scholarly journals In Vivo and in Vitro Inhibition of cyp19 Gene Expression by Prostaglandin F2α in Murine Luteal Cells: Implication of GATA-4

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 4957-4966 ◽  
Author(s):  
Carlos Stocco
Keyword(s):  
Time Course ◽  
Cell Function ◽  
Prostaglandin F2α ◽  
Luteal Cell ◽  
Mrna Levels ◽  
Luteal Cells ◽  
Cyp19 Gene ◽  
17Β Estradiol

Abstract A major function of the corpus luteum (CL) is to secrete progesterone. In rats, this gland also produces significant amounts of 17β-estradiol. Progesterone and 17β-estradiol are important regulators of rat luteal cell function. Estrogen biosynthesis is catalyzed by P450aromatase (P450arom), which is encoded by the cyp19 gene. In the rat CL, P450arom is expressed throughout pregnancy until the day before parturition, when it rapidly decreases. The mechanisms that control P450arom expression in luteal cells, particularly, the one or more factors that cause its rapid fall before parturition, are not known. Inasmuch as prostaglandin (PG) F2α plays a key role in the regulation of luteal function at the end of pregnancy, the purpose of this investigation was to determine whether PGF2α affect the expression of P450arom in the CL before parturition. PGF2α decreased luteal P450arom mRNA and protein levels in vivo and in vitro. A decrease in P450arom mRNA was also observed in mice CL just before parturition, but this change did not take place in PGF2α receptor knockout mice. The time course of the decrease in P450arom mRNA by PGF2α reflected the P450arom mRNA half-life determined by actinomycin D. Moreover, nuclear run-on assay showed that PGF2α attenuates P450arom gene transcription. Gel shift assays revealed that GATA-4 binds to the P450aromatase promoter, and that such binding is increased by PGF2α. It is concluded that PGF2α decreases luteal P450arom mRNA levels at the end of pregnancy in rodents by inhibiting cyp19 expression.

scholarly journals Effects of IL8 and immune cells on the regulation of luteal progesterone secretion

Reproduction ◽  
2014 ◽  
Vol 148 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Heather Talbott ◽  
Abigail Delaney ◽  
Pan Zhang ◽  
Yangsheng Yu ◽  
Robert A Cushman ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Immune Cell ◽  
Neutrophil Migration ◽  
Prostaglandin F2α ◽  
Cell Types ◽  
Luteal Cell ◽  
Fibroblast Cells ◽  
Progesterone Synthesis

Recent studies have suggested that chemokines may mediate the luteolytic action of prostaglandin F2α (PGF). Our objective was to identify chemokines induced by PGFin vivoand to determine the effects of interleukin 8 (IL8) on specific luteal cell typesin vitro. Mid-cycle cows were injected with saline or PGF, ovaries were removed after 0.5–4 h, and expression of chemokine was analyzed by qPCR.In vitroexpression of IL8 was analyzed after PGF administration and with cell signaling inhibitors to determine the mechanism of PGF-induced chemokine expression. Purified neutrophils were analyzed for migration and activation in response to IL8 and PGF. Purified luteal cell types (steroidogenic, endothelial, and fibroblast cells) were used to identify which cells respond to chemokines. Neutrophils and peripheral blood mononuclear cells (PBMCs) were cocultured with steroidogenic cells to determine their effect on progesterone production.IL8,CXCL2,CCL2, andCCL8transcripts were rapidly increased following PGF treatmentin vivo. The stimulatory action of PGF onIL8mRNA expressionin vitrowas prevented by inhibition of p38 and JNK signaling. IL8, but not PGF, TNF, or TGFB1, stimulated neutrophil migration. IL8 had no apparent action in purified luteal steroidogenic, endothelial, or fibroblast cells, but stimulated ERK phosphorylation in neutrophils. In coculture experiments neither IL8 nor activated neutrophils altered basal or LH-stimulated luteal cell progesterone synthesis. In contrast, activated PBMCs inhibited LH-stimulated progesterone synthesis from cultured luteal cells. These data implicate a complex cascade of events during luteolysis, involving chemokine signaling, neutrophil recruitment, and immune cell action within the corpus luteum.

