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Shiozaki‐Takagi Y, Ozaki N, Toyoda Y. Epac2 activation mediates glucagon-induced glucogenesis in primary rat hepatocytes. J Diabetes Investig 2024; 15:429-436. [PMID: 38243676 PMCID: PMC10981141 DOI: 10.1111/jdi.14142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/06/2023] [Accepted: 12/21/2023] [Indexed: 01/21/2024] Open
Abstract
AIMS/INTRODUCTION Glucagon plays an essential role in hepatic glucogenesis by enhancing glycogen breakdown, inducing gluconeogenesis, and suppressing glycogenesis. Moreover, glucagon increases cyclic adenosine monophosphate (cAMP) levels, thereby activating protein kinase A (PKA) and cAMP guanine nucleotide exchange factor (also known as Epac). Although the function of PKA in the liver has been studied extensively, the function of hepatic Epac is poorly understood. The aim of this study was to elucidate the role of Epac in mediating the action of glucagon on the hepatocytes. MATERIALS AND METHODS Epac mRNA and protein expression, localization, and activity in the hepatocytes were analyzed by reverse transcription polymerase chain reaction, western blotting, immunofluorescence staining, and Rap1 activity assay, respectively. Additionally, we investigated the effects of an Epac-specific activator, 8-CPT, and an Epac-specific inhibitor, ESI-05, on glycogen metabolism in isolated rat hepatocytes. Further mechanisms of glycogen metabolism were evaluated by examining glucokinase (GK) translocation and mRNA expression of gluconeogenic enzymes. RESULTS Epac2, but not Epac1, was predominantly expressed in the liver. Moreover, 8-CPT inhibited glycogen accumulation and GK translocation and enhanced the mRNA expression of gluconeogenic enzymes. ESI-05 failed to reverse glucagon-induced suppression of glycogen storage and partially inhibited glucagon-induced GK translocation and the mRNA expression of gluconeogenic enzymes. CONCLUSIONS Epac signaling plays a role in mediating the glucogenic action of glucagon in the hepatocytes.
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Affiliation(s)
- Yusuke Shiozaki‐Takagi
- Research Center of Health, Physical Fitness and SportsNagoya UniversityNagoyaJapan
- Department of Pathobiochemistry, Faculty of PharmacyMeijo UniversityNagoyaJapan
- Present address:
Division of Cell Signaling and Molecular Medicine, Institute of Medical ScienceThe University of TokyoTokyoJapan
| | - Nobuaki Ozaki
- Research Center of Health, Physical Fitness and SportsNagoya UniversityNagoyaJapan
- Division of EndocrinologyJapanese Red Cross Aichi Medical Center Nagoya Daiichi HospitalNagoyaJapan
| | - Yukiyasu Toyoda
- Department of Pathobiochemistry, Faculty of PharmacyMeijo UniversityNagoyaJapan
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Ferri G, Fernández LR, Di Mario G, Musikant D, Palermo JA, Edreira MM. Host cell cAMP- Epac-Rap1b pathway inhibition by hawthorn extract as a potential target against Trypanosoma cruzi infection. Front Microbiol 2023; 14:1301862. [PMID: 38156015 PMCID: PMC10754523 DOI: 10.3389/fmicb.2023.1301862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 11/16/2023] [Indexed: 12/30/2023] Open
Abstract
Although the two drugs currently available for the treatment of Chagas disease, Benznidazole and Nifurtimox, have proven to be effective in the acute phase of the disease, the 60-90-day treatment leads to high toxicity and unwanted side effects, presenting, in addition, a low efficacy in the chronic phase of the disease. For this reason, new therapies that are more effective are needed. In this regard, we have recently shown that the inhibition of the Epac-Rap1b pathway suppressed the cAMP-mediated host cell invasion by Trypanosoma cruzi. Interestingly, it has been described that vitexin, a natural flavone that protects against ischemia-reperfusion damage, acts by inhibiting the expression of Epac and Rap1 proteins. Vitexin can be found in plants of the genus Crataegus spp., traditionally known as hawthorn, which are of great interest considering their highly documented use as cardio-protectors. Pre-treating cells with an extract of Crataegus oxyacantha produced levels of T. cruzi invasion comparable to the ones observed for the commercially available Epac1-specific inhibitor, ESI-09. In addition, extract-treated cells exhibited a decrease in the activation of Rap1b, suggesting that the effects of the extract would be mediated by the inhibition of the cAMP-Epac-Rap1 signaling pathway. Using HPLC-HRMS2, we could confirm the presence of vitexin, and other flavones that could act as inhibitors of Epac/Rap1b, in the extracts of C. oxyacantha. Most significantly, when cells were treated with the extract of C. oxyacantha in conjunction with Nifurtimox, an increased modulation of invasion was observed.
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Affiliation(s)
- Gabriel Ferri
- CONICET-Universidad de Buenos Aires, IQUIBICEN, Ciudad de Buenos Aires, Argentina
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
| | - Lucía R. Fernández
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Unidad de Microanálisis y Métodos Físicos Aplicados a la Química Orgánica (UMYMFOR), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Guillermo Di Mario
- CONICET-Universidad de Buenos Aires, IQUIBICEN, Ciudad de Buenos Aires, Argentina
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
| | - Daniel Musikant
- CONICET-Universidad de Buenos Aires, IQUIBICEN, Ciudad de Buenos Aires, Argentina
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
| | - Jorge A. Palermo
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Unidad de Microanálisis y Métodos Físicos Aplicados a la Química Orgánica (UMYMFOR), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Martin M. Edreira
- CONICET-Universidad de Buenos Aires, IQUIBICEN, Ciudad de Buenos Aires, Argentina
- Laboratorio de Biología Molecular de Trypanosomas, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos, Ciudad de Buenos Aires, Argentina
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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Aslam M, Ladilov Y. Editorial: Advances in cAMP signaling research: basic and translational aspects. Front Physiol 2023; 14:1266718. [PMID: 37727656 PMCID: PMC10505720 DOI: 10.3389/fphys.2023.1266718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 08/22/2023] [Indexed: 09/21/2023] Open
Affiliation(s)
- Muhammad Aslam
- Experimental Cardiology, Department of Internal Medicine I, Justus Liebig University, Giessen, Germany
- Department of Cardiology, Kerckhoff Clinic GmbH, Bad Nauheim, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Rhein-Main, Bad Nauheim, Germany
| | - Yury Ladilov
- Department of Cardiovascular Surgery, Heart Center Brandenburg, Brandenburg Medical School Theodor Fontane, Bernau bei Berlin, Germany
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Gárriz A, Morokuma J, Toribio D, Zoukhri D. Role of the adenylate cyclase/cyclic AMP pathway in oxytocin-induced lacrimal gland myoepithelial cells contraction. Exp Eye Res 2023; 233:109526. [PMID: 37290630 PMCID: PMC10527592 DOI: 10.1016/j.exer.2023.109526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 05/03/2023] [Accepted: 06/06/2023] [Indexed: 06/10/2023]
Abstract
The aim of these studies was to investigate the involvement of the second messenger 3',5'-cyclic adenosine monophosphate (cAMP) and its downstream effectors in oxytocin (OXT)-mediated lacrimal gland myoepithelial cell (MEC) contraction. Lacrimal gland MEC were isolated and propagated from alpha-smooth muscle actin (SMA)-GFP mice. RNA and protein samples were prepared to analyze G protein expression by RT-PCR and western blotting; respectively. Changes in intracellular cAMP concentration were measured using a competitive ELISA kit. To increase intracellular cAMP concentration, the following agents were used: forskolin (FKN, a direct activator of adenylate cyclase), 3-isobutyl-1-methylxanthine (IBMX, an inhibitor of the phosphodiesterase that hydrolyzes cAMP), or a cell permeant cAMP analog, dibutyryl (db)-cAMP. In addition, inhibitors and selective agonists were used to investigate the role of cAMP effector molecules, protein kinase A (PKA) and exchange protein activated by cAMP (EPAC) in OXT-induced MEC contraction. MEC contraction was monitored in real time and changes in cell size were quantified using ImageJ software. The adenylate cyclase coupling G proteins, Gαs, Gαo, and Gαi, are expressed in lacrimal gland MEC at both the mRNA and protein levels. OXT increased intracellular cAMP in a concentration-dependent manner. FKN, IBMX and db-cAMP significantly stimulated MEC contraction. Preincubation of cells with either Myr-PKI, a specific PKA inhibitor or ESI09, an EPAC inhibitor, resulted in almost complete inhibition of both FKN- as well as OXT-stimulated MEC contraction. Finally, direct activation of PKA or EPAC using selective agonists triggered MEC contraction. We conclude that cAMP agonists modulate lacrimal gland MEC contraction via PKA and EPAC activation which also play a major role in OXT induced MEC contraction.
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Affiliation(s)
- Angela Gárriz
- Department of Comprehensive Care, Tufts University School of Dental Medicine, Boston, MA, USA
| | - Junji Morokuma
- Department of Comprehensive Care, Tufts University School of Dental Medicine, Boston, MA, USA
| | - Danny Toribio
- Department of Comprehensive Care, Tufts University School of Dental Medicine, Boston, MA, USA
| | - Driss Zoukhri
- Department of Comprehensive Care, Tufts University School of Dental Medicine, Boston, MA, USA; Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA.
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Boulton S, Crupi MJF, Singh S, Carter-Timofte ME, Azad T, Organ BC, He X, Gill R, Neault S, Jamieson T, Dave J, Kurmasheva N, Austin B, Petryk J, Singaravelu R, Huang BZ, Franco N, Babu K, Parks RJ, Ilkow CS, Olagnier D, Bell JC. Inhibition of Exchange Proteins Directly Activated by cAMP ( EPAC) as a Strategy for Broad-Spectrum Antiviral Development. J Biol Chem 2023; 299:104749. [PMID: 37100284 PMCID: PMC10124099 DOI: 10.1016/j.jbc.2023.104749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 04/28/2023] Open
Abstract
The recent SARS-CoV-2 and mpox outbreaks have highlighted the need to expand our arsenal of broad-spectrum antiviral agents for future pandemic preparedness. Host-directed antivirals are an important tool to accomplish this as they typically offer protection against a broader range of viruses than direct-acting antivirals and have a lower susceptibility to viral mutations that cause drug resistance. In this study, we investigate the Exchange Protein Activated by cAMP (EPAC) as a target for broad-spectrum antiviral therapy. We find that the EPAC-selective inhibitor, ESI-09 provides robust protection against a variety of viruses, including SARS-CoV-2 and Vaccinia (VACV) - an orthopoxvirus from the same family as mpox. We show, using a series of immunofluorescence experiments, that ESI-09 remodels the actin cytoskeleton through Rac1/Cdc42 GTPases and the Arp2/3 complex, impairing internalization of viruses that use clathrin-mediated endocytosis (e.g. VSV) or micropinocytosis (e.g. VACV). Additionally, we find that ESI-09 disrupts syncytia formation and inhibits cell-to-cell transmission of viruses such as measles and VACV. When administered to immune-deficient mice in an intranasal challenge model, ESI-09 protects mice from lethal doses of VACV and prevents formation of pox lesions. Altogether, our finding show that EPAC antagonists such as ESI-09 are promising candidates for broad-spectrum antiviral therapy that can aid in the fight against ongoing and future viral outbreaks.
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Affiliation(s)
- Stephen Boulton
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.
| | - Mathieu J F Crupi
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Siddharth Singh
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | | | - Taha Azad
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada; Faculty of Medicine and Health Sciences, Department of microbiology and infectious diseases, Université de Sherbrooke, Sherbrooke, QC J1E 4K8, Canada; Centre de Recherche du CHUS, Sherbrooke, QC J1H 5N4, Canada
| | - Bailey C Organ
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Xiaohong He
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Rida Gill
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Serge Neault
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Taylor Jamieson
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Jaahnavi Dave
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Naziia Kurmasheva
- Aarhus University, Department of Biomedicine, Aarhus C, 8000, Denmark
| | - Bradley Austin
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada
| | - Julia Petryk
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada
| | - Ragunath Singaravelu
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada; Public Health Agency of Canada, Ottawa, Ontario, Canada, K1A 0K9
| | - Ben Zhen Huang
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Noah Franco
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Kaaviya Babu
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Robin J Parks
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada; Department of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Carolina S Ilkow
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - David Olagnier
- Aarhus University, Department of Biomedicine, Aarhus C, 8000, Denmark
| | - John C Bell
- Ottawa Hospital Research Institute, Ottawa, ON, K1H 8L6, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, K1H 8M5, Canada; Department of Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada.
