scholarly journals Cocaine- and Amphetamine-Regulated Transcript Regulation of Follicle-Stimulating Hormone Signal Transduction in Bovine Granulosa Cells

Endocrinology ◽  
2007 ◽  
Vol 148 (9) ◽  
pp. 4400-4410 ◽  
Author(s):  
Aritro Sen ◽  
Anilkumar Bettegowda ◽  
Fermin Jimenez-Krassel ◽  
James J. Ireland ◽  
George W. Smith
Keyword(s):  
Granulosa Cells ◽  
Intracellular Signaling ◽  
Kinase Inhibitors ◽  
Calcium Influx ◽  
Primary Cultures ◽  
Follicular Development ◽  
Protein Kinase Inhibitors ◽  
Intracellular Camp ◽  
Aromatase Mrna ◽  
Camp Levels

Regulation of estradiol production, central to ovarian follicular development and reproductive function, is mediated by a complex interaction of pituitary gonadotropins such as FSH with locally produced regulatory molecules. We previously demonstrated a negative association of expression of cocaine-and amphetamine-regulated transcript (CART) with follicle health status and a novel local negative role for CART in regulation of basal estradiol production by bovine granulosa cells. However, effects of CART on FSH-induced estradiol production and the underlying mechanism(s) mediating the physiological actions of CART on granulosa cells are not known. Objectives of the present study were to determine effects of CART on basal and FSH-induced intracellular cAMP levels, aromatase mRNA, estradiol accumulation, calcium signaling, and the intracellular signaling pathways involved using primary cultures of bovine granulosa cells. CART treatment potently inhibits the FSH-induced rise in granulosa cell cAMP levels, estradiol accumulation, and aromatase mRNA. Furthermore, results show that calcium is essential for FSH-induced cAMP and estradiol accumulation, and CART significantly inhibits FSH-induced calcium influx. Select G protein and protein kinase inhibitors were used to elucidate pathways involved in CART actions. The inhibitory actions of CART on FSH signaling and estradiol production are mediated via a Go/i-dependent pathway, whereas none of the other signaling inhibitors had any effect on CART actions. Results demonstrate novel potent inhibitory effects of CART on multiple components of the FSH signaling pathway linked to estradiol production and follicular development and shed new insight into the mechanism of action of CART potentially pertinent within and beyond the reproductive system.

Transmembrane Calcium Influx Associated with von Willebrand Factor Binding to GP Ib in the Initiation of Shear-Induced Platelet Aggregation

1993 ◽  
Vol 69 (05) ◽  
pp. 496-502 ◽  
Author(s):  
Yasuo Ikeda ◽  
Makoto Handa ◽  
Tetsuji Kamata ◽  
Koichi Kawano ◽  
Yohko Kawai ◽  
...  
Keyword(s):  
Shear Force ◽  
Calcium Influx ◽  
Fold Increase ◽  
Intracellular Camp ◽  
Recombinant Fragment ◽  
Transmembrane Flux ◽  
Irreversible Aggregation ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Camp Levels

SummaryWe found that the binding of multimeric vWF to GP Ib under a shear force of 108 dynes/cm2 resulted in the transmembrane flux of Ca2+ ions with a two-to three-fold increase in their intracellular concentration ([Ca2+]i). The blockage of this event, obtained by inhibiting the vWF-GP Ib interaction, suppressed aggregation. In contrast, the blockage of vWF binding to GP IIb-IIIa, as well as the prevention of activation caused by increased intracellular cAMP levels, inhibited aggregation but had no significant effect on [Ca2+]i increase. A monomeric recombinant fragment of vWF containing the GP Ib-binding domain of the molecule (residues 445-733) prevented all effects mediated by multimeric vWF but, by itself, failed to support the increase in [Ca2+]i and aggregation. These results suggest that the binding of multimeric vWF to GP Ib initiates platelets aggregation induced by high shear stress by mediating a transmembrane flux of Ca2+ ions, perhaps through a receptor-dependent calcium channel. The increase in [Ca2+]i may act as an intracellular message and cause the activation of GP IIb-IIIa; the latter receptor then binds vWF and mediates irreversible aggregation.

