scholarly journals Characterization of the signalling modalities of prostaglandin E2 receptors EP2 and EP4 reveals crosstalk and a role for microtubules

2020 ◽  
Author(s):  
Ward Vleeshouwers ◽  
Koen van den Dries ◽  
Sandra de Keijzer ◽  
Ben Joosten ◽  
Diane S. Lidke ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Quantitative Imaging ◽  
Myeloid Cells ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Lipid Mediator ◽  
Camp Production ◽  
Microtubule Network ◽  
Immune Modulators ◽  
G Protein Coupled

AbstractProstaglandin E2 (PGE2) is a lipid mediator that modulates the function of myeloid immune cells such as macrophages and dendritic cells (DCs) through the activation of the G protein-coupled receptors EP2 and EP4. While both EP2 and EP4 signalling leads to an elevation of intracellular cyclic adenosine monophosphate (cAMP) levels through the stimulating Gαs protein, EP4 also couples to the inhibitory Gαi protein to decrease the production of cAMP. The receptor-specific contributions to downstream immune modulatory functions are still poorly defined. Here, we employed quantitative imaging methods to characterize the early EP2 and EP4 signalling events in myeloid cells and their contribution to the dissolution of adhesion structures called podosomes, which is a first and essential step in DC maturation. We first show that podosome loss in DCs is primarily mediated by EP4. Next, we demonstrate that EP2 and EP4 signalling leads to distinct cAMP production profiles, with EP4 inducing a transient cAMP response and EP2 inducing a sustained cAMP response only at high PGE2 levels. We further find that simultaneous EP2 and EP4 stimulation attenuates cAMP production, suggesting a reciprocal control of EP2 and EP4 signaling. Finally, we demonstrate that efficient signaling of both EP2 and EP4 relies on an intact microtubule network. Together, these results enhance our understanding of early EP2 and EP4 signalling in myeloid cells. Considering that modulation of PGE2 signalling is regarded as an important therapeutic possibility in anti-tumour immunotherapy, our findings may facilitate the development of efficient and specific immune modulators of PGE2 receptors.

scholarly journals Characterization of the Signaling Modalities of Prostaglandin E2 Receptors EP2 and EP4 Reveals Crosstalk and a Role for Microtubules

2021 ◽  
Vol 11 ◽  
Author(s):  
Ward Vleeshouwers ◽  
Koen van den Dries ◽  
Sandra de Keijzer ◽  
Ben Joosten ◽  
Diane S. Lidke ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Quantitative Imaging ◽  
Myeloid Cells ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Lipid Mediator ◽  
Camp Production ◽  
Microtubule Network ◽  
Immune Modulators ◽  
G Protein Coupled

Prostaglandin E2 (PGE2) is a lipid mediator that modulates the function of myeloid immune cells such as macrophages and dendritic cells (DCs) through the activation of the G protein-coupled receptors EP2 and EP4. While both EP2 and EP4 signaling leads to an elevation of intracellular cyclic adenosine monophosphate (cAMP) levels through the stimulating Gαs protein, EP4 also couples to the inhibitory Gαi protein to decrease the production of cAMP. The receptor-specific contributions to downstream immune modulatory functions are still poorly defined. Here, we employed quantitative imaging methods to characterize the early EP2 and EP4 signaling events in myeloid cells and their contribution to the dissolution of adhesion structures called podosomes, which is a first and essential step in DC maturation. We first show that podosome loss in DCs is primarily mediated by EP4. Next, we demonstrate that EP2 and EP4 signaling leads to distinct cAMP production profiles, with EP4 inducing a transient cAMP response and EP2 inducing a sustained cAMP response only at high PGE2 levels. We further find that simultaneous EP2 and EP4 stimulation attenuates cAMP production, suggesting a reciprocal control of EP2 and EP4 signaling. Finally, we demonstrate that efficient signaling of both EP2 and EP4 relies on an intact microtubule network. Together, these results enhance our understanding of early EP2 and EP4 signaling in myeloid cells. Considering that modulation of PGE2 signaling is regarded as an important therapeutic possibility in anti-tumor immunotherapy, our findings may facilitate the development of efficient and specific immune modulators of PGE2 receptors.

