9 ◽

1983 ◽

Vol 258 (1) ◽

pp. 227-234 ◽

Cited By ~ 27

Author(s):

M J Rebecchi ◽

R N Kolesnick ◽

M C Gershengorn

Keyword(s):

Phosphatidic Acid ◽

Prolactin Secretion ◽

Calcium Mobilization ◽

Thyrotropin Releasing Hormone ◽

Pituitary Cells ◽

Rapid Loss ◽

Releasing Hormone

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A COMPARISON OF THE EFFECTS OF FOUR ERGOT DERIVATIVES ON PROLACTIN SECRETION BY DISPERSED RAT PITUITARY CELLS

Journal of Endocrinology ◽

10.1677/joe.0.0870095 ◽

1980 ◽

Vol 87 (1) ◽

pp. 95-103 ◽

Cited By ~ 11

Author(s):

G. DELITALA ◽

T. YEO ◽

ASHLEY GROSSMAN ◽

N. R. HATHWAY ◽

G. M. BESSER

Keyword(s):

Anterior Pituitary ◽

Ergot Alkaloids ◽

Prolactin Secretion ◽

Pituitary Cells ◽

Inhibitory Effects ◽

Prolactin Release ◽

Ergot Derivatives ◽

Rat Pituitary ◽

Rat Pituitary Cells

The inhibitory effects of dopamine and various ergot alkaloids on prolactin secretion were studied using continuously perfused columns of dispersed rat anterior pituitary cells. Bromocriptine (5 nmol/l) and lisuride hydrogen maleate (5 nmol/l) both inhibited prolactin secretion, the effects persisting for more than 3 h after the end of the administration of the drugs. A similar although less long-lasting effect was observed with lergotrile (50 nmol/l) and the new ergoline derivative, pergolide (5 nmol/l). These effects contrasted with the rapid disappearance of the action of dopamine. The potency estimates of the ergots relative to that of dopamine were: lergotrile, 2·3; bromocriptine, 13; lisuride, 15; pergolide, 23. The dopamine-receptor blocking drugs, metoclopramide and haloperidol, antagonized the prolactin release-inhibiting activity of the compounds; bromocriptine and lisuride showed the highest resistance to this dopaminergic blockade. The results suggested that the direct effect of the ergot derivatives on dispersed pituitary cells was mediated through dopamine receptors and emphasized the long-lasting action of bromocriptine and lisuride in vitro.

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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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