scholarly journals Protein kinase C regulation of p-glycoprotein-mediated xenobiotic secretion in renal proximal tubule

1998 ◽  
Vol 275 (5) ◽  
pp. F785-F795 ◽  
Author(s):  
David S. Miller ◽  
Caroline R. Sussman ◽  
J. Larry Renfro
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Proximal Tubule ◽  
Kinase Inhibitors ◽  
Primary Cultures ◽  
Renal Proximal Tubule ◽  
Protein Kinase Inhibitors ◽  
Drug Accumulation ◽  
Kinase C ◽  
P Glycoprotein

Fluorescence microscopy, fluorescent substrates [daunomycin and a fluorescent cyclosporin A (CSA) derivative] and digital image analysis were used to examine the role of protein kinase C (PKC) in the control of p-glycoprotein in killifish renal proximal tubules. PKC activators, phorbol ester (phorbol 12-myristate 13-acetate, PMA) and dioctylglycerol, reduced luminal drug accumulation, and protein kinase inhibitors, staurosporine and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), increased luminal accumulation; a PMA analog that does not activate PKC was without effect. PMA effects were blocked by staurosporine. The increase in luminal fluorescence caused by staurosporine was blocked by the p-glycoprotein substrate, CSA, indicating that this component of transport was indeed mediated by p-glycoprotein. Neither PMA, dioctylglycerol, nor protein kinase inhibitors altered cellular drug accumulation. Finally, in primary cultures of flounder proximal tubule cells, PMA decreased transepithelial [3H]daunomycin secretion. This pharmacological approach demonstrates that in teleost renal proximal tubule, p-glycoprotein-mediated xenobiotic secretion is negatively correlated with changes in PKC activity, a finding that conflicts with results from studies using mammalian tumor cells that express p-glycoprotein.

Expression of the c-myc gene in human adrenals: regulation by adrenocorticotropin in primary cultures

1996 ◽  
Vol 148 (3) ◽  
pp. 523-529 ◽  
Author(s):  
J Liu ◽  
R Voutilainen ◽  
A I Kahri ◽  
P Heikkilä
Keyword(s):  
Kinase Inhibitors ◽  
Primary Cultures ◽  
Calf Serum ◽  
Protein Kinase Inhibitors ◽  
Maximal Effect ◽  
Mrna Levels ◽  
Mrna Accumulation ◽  
Liver And Kidney ◽  
Myc Gene

Abstract We have analyzed the expression of the c-myc proto-oncogene in human adrenal glands in vivo and in primary cell cultures by Northern blot analysis. c-myc mRNA was consistently expressed in all human adrenals studied. Expression in adult adrenals was found to be approximately 50% of that in fetal adrenals, but much higher than that in adult liver and kidney. Adrenocorticotropin (ACTH) treatment increased c-myc mRNA accumulation dose- and time-dependently up to more than 5-fold (on average), with the maximal effect at 2 h. (Bu)2cAMP and 12-O-tetradecanoyl phorbol 13-acetate (TPA) also induced c-myc gene expression. There was no synergistic effect between the ACTH, (Bu)2cAMP and TPA treatments. The basal level of c-myc expression was reduced by the protein kinase inhibitors H-7 (1-(5-isoquinolinesulfonyl)-2-methyl-piperazine dihydrochloride), staurosporine and HA1004 (N-(2-guanidinoethyl)-5-isoquinolinesulfonamide hydrochloride). H-7 totally abolished ACTH-, TPA- and (Bu)2cAMP-induced c-myc expression, while staurosporine inhibited the stimulatory effects of ACTH and TPA, and HA1004 weakly inhibited the effects of ACTH and (Bu)2cAMP. Incubation with cycloheximide or 10% fetal calf serum increased c-myc mRNA levels 3- and 4-fold respectively. Our data show that the c-myc gene is expressed abundantly in normal human adrenals, and that this expression can be regulated by multiple factors in the primary cultures. Journal of Endocrinology (1996) 148, 523–529

scholarly journals The cAMP-ERK1/2 signaling pathway regulates urokinase-type plasminogen activator-induced bovine granulosa cell proliferation