scholarly journals Members of the KCTD family are major regulators of cAMP signaling

2021 ◽  
Vol 119 (1) ◽  
pp. e2119237119
Author(s):  
Brian S. Muntean ◽  
Subhi Marwari ◽  
Xiaona Li ◽  
Douglas C. Sloan ◽  
Brian D. Young ◽  
...  
Keyword(s):  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Camp Signaling ◽  
Motor Deficits ◽  
Adenylyl Cyclases ◽  
Striatal Neurons ◽  
Camp Production ◽  
Neuronal Function ◽  
Signaling Systems ◽  
G Protein Coupled

Cyclic adenosine monophosphate (cAMP) is a pivotal second messenger with an essential role in neuronal function. cAMP synthesis by adenylyl cyclases (AC) is controlled by G protein–coupled receptor (GPCR) signaling systems. However, the network of molecular players involved in the process is incompletely defined. Here, we used CRISPR/Cas9–based screening to identify that members of the potassium channel tetradimerization domain (KCTD) family are major regulators of cAMP signaling. Focusing on striatal neurons, we show that the dominant isoform KCTD5 exerts its effects through an unusual mechanism that modulates the influx of Zn2+ via the Zip14 transporter to exert unique allosteric effects on AC. We further show that KCTD5 controls the amplitude and sensitivity of stimulatory GPCR inputs to cAMP production by Gβγ-mediated AC regulation. Finally, we report that KCTD5 haploinsufficiency in mice leads to motor deficits that can be reversed by chelating Zn2+. Together, our findings uncover KCTD proteins as major regulators of neuronal cAMP signaling via diverse mechanisms.

Mapping the Heart

2010 ◽  
Vol 18 (4) ◽  
pp. 6-8
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
G Protein Coupled Receptors ◽  
Receptor Subtypes ◽  
Cardiac Muscle Cells ◽  
Guanine Nucleotide Binding Protein ◽  
The Common ◽  
Guanine Nucleotide Binding ◽  
First Time ◽  
G Protein Coupled

Some of the receptors on the surface of cardiac muscle cells (cardiomyocytes) mediate the response of these cells to catecholamines by causing the production of the common second messenger cyclic adenosine monophosphate (cAMP). An example of such receptors are the β1- and β2-adrenergic receptors (βARs) that are heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors. Selective stimulation of these two receptor subtypes leads to distinct physiological and pathophysiological responses, but their precise location on the surface of cardiomyocytes has not been correlated with these responses. In an ingenious combination of techniques, Viacheslav Nikolaev, Alexey Moshkov, Alexander Lyon, Michele Miragoli, Pavel Novak, Helen Paur, Martin Lohse, Yuri Korchev, Sian Harding, and Julia Gorelik have mapped the function of these receptors for the first time.

Dobutamine Antagonizes Epinephrine's Biochemical and Cardiotonic Effects 

1998 ◽  
Vol 89 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Richard C. Prielipp ◽  
Drew A. MacGregor ◽  
Roger L. Royster ◽  
Neal D. Kon ◽  
Michael H. Hines ◽  
...  
Keyword(s):  
Artery Bypass ◽  
Phase 1 ◽  
Human Lymphocytes ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Camp Production ◽  
Isobolographic Analysis ◽  
Camp Generation ◽  
Vitro Model