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6
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Guillot B, Boileve A, Walton R, Harfoush A, Conte C, Sainte-Marie Y, Charron S, Bernus O, Recalde A, Sallé L, Brette F, Lezoualc'h F. Inhibition of EPAC1 signaling pathway alters atrial electrophysiology and prevents atrial fibrillation. Front Physiol 2023; 14:1120336. [PMID: 36909224 PMCID: PMC9992743 DOI: 10.3389/fphys.2023.1120336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/09/2023] [Indexed: 02/24/2023] Open
Abstract
Introduction: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with increased mortality and morbidity. The Exchange Protein directly Activated by cAMP (EPAC), has been implicated in pro-arrhythmic signaling pathways in the atria, but the underlying mechanisms remain unknown. Methods: In this study, we investigated the involvement of EPAC1 and EPAC2 isoforms in the genesis of AF in wild type (WT) mice and knockout (KO) mice for EPAC1 or EPAC2. We also employed EPAC pharmacological modulators to selectively activate EPAC proteins (8-CPT-AM; 10 μM), or inhibit either EPAC1 (AM-001; 20 μM) or EPAC2 (ESI-05; 25 μM). Transesophageal stimulation was used to characterize the induction of AF in vivo in mice. Optical mapping experiments were performed on isolated mouse atria and cellular electrophysiology was examined by whole-cell patch-clamp technique. Results: In wild type mice, we found 8-CPT-AM slightly increased AF susceptibility and that this was blocked by the EPAC1 inhibitor AM-001 but not the EPAC2 inhibitor ESI-05. Consistent with this, in EPAC1 KO mice, occurrence of AF was observed in 3/12 (vs. 4/10 WT littermates) and 4/10 in EPAC2 KO (vs. 5/10 WT littermates). In wild type animals, optical mapping experiments revealed that 8-CPT-AM perfusion increased action potential duration even in the presence of AM-001 or ESI-05. Interestingly, 8-CPT-AM perfusion decreased conduction velocity, an effect blunted by AM-001 but not ESI-05. Patch-clamp experiments demonstrated action potential prolongation after 8-CPT-AM perfusion in both wild type and EPAC1 KO mice and this effect was partially prevented by AM-001 in WT. Conclusion: Together, these results indicate that EPAC1 and EPAC2 signaling pathways differentially alter atrial electrophysiology but only the EPAC1 isoform is involved in the genesis of AF. Selective blockade of EPAC1 with AM-001 prevents AF in mice.
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Affiliation(s)
- Bastien Guillot
- IHU LIRYC -CRCTB U1045, Pessac, France.,INSERM U1045 -Université de Bordeaux, Bordeaux, France
| | - Arthur Boileve
- UR 4650 PSIR, GIP Cyceron, Caen, France.,Université de Caen-Normandie, Caen, France
| | - Richard Walton
- IHU LIRYC -CRCTB U1045, Pessac, France.,INSERM U1045 -Université de Bordeaux, Bordeaux, France
| | - Alexandre Harfoush
- UR 4650 PSIR, GIP Cyceron, Caen, France.,Université de Caen-Normandie, Caen, France
| | - Caroline Conte
- Université de Toulouse-Paul Sabatier, Toulouse, France.,Institut des maladies métaboliques et cardiovasculaires, INSERM UMR-1297, Toulouse, France
| | - Yannis Sainte-Marie
- Université de Toulouse-Paul Sabatier, Toulouse, France.,Institut des maladies métaboliques et cardiovasculaires, INSERM UMR-1297, Toulouse, France
| | - Sabine Charron
- IHU LIRYC -CRCTB U1045, Pessac, France.,INSERM U1045 -Université de Bordeaux, Bordeaux, France
| | - Olivier Bernus
- IHU LIRYC -CRCTB U1045, Pessac, France.,INSERM U1045 -Université de Bordeaux, Bordeaux, France
| | - Alice Recalde
- IHU LIRYC -CRCTB U1045, Pessac, France.,INSERM U1045 -Université de Bordeaux, Bordeaux, France
| | - Laurent Sallé
- UR 4650 PSIR, GIP Cyceron, Caen, France.,Université de Caen-Normandie, Caen, France
| | - Fabien Brette
- IHU LIRYC -CRCTB U1045, Pessac, France.,INSERM U1045 -Université de Bordeaux, Bordeaux, France.,PhyMedExp, INSERM U1046, CNRS 9412, Université de Montpellier, Montpellier, France
| | - Frank Lezoualc'h
- Université de Toulouse-Paul Sabatier, Toulouse, France.,Institut des maladies métaboliques et cardiovasculaires, INSERM UMR-1297, Toulouse, France
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Kilanowska A, Ziółkowska A, Stasiak P, Gibas-Dorna M. cAMP-Dependent Signaling and Ovarian Cancer. Cells 2022; 11:cells11233835. [PMID: 36497095 PMCID: PMC9738761 DOI: 10.3390/cells11233835] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/02/2022] Open
Abstract
cAMP-dependent pathway is one of the most significant signaling cascades in healthy and neoplastic ovarian cells. Working through its major effector proteins-PKA and EPAC-it regulates gene expression and many cellular functions. PKA promotes the phosphorylation of cAMP response element-binding protein (CREB) which mediates gene transcription, cell migration, mitochondrial homeostasis, cell proliferation, and death. EPAC, on the other hand, is involved in cell adhesion, binding, differentiation, and interaction between cell junctions. Ovarian cancer growth and metabolism largely depend on changes in the signal processing of the cAMP-PKA-CREB axis, often associated with neoplastic transformation, metastasis, proliferation, and inhibition of apoptosis. In addition, the intracellular level of cAMP also determines the course of other pathways including AKT, ERK, MAPK, and mTOR, that are hypo- or hyperactivated among patients with ovarian neoplasm. With this review, we summarize the current findings on cAMP signaling in the ovary and its association with carcinogenesis, multiplication, metastasis, and survival of cancer cells. Additionally, we indicate that targeting particular stages of cAMP-dependent processes might provide promising therapeutic opportunities for the effective management of patients with ovarian cancer.
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Affiliation(s)
- Agnieszka Kilanowska
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
- Correspondence: ; Tel.: +48-683-283-148
| | - Agnieszka Ziółkowska
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
| | - Piotr Stasiak
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
| | - Magdalena Gibas-Dorna
- Department of Anatomy and Histology, Collegium Medicum, University of Zielona Gora, 65-046 Zielona Gora, Poland
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Mecca AA, Caprara GA, Peng AW. cAMP and voltage modulate rat auditory mechanotransduction by decreasing the stiffness of gating springs. Proc Natl Acad Sci U S A 2022; 119:e2107567119. [PMID: 35858439 DOI: 10.1073/pnas.2107567119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Regulation of auditory sensitivity contributes to the precision, dynamic range, and protection of the auditory system. Regulation of the hair cell mechanotransduction channel is a major contributor to controlling the sensitivity of the auditory transduction process. The gating spring is a critical piece of the mechanotransduction machinery because it opens and closes the mechanotransduction channel, and its stiffness regulates the sensitivity of the mechanotransduction process. In the present work, we characterize the effect of the second-messenger signaling molecule cyclic adenosine monophosphate (cAMP) and identify that it reduces gating spring stiffness likely through an exchange protein directly activated by cAMP (EPAC)-mediated pathway. This is a unique physiologic mechanism to regulate gating spring stiffness. Hair cells of the auditory and vestibular systems transform mechanical input into electrical potentials through the mechanoelectrical transduction process (MET). Deflection of the mechanosensory hair bundle increases tension in the gating springs that open MET channels. Regulation of MET channel sensitivity contributes to the auditory system’s precision, wide dynamic range and, potentially, protection from overexcitation. Modulating the stiffness of the gating spring modulates the sensitivity of the MET process. Here, we investigated the role of cyclic adenosine monophosphate (cAMP) in rat outer hair cell MET and found that cAMP up-regulation lowers the sensitivity of the channel in a manner consistent with decreasing gating spring stiffness. Direct measurements of the mechanical properties of the hair bundle confirmed a decrease in gating spring stiffness with cAMP up-regulation. In parallel, we found that prolonged depolarization mirrored the effects of cAMP. Finally, a limited number of experiments implicate that cAMP activates the exchange protein directly activated by cAMP to mediate the changes in MET sensitivity. These results reveal that cAMP signaling modulates gating spring stiffness to affect auditory sensitivity.
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Takahashi T, Ogiwara K. Signal pathway of LH-induced expression of nuclear progestin receptor in vertebrate ovulation. Gen Comp Endocrinol 2022; 321-322:114025. [PMID: 35292264 DOI: 10.1016/j.ygcen.2022.114025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 02/18/2022] [Accepted: 03/10/2022] [Indexed: 11/19/2022]
Abstract
Nuclear progestin receptor (PGR), which is induced in the follicles destined to undergo ovulation, is believed to be obligatory for rupture of the follicles during ovulation in vertebrates. Studies in some mammals and teleost medaka have revealed the outline of the central signaling pathway that leads to the PGR expression in the preovulatory follicles at ovulation. In this review, we summarize the current knowledge on what signaling mediators are involved in the LH-induced follicular expression of PGR at ovulation in these animals. LH-inducibility of follicular PGR expression is conserved. In both group of animals, activation of the LH receptor on the granulosa cell surface with LH commonly results in the increase of intracellular cAMP levels, while the downstream signaling cascades activated by high level of cAMP are totally different between mice and medaka. PGR is currently presumed to be induced via PKA/CREB-mediated transactivation and ERK1/2-dependent signaling in mice, but the receptor is induced via EPAC/RAP and AKT/CREB pathways in the teleost medaka. The differences and similarities in the signaling pathways for PGR expression between them is discussed from comparative and evolutionary aspects. We also discussed questions concerning PGR expression and its regulation needed to be investigated in future.
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Affiliation(s)
- Takayuki Takahashi
- Laboratory of Reproductive and Developmental Biology, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
| | - Katsueki Ogiwara
- Laboratory of Reproductive and Developmental Biology, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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Mohamed H, Baryar U, Bashiri A, Selvaratnam R, VanSchouwen B, Melacini G. Identification of Core Allosteric Sites through Temperature- and Nucleus-Invariant Chemical Shift Covariance. Biophys J 2022:S0006-3495(22)00371-X. [PMID: 35538664 DOI: 10.1016/j.bpj.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/11/2022] [Accepted: 05/04/2022] [Indexed: 11/22/2022] Open
Abstract
Allosteric regulation is essential to control biological function. In addition, allosteric sites offer a promising venue for selective drug targeting. However, accurate mapping of allosteric sites remains challenging since allostery relies on often subtle, yet functionally relevant, structural and dynamical changes. A viable approach proposed to overcome such challenge is the chemical shift covariance analysis (CHESCA). Although CHESCA offers an exhaustive map of allosteric networks, it is critical to define the core allosteric sites to be prioritized in subsequent functional studies or the design of allosteric drugs. Here we propose two new CHESCA-based methodologies, called temperature CHESCA (T-CHESCA) and CLASS-CHESCA, aimed at narrowing down allosteric maps to the core allosteric residues. Both T- and CLASS-CHESCAs rely on the invariance of core inter-residue correlations to changes in the chemical shifts of the active and inactive conformations interconverting in fast exchange. In the T-CHESCA the chemical shifts of such states are modulated through temperature changes, while in the CLASS-CHESCA through variations in the spin-active nuclei involved in pairwise correlations. The T- and CLASS-CHESCAs as well as complete-linkage CHESCA were applied to the cAMP-binding domain of the exchange protein directly activated by cAMP (EPAC), which serves as a prototypical allosteric switch. Residues consistently identified by the three CHESCA methods were found in previously identified EPAC allosteric core sites. Hence, the T-, CLASS- and CL-CHESCA provide a toolset to establish allosteric site hierarchy and triage allosteric sites to be further analyzed by mutations and functional assays. Furthermore, the core allosteric networks selectively revealed through T- and CLASS-CHESCA are expected to facilitate the mechanistic understanding of disease-related mutations and the design of selective allosteric modulators.
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11
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Kukk O, Klarenbeek J, Jalink K. Time-Domain Fluorescence Lifetime Imaging of cAMP Levels with EPAC-Based FRET Sensors. Methods Mol Biol 2022; 2483:105-116. [PMID: 35286672 DOI: 10.1007/978-1-0716-2245-2_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Second messenger molecules in eukaryotic cells relay the signals from activated cell surface receptors to intracellular effector proteins. FRET-based sensors are ideal to visualize and measure the often rapid changes of second messenger concentrations in time and place. Fluorescence Lifetime Imaging (FLIM) is an intrinsically quantitative technique for measuring FRET. Given the recent development of commercially available, sensitive and photon-efficient FLIM instrumentation, it is becoming the method of choice for FRET detection in signaling studies. Here, we describe a detailed protocol for time domain FLIM, using the EPAC-based FRET sensor to measure changes in cellular cAMP levels with high spatiotemporal resolution as an example.