Effects of a high-glucose environment on the pituitary growth hormone-releasing hormone receptor: type 1 diabetes compared with in vitro glucotoxicity

2008 ◽  
Vol 294 (4) ◽  
pp. E740-E751 ◽  
Author(s):  
Karine Bédard ◽  
Julie Strecko ◽  
Karyne Thériault ◽  
Julie Bédard ◽  
Christelle Veyrat-Durebex ◽  
...  
Keyword(s):  
High Glucose ◽  
Time Course ◽  
Diabetic Rats ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Mrna Transcript ◽  
Protein Levels ◽  
Igf I

The present study investigated the effects of diabetes and high glucose on GHRH receptor (GHRH-R) mRNA and protein levels in the pituitary of diabetic rats 2, 21, and 60 days post-streptozotocin (post-STZ) administration. Two days post-STZ, the 2.5-kb GHRH-R mRNA transcript was increased. Twenty-one days post-STZ, both the 2.5- and 4-kb transcripts and a 72-kDa 125I-GHRH-GHRH-R complex were elevated. Sixty days post-STZ, the 4-kb transcript remained increased and the 45-kDa 125I-GHRH-GHRH-R complex (functional receptor) was decreased. Hypothalamic GHRH mRNA and serum total IGF-I levels were reduced at all three time points. To better understand the role of high glucose on GHRH-R regulation, time-course effects of 33 compared with 6 mM d-glucose (DG) were examined in cultured anterior pituitary cells from 2-mo-old healthy rats. Membrane lipoperoxidation was present in 33 mM DG, and GHRH-R mRNA levels were diminished after 24 h, Fluo-GHRH internalization was marginal after 16–24 h, and GHRH-induced cAMP levels were decreased after 24 and 48 h. Altogether, these results indicate that the increase of the 2.5-kb GHRH-R mRNA transcript in vivo could be a consequence of a decrease of hypothalamic GHRH mRNA levels in STZ rats. Since it does not affect primarily functional GHRH-R levels, the initial diminution of circulating IGF-I levels could result from a decreased GHRH-R stimulation by GHRH. Thus, the effect of glucotoxicity would be related to a decrease of functional GHRH-R protein, as observed in rats 60 days post-STZ and in cultured pituitary cells from healthy rats exposed to a high-glucose environment.

scholarly journals Prostaglandin F2α (PGF2α) and Prolactin Signaling: PGF2α-Mediated Inhibition of Prolactin Receptor Expression in the Corpus Luteum

Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3301-3305 ◽  
Author(s):  
Carlos Stocco ◽  
Jean Djiane ◽  
Geula Gibori
Keyword(s):  
Corpus Luteum ◽  
Time Course ◽  
Prolactin Receptor ◽  
Prostaglandin F2α ◽  
Receptor Expression ◽  
Luteal Cell ◽  
Pregnant Rats ◽  
Prolactin Signaling ◽  
Stimulation Of