Reproduction ◽  
2020 ◽  
Vol 160 (6) ◽  
pp. 853-862
Author(s):  
Yufen Zhao ◽  
Boyang Yu ◽  
Xinyu Liu ◽  
Jitu Hu ◽  
Yanyan Yang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Plasminogen Activator ◽  
Granulosa Cells ◽  
Ovarian Function ◽  
Follicular Development ◽  
Intracellular Camp ◽  
Intracellular Signals ◽  
Type Plasminogen Activator ◽  
Urokinase Type Plasminogen Activator ◽  
Plasminogen Activator Receptor

Although urokinase-type plasminogen activator (PLAU) and urokinase-type plasminogen activator receptor (PLAUR) have been reported to play key roles in ovarian function, their precise contribution to mammalian follicular development remains unclear. In this study, we first observed that PLAU and PLAUR were present in bovine granulosa cells (GCs). Following culture of granulosa cells with PLAU (0.5 ng/mL) and PLAUR antibody (10 µg/mL) separately and together for 24 or 48 h, a proliferation assay showed that interaction between PLAU and PLAUR contributes to bovine GC proliferation. To study the potential pathways involved in PLAU/PLAUR-induced cell proliferation, ELISA and Western blotting were performed. We found that PLAU significantly increased the ratio of phosphorylated to non-phosphorylated ERK1/2 through PLAUR signaling. Further treatment with U0126, a specific ERK1/2 phosphorylation inhibitor, markedly suppressed PLAU/PLAUR-induced ERK1/2 phosphorylation and cell proliferation. In addition, we found that PLAU and PLAUR significantly increased the intracellular cAMP level and the use of Rp-cAMP, a specific PKA inhibitor, prevented PLAU/PLAUR from promoting activation of the ERK1/2 pathway and GC proliferation. Therefore, the interaction between PLAU and PLAUR may be involved in accumulating cAMP signals and enabling MAPK/ERK1/2 activation, affecting GC proliferation. Here, we provide new mechanistic insights into the roles of PLAU and PLAUR on promoting bovine GC proliferation. The finding that potential cross-points between PLAU/PLAUR-induced intracellular signals affect GC proliferation will help in understanding the mechanisms regulating early follicular development.

scholarly journals MON-012 The Direct Effect of Kisspeptin on Human Ovarian Granulosa Cells to Regulate Steroidogenesis

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Lixian Qin ◽  
Chantacha Sitticharoon ◽  
Rungnapa Sririwichitchai ◽  
Issarawan Keadkraichaiwat ◽  
Pailin Maikaew ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Granulosa Cells ◽  
Follicular Development ◽  
Tumor Cell Line ◽  
High Dose ◽  
Human Granulosa Cells ◽  
Ovarian Granulosa Cells ◽  
Estrogen Synthesis ◽  
Aromatase Mrna ◽  
Different Doses