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Affiliation(s)
- Olga Kukk
- The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | | - Kees Jalink
- The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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12
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Meadows MA, Balakrishnan V, Wang X, von Gersdorff H. Glycine Release Is Potentiated by cAMP via EPAC2 and Ca(2+) Stores in a Retinal Interneuron. J Neurosci 2021; 41:9503-20. [PMID: 34620721 DOI: 10.1523/JNEUROSCI.0670-21.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/21/2022] Open
Abstract
Neuromodulation via the intracellular second messenger cAMP is ubiquitous at presynaptic nerve terminals. This modulation of synaptic transmission allows exocytosis to adapt to stimulus levels and reliably encode information. The AII amacrine cell (AII-AC) is a central hub for signal processing in the mammalian retina. The main apical dendrite of the AII-AC is connected to several lobular appendages that release glycine onto OFF cone bipolar cells and ganglion cells. However, the influence of cAMP on glycine release is not well understood. Using membrane capacitance measurements from mouse AII-ACs to directly measure exocytosis, we observe that intracellular dialysis of 1 mm cAMP enhances exocytosis without affecting the L-type Ca2+ current. Responses to depolarizing pulses of various durations show that the size of the readily releasable pool of vesicles nearly doubles with cAMP, while paired-pulse depression experiments suggest that release probability does not change. Specific agonists and antagonists for exchange protein activated by cAMP 2 (EPAC2) revealed that the cAMP-induced enhancement of exocytosis requires EPAC2 activation. Furthermore, intact Ca2+ stores were also necessary for the cAMP potentiation of exocytosis. Postsynaptic recordings from OFF cone bipolar cells showed that increasing cAMP with forskolin potentiated the frequency of glycinergic spontaneous IPSCs. We propose that cAMP elevations in the AII-AC lead to a robust enhancement of glycine release through an EPAC2 and Ca2+ store signaling pathway. Our results thus contribute to a better understanding of how AII-AC crossover inhibitory circuits adapt to changes in ambient luminance.SIGNIFICANCE STATEMENT The mammalian retina operates over a wide dynamic range of light intensities and contrast levels. To optimize the signal-to-noise ratio of processed visual information, both excitatory and inhibitory synapses within the retina must modulate their gain in synaptic transmission to adapt to different levels of ambient light. Here we show that increases of cAMP concentration within AII amacrine cells produce enhanced exocytosis from these glycinergic interneurons. Therefore, we propose that light-sensitive neuromodulators may change the output of glycine release from AII amacrine cells. This novel mechanism may fine-tune the amount of tonic and phasic synaptic inhibition received by bipolar cell terminals and, consequently, the spiking patterns that ganglion cells send to the upstream visual areas of the brain.
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13
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Mora FAA, Musheshe N, Arroyave Ospina JC, Geng Y, Soto JM, Rodrigo JA, Alieva T, Buist-Homan M, Lezoualc'h F, Cheng X, Schmidt M, Moshage H. Metformin protects against diclofenac-induced toxicity in primary rat hepatocytes by preserving mitochondrial integrity via a pathway involving EPAC. Biomed Pharmacother 2021; 143:112072. [PMID: 34464747 DOI: 10.1016/j.biopha.2021.112072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/23/2021] [Accepted: 08/17/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE It has been shown that the antidiabetic drug metformin protects hepatocytes against toxicity by various stressors. Chronic or excessive consumption of diclofenac (DF) - a pain-relieving drug, leads to drug-induced liver injury via a mechanism involving mitochondrial damage and ultimately apoptotic death of hepatocytes. However, whether metformin protects against DF-induced toxicity is unknown. Recently, it was also shown that cAMP elevation is protective against DF-induced apoptotic death in hepatocytes, a protective effect primarily involving the downstream cAMP effector EPAC and preservation of mitochondrial function. This study therefore aimed at investigating whether metformin protects against DF-induced toxicity via cAMP-EPACs. EXPERIMENTAL APPROACH Primary rat hepatocytes were exposed to 400 µmol/L DF. CE3F4 or ESI-O5 were used as EPAC-1 or 2 inhibitors respectively. Apoptosis was measured by caspase-3 activity and necrosis by Sytox green staining. Seahorse X96 assay was used to determine mitochondrial function. Mitochondrial reactive oxygen species (ROS) production was measured using MitoSox, mitochondrial MnSOD expression was determined by immunostaining and mitochondrial morphology (fusion and fission ratio) by 3D refractive index imaging. KEY RESULTS Metformin (1 mmol/L) was protective against DF-induced apoptosis in hepatocytes. This protective effect was EPAC-dependent (mainly EPAC-2). Metformin restored mitochondrial morphology in an EPAC-independent manner. DF-induced mitochondrial dysfunction which was demonstrated by decreased oxygen consumption rate, an increased ROS production and a reduced MnSOD level, were all reversed by metformin in an EPAC-dependent manner. CONCLUSION AND IMPLICATIONS Metformin protects hepatocytes against DF-induced toxicity via cAMP-dependent EPAC-2.
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Affiliation(s)
- Fabio Alejandro Aguilar Mora
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Nshunge Musheshe
- Deptartment Molecular Pharmacology, Groningen Research Institute of Pharmacy, Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen University of Groningen, Groningen, The Netherlands.
| | - Johanna C Arroyave Ospina
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Yana Geng
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Juan M Soto
- Department of Optics and Faculty of Physical Sciences, Complutense University of Madrid, Spain.
| | - José A Rodrigo
- Department of Optics and Faculty of Physical Sciences, Complutense University of Madrid, Spain.
| | - Tatiana Alieva
- Department of Optics and Faculty of Physical Sciences, Complutense University of Madrid, Spain.
| | - Manon Buist-Homan
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
| | - Frank Lezoualc'h
- Inserm UMR-1048, Institut des Maladies Metaboliques et Cardiovasculaires, Univ Toulouse Paul Sabatier, Toulouse, France.
| | - Xiaodong Cheng
- Department of Integrative Biology & Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center at Houston, Houston, TX, USA.
| | - Martina Schmidt
- Deptartment Molecular Pharmacology, Groningen Research Institute of Pharmacy, Groningen Research Institute for Asthma and COPD, GRIAC, University Medical Center Groningen University of Groningen, Groningen, The Netherlands.
| | - Han Moshage
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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14
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Xiao J, Zhang B, Su Z, Liu Y, Shelite TR, Chang Q, Qiu Y, Bei J, Wang P, Bukreyev A, Soong L, Jin Y, Ksiazek T, Gaitas A, Rossi SL, Zhou J, Laposata M, Saito TB, Gong B. Intracellular receptor EPAC regulates von Willebrand factor secretion from endothelial cells in a PI3K-/eNOS-dependent manner during inflammation. J Biol Chem 2021; 297:101315. [PMID: 34678311 PMCID: PMC8526113 DOI: 10.1016/j.jbc.2021.101315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 02/06/2023] Open
Abstract
Coagulopathy is associated with both inflammation and infection, including infections with novel severe acute respiratory syndrome coronavirus-2, the causative agent Coagulopathy is associated with both inflammation and infection, including infection with novel severe acute respiratory syndrome coronavirus-2, the causative agent of COVID-19. Clot formation is promoted via cAMP-mediated secretion of von Willebrand factor (vWF), which fine-tunes the process of hemostasis. The exchange protein directly activated by cAMP (EPAC) is a ubiquitously expressed intracellular cAMP receptor that plays a regulatory role in suppressing inflammation. To assess whether EPAC could regulate vWF release during inflammation, we utilized our EPAC1-null mouse model and revealed increased secretion of vWF in endotoxemic mice in the absence of the EPAC1 gene. Pharmacological inhibition of EPAC1 in vitro mimicked the EPAC1-/- phenotype. In addition, EPAC1 regulated tumor necrosis factor-α-triggered vWF secretion from human umbilical vein endothelial cells in a manner dependent upon inflammatory effector molecules PI3K and endothelial nitric oxide synthase. Furthermore, EPAC1 activation reduced inflammation-triggered vWF release, both in vivo and in vitro. Our data delineate a novel regulatory role for EPAC1 in vWF secretion and shed light on the potential development of new strategies to control thrombosis during inflammation.
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Affiliation(s)
- Jie Xiao
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Ben Zhang
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Zhengchen Su
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yakun Liu
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Thomas R Shelite
- Department of Internal Medicine, Infectious Diseases, University of Texas Medical Branch, Galveston, Texas, USA
| | - Qing Chang
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yuan Qiu
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jiani Bei
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Pingyuan Wang
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Alexander Bukreyev
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Yang Jin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Boston University Medical Campus, Boston, Massachusetts, USA
| | - Thomas Ksiazek
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Angelo Gaitas
- The Estelle and Daniel Maggin Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Shannan L Rossi
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jia Zhou
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Michael Laposata
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Tais B Saito
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Bin Gong
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA.
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15
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Fong Z, Griffin CS, Large RJ, Hollywood MA, Thornbury KD, Sergeant GP. Regulation of P2X1 receptors by modulators of the cAMP effectors PKA and EPAC. Proc Natl Acad Sci U S A 2021; 118:e2108094118. [PMID: 34508006 DOI: 10.1073/pnas.2108094118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2021] [Indexed: 11/18/2022] Open
Abstract
P2X1 receptors are adenosine triphosphate (ATP)-gated cation channels that are functionally important for male fertility, bladder contraction, and platelet aggregation. The activity of P2X1 receptors is modulated by lipids and intracellular messengers such as cAMP, which can stimulate protein kinase A (PKA). Exchange protein activated by cAMP (EPAC) is another cAMP effector; however, its effect on P2X1 receptors has not yet been determined. Here, we demonstrate that P2X1 currents, recorded from human embryonic kidney (HEK) cells transiently transfected with P2X1 cDNA, were inhibited by the highly selective EPAC activator 007-AM. In contrast, EPAC activation enhanced P2X2 current amplitude. The PKA activator 6-MB-cAMP did not affect P2X1 currents, but inhibited P2X2 currents. The inhibitory effects of EPAC on P2X1 were prevented by triple mutation of residues 21 to 23 on the amino terminus of P2X1 subunits to the equivalent amino acids on P2X2 receptors. Double mutation of residues 21 and 22 and single mutation of residue 23 also protected P2X1 receptors from inhibition by EPAC activation. Finally, the inhibitory effects of EPAC on P2X1 were also prevented by NSC23766, an inhibitor of Rac1, a member of the Rho family of small GTPases. These data suggest that EPAC is an important regulator of P2X1 and P2X2 receptors.
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16
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Zhang Q, Fan Z, Xue W, Sun F, Zhu H, Huang D, Wang Z, Dong L. Vitexin regulates Epac and NLRP3 and ameliorates chronic cerebral hypoperfusion injury. Can J Physiol Pharmacol 2021; 99:1079-1087. [PMID: 33915055 DOI: 10.1139/cjpp-2021-0034] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Chronic cerebral hypoperfusion (CCH), as a critical factor of chronic cerebrovascular diseases, has greatly influenced the health of patients with vascular dementia. Vitexin, a flavone C-glycoside (apigenin-8-C-β-D-glucopyranoside) that belongs to the flavone subclass of flavonoids, has been shown to possess antioxidant and anti-ischemic properties; however, the putative protective effects of vitexin on the CCH need further investigation. In the current study, the role of vitexin and its underlying mechanism were investigated with permanent bilateral common carotid artery occlusion (2VO) in rats as well as mouse hippocampal neuronal (HT22) cells with oxygen and glucose deprivation/reoxygenation (OGD/R) injury model. The results demonstrated that vitexin improved cognitive dysfunction as well as alleviated pathological neuronal damage in hematoxylin plus eosin (HE) and TUNEL results. The decreased levels of exchange protein directly activated by cAMP 1 (Epac1), Epac2, Ras-associated protein 1 (Rap1), and phospho-extracellular signal-regulated kinase (p-ERK) were reversed by vitexin in rats with CCH. Furthermore, this study indicated that vitexin alleviated CCH-induced inflammation injuries by reducing the expression of NOD-like receptor 3 (NLRP3), caspase-1, interleukin 1β (IL-1β), IL-6, and cleaved caspase-3. In vitro, vitexin increased the expression of Epac1 and Epac2, decreased the activation of the NLRP3-mediated inflammation, and improved cell viability. Taken together, our findings suggest that vitexin can reduce the degree of the progressing pathological damage in the cortex and hippocampus and inhibit further deterioration of cognitive function in rats with CCH. Epac and NLRP3 can be regulated by vitexin in vivo and in vitro, which provides enlightenment for the protection of CCH injury.