Abstract It is well established that prolactin (PRL) sustains, whereas prostaglandin F2α (PGF2α) curtails, progesterone production by the rodent corpus luteum (CL). We have previously shown that PGF2α inhibits the expression of several luteal genes stimulated by PRL, whereas it stimulates other genes inhibited by this hormone. We have also found that PGF2α stimulation of 20α-hydroxysteroid dehydrogenase (20αHSD), an enzyme that catabolizes progesterone, at the end of pregnancy is accompanied by a dramatic decrease in PRL receptor (PRL-R) expression. These findings, and the fact that the factors that inhibit PRL-R are not known, led us to examine in vivo whether the decline in PRL-R at the end of pregnancy is due to PGF2α and to also find out whether PGF2α opposes PRL action by inhibiting PRL-R expression. Using the PGF2α receptor (PGF2α-R) knockout, we examined whether the absence of the PGF2α-R prevents the decline in the expression of both the short and long forms of the PRL-R in the CL. We found that, in sharp contrast to the wild-type mice, in which both forms of the PRL-R decline to low levels between d 18–20 of pregnancy, expression of these receptors remained elevated in the PGF2α-R null mice. Furthermore, administration of PGF2α to pregnant rats inhibited PRL-R expression. Time-course analysis revealed that PGF2α treatment decreases both isoforms of PRL-R within 1 h of treatment in vivo, whereas its stimulatory effect on 20αHSD expression was further delayed. Similar results were obtained with luteinized granulosa cells in culture. To examine whether the decline in PRL-R is involved/necessary for PGF2α action, cells were transfected with a constitutively active PRL-R. The expression of this receptor did not prevent PGF2α effect on PRL-R or 20αHSD expression. Taken together, these results demonstrate that PGF2α inhibits the expression of the PRL-R and that the decline in both forms of the PRL-R that occurs at the end of pregnancy in the CL is due to PGF2α. The results further suggest that PGF2α-mediated stimulation of 20αHSD is independent from PGF2α inhibition of PRL signaling in luteal cell.

Growth hormone-induced STAT5B regulates Star gene expression through a cooperation with cJUN in mouse MA-10 Leydig cells

Endocrinology ◽  
2021 ◽  
Author(s):  
Pierre-Olivier Hébert-Mercier ◽  
Francis Bergeron ◽  
Nicholas M Robert ◽  
Samir Mehanovic ◽  
Kenley Joule Pierre ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Leydig Cell ◽  
Leydig Cells ◽  
Cell Function ◽  
Mrna Levels ◽  
Leydig Cell Function ◽  
Star Gene

Abstract Leydig cells produce androgens that are essential for male sex differentiation and reproductive function. Leydig cell function is regulated by several hormones and signaling molecules, including growth hormone (GH). Although GH is known to upregulate Star gene expression in Leydig cells, its molecular mechanism of action remains unknown. The STAT5B transcription factor is a downstream effector of GH signaling in other systems. While STAT5B is present in both primary and Leydig cell lines, its function in these cells has yet to be ascertained. Here we report that treatment of MA-10 Leydig cells with GH or overexpression of STAT5B induces Star mRNA levels and increases steroid hormone output. The mouse Star promoter contains a consensus STAT5B element (TTCnnnGAA) at -756 bp to which STAT5B binds in vitro (EMSA and supershift) and in vivo (ChIP) in a GH-induced manner. In functional promoter assays, STAT5B was found to activate a -980 bp mouse Star reporter. Mutating the -756 bp element prevented STAT5B binding but did not abrogate STAT5B-responsiveness. STAT5B was found to functionally cooperate with DNA-bound cJUN. The STAT5B/cJUN cooperation was only observed in Leydig cells and not in Sertoli or fibroblast cells, indicating that additional Leydig cell-enriched transcription factors are required. The STAT5B/cJUN cooperation was lost only when both STAT5B and cJUN elements were mutated. In addition to identifying the Star gene as a novel target for STAT5B in Leydig cells, our data provide important new insights into the mechanism of GH and STAT5B action in the regulation of Leydig cell function.

scholarly journals Cdk8 directly regulates glycolysis via phosphorylation of Gcr2

2021 ◽  
Author(s):  
Maria J. Aristizabal ◽  
Eoghan O’Duibhir ◽  
Wim de Jonge ◽  
Kristy Dever ◽  
Nicole Hawe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Regulation ◽  
Time Course ◽  
Phosphorylation Site ◽  
Mrna Levels ◽  
Functional Link ◽  
Genes Encoding ◽  
Context Specific