Abstract Kisspeptin has a central role to stimulate the hypothalamic-pituitary-gonadal (HPG) axis. Furthermore, a previous study has suggested that kisspeptin might have a peripheral role in follicular development (1). This study aimed to 1) explore the effect of kisspeptin on CYP19A1 (aromatase) mRNA expression in human granulosa cells and aromatase concentrations in the supernatant; and 2) investigate the effect of kisspeptin on FSHR mRNA expression in human granulosa cells. In this study, human granulosa-like tumor cell line (KGN) (n=3) was incubated for 24 hours with FSH (10-8 M); FSH with IGF-1 (10-8 M); different doses of kisspeptin including 1, 10, 100, 1,000, and 10,000 nM; FSH with different doses of kisspeptin; and FSH with IGF-1 together with different doses of kisspeptin. FSH treatment alone or FSH with IGF-1 did not increase CYP19A1 mRNA expression when compared to control. Interestingly, kisspeptin treatment at the doses of 100 nM (P=0.028), 1,000 nM (P=0.005), and 10,000 nM (P=0.009) in the presence of FSH together with IGF-1 enhanced CYP19A1 mRNA expression when compared with control. Furthermore, FSH or FSH with IGF-1 or FSH with all doses of kisspeptin or FSH with IGF-1 together with all doses of kisspeptin increased aromatase concentrations in the supernatant when compared to control (P<0.01 all). Surprisingly, kisspeptin at the dose of 10,000 nM with FSH or FSH together with IGF-1 statistically increased aromatase concentrations in the supernatant when compared with FSH treatment alone or FSH with IGF-1 treatment (P<0.01 all). FSHR mRNA expression was comparable between control and all treatments. As a result, kisspeptin combined with FSH and IGF-1 could enhance CYP19A1 mRNA expression in human granulosa cells and the high dose of kisspeptin (10,000 nM) might be able to augment aromatase secretion in the supernatant. These results suggest that kisspeptin might enhance aromatase expression and secretion, which probably leads to enhance estrogen synthesis. Further studies regarding kisspeptin treatment on estrogen synthesis or secretion in human granulosa cells should be confirmed. Reference: (1) Fernandois D, et al. J Endocrinol. 2016;228(3):161-70.

D1/D5 Dopamine Receptors Stimulate Intracellular Calcium Release in Primary Cultures of Neocortical and Hippocampal Neurons

2002 ◽  
Vol 87 (4) ◽  
pp. 2167-2175 ◽  
Author(s):  
Nelson Lezcano ◽  
Clare Bergson
Keyword(s):  
Intracellular Calcium ◽  
Dopamine Receptors ◽  
Intracellular Signaling ◽  
Hippocampal Neurons ◽  
Calcium Release ◽  
Neuronal Excitability ◽  
Primary Cultures ◽  
Synaptic Function ◽  
State Dependent ◽  
Camp Levels

D1/D5 dopamine receptors in basal ganglia, hippocampus, and cerebral cortex modulate motor, reward, and cognitive behavior. Previous work with recombinant proteins revealed that in cells primed with heterologous Gq/11-coupled G-protein-coupled receptor (GPCR) agonists, the typically Gs-linked D1/D5 receptors can stimulate robust release of calcium from internal stores when coexpressed with calcyon. To learn more about the intracellular signaling mechanisms underlying these D1/D5 receptor regulated behaviors, we explored the possibility that endogenous receptors stimulate internal release of calcium in neurons. We have identified a population of neurons in primary cultures of hippocampus and neocortex that respond to D1/D5 dopamine receptor agonists with a marked increase in intracellular calcium (Ca[Formula: see text]) levels. The D1/D5 receptor stimulated responses occurred in the absence of extracellular Ca2+ indicating the rises in Ca[Formula: see text] involve release from internal stores. In addition, the responses were blocked by D1/D5 receptor antagonists. Further, the D1/D5 agonist-evoked responses were state dependent, requiring priming with agonists of Gq/11-coupled glutamate, serotonin, muscarinic, and adrenergic receptors or with high external K+solution. In contrast, D1/D5 receptor agonist-evoked Ca2+ responses were not detected in neurons derived from striatum. However, D1/D5 agonists elevated cAMP levels in striatal cultures as effectively as in neocortical and hippocampal cultures. Further, neither forskolin nor 8-Br-cAMP stimulation following priming was able to mimic the D1/D5 agonist-evoked Ca2+ response in neocortical neurons indicating that increased cAMP levels are not sufficient to stimulate Ca[Formula: see text] release. Our data suggest that D1-like dopamine receptors likely modulate neocortical and hippocampal neuronal excitability and synaptic function via Ca2+ as well as cAMP-dependent signaling.