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Affiliation(s)
- Qilong Zhang
- Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology of Ministry of Education, Key Laboratory of Chinese Medicine Research and Development of State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Zhijia Fan
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Wei Xue
- Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology of Ministry of Education, Key Laboratory of Chinese Medicine Research and Development of State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Fanfan Sun
- Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology of Ministry of Education, Key Laboratory of Chinese Medicine Research and Development of State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Huaqing Zhu
- Laboratory of Molecular Biology and Department of Biochemistry, Anhui Medical University, Hefei, Anhui, China
| | - Dake Huang
- Synthetic Laboratory of School of Basic Medicine Sciences, Anhui Medical University, Hefei, Anhui, China
| | - Zhicheng Wang
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Liuyi Dong
- Department of Pharmacology, Key Laboratory of Anti-Inflammatory and Immunopharmacology of Ministry of Education, Key Laboratory of Chinese Medicine Research and Development of State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei, Anhui, China
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17
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Cao X, Li Y, Shi J, Tang H. The Potentially Therapeutic Role of EPAC in Curbing the Process of Idiopathic Pulmonary Fibrosis via Differential Cellular Pathways. J Inflamm Res 2021; 14:611-619. [PMID: 33679138 PMCID: PMC7926039 DOI: 10.2147/jir.s296382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrosis disease caused by genetic susceptibility (causative) and other indirect risk factors such as smoking, micro-aspiration and air pollution. Repeated damage of lung epithelial cells can cause fibroblast activation and excessive collagen will lead the scar formation and severe fibrosis. It has been decades since drugs for the treatment of IPF were developed, but clinical choices were limited. Exchange Protein directly Activated by cAMP (EPAC), as a newly emerging cAMP (adenosine 3ʹ,5ʹ-cyclic monophosphate) downstream molecule, plays a vital role in the cellular pathways of IPF such as inhibiting fibroblast proliferation, stress fiber formation and epithelium cell adhesion, so it may be a novel target for drug development and treatment for curbing IPF. Here, we hypothesize that EPAC may participate in the signaling pathways related to IPF in different cell types (fibroblasts; airway smooth muscle cells; vascular endothelial cells; lung epithelial cells; macrophages; mesenchymal stem cells; T cells), thereby playing a potentially therapeutic role in resisting the process of fibrosis. We summarize the current correlation between EPAC and IPF in these different cell types, and further insights into EPAC will help to optimize the pharmacological treatment for IPF.
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Affiliation(s)
- Xinwei Cao
- Department of Pharmacology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Yajun Li
- Department of Pharmacology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Jianrong Shi
- Department of Clinical Laboratory, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou, 310003, People's Republic of China
| | - Huifang Tang
- Department of Pharmacology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
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18
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Aslam M, Ladilov Y. Regulation of Mitochondrial Homeostasis by sAC-Derived cAMP Pool: Basic and Translational Aspects. Cells 2021; 10:473. [PMID: 33671810 DOI: 10.3390/cells10020473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 01/21/2023] Open
Abstract
In contrast to the traditional view of mitochondria being solely a source of cellular energy, e.g., the "powerhouse" of the cell, mitochondria are now known to be key regulators of numerous cellular processes. Accordingly, disturbance of mitochondrial homeostasis is a basic mechanism in several pathologies. Emerging data demonstrate that 3'-5'-cyclic adenosine monophosphate (cAMP) signalling plays a key role in mitochondrial biology and homeostasis. Mitochondria are equipped with an endogenous cAMP synthesis system involving soluble adenylyl cyclase (sAC), which localizes in the mitochondrial matrix and regulates mitochondrial function. Furthermore, sAC localized at the outer mitochondrial membrane contributes significantly to mitochondrial biology. Disturbance of the sAC-dependent cAMP pools within mitochondria leads to mitochondrial dysfunction and pathology. In this review, we discuss the available data concerning the role of sAC in regulating mitochondrial biology in relation to diseases.
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19
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Byun JA, VanSchouwen B, Akimoto M, Melacini G. Allosteric inhibition explained through conformational ensembles sampling distinct "mixed" states. Comput Struct Biotechnol J 2020; 18:3803-3818. [PMID: 33335680 PMCID: PMC7720024 DOI: 10.1016/j.csbj.2020.10.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/24/2020] [Accepted: 10/25/2020] [Indexed: 11/29/2022] Open
Abstract
Allosteric modulation provides an effective avenue for selective and potent enzyme inhibition. Here, we summarize and critically discuss recent advances on the mechanisms of allosteric partial agonists for three representative signalling enzymes activated by cyclic nucleotides: the cAMP-dependent protein kinase (PKA), the cGMP-dependent protein kinase (PKG), and the exchange protein activated by cAMP (EPAC). The comparative analysis of partial agonism in PKA, PKG and EPAC reveals a common emerging theme, i.e. the sampling of distinct “mixed” conformational states, either within a single domain or between distinct domains. Here, we show how such “mixed” states play a crucial role in explaining the observed functional response, i.e. partial agonism and allosteric pluripotency, as well as in maximizing inhibition while minimizing potency losses. In addition, by combining Nuclear Magnetic Resonance (NMR), Molecular Dynamics (MD) simulations and Ensemble Allosteric Modeling (EAM), we also show how to map the free-energy landscape of conformational ensembles containing “mixed” states. By discussing selected case studies, we illustrate how MD simulations and EAM complement NMR to quantitatively relate protein dynamics to function. The resulting NMR- and MD-based EAMs are anticipated to inform not only the design of new generations of highly selective allosteric inhibitors, but also the choice of multidrug combinations.
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Affiliation(s)
- Jung Ah Byun
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Bryan VanSchouwen
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Madoka Akimoto
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Giuseppe Melacini
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.,Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
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20
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Abstract
The cyclic nucleotides 3′,5′-adenosine monophosphate (cyclic AMP) signalling system underlies the control of many biological events and disease processes in man. Cyclic AMP is synthesised by adenylate cyclase (AC) enzymes in order to activate effector proteins and it is then degraded by phosphodiesterase (PDE) enzymes. Research in recent years has identified a range of cell-type-specific cyclic AMP effector proteins, including protein kinase A (PKA), exchange factor directly activated by cyclic AMP (EPAC), cyclic AMP responsive ion channels (CICs), and the Popeye domain containing (POPDC) proteins, which participate in different signalling mechanisms. In addition, recent advances have revealed new mechanisms of action for cyclic AMP signalling, including new effectors and new levels of compartmentalization into nanodomains, involving AKAP proteins and targeted adenylate cyclase and phosphodiesterase enzymes. This Special Issue contains 21 papers that highlight advances in our current understanding of the biology of compartmentlised cyclic AMP signalling. This ranges from issues of pathogenesis and associated molecular pathways, functional assessment of novel nanodomains, to the development of novel tool molecules and new techniques for imaging cyclic AMP compartmentilisation. This editorial aims to summarise these papers within the wider context of cyclic AMP signalling.
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Affiliation(s)
- Stephen John Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK
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21
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Aslam M, Ladilov Y. Targeting the sAC-Dependent cAMP Pool to Prevent SARS-Cov-2 Infection. Cells 2020; 9:cells9091962. [PMID: 32854430 PMCID: PMC7563949 DOI: 10.3390/cells9091962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 12/11/2022] Open
Abstract
An outbreak of the novel coronavirus (CoV) SARS-CoV-2, the causative agent of COVID-19 respiratory disease, infected millions of people since the end of 2019, led to high-level morbidity and mortality and caused worldwide social and economic disruption. There are currently no antiviral drugs available with proven efficacy or vaccines for its prevention. An understanding of the underlying cellular mechanisms involved in virus replication is essential for repurposing the existing drugs and/or the discovery of new ones. Endocytosis is the important mechanism of entry of CoVs into host cells. Endosomal maturation followed by the fusion with lysosomes are crucial events in endocytosis. Late endosomes and lysosomes are characterized by their acidic pH, which is generated by a proton transporter V-ATPase and required for virus entry via endocytic pathway. The cytoplasmic cAMP pool produced by soluble adenylyl cyclase (sAC) promotes V-ATPase recruitment to endosomes/lysosomes and thus their acidification. In this review, we discuss targeting the sAC-specific cAMP pool as a potential strategy to impair the endocytic entry of the SARS-CoV-2 into the host cell. Furthermore, we consider the potential impact of sAC inhibition on CoV-induced disease via modulation of autophagy and apoptosis.
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Affiliation(s)
- Muhammad Aslam
- Experimental Cardiology, Department of Internal Medicine, Justus Liebig University, 35392 Giessen, Germany;
- DZHK (German Centre for Cardiovascular Research), Department of Cardiology, Kerckhoff Clinic GmbH partner site Rhein-Main, 61231 Bad Nauheim, Germany
| | - Yury Ladilov
- Independent Researcher, 42929 Wermelskirchen, Germany
- Correspondence:
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22
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Hoy JJ, Salinas Parra N, Park J, Kuhn S, Iglesias-Bartolome R. Protein kinase A inhibitor proteins (PKIs) divert GPCR-Gαs-cAMP signaling toward EPAC and ERK activation and are involved in tumor growth. FASEB J 2020; 34:13900-13917. [PMID: 32830375 DOI: 10.1096/fj.202001515r] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/30/2020] [Accepted: 08/07/2020] [Indexed: 01/12/2023]
Abstract
The PKA-inhibitor (PKI) family members PKIα, PKIβ, and PKIγ bind with high affinity to PKA and block its kinase activity, modulating the extent, and duration of PKA-mediated signaling events. While PKA is a well-known regulator of physiological and oncogenic events, the role of PKI proteins in these pathways has remained elusive. Here, by measuring activation of the MAPK pathway downstream of GPCR-Gαs-cAMP signaling, we show that the expression levels of PKI proteins can alter the balance of activation of two major cAMP targets: PKA and EPAC. Our results indicate that PKA maintains repressive control over MAPK signaling as well as a negative feedback on cAMP concentration. Overexpression of PKI and its subsequent repression of PKA dysregulates these signaling pathways, resulting in increased intracellular cAMP, and enhanced activation of EPAC and MAPK. We also find that amplifications of PKIA are common in prostate cancer and are associated with reduced progression free survival. Depletion of PKIA in prostate cancer cells leads to reduced migration, increased sensitivity to anoikis and reduced tumor growth. By altering PKA activity PKI can act as a molecular switch, driving GPCR-Gαs-cAMP signaling toward activation of EPAC-RAP1 and MAPK, ultimately modulating tumor growth.
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Affiliation(s)
- James J Hoy
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Natalia Salinas Parra
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jeannie Park
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Skyler Kuhn
- Collaborative Bioinformatics Resource, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ramiro Iglesias-Bartolome
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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Bufano M, Laudette M, Blondeau JP, Lezoualc'h F, Nalli M, Silvestri R, Brancale A, Coluccia A. Modeling Epac1 interactions with the allosteric inhibitor AM-001 by co-solvent molecular dynamics. J Comput Aided Mol Des 2020; 34:1171-9. [PMID: 32700175 DOI: 10.1007/s10822-020-00332-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 07/13/2020] [Indexed: 12/13/2022]
Abstract
The exchange proteins activated by cAMP (EPAC) are implicated in a large variety of physiological processes and they are considered as promising targets for a wide range of therapeutic applications. Several recent reports provided evidence for the therapeutic effectiveness of the inhibiting EPAC1 activity cardiac diseases. In that context, we recently characterized a selective EPAC1 antagonist named AM-001. This compound was featured by a non-competitive mechanism of action but the localization of its allosteric site to EPAC1 structure has yet to be investigated. Therefore, we performed cosolvent molecular dynamics with the aim to identify a suitable allosteric binding site. Then, the docking and molecular dynamics were used to determine the binding of the AM-001 to the regions highlighted by cosolvent molecular dynamics for EPAC1. These analyses led us to the identification of a suitable allosteric AM-001 binding pocket at EPAC1. As a model validation, we also evaluated the binding poses of the available AM-001 analogues, with a different biological potency. Finally, the complex EPAC1 with AM-001 bound at the putative allosteric site was further refined by molecular dynamics. The principal component analysis led us to identify the protein motion that resulted in an inactive like conformation upon the allosteric inhibitor binding.