Background Patients may receive more than one positive inotropic drug to improve myocardial function and cardiac output, with the assumption that the effects of two drugs are additive. The authors hypothesized that combinations of dobutamine and epinephrine would produce additive biochemical and hemodynamic effects. Methods The study was performed in two parts. Phase 1 used human lymphocytes in an in vitro model of cyclic adenosine monophosphate (cAMP) generation in response to dobutamine (10(-8) to 10(-4) M) or epinephrine (10(-9) M to 10(-5) M), and dobutamine and epinephrine together. Phase 2 was a clinical study in patients after aortocoronary artery bypass in which isobolographic analysis compared the cardiotonic effects of dobutamine (1.25, 2.5, or 5 microg x kg(-1) x min(-1)) or epinephrine (10, 20, or 40 ng x kg(-l) x min(-1)), alone or in combination. Results In phase 1, dobutamine increased cAMP production 41%, whereas epinephrine increased cAMP concentration approximately 200%. However, when epinephrine (10(-6) M) and dobutamine were combined, dobutamine reduced cAMP production at concentrations between 10(-6) to 10(-4) M (P = 0.001). In patients, 1.25 to 5 microg x kg(-1) x min(-1) dobutamine increased the cardiac index (CI) 15-28%. Epinephrine also increased the CI with each increase in dose. However, combining epinephrine with the two larger doses of dobutamine (2.5 and 5microg x kg(-1) x mi(-1)) did not increase the CI beyond that achieved with epinephrine and the lowest dose of dobutamine (1.25 microg x kg(-1) x min(-1)). In addition, the isobolographic analysis for equieffective concentrations of dobutamine and epinephrine suggests subadditive effects. Conclusions Dobutamine inhibits epinephrine-induced production of cAMP in human lymphocytes and appears to be subadditive by clinical and isobolographic analyses of the cardiotonic effects. These findings suggest that combinations of dobutamine and epinephrine may be less than additive.

scholarly journals Microglia control the glycinergic but not the GABAergic synapses via prostaglandin E2 in the spinal cord

2017 ◽  
Vol 216 (9) ◽  
pp. 2979-2989 ◽  
Author(s):  
Yasmine Cantaut-Belarif ◽  
Myriam Antri ◽  
Rocco Pizzarelli ◽  
Sabrina Colasse ◽  
Ilaria Vaccari ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Brain Diseases ◽  
Excitatory Synapses ◽  
Diffusion Dynamics ◽  
Gabaergic Synapses ◽  
Dependent Protein ◽  
Activity Dependent ◽  
Early Features

Microglia control excitatory synapses, but their role in inhibitory neurotransmission has been less well characterized. Herein, we show that microglia control the strength of glycinergic but not GABAergic synapses via modulation of the diffusion dynamics and synaptic trapping of glycine (GlyR) but not GABAA receptors. We further demonstrate that microglia regulate the activity-dependent plasticity of glycinergic synapses by tuning the GlyR diffusion trap. This microglia–synapse cross talk requires production of prostaglandin E2 by microglia, leading to the activation of neuronal EP2 receptors and cyclic adenosine monophosphate–dependent protein kinase. Thus, we now provide a link between microglial activation and synaptic dysfunctions, which are common early features of many brain diseases.

scholarly journals Absence of antibodies stimulating H2-receptor mediated cyclic adenosine monophosphate (cAMP) production in peptic ulcer disease.

Gut ◽  
1992 ◽  
Vol 33 (3) ◽  
pp. 424-424
Author(s):  
A Sarem-Aslani ◽  
C Bergmann ◽  
S Walker ◽  
D Ratge ◽  
U Klotz ◽  
...  
Keyword(s):  
Peptic Ulcer ◽  
Peptic Ulcer Disease ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Camp Production ◽  
H2 Receptor ◽  
Ulcer Disease

scholarly journals Identification and characterization of an atypical Gαs-biased β2AR agonist that fails to evoke airway smooth muscle cell tachyphylaxis

2021 ◽  
Vol 118 (49) ◽  
pp. e2026668118
Author(s):  
Donghwa Kim ◽  
Alina Tokmakova ◽  
Lauren K. Lujan ◽  
Hannah R. Strzelinski ◽  
Nicholas Kim ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Chemical Space ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Airway Smooth Muscle Cell ◽  
Functional Studies ◽  
G Protein Coupled ◽  
Identification And Characterization