Adrenergic regulation of salt and fluid secretion in human medullary collecting duct cells

2004 ◽  
Vol 287 (4) ◽  
pp. F639-F648 ◽  
Author(s):  
Darren P. Wallace ◽  
Gail Reif ◽  
Anne-Marie Hedge ◽  
J. Brantley Thrasher ◽  
Paul Pietrow
Keyword(s):  
Collecting Duct ◽  
Short Circuit ◽  
Primary Cultures ◽  
Short Circuit Current ◽  
Fluid Secretion ◽  
Intracellular Camp ◽  
Anion Secretion ◽  
Cell Monolayers ◽  
Urine Composition ◽  
Camp Levels

Transepithelial salt and fluid secretion mediated by cAMP in initial inner medullary collecting ducts (IMCDi) may be important for making final adjustments to urine composition. We examined in primary cultures of human IMCDi cells the effects of adrenergic receptor (AR) agonists and antagonists on intracellular cAMP levels, short-circuit current ( ISC), and fluid secretion. Epinephrine (1 μM), norepinephrine (1 μM), and isoproterenol (10 nM) individually increased intracellular cAMP levels 57-, 2-, and 25-fold, respectively, and stimulated ISC 3.3-, 2.9-, and 3.4-fold, respectively. β-AR activation increased net fluid secretion by cultured human IMCDi cell monolayers from 0.09 ± 0.04 to 0.26 ± 0.05 μl·h−1·cm−2 and freshly isolated rat IMCDi from 0.02 ± 0.01 to 0.09 ± 0.02 nl·h−1·mm−1. In monolayers, these effects were eliminated by blocking β2-AR, but not β1-AR. Activation of α2-AR with guanabenz inhibited isoproterenol-induced ISC by 37% in human IMCDi monolayers and fluid secretion by 91% in rat IMCDi. Immunohistochemistry of human medullary tissue sections revealed greater expression of β2-AR than β1-AR; β2-AR was localized to the basolateral membranes of human IMCDi. Immunoblots identified α2A-AR and α2B-AR in cultured human IMCDi cell monolayers. We conclude that 1) catecholamines stimulate cAMP-dependent anion and fluid secretion by IMCDi cells primarily through β2-AR activation and 2) α2-AR activation attenuates cAMP-dependent anion secretion.

scholarly journals ID: 1039 The antidepressant fluoxetine inhibits adenylate cyclase stimulation by FSH or Forskolin in the COV434 human ovarian granulosa tumor cell line

2017 ◽  
Vol 4 (S) ◽  
pp. 117
Author(s):  
Thi Mong Diep Nguyen ◽  
Danièle Klett ◽  
Minh Thu Vo ◽  
Yves Combarnous
Keyword(s):  
Signaling Pathways ◽  
Granulosa Cells ◽  
Molecular Mechanisms ◽  
Follicular Development ◽  
Tumor Cell Line ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cell Types ◽  
Intracellular Camp ◽  
Human Granulosa Cells

Fluoxetine (Prozac), a selective Serotonin Reuptake Inhibitor antidepressant, exhibits other mechanisms of action in various cell types and has been shown to induce cell death in cancer cells, paving the way for its potential use in cancer therapy. The ovary is a complex endocrine organ responsible for steroidogenesis and folliculogenesis, and human granulosa cells are essential for scientific research to improve the understanding of these two processes. However, little is known about fundamental signaling pathways in human granulosa cells. In this study, we investigated the dynamics of intracellular cyclic adenosine monophosphate AMP, a conserved signaling messenger that can regulate virtually every physiological process. We show that incubating COV434 human ovarian granulosa cells with fluoxetine induces a decrease in intracellular cAMP response to Follicle-stimulating hormone (FSH) and forskolin (FSK). In order to study the intracellular cAMP kinetic responses of COV434 cells to FSH or FSK, we used COV434 cells transiently expressing a chimeric cAMP-responsive luciferase so that real-time variations of intracellular cAMP concentration could be monitored, by using oxiluciferin luminescence produced from catalyzed luciferin oxidation. Our data show that fluoxetine induces an increase in the extracellular Ca2+ entry and reduces ATP concentration as well as cell viability. Targeting these signaling pathways with fluoxetine could permit to get better knowledge in the molecular mechanisms involved in ovarian follicular development

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