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24
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Wehbe N, Nasser SA, Al-Dhaheri Y, Iratni R, Bitto A, El-Yazbi AF, Badran A, Kobeissy F, Baydoun E, Eid AH. EPAC in Vascular Smooth Muscle Cells. Int J Mol Sci 2020; 21:E5160. [PMID: 32708284 DOI: 10.3390/ijms21145160] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/09/2020] [Accepted: 07/19/2020] [Indexed: 02/07/2023] Open
Abstract
Vascular smooth muscle cells (VSMCs) are major components of blood vessels. They regulate physiological functions, such as vascular tone and blood flow. Under pathological conditions, VSMCs undergo a remodeling process known as phenotypic switching. During this process, VSMCs lose their contractility and acquire a synthetic phenotype, where they over-proliferate and migrate from the tunica media to the tunica interna, contributing to the occlusion of blood vessels. Since their discovery as effector proteins of cyclic adenosine 3′,5′-monophosphate (cAMP), exchange proteins activated by cAMP (EPACs) have been shown to play vital roles in a plethora of pathways in different cell systems. While extensive research to identify the role of EPAC in the vasculature has been conducted, much remains to be explored to resolve the reported discordance in EPAC’s effects. In this paper, we review the role of EPAC in VSMCs, namely its regulation of the vascular tone and phenotypic switching, with the likely involvement of reactive oxygen species (ROS) in the interplay between EPAC and its targets/effectors.
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van der Horst J, Greenwood IA, Jepps TA. Cyclic AMP-Dependent Regulation of Kv7 Voltage-Gated Potassium Channels. Front Physiol 2020; 11:727. [PMID: 32695022 PMCID: PMC7338754 DOI: 10.3389/fphys.2020.00727] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/04/2020] [Indexed: 01/08/2023] Open
Abstract
Voltage-gated Kv7 potassium channels, encoded by KCNQ genes, have major physiological impacts cardiac myocytes, neurons, epithelial cells, and smooth muscle cells. Cyclic adenosine monophosphate (cAMP), a well-known intracellular secondary messenger, can activate numerous downstream effector proteins, generating downstream signaling pathways that regulate many functions in cells. A role for cAMP in ion channel regulation has been established, and recent findings show that cAMP signaling plays a role in Kv7 channel regulation. Although cAMP signaling is recognized to regulate Kv7 channels, the precise molecular mechanism behind the cAMP-dependent regulation of Kv7 channels is complex. This review will summarize recent research findings that support the mechanisms of cAMP-dependent regulation of Kv7 channels.
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Affiliation(s)
- Jennifer van der Horst
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iain A Greenwood
- Molecular and Clinical Sciences Institute, St. George's University of London, London, United Kingdom
| | - Thomas A Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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26
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Gao ZZ, Li YC, Shao CY, Xiao J, Shen Y, Zhou L. EPAC Negatively Regulates Myelination via Controlling Proliferation of Oligodendrocyte Precursor Cells. Neurosci Bull 2020; 36:639-648. [PMID: 32303914 DOI: 10.1007/s12264-020-00495-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/05/2020] [Indexed: 12/17/2022] Open
Abstract
Increasing evidence suggests that a cyclic adenosine monophosphate (cAMP)-dependent intracellular signal drives the process of myelination. Yet, the signal transduction underlying the action of cAMP on central nervous system myelination remains undefined. In the present work, we sought to determine the role of EPAC (exchange protein activated by cAMP), a downstream effector of cAMP, in the development of the myelin sheath using EPAC1 and EPAC2 double-knockout (EPACdKO) mice. The results showed an age-dependent regulatory effect of EPAC1 and EPAC2 on myelin development, as their deficiency caused more myelin sheaths in postnatal early but not late adult mice. Knockout of EPAC promoted the proliferation of oligodendrocyte precursor cells and had diverse effects on myelin-related transcription factors, which in turn increased the expression of myelin-related proteins. These results indicate that EPAC proteins are negative regulators of myelination and may be promising targets for the treatment of myelin-related diseases.
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Affiliation(s)
- Zhen-Zhen Gao
- Molecular Pharmacology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Ying-Cong Li
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Chong-Yu Shao
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Jian Xiao
- Molecular Pharmacology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, 325035, China
| | - Ying Shen
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - Liang Zhou
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,Key Laboratory of Brain Science, Guizhou Institution of Higher Education, Zunyi Medical University, Zunyi, 563000, China.
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Massimi M, Ragusa F, Cardarelli S, Giorgi M. Targeting Cyclic AMP Signalling in Hepatocellular Carcinoma. Cells 2019; 8:cells8121511. [PMID: 31775395 PMCID: PMC6952960 DOI: 10.3390/cells8121511] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 02/06/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a major healthcare problem worldwide, representing one of the leading causes of cancer mortality. Since there are currently no predictive biomarkers for early stage diagnosis, HCC is detected only in advanced stages and most patients die within one year, as radical tumour resection is generally performed late during the disease. The development of alternative therapeutic approaches to HCC remains one of the most challenging areas of cancer. This review focuses on the relevance of cAMP signalling in the development of hepatocellular carcinoma and identifies the modulation of this second messenger as a new strategy for the control of tumour growth. In addition, because the cAMP pathway is controlled by phosphodiesterases (PDEs), targeting these enzymes using PDE inhibitors is becoming an attractive and promising tool for the control of HCC. Among them, based on current preclinical and clinical findings, PDE4-specific inhibitors remarkably demonstrate therapeutic potential in the management of cancer outcomes, especially as adjuvants to standard therapies. However, more preclinical studies are warranted to ascertain their efficacy during the different stages of hepatocyte transformation and in the treatment of established HCC.
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Affiliation(s)
- Mara Massimi
- Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
- Correspondence: (M.M.); (M.G.); Tel.: +39-0862-433219 (M.M.); +39-06-49912308 (M.G.)
| | - Federica Ragusa
- Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy;
| | - Silvia Cardarelli
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy;
| | - Mauro Giorgi
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy;
- Correspondence: (M.M.); (M.G.); Tel.: +39-0862-433219 (M.M.); +39-06-49912308 (M.G.)
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Ahmed A, Boulton S, Shao H, Akimoto M, Natarajan A, Cheng X, Melacini G. Recent Advances in EPAC-Targeted Therapies: A Biophysical Perspective. Cells 2019; 8:cells8111462. [PMID: 31752286 PMCID: PMC6912387 DOI: 10.3390/cells8111462] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 02/07/2023] Open
Abstract
The universal second messenger cAMP regulates diverse intracellular processes by interacting with ubiquitously expressed proteins, such as Protein Kinase A (PKA) and the Exchange Protein directly Activated by cAMP (EPAC). EPAC is implicated in multiple pathologies, thus several EPAC-specific inhibitors have been identified in recent years. However, the mechanisms and molecular interactions underlying the EPAC inhibition elicited by such compounds are still poorly understood. Additionally, being hydrophobic low molecular weight species, EPAC-specific inhibitors are prone to forming colloidal aggregates, which result in non-specific aggregation-based inhibition (ABI) in aqueous systems. Here, we review from a biophysical perspective the molecular basis of the specific and non-specific interactions of two EPAC antagonists—CE3F4R, a non-competitive inhibitor, and ESI-09, a competitive inhibitor of EPAC. Additionally, we discuss the value of common ABI attenuators (e.g., TX and HSA) to reduce false positives at the expense of introducing false negatives when screening aggregation-prone compounds. We hope this review provides the EPAC community effective criteria to evaluate similar compounds, aiding in the optimization of existing drug leads, and informing the development of the next generation of EPAC-specific inhibitors.
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Affiliation(s)
- Alveena Ahmed
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.A.); (S.B.)
| | - Stephen Boulton
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.A.); (S.B.)
| | - Hongzhao Shao
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (H.S.); (M.A.)
| | - Madoka Akimoto
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (H.S.); (M.A.)
| | - Amarnath Natarajan
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Xiaodong Cheng
- Department of Integrative Biology & Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
- Texas Therapeutics Institute, Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Giuseppe Melacini
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; (A.A.); (S.B.)
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada; (H.S.); (M.A.)
- Correspondence:
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29
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M. Beck E, Parnell E, Cowley A, Porter A, Gillespie J, Robinson J, Robinson L, Pannifer AD, Hamon V, Jones P, Morrison A, McElroy S, Timmerman M, Rutjes H, Mahajan P, Wiejak J, Luchowska-Stańska U, Morgan D, Barker G, Rehmann H, Yarwood SJ. Identification of A Novel Class of Benzofuran Oxoacetic Acid-Derived Ligands that Selectively Activate Cellular EPAC1. Cells 2019; 8:cells8111425. [PMID: 31726720 PMCID: PMC6912754 DOI: 10.3390/cells8111425] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/06/2019] [Accepted: 11/07/2019] [Indexed: 12/20/2022] Open
Abstract
Cyclic AMP promotes EPAC1 and EPAC2 activation through direct binding to a specific cyclic nucleotide-binding domain (CNBD) within each protein, leading to activation of Rap GTPases, which control multiple cell responses, including cell proliferation, adhesion, morphology, exocytosis, and gene expression. As a result, it has become apparent that directed activation of EPAC1 and EPAC2 with synthetic agonists may also be useful for the future treatment of diabetes and cardiovascular diseases. To identify new EPAC agonists we have developed a fluorescent-based, ultra-high-throughput screening (uHTS) assay that measures the displacement of binding of the fluorescent cAMP analogue, 8-NBD-cAMP to the EPAC1 CNBD. Triage of the output of an approximately 350,000 compound screens using this assay identified a benzofuran oxaloacetic acid EPAC1 binder (SY000) that displayed moderate potency using orthogonal assays (competition binding and microscale thermophoresis). We next generated a limited library of 91 analogues of SY000 and identified SY009, with modifications to the benzofuran ring associated with a 10-fold increase in potency towards EPAC1 over SY000 in binding assays. In vitro EPAC1 activity assays confirmed the agonist potential of these molecules in comparison with the known EPAC1 non-cyclic nucleotide (NCN) partial agonist, I942. Rap1 GTPase activation assays further demonstrated that SY009 selectively activates EPAC1 over EPAC2 in cells. SY009 therefore represents a novel class of NCN EPAC1 activators that selectively activate EPAC1 in cellulae.
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Affiliation(s)
- Elizabeth M. Beck
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Euan Parnell
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
| | - Angela Cowley
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Alison Porter
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Jonathan Gillespie
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - John Robinson
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Lindsay Robinson
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Andrew D. Pannifer
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Veronique Hamon
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Philip Jones
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Angus Morrison
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Stuart McElroy
- European Screening Centre Newhouse, University of Dundee, Biocity Scotland, Bo’Ness Road, Newhouse, Lanarkshire ML1 5UH, UK; (E.M.B.); (A.C.); (A.P.); (J.G.); (J.R.); (L.R.); (A.D.P.); (V.H.); (P.J.); (A.M.); (S.M.)
| | - Martin Timmerman
- Pivot Park Screening Centre, Kloosterstraat 9, 5349 AB Oss, The Netherlands; (M.T.); (H.R.)
| | - Helma Rutjes
- Pivot Park Screening Centre, Kloosterstraat 9, 5349 AB Oss, The Netherlands; (M.T.); (H.R.)
| | - Pravin Mahajan
- Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, UK;
| | - Jolanta Wiejak
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK; (J.W.); (U.L.-S.)
| | - Urszula Luchowska-Stańska
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK; (J.W.); (U.L.-S.)
| | - David Morgan
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK; (D.M.); (G.B.)
| | - Graeme Barker
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK; (D.M.); (G.B.)
| | - Holger Rehmann
- Department of Molecular Cancer Research, Centre of Biomedical Genetics and Cancer Genomics Centre, University Medical Centre Utrecht, 3508 TC Utrecht, The Netherlands;
| | - Stephen J. Yarwood
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh Campus, Edinburgh EH14 4AS, UK; (J.W.); (U.L.-S.)
- Correspondence:
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Abstract
Gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are heterodimers of a common α subunit and unique β subunits. Regulation of their levels, primarily by GnRH, is critical for reproductive function. Several other hormones modulate gonadotropin expression, either independently or by modifying the responsiveness to GnRH. Pituitary adenylate cyclase activating peptide (PACAP) is one such hormone. Four-hour treatment of female mouse primary pituitary cells by either GnRH or PACAP induced FSHβ expression, while 24-h treatment repressed FSHβ. Both PACAP and GnRH caused FSH secretion into the medium. In the gonadotropes, PACAP activates primarily Gαs and increases concentration of cAMP, while GnRH primarily functions via Gαq and increases calcium concentration. Herein, we compared PACAP and GnRH signaling pathways that lead to the induction of FSHβ expression. Interestingly, constitutively active Gαs represses LHβ and induces FSHβ expression, while Gαq induces both β-subunits. We determined that FSHβ induction by PACAP requires functional EPAC, a cAMP sensor protein that serves as a guanine exchange factors for small G proteins that then bridges cAMP signaling to MAPK pathway. We further demonstrate that in addition to the prototypical small G protein Ras, two members of the Rho subfamily, Rac and CDC42 are also necessary for PACAP induction of FSHβ, likely via activation of p38 MAPK that leads to induction of cFOS, a critical transcription factor that is necessary and sufficient for FSHβ induction. Therefore, PACAP-induced cAMP pathway leads to MAPK activation that stimulates cFOS induction, to induce the expression of FSHβ subunit and increase FSH concentration.