AbstractCDK8encodes an evolutionarily conserved Mediator complex kinase subunit that functions in general and context-specific transcription regulation by phosphorylating core components of the transcription machinery and gene-specific transcription factors. To better understand the role Cdk8 in transcription regulation, we performed high-resolution gene expression time course analysis following nuclear depletion of Cdk8. Focusing on the earliest gene expression alterations revealed dysregulation of genes encoding glycolysis enzymes, suggesting a functional link to Gcr1 and Gcr2, key transcriptional activators of these genes. Consistently, we found that nuclear depletion of Cdk8 altered the mRNA levels of glycolysis genes as well as the promoter occupancy of Gcr2, but not Gcr1. Examination of the Gcr2 protein sequence revealed a putative Cdk8 phosphorylation site at serine 365, which we confirmed usingin vitroandin vivoassays. Importantly, phospho-mutantGCR2recapitulated the growth and gene expression defects of theGCR2deletion mutant, effects not observed with a phospho mimetic mutant. As such, our work highlights Gcr2 as a new Cdk8 substrate, revealing that its phosphorylation is critical for the activation of genes encoding glycolysis enzymes.

Prostaglandin F2α promotes the inhibitory action of endothelin-1 on the bovine luteal function in vitro

1997 ◽  
Vol 152 (2) ◽  
pp. R7-R11 ◽  
Author(s):  
A. Miyamoto ◽  
S. Kobayashi ◽  
S. Arata ◽  
M. Ohtani ◽  
Y. Fukui ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Direct Action ◽  
Prostaglandin F2α ◽  
Luteal Function ◽  
Luteal Cells ◽  
Endothelin 1 ◽  
Oxytocin Release ◽  
Physiological Impact

ABSTRACT Prostaglandin F2α (PGF2α) is a primary luteolysin in the cow. Although the mechanisms involved in luteolysis are thought to be a complex of its direct action on luteal cells and indirect effect on luteal blood flow, the detailed mechanisms remain to be elucidated. This study focuses on the possible interaction of endothelial cells-derived endothelin-1 (ET-1) with PGF2α in the rapid suppression of progesterone release from the bovine corpus luteum (CL). In in vitro microdialysis system (MDS) of CL, PGF2α acutely stimulated the release of progesterone and oxytocin during infusion and ET-1 release after infusion. Moreover, PGF2α induced slight decrease of progesterone release during the last period of the experiment (8-11 h after PGF2α exposure). Two 1 h-perfusions of ET-1 at 3 h intervals induced only a slight decrease of progesterone release after the second perfusion. This treatment also affected the oxytocin release; the first ET-1 perfusion produced an acute stimulation, whereas the second ET-1 perfusion inhibited the release to below 50%. When the CL pieces were pre-perfused with PGF2α for 2 h, the two consecutive perfusion of ET-1 at 3 h intervals induced drastic decrease in progesterone and oxytocin release only after the second ET-1 perfusion. Thus, a pre-exposure with PGF2α clearly potentiated the inhibiting activity of ET-1 in the progesterone release. These results suggest a physiological impact of PGF2α and ET-1 in the rapid cascade of functional luteolysis in vivo, and a possible interaction between endothelial cells and luteal cells.

scholarly journals Matrix γ-Carboxyglutamic Acid Protein Is a Key Regulator of PTH-Mediated Inhibition of Mineralization in MC3T3-E1 Osteoblast-Like Cells

Endocrinology ◽  
2001 ◽  
Vol 142 (10) ◽  
pp. 4379-4388 ◽  
Author(s):  
Rajaram Gopalakrishnan ◽  
Hongjiao Ouyang ◽  
Martha J. Somerman ◽  
Laurie K. McCauley ◽  
Renny T. Franceschi
Keyword(s):  
Extracellular Matrix ◽  
Time Course ◽  
The Other ◽  
Activity Levels ◽  
Mrna Levels ◽  
Acid Protein ◽  
Carboxyglutamic Acid ◽  
Dependent Inhibition