G protein–coupled receptors display multifunctional signaling, offering the potential for agonist structures to promote conformational selectivity for biased outputs. For β2-adrenergic receptors (β2AR), unbiased agonists stabilize conformation(s) that evoke coupling to Gαs (cyclic adenosine monophosphate [cAMP] production/human airway smooth muscle [HASM] cell relaxation) and β-arrestin engagement, the latter acting to quench Gαs signaling, contributing to receptor desensitization/tachyphylaxis. We screened a 40-million-compound scaffold ranking library, revealing unanticipated agonists with dihydroimidazolyl-butyl-cyclic urea scaffolds. The S-stereoisomer of compound C1 shows no detectable β-arrestin engagement/signaling by four methods. However, C1-S retained Gαs signaling—a divergence of the outputs favorable for treating asthma. Functional studies with two models confirmed the biasing: β2AR-mediated cAMP signaling underwent desensitization to the unbiased agonist albuterol but not to C1-S, and desensitization of HASM cell relaxation was observed with albuterol but not with C1-S. These HASM results indicate biologically pertinent biasing of C1-S, in the context of the relevant physiologic response, in the human cell type of interest. Thus, C1-S was apparently strongly biased away from β-arrestin, in contrast to albuterol and C5-S. C1-S structural modeling and simulations revealed binding differences compared with unbiased epinephrine at transmembrane (TM) segments 3,5,6,7 and ECL2. C1-S (R2 = cyclohexane) was repositioned in the pocket such that it lost a TM6 interaction and gained a TM7 interaction compared with the analogous unbiased C5-S (R2 = benzene group), which appears to contribute to C1-S biasing away from β-arrestin. Thus, an agnostic large chemical-space library identified agonists with receptor interactions that resulted in relevant signal splitting of β2AR actions favorable for treating obstructive lung disease.

scholarly journals Nomad Biosensors: A New Multiplexed Technology for the Screening of GPCR Ligands

2018 ◽  
Vol 23 (3) ◽  
pp. 207-216 ◽  
Author(s):  
Rosa M. Mella ◽  
Danel Kortazar ◽  
Meritxell Roura-Ferrer ◽  
Clarisa Salado ◽  
María Valcárcel ◽  
...  
Keyword(s):  
New Technology ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Chemical Library ◽  
Fluorescent Biosensors ◽  
Physiological Processes ◽  
Gpcr Activation ◽  
Large Numbers ◽  
Therapeutic Research ◽  
G Protein Coupled

Nomad Technology (Innoprot [Innovative Technologies in Biological Systems], Derio, Spain), a novel tool for multiplexing high-throughput cell-based G protein–coupled receptor (GPCR) assays, is described in this work. This new technology comprises a family of fluorescent biosensors called Nomad Biosensors that allow for the measurement of responses mediated by G proteins through their interactions with second-messenger transduction proteins. GPCRs are one of the largest protein families of receptors in eukaryotes, and their signaling mediates important physiological processes within cells. Thus, GPCRs are associated with a wide variety of diseases, and considered major targets in therapeutic research. Nomad constitutes a novel tool for unraveling the mechanism of GPCR signal transduction by simultaneously tracing different pathways. GPCR activation changes the structural folding of the biosensor and promotes its vesicularization, as well as an increase in the fluorescence intensity. Based on this technology, the MPXNomad cellular model was developed to discriminate between the Ca2+-mediated pathway and the cyclic adenosine monophosphate (cAMP)–mediated pathway. To validate this model, endothelin receptor B (ETBR) was coexpressed into the MPXNomad cell line and assessed with a specific agonist, an antagonist, and a chemical library of compounds. Nomad Technology optimizes the identification of novel GPCR ligands and enables the testing of large numbers of compounds.

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