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Affiliation(s)
| | - Djurdjica Coss
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA, 92521, USA.
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Trogden KP, Zhu X, Lee JS, Wright CVE, Gu G, Kaverina I. Regulation of Glucose-Dependent Golgi-Derived Microtubules by cAMP/ EPAC2 Promotes Secretory Vesicle Biogenesis in Pancreatic β Cells. Curr Biol 2019; 29:2339-2350.e5. [PMID: 31303487 DOI: 10.1016/j.cub.2019.06.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 04/23/2019] [Accepted: 06/10/2019] [Indexed: 11/23/2022]
Abstract
The microtubule (MT) network is an essential regulator of insulin secretion from pancreatic β cells, which is central to blood-sugar homeostasis. We find that when glucose metabolism induces insulin secretion, it also increases formation of Golgi-derived microtubules (GDMTs), notably with the same biphasic kinetics as insulin exocytosis. Furthermore, GDMT nucleation is controlled by a glucose signal-transduction pathway through cAMP and its effector EPAC2. Preventing new GDMT nucleation dramatically affects the pipeline of insulin production, storage, and release. There is an overall reduction of β-cell insulin content, and remaining insulin becomes retained within the Golgi, likely because of stalling of insulin-granule budding. While not preventing glucose-induced insulin exocytosis, the diminished granule availability substantially blunts the amount secreted. Constant dynamic maintenance of the GDMT network is therefore critical for normal β-cell physiology. Our study demonstrates that the biogenesis of post-Golgi carriers, particularly large secretory granules, requires ongoing nucleation and replenishment of the GDMT network.
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32
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Ebrahimighaei R, McNeill MC, Smith SA, Wray JP, Ford KL, Newby AC, Bond M. Elevated cyclic-AMP represses expression of exchange protein activated by cAMP ( EPAC1) by inhibiting YAP-TEAD activity and HDAC-mediated histone deacetylation. Biochim Biophys Acta Mol Cell Res 2019; 1866:1634-1649. [PMID: 31255721 DOI: 10.1016/j.bbamcr.2019.06.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/19/2019] [Accepted: 06/26/2019] [Indexed: 02/05/2023]
Abstract
Ligand-induced activation of Exchange Protein Activated by cAMP-1 (EPAC1) is implicated in numerous physiological and pathological processes, including cardiac fibrosis where changes in EPAC1 expression have been detected. However, little is known about how EPAC1 expression is regulated. Therefore, we investigated regulation of EPAC1 expression by cAMP in cardiac fibroblasts. Elevation of cAMP using forskolin, cAMP-analogues or adenosine A2B-receptor activation significantly reduced EPAC1 mRNA and protein levels and inhibited formation of F-actin stress fibres. Inhibition of actin polymerisation with cytochalasin-D, latrunculin-B or the ROCK inhibitor, Y-27632, mimicked effects of cAMP on EPAC1 mRNA and protein levels. Elevated cAMP also inhibited activity of an EPAC1 promoter-reporter gene, which contained a consensus binding element for TEAD, which is a target for inhibition by cAMP. Inhibition of TEAD activity using siRNA-silencing of its co-factors YAP and TAZ, expression of dominant-negative TEAD or treatment with YAP-TEAD inhibitors, significantly inhibited EPAC1 expression. However, whereas expression of constitutively-active YAP completely reversed forskolin inhibition of EPAC1-promoter activity it did not rescue EPAC1 mRNA levels. Chromatin-immunoprecipitation detected a significant reduction in histone3-lysine27-acetylation at the EPAC1 proximal promoter in response to forskolin stimulation. HDAC1/3 inhibition partially reversed forskolin inhibition of EPAC1 expression, which was completely rescued by simultaneously expressing constitutively active YAP. Taken together, these data demonstrate that cAMP downregulates EPAC1 gene expression via disrupting the actin cytoskeleton, which inhibits YAP/TAZ-TEAD activity in concert with HDAC-mediated histone deacetylation at the EPAC1 proximal promoter. This represents a novel negative feedback mechanism controlling EPAC1 levels in response to cAMP elevation.
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Affiliation(s)
- Reza Ebrahimighaei
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Madeleine C McNeill
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Sarah A Smith
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Jason P Wray
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Kerrie L Ford
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Andrew C Newby
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - Mark Bond
- School of Translational Health Sciences, Faculty of Health Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK.
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Jakobsen E, Lange SC, Bak LK. Soluble adenylyl cyclase-mediated cAMP signaling and the putative role of PKA and EPAC in cerebral mitochondrial function. J Neurosci Res 2019; 97:1018-1038. [PMID: 31172581 DOI: 10.1002/jnr.24477] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 05/16/2019] [Accepted: 05/16/2019] [Indexed: 12/20/2022]
Abstract
Mitochondria produce the bulk of the ATP in most cells, including brain cells. Regulating this complex machinery to match the energetic needs of the cell is a complicated process that we have yet to understand in its entirety. In this context, 3',5'-cyclic AMP (cAMP) has been suggested to play a seminal role in signaling-metabolism coupling and regulation of mitochondrial ATP production. In cells, cAMP signals may affect mitochondria from the cytosolic side but more recently, a cAMP signal produced within the matrix of mitochondria by soluble adenylyl cyclase (sAC) has been suggested to regulate respiration and thus ATP production. However, little is known about these processes in brain mitochondria, and the effectors of the cAMP signal generated within the matrix are not completely clear since both protein kinase A (PKA) and exchange protein activated by cAMP 1 (EPAC1) have been suggested to be involved. Here, we review the current knowledge and relate it to brain mitochondria. Further, based on measurements of respiration, membrane potential, and ATP production in isolated mouse brain cortical mitochondria we show that inhibitors of sAC, PKA, or EPAC affect mitochondrial function in distinct ways. In conclusion, we suggest that brain mitochondria do regulate their function via sAC-mediated cAMP signals and that both PKA and EPAC could be involved downstream of sAC. Finally, due to the role of faulty mitochondrial function in a range of neurological diseases, we expect that the function of sAC-cAMP-PKA/EPAC signaling in brain mitochondria will likely attract further attention.
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Affiliation(s)
- Emil Jakobsen
- Faculty of Health and Medical Sciences, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Sofie C Lange
- Faculty of Health and Medical Sciences, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Lasse K Bak
- Faculty of Health and Medical Sciences, Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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Portugal CC, da Encarnação TG, Domith I, Dos Santos Rodrigues A, de Oliveira NA, Socodato R, Paes-de-Carvalho R. Dopamine-Induced Ascorbate Release From Retinal Neurons Involves Glutamate Release, Activation of AMPA/Kainate Receptors and Downstream Signaling Pathways. Front Neurosci 2019; 13:453. [PMID: 31143097 PMCID: PMC6521073 DOI: 10.3389/fnins.2019.00453] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 04/23/2019] [Indexed: 01/28/2023] Open
Abstract
Ascorbate, the reduced form of Vitamin C, is one of the most abundant and important low-molecular weight antioxidants in living tissues. Most animals synthesize vitamin C, but some primates, including humans, have lost this capacity due to disruption in L-gulono-gamma-lactone oxidase gene. Because of this incapacity, those animals must obtain Vitamin C from the diet. Ascorbate is highly concentrated in the central nervous system (CNS), including the retina, and plays essential roles in neuronal physiology. Ascorbate transport into cells is controlled by Sodium Vitamin C Co-Transporters (SVCTs). There are four SVCT isoforms and SVCT2 is the major isoform controlling ascorbate transport in the CNS. Regarding ascorbate release from retinal neurons, Glutamate, by activating its ionotropic receptors leads to ascorbate release via the reversion of SVCT2. Moreover, dopamine, via activation of D1 receptor/cyclic AMP/EPAC2 pathway, also induces ascorbate release via SVCT2 reversion. Because the dopaminergic and glutamatergic systems are interconnected in the CNS, we hypothesized that dopamine could regulate ascorbate release indirectly, via the glutamatergic system. Here we reveal that dopamine increases the release of D-Aspartate from retinal neurons in a way independent on calcium ions and dependent on excitatory amino acid transporters. In addition, dopamine-dependent SVCT2 reversion leading to ascorbate release occurs by activation of AMPA/Kainate receptors and downstream ERK/AKT pathways. Overall, our data reveal a dopamine-to-glutamate signaling that regulates the bioavailability of ascorbate in neuronal cells.
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Affiliation(s)
- Camila Cabral Portugal
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Thaísa Godinho da Encarnação
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - Ivan Domith
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - Alexandre Dos Santos Rodrigues
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - Nádia Almeida de Oliveira
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
| | - Renato Socodato
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Roberto Paes-de-Carvalho
- Department of Neurobiology and Program of Neurosciences, Institute of Biology, Fluminense Federal University, Niterói, Brazil
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Brouwer S, Hoffmeister T, Gresch A, Schönhoff L, Düfer M. Resveratrol Influences Pancreatic Islets by Opposing Effects on Electrical Activity and Insulin Release. Mol Nutr Food Res 2019; 62. [PMID: 29341416 DOI: 10.1002/mnfr.201700902] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/19/2017] [Indexed: 01/27/2023]
Abstract
SCOPE Resveratrol is suggested to improve glycemic control by activation of sirtuin 1 (SIRT1) and has already been tested clinically. Our investigation characterizes the targets of resveratrol in pancreatic beta cells and their contribution to short- and long-term effects on insulin secretion. METHODS AND RESULTS Islets or beta cells are isolated from C57BL/6N mice. Electrophysiology is performed with microelectrode arrays and patch-clamp technique, insulin secretion and content are determined by radioimmunoassay, cAMP is measured by enzyme-linked immunosorbent assay, and cytosolic Ca2+ concentration by fluorescence methods. Resveratrol (25 μmol L-1 ) elevates [Ca2+ ]c and potentiates glucose-stimulated insulin secretion. These effects are associated with increased intracellular cAMP and are sensitive to the SIRT1 blocker Ex-527. Inhibition of EPAC1 by CE3F4 also abolishes the stimulatory effect of resveratrol. The underlying mechanism does not involve membrane depolarization as resveratrol even reduces electrical activity despite blocking KATP channels. Importantly, after prolonged exposure to resveratrol (14 days), the beneficial influence of the polyphenol on insulin release is lost. CONCLUSION Resveratrol addresses multiple targets in pancreatic islets. Potentiation of insulin secretion is mediated by SIRT1-dependent activation of cAMP/EPAC1. Considering resveratrol as therapeutic supplement for patients with type 2 diabetes mellitus, the inhibitory influence on electrical excitability attenuates positive effects.
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Affiliation(s)
- Simone Brouwer
- University of Münster, Pharmaceutical and Medicinal Chemistry, Dept. of Pharmacology, Münster, Germany
| | - Theresa Hoffmeister
- University of Münster, Pharmaceutical and Medicinal Chemistry, Dept. of Pharmacology, Münster, Germany
| | - Anne Gresch
- University of Münster, Pharmaceutical and Medicinal Chemistry, Dept. of Pharmacology, Münster, Germany
| | - Lisa Schönhoff
- University of Münster, Pharmaceutical and Medicinal Chemistry, Dept. of Pharmacology, Münster, Germany
| | - Martina Düfer
- University of Münster, Pharmaceutical and Medicinal Chemistry, Dept. of Pharmacology, Münster, Germany
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Yun SJ, Lee B, Komori K, Lee MJ, Lee BG, Kim K, Park S. Regulation of TIM-3 expression in a human T cell line by tumor-conditioned media and cyclic AMP-dependent signaling. Mol Immunol 2018; 105:224-232. [PMID: 30554083 DOI: 10.1016/j.molimm.2018.12.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/01/2018] [Accepted: 12/08/2018] [Indexed: 12/17/2022]
Abstract
T cell immunoglobulin and mucin domain-3 (TIM-3) expression increases in exhausted T cells, which inhibits T cell function. TIM-3 expression is supposedly up-regulated in tumor-bearing individuals via chronic antigenic stimulation of T cells. Considering the immunosuppressive nature of the tumor microenvironment, we investigated whether tumor-secreted molecules might enhance TIM-3 expression in Jurkat T cells. We observed that TIM-3 expression was increased by the activation of prostaglandin (PG) E2 and cyclic AMP (cAMP) signaling pathways. Adenylate cyclase activation led to protein kinase A (PKA)-dependent upregulation of the TIM-3 minimal promoter region and of upstream conserved non-coding sequences. TIM-3 expression in Jurkat T cells was increased by the exposure to breast tumor cell-conditioned media partially through the interaction between PGE2 and its receptor, EP4. Our results propose that tumor-secreted molecules such as PGE2, which activates PKA and EPAC, may regulate TIM-3 expression in T cells.