Abstract As part of its overall function as a major regulator of calcium homeostasis, PTH stimulates bone resorption and inhibits osteoblast-mediated biomineralization. To determine the basis for the inhibitory actions of this hormone, we compared the time course of PTH-dependent inhibition of mineralization in MC3T3-E1 osteoblast-like cells with changes in mRNA levels for several extracellular matrix proteins previously associated either with induction or inhibition of mineralization. Mineralizing activity was rapidly lost in PTH-treated cells (∼30% inhibition after 3 h, 50% inhibition at 6 h). Of the proteins examined, changes in matrix γ-carboxyglutamic acid protein were best correlated with PTH-dependent inhibition of mineralization. Matrix γ-carboxyglutamic acid protein mRNA was rapidly induced 3 h after PTH treatment, with a 6- to 8-fold induction seen after 6 h. Local in vivo injection of PTH over the calvaria of mice also induced a 2-fold increase in matrix γ-carboxyglutamic acid protein mRNA. Warfarin, an inhibitor of matrix γ-carboxyglutamic acid protein γ-carboxylation, reversed the effects of PTH on mineralization in MC3T3-E1 cells, whereas vitamin K enhanced PTH activity, as would be expected if a γ-carboxyglutamic acid-containing protein were required for PTH activity. Levels of the other mRNAs examined were not well correlated with the observed changes in mineralization. Osteopontin, an in vitro inhibitor of mineralization, was induced approximately 4-fold 12 h after PTH addition. Bone sialoprotein mRNA, which encodes an extracellular matrix component most frequently associated with mineral induction, was inhibited by 50% after 12 h of PTH treatment. Osteocalcin mRNA, encoding the other known γ-carboxyglutamic acid protein in bone, was also inhibited by PTH, but, again, with a significantly slower time course than was seen for mineral inhibition. Taken together, these results show that the rapid inhibition of osteoblast mineralization induced by in vitro PTH treatment is at least in part explained by induction of matrix γ-carboxyglutamic acid protein.

scholarly journals Estrogen promotes luteolysis by redistributing prostaglandin F2α receptors within primate luteal cells

Reproduction ◽  
2015 ◽  
Vol 149 (5) ◽  
pp. 453-464 ◽  
Author(s):  
Soon Ok Kim ◽  
Nune Markosyan ◽  
Gerald J Pepe ◽  
Diane M Duffy
Keyword(s):  
Estrogen Receptor ◽  
Granulosa Cells ◽  
Prostaglandin F2α ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Dependent Manner ◽  
Perinuclear Region ◽  
Luteal Cells ◽  
Progesterone Production

Prostaglandin F2α (PGF2α) has been proposed as a functional luteolysin in primates. However, administration of PGF2α or prostaglandin synthesis inhibitors in vivo both initiate luteolysis. These contradictory findings may reflect changes in PGF2α receptors (PTGFRs) or responsiveness to PGF2α at a critical point during the life span of the corpus luteum. The current study addressed this question using ovarian cells and tissues from female cynomolgus monkeys and luteinizing granulosa cells from healthy women undergoing follicle aspiration. PTGFRs were present in the cytoplasm of monkey granulosa cells, while PTGFRs were localized in the perinuclear region of large, granulosa-derived monkey luteal cells by mid-late luteal phase. A PTGFR agonist decreased progesterone production in luteal cells obtained at mid-late and late luteal phases, but did not decrease progesterone production by granulosa cells or luteal cells from younger corpora lutea. These findings are consistent with a role for perinuclear PTGFRs in functional luteolysis. This concept was explored using human luteinizing granulosa cells maintained in vitro as a model for luteal cell differentiation. In these cells, PTGFRs relocated from the cytoplasm to the perinuclear area in an estrogen- and estrogen receptor-dependent manner. Similar to our findings with monkey luteal cells, human luteinizing granulosa cells with perinuclear PTGFRs responded to a PTGFR agonist with decreased progesterone production. These data support the concept that PTGFR stimulation promotes functional luteolysis only when PTGFRs are located in the perinuclear region. Estrogen receptor-mediated relocation of PTGFRs within luteal cells may be a necessary step in the initiation of luteolysis in primates.