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Affiliation(s)
- Su Jin Yun
- Department of Microbiology and Ajou University School of Medicine, Youngtongku Worldcupro 206, Suwon, 16499, Republic of Korea; Department of Biomedical Sciences (Graduate Program of Molecular Medicine), Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Bokyoung Lee
- Department of Microbiology and Ajou University School of Medicine, Youngtongku Worldcupro 206, Suwon, 16499, Republic of Korea; Department of Biomedical Sciences (Graduate Program of Molecular Medicine), Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Kuniharu Komori
- Department of Microbiology and Ajou University School of Medicine, Youngtongku Worldcupro 206, Suwon, 16499, Republic of Korea; Department of Biomedical Sciences (Graduate Program of Molecular Medicine), Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Mi Jin Lee
- Department of Microbiology and Ajou University School of Medicine, Youngtongku Worldcupro 206, Suwon, 16499, Republic of Korea
| | - Byoung Gill Lee
- Department of Microbiology and Ajou University School of Medicine, Youngtongku Worldcupro 206, Suwon, 16499, Republic of Korea; Department of Biomedical Sciences (Graduate Program of Molecular Medicine), Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Kyongmin Kim
- Department of Microbiology and Ajou University School of Medicine, Youngtongku Worldcupro 206, Suwon, 16499, Republic of Korea; Department of Biomedical Sciences (Graduate Program of Molecular Medicine), Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea
| | - Sun Park
- Department of Microbiology and Ajou University School of Medicine, Youngtongku Worldcupro 206, Suwon, 16499, Republic of Korea; Department of Biomedical Sciences (Graduate Program of Molecular Medicine), Ajou University Graduate School of Medicine, Suwon, 16499, Republic of Korea.
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Choi EJ, Ren Y, Chen Y, Liu S, Wu W, Ren J, Wang P, Garofalo RP, Zhou J, Bao X. Exchange Proteins Directly Activated by cAMP and Their Roles in Respiratory Syncytial Virus Infection. J Virol 2018; 92:e01200-18. [PMID: 30185593 DOI: 10.1128/JVI.01200-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/24/2018] [Indexed: 12/28/2022] Open
Abstract
Respiratory syncytial virus (RSV) is the leading cause of respiratory infection in young children and high-risk adults. However, a specific treatment for this viral infection is not currently available. In this study, we discovered that an exchange protein directly activated by cyclic AMP (EPAC) can serve as a potential therapeutic target for RSV. In both lower and upper epithelial cells, treatment with EPAC inhibitor (ESI-09), but not protein kinase A inhibitor (H89), significantly inhibits RSV replication and proinflammatory cytokine/chemokine induction. In addition, RSV-activated transcriptional factors belonging to the NF-κB and IRF families are also suppressed by ESI-09. Through isoform-specific gene knockdown, we found that EPAC2, but not EPAC1, plays a dominant role in controlling RSV replication and virus-induced host responses. Experiments using both EPAC2 knockout and EPAC2-specific inhibitor support such roles of EPAC2. Therefore, EPAC2 is a promising therapeutic target to regulate RSV replication and associated inflammation.IMPORTANCE RSV is a serious public health problem, as it is associated with bronchiolitis, pneumonia, and asthma exacerbations. Currently no effective treatment or vaccine is available, and many molecular mechanisms regarding RSV-induced lung disease are still significantly unknown. This project aims to elucidate an important and novel function of a protein, called EPAC2, in RSV replication and innate inflammatory responses. Our results should provide an important insight into the development of new pharmacologic strategies against RSV infection, thereby reducing RSV-associated morbidity and mortality.
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Balasubramaniam A, Sheriff S, Friend LA, James JH. Phosphodiesterase 4B knockout prevents skeletal muscle atrophy in rats with burn injury. Am J Physiol Regul Integr Comp Physiol 2018; 315:R429-R433. [PMID: 29693432 DOI: 10.1152/ajpregu.00042.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The phosphodiesterase 4 (PDE4)-cAMP pathway plays a predominant role in mediating skeletal muscle proteolysis in burn injury. The present investigations to determine the PDE4 isoform(s) involved in this action revealed that burn injury increased the expression of rat skeletal muscle PDE4B mRNA by sixfold but had little or no effect on expression of other PDE4 isoforms. These observations led us to study the effects of burn in PDE4B knockout (KO) rats. As reported by us previously, burn injury significantly increased extensor digitorum longus (EDL) muscle total and myofibrillar proteolysis in wild-type (WT) rats, but there were no significant effects on either total or myofibrillar protein breakdown in EDL muscle of PDE4B KO rats with burn injury. Moreover, burn injury increased PDE4 activity in the skeletal muscle of WT rats, but this was reduced by >80% in PDE4B KO rats. Also, burn injury decreased skeletal muscle cAMP concentration in WT rats but had no significant effects in the muscles of PDE4B KO rats. Incubation of the EDL muscle of burn-PDE4B KO rats with an inhibitor of the exchange factor directly activated by cAMP, but not with a protein kinase A inhibitor, eliminated the protective effects of PDE4B KO on EDL muscle proteolysis and increased muscle proteolysis to the same extent as in the EDL of burn-WT rats. These novel findings confirm a major role for PDE4B in skeletal muscle proteolysis in burn injury and suggest that an innovative therapy based on PDE4B-selective inhibitors could be developed to treat skeletal muscle cachexia in burn injury without the fear of causing emesis, which is associated with PDE4D inhibition.
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Affiliation(s)
- Ambikaipakan Balasubramaniam
- Department of Surgery, University of Cincinnati Medical Center , Cincinnati, Ohio.,Shriner's Hospital for Children , Cincinnati, Ohio
| | - Sulaiman Sheriff
- Department of Surgery, University of Cincinnati Medical Center , Cincinnati, Ohio
| | - Lou Ann Friend
- Department of Surgery, University of Cincinnati Medical Center , Cincinnati, Ohio
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Garg J, Feng YX, Jansen SR, Friedrich J, Lezoualc'h F, Schmidt M, Wieland T. Catecholamines facilitate VEGF-dependent angiogenesis via β2-adrenoceptor-induced Epac1 and PKA activation. Oncotarget 2018; 8:44732-44748. [PMID: 28512254 PMCID: PMC5546514 DOI: 10.18632/oncotarget.17267] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 03/30/2017] [Indexed: 01/16/2023] Open
Abstract
Chronic stress has been associated with the progression of cancer and antagonists for β-adrenoceptors (βAR) are regarded as therapeutic option. As they are also used to treat hemangiomas as well as retinopathy of prematurity, a role of endothelial β2AR in angiogenesis can be envisioned. We therefore investigated the role of β2AR-induced cAMP formation by analyzing the role of the cAMP effector molecules exchange factor directly activated by cAMP 1 (Epac1) and protein kinase A (PKA) in endothelial cells (EC). Epac1-deficient mice showed a reduced amount of pre-retinal neovascularizations in the model of oxygen-induced retinopathy, which is predominantly driven by vascular endothelial growth factor (VEGF). siRNA-mediated knockdown of Epac1 in human umbilical vein EC (HUVEC) decreased angiogenic sprouting by lowering the expression of the endothelial VEGF-receptor-2 (VEGFR-2). Conversely, Epac1 activation by β2AR stimulation or the Epac-selective activator cAMP analog 8-p-CPT-2’-O-Me-cAMP (8-pCPT) increased VEGFR-2 levels and VEGF-dependent sprouting. Similar to Epac1 knockdown, depletion of the monomeric GTPase Rac1 decreased VEGFR-2 expression. As Epac1 stimulation induces Rac1 activation, Epac1 might regulate VEGFR-2 expression through Rac1. In addition, we found that PKA was also involved in the regulation of angiogenesis in EC since the adenylyl cyclase (AC) activator forskolin (Fsk), but not 8-pCPT, increased sprouting in Epac1-depleted HUVEC and this increase was sensitive to a selective synthetic peptide PKA inhibitor. In accordance, β2AR- and AC-activation, but not Epac1 stimulation increased VEGF secretion in HUVEC. Our data indicate that high levels of catecholamines, which occur during chronic stress, prime the endothelium for angiogenesis through a β2AR-mediated increase in endothelial VEGFR-2 expression and VEGF secretion.
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Affiliation(s)
- Jaspal Garg
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Yu-Xi Feng
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Sepp R Jansen
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Julian Friedrich
- 5th Medical Clinic, University Hospital Mannheim, Heidelberg University, Mannheim, Germany
| | - Frank Lezoualc'h
- Institute of Cardiovascular and Metabolic Diseases, Inserm UMR-1048, Université Toulouse -Paul Sabatier, Toulouse, France
| | - Martina Schmidt
- Department of Molecular Pharmacology, Center of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Thomas Wieland
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Akimoto M, VanSchouwen B, Melacini G. The structure of the apo cAMP-binding domain of HCN4 - a stepping stone toward understanding the cAMP-dependent modulation of the hyperpolarization-activated cyclic-nucleotide-gated ion channels. FEBS J 2018; 285:2182-2192. [PMID: 29444387 DOI: 10.1111/febs.14408] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/31/2018] [Accepted: 02/09/2018] [Indexed: 12/14/2022]
Abstract
The hyperpolarization-activated cyclic-nucleotide-gated (HCN) ion channels control nerve impulse transmission and cardiac pacemaker activity. The modulation by cAMP is critical for the regulatory function of HCN in both neurons and cardiomyocytes, but the underlying mechanism is not fully understood. Here, we show how the structure of the apo cAMP-binding domain of the HCN4 isoform has contributed to a model for the cAMP-dependent modulation of the HCN ion-channel. This model recapitulates the structural and dynamical changes that occur along the thermodynamic cycle arising from the coupling of cAMP-binding and HCN self-association equilibria. The proposed model addresses some of the questions previously open about the auto-inhibition of HCN and its cAMP-induced activation, while opening new opportunities for selectively targeting HCN through allosteric ligands. A remaining challenge is the investigation of HCN dimers and their regulatory role. Overcoming this challenge will require the integration of crystallography, cryo electron microscopy, NMR, electrophysiology and simulations.
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Affiliation(s)
- Madoka Akimoto
- Department of Chemistry and Chemical Biology, McMaster University, ON, Canada
| | - Bryan VanSchouwen
- Department of Chemistry and Chemical Biology, McMaster University, ON, Canada
| | - Giuseppe Melacini
- Department of Chemistry and Chemical Biology, McMaster University, ON, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, ON, Canada
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Kumar N, Prasad P, Jash E, Saini M, Husain A, Goldman A, Sehrawat S. Insights into exchange factor directly activated by cAMP ( EPAC) as potential target for cancer treatment. Mol Cell Biochem 2018; 447:77-92. [PMID: 29417338 DOI: 10.1007/s11010-018-3294-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 01/19/2018] [Indexed: 01/02/2023]
Abstract
Cancer remains a global health problem and approximately 1.7 million new cancer cases are diagnosed every year worldwide. Although diverse molecules are currently being explored as targets for cancer therapy the tumor treatment and therapy is highly tricky. Secondary messengers are important for hormone-mediated signaling pathway. Cyclic AMP (cAMP), a secondary messenger responsible for various physiological processes regulates cell metabolism by activating Protein kinase A (PKA) and by targeting exchange protein directly activated by cAMP (EPAC). EPAC is present in two isoforms EPAC1 and EPAC2, which exhibit different tissue distribution and is involved in GDP/GTP exchange along with activating Rap1- and Rap2-mediated signaling pathways. EPAC is also known for its dual role in cancer as pro- and anti-proliferative in addition to metastasis. Results after perturbing EPAC activity suggests its involvement in cancer cell migration, proliferation, and cytoskeleton remodeling which makes it a potential therapeutic target for cancer treatments.
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Ramos CJ, Lin C, Liu X, Antonetti DA. The EPAC-Rap1 pathway prevents and reverses cytokine-induced retinal vascular permeability. J Biol Chem 2017; 293:717-730. [PMID: 29158262 DOI: 10.1074/jbc.m117.815381] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/15/2017] [Indexed: 12/31/2022] Open
Abstract
Increased retinal vascular permeability contributes to macular edema, a leading cause of vision loss in eye pathologies such as diabetic retinopathy, age-related macular degeneration, and central retinal vein occlusions. Pathological changes in vascular permeability are driven by growth factors such as VEGF and pro-inflammatory cytokines such as TNF-α. Identifying the pro-barrier mechanisms that block vascular permeability and restore the blood-retinal barrier (BRB) may lead to new therapies. The cAMP-dependent guanine nucleotide exchange factor (EPAC) exchange-protein directly activated by cAMP promotes exchange of GTP in the small GTPase Rap1. Rap1 enhances barrier properties in human umbilical endothelial cells by promoting adherens junction assembly. We hypothesized that the EPAC-Rap1 signaling pathway may regulate the tight junction complex of the BRB and may restore barrier properties after cytokine-induced permeability. Here, we show that stimulating EPAC or Rap1 activation can prevent or reverse VEGF- or TNF-α-induced permeability in cell culture and in vivo Moreover, EPAC activation inhibited VEGF receptor (VEGFR) signaling through the Ras/MEK/ERK pathway. We also found that Rap1B knockdown or an EPAC antagonist increases endothelial permeability and that VEGF has no additive effect, suggesting a common pathway. Furthermore, GTP-bound Rap1 promoted tight junction assembly, and loss of Rap1B led to loss of junctional border organization. Collectively, our results indicate that the EPAC-Rap1 pathway helps maintain basal barrier properties in the retinal vascular endothelium and activation of the EPAC-Rap1 pathway may therefore represent a potential therapeutic strategy to restore the BRB.
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Affiliation(s)
- Carla J Ramos
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
| | - Chengmao Lin
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
| | - Xuwen Liu
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
| | - David A Antonetti
- From the Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105
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Ichikawa H, Itsumi M, Kajioka S, Maki T, Lee K, Tomita M, Yamaoka S. Overexpression of exchange protein directly activated by cAMP-1 ( EPAC1) attenuates bladder cancer cell migration. Biochem Biophys Res Commun 2018; 495:64-70. [PMID: 29111327 DOI: 10.1016/j.bbrc.2017.10.142] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 10/26/2017] [Indexed: 12/11/2022]
Abstract
Exchange protein directly activated by cAMP (EPAC) is a mediator of a cAMP signaling pathway that is independent of protein kinase A. EPAC has two isoforms (EPAC1 and EPAC2) and is a cAMP-dependent guanine nucleotide exchange factor for the small GTPases, Rap1 and Rap2. Recent studies suggest that EPAC1 has both positive and negative influences on cancer and is involved in cell proliferation, apoptosis, migration and metastasis. We report that EPAC1 and EPAC2 expression levels were significantly lower in bladder cancer tissue than in normal bladder tissue. In addition, bladder cancer cell lines showed reduced EPAC1 mRNA expression. Furthermore, EPAC1 overexpression in bladder cancer cell lines induced morphologic changes and markedly suppressed cell migration without affecting cell viability. The overexpressed EPAC1 preferentially localized at cell-cell interfaces. In conclusion, reduced EPAC1 expression in bladder tumors and poor migration of EPAC1-overexpressing cells implicate EPAC1 as an inhibitor of bladder cancer cell migration.
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Liu Z, Zhu Y, Chen H, Wang P, Mei FC, Ye N, Cheng X, Zhou J. Structure-activity relationships of 2-substituted phenyl-N-phenyl-2-oxoacetohydrazonoyl cyanides as novel antagonists of exchange proteins directly activated by cAMP ( EPACs). Bioorg Med Chem Lett 2017; 27:5163-5166. [PMID: 29100797 DOI: 10.1016/j.bmcl.2017.10.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/19/2017] [Accepted: 10/22/2017] [Indexed: 11/24/2022]
Abstract
Exchange proteins directly activated by cAMP (EPACs) are critical cAMP-dependent signaling pathway mediators that play important roles in cancer, diabetes, heart failure, inflammations, infections, neurological disorders and other human diseases. EPAC specific modulators are urgently needed to explore EPAC's physiological function, mechanism of action and therapeutic applications. On the basis of a previously identified EPAC specific inhibitor hit ESI-09, herein we have designed and synthesized a novel series of 2-substituted phenyl-N-phenyl-2-oxoacetohydrazonoyl cyanides as potent EPAC inhibitors. Compound 31 (ZL0524) has been discovered as the most potent EPAC inhibitor with IC50 values of 3.6 µM and 1.2 µM against EPAC1 and EPAC2, respectively. Molecular docking of 31 onto an active EPAC2 structure predicts that 31 occupies the hydrophobic pocket in cAMP binding domain (CBD) and also opens up new space leading to the solvent region. These findings provide inspirations for discovering next generation of EPAC inhibitors.
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Affiliation(s)
- Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Yingmin Zhu
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The University of Texas Health Science Center, 7000 Fannin St #1200, Houston, TX 77030, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Fang C Mei
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The University of Texas Health Science Center, 7000 Fannin St #1200, Houston, TX 77030, United States
| | - Na Ye
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The University of Texas Health Science Center, 7000 Fannin St #1200, Houston, TX 77030, United States.
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, United States.
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45
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Romero F, Santana-Calvo C, Sánchez-Guevara Y, Nishigaki T. FRET-based binding assay between a fluorescent cAMP analogue and a cyclic nucleotide-binding domain tagged with a CFP. FEBS Lett 2017; 591:2869-2878. [PMID: 28734016 DOI: 10.1002/1873-3468.12760] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/29/2017] [Accepted: 07/18/2017] [Indexed: 11/12/2022]
Abstract
The cyclic nucleotide-binding domain (CNBD) functions as a regulatory domain of many proteins involved in cyclic nucleotide signalling. We developed a straightforward and reliable binding assay based on intermolecular fluorescence resonance energy transfer (FRET) between an adenosine-3', 5'-cyclic monophosphate analogue labelled with fluorescein and a recombinant CNBD of human EPAC1 tagged with a cyan fluorescence protein (CFP). The high FRET efficiency of this method (~ 80%) allowed us to perform several types of binding experiments with nanomolar range of sample using conventional equipment. In addition, the CFP tag on the CNBD enabled us to perform a specific binding experiment using an unpurified protein. Considering these advantages, this technique is useful to study poorly characterized CNBDs.
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Affiliation(s)
- Francisco Romero
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Carmen Santana-Calvo
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Yoloxochitl Sánchez-Guevara
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | - Takuya Nishigaki
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
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Wang P, Liu Z, Chen H, Ye N, Cheng X, Zhou J. Exchange proteins directly activated by cAMP ( EPACs): Emerging therapeutic targets. Bioorg Med Chem Lett 2017; 27:1633-1639. [PMID: 28283242 PMCID: PMC5397994 DOI: 10.1016/j.bmcl.2017.02.065] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/07/2017] [Accepted: 02/26/2017] [Indexed: 11/22/2022]
Abstract
Exchange proteins directly activated by cAMP (EPACs) are critical cAMP-dependent signaling pathway mediators. The discovery of EPAC proteins has significantly facilitated understanding on cAMP-dependent signaling pathway and efforts along this line open new avenues for developing novel therapeutics for cancer, diabetes, heart failure, inflammation, infections, neurological disorders and other human diseases. Over the past decade, important progress has been made in the identification of EPAC agonists, antagonists and their biological and pharmacological applications. In this review, we briefly summarize recently reported novel functions of EPACs and the discovery of their small molecule modulators. The challenges and future perspectives are also discussed.
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Affiliation(s)
- Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Na Ye
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center, Houston, TX 77030, United States
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States.
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47
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Ye N, Zhu Y, Liu Z, Mei FC, Chen H, Wang P, Cheng X, Zhou J. Identification of novel 2-(benzo[d]isoxazol-3-yl)-2-oxo-N-phenylacetohydrazonoyl cyanide analoguesas potent EPAC antagonists. Eur J Med Chem 2017; 134:62-71. [PMID: 28399451 DOI: 10.1016/j.ejmech.2017.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/30/2017] [Accepted: 04/01/2017] [Indexed: 12/28/2022]
Abstract
Two series of novel EPAC antagonists are designed, synthesized and evaluated in an effort to develop diversified analogues based on the scaffold of the previously identified high-throughput (HTS) hit 1 (ESI-09). Further SAR studies reveal that the isoxazole ring A of 1 can tolerate chemical modifications with either introduction of flexible electron-donating substitutions or structurally restrictedly fusing with a phenyl ring, leading to identification of several more potent and diversified EPAC antagonists (e.g., 10 (NY0617), 14 (NY0460), 26 (NY0725), 32 (NY0561), and 33 (NY0562)) with low micromolar inhibitory activities. Molecular docking studies on compounds 10 and 33 indicate that these two series of compounds bind at a similar site with substantially different interactions with the EPAC proteins. The findings may serve as good starting points for the development of more potent EPAC antagonists as valuable pharmacological probes or potential drug candidates.
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Affiliation(s)
- Na Ye
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States; Department of Medicinal Chemistry, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Yingmin Zhu
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX 77030, United States
| | - Zhiqing Liu
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Fang C Mei
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX 77030, United States
| | - Haiying Chen
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Pingyuan Wang
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX 77030, United States.
| | - Jia Zhou
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, United States.
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Samuchiwal SK, Balestrieri B, Raff H, Boyce JA. Endogenous prostaglandin E 2 amplifies IL-33 production by macrophages through an E prostanoid (EP) 2/EP 4-cAMP- EPAC-dependent pathway. J Biol Chem 2017; 292:8195-8206. [PMID: 28341741 DOI: 10.1074/jbc.m116.769422] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 03/14/2017] [Indexed: 11/06/2022] Open
Abstract
When activated through toll-like receptors (TLRs), macrophages generate IL-33, an IL-1 family member that induces innate immune responses through ST2 signaling. LPS, a TLR4 ligand, induces macrophages to generate prostaglandin E2 (PGE2) through inducible COX-2 and microsomal PGE2 synthase 1 (mPGES-1) (1). We demonstrate that IL-33 production by bone marrow-derived murine macrophages (bmMFs) requires the generation of endogenous PGE2 and the intrinsic expression of EP2 receptors to amplify NF-κB-dependent, LPS-induced IL-33 expression via exchange protein activated by cAMP (EPAC). Compared with WT cells, bmMFs lacking either mPGES-1 or EP2 receptors displayed reduced LPS-induced IL-33 levels. A selective EP2 agonist and, to a lesser extent, EP4 receptor agonist potentiated LPS-induced IL-33 generation from both mPGES-1-null and WT bmMFs, whereas EP1 and EP3 receptor agonists were inactive. The effects of PGE2 depended on cAMP, were mimicked by an EPAC-selective agonist, and were attenuated by EPAC-selective antagonism and knockdown. LPS-induced p38 MAPK and NF-κB activations were necessary for both IL-33 production and PGE2 generation, and exogenous PGE2 partly reversed the suppression of IL-33 production caused by p38 MAPK and NF-κB inhibition. Mice lacking mPGES-1 showed lower IL-33 levels and attenuated lung inflammation in response to repetitive Alternaria inhalation challenges. Cumulatively, our data demonstrate that endogenous PGE2, EP2 receptors, and EPAC are prerequisites for maximal LPS-induced IL-33 expression and that exogenous PGE2 can amplify IL-33 production via EP2 and EP4 receptors. The ubiquitous induction of mPGES-1-dependent PGE2 may be crucial for innate immune system activation during various IL-33 driven pathologic disorders.
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Affiliation(s)
- Sachin K Samuchiwal
- Department of Medicine, Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, Massachusetts 02115; Harvard Medical School, Boston, Massachusetts 02115
| | - Barbara Balestrieri
- Department of Medicine, Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, Massachusetts 02115; Harvard Medical School, Boston, Massachusetts 02115
| | - Hannah Raff
- Department of Medicine, Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Joshua A Boyce
- Department of Medicine, Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, Massachusetts 02115; Harvard Medical School, Boston, Massachusetts 02115.
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Muñoz-Llancao P, de Gregorio C, Las Heras M, Meinohl C, Noorman K, Boddeke E, Cheng X, Lezoualc'h F, Schmidt M, Gonzalez-Billault C. Microtubule-regulating proteins and cAMP-dependent signaling in neuroblastoma differentiation. Cytoskeleton (Hoboken) 2017; 74:143-158. [PMID: 28164467 DOI: 10.1002/cm.21355] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 01/15/2023]
Abstract
Neurons are highly differentiated cells responsible for the conduction and transmission of information in the nervous system. The proper function of a neuron relies on the compartmentalization of their intracellular domains. Differentiated neuroblastoma cells have