A POSSIBLE INTERRELATIONSHIP BETWEEN GONADOTROPHIN STIMULATION AND PROSTAGLANDIN F2α INHIBITION OF STEROIDOGENESIS BY GRANULOSA-LUTEAL CELLS IN VITRO

1977 ◽  
Vol 73 (1) ◽  
pp. 71-78 ◽  
Author(s):  
K. M. HENDERSON ◽  
K. P. McNATTY
Keyword(s):  
Tissue Culture ◽  
Corpus Luteum ◽  
Prostaglandin F2α ◽  
Luteal Cell ◽  
Luteal Cells ◽  
Lytic Action ◽  
Progesterone Production ◽  
Prostaglandin F

SUMMARY The newly formed corpus luteum of many species is refractory to the lytic action of prostaglandin F2α (PGF2α). This phenomenon was studied utilizing porcine, bovine and human granulosa-luteal cells in tissue culture. The steroidogenic potential of the granulosa-luteal cells was critical in determining whether PGF2α could inhibit progesterone production. Since the steroidogenic potential of the granulosa-luteal cell is related to the amount of LH bound to the cell, the bound LH may protect the granulosa-luteal cells from the lytic action of PGF2α. Finally, a 'see-saw' type of interaction between LH and PGF2α is postulated to account for the resistance of the newly formed corpus luteum to PGF2α

Contrasting effects of prolactin on luteal and follicular steroidogenesis

1985 ◽  
Vol 104 (2) ◽  
pp. 241-250 ◽  
Author(s):  
B. Kalison ◽  
M. L. Warshaw ◽  
G. Gibori
Keyword(s):  
Luteal Cell ◽  
Corpora Lutea ◽  
Aromatase Activity ◽  
Luteal Cells ◽  
Progesterone Production ◽  
Progesterone Secretion ◽  
Hypophysectomized Rats ◽  
Stimulation Of

ABSTRACT To determine whether prolactin affects both luteal and follicular production of testosterone and oestradiol, pseudopregnant rats, either intact or hypophysectomized on day 8, were injected daily between days 8 and 9 with 1·5 i.u. human chorionic gonadotrophin (hCG), 250 μg prolactin or a combination of both. Control rats were given vehicle. On day 9, blood was obtained from the ovarian vein and corpora lutea and follicles were isolated and incubated in vitro for 2 h. Administration of hCG to intact rats increased ovarian secretion of testosterone and oestradiol dramatically, but did not affect progesterone secretion. Hypophysectomy on day 8 of pseudopregnancy was followed by a drop in ovarian steroid secretion. Prolactin treatment of hypophysectomized rats markedly enhanced progesterone production but had no stimulatory effect on either testosterone or oestradiol. In contrast, hCG dramatically enhanced ovarian secretion of both testosterone and oestradiol without affecting progesterone secretion. Prolactin administered together with hCG antagonized the stimulation of both testosterone and oestradiol secretion by hCG, yet increased progesterone production. When the specific effects of hCG and prolactin administration on follicles and corpora lutea were studied separately, it was found that hCG treatment in vivo greatly stimulated testosterone and oestradiol production by both tissues in vitro. Since hCG only marginally affected aromatase activity in the follicle, had no effect on aromatase activity in luteal cells and did not increase progesterone synthesis, it appears that hCG acts to increase the formation of androgen substrate for oestradiol biosynthesis. Prolactin, administered with or without hCG, inhibited both basal and hCG-stimulated testosterone and oestradiol synthesis by the follicle. In sharp contrast to its inhibitory effect on follicular production of steroids, prolactin appears to be essential for LH stimulation of testosterone and oestradiol by the corpus luteum. In the absence of prolactin, luteal cells gradually ceased to respond to LH and decreased their output of testosterone and oestradiol. Prolactin administration to hypophysectomized rats did not affect luteal cell production of either steroid. However, corpora lutea of rats treated with prolactin responded to the hCG challenge with an increase in testosterone and oestradiol synthesis. In summary, results of this investigation demonstrate that prolactin affects follicular and luteal production of testosterone and oestradiol in opposite ways. It acts on the follicle to inhibit both basal and LH-stimulated production of testosterone and oestradiol, yet it markedly enhances LH stimulation of testosterone and oestradiol synthesis by luteal cells. J. Endocr. (1985) 104, 241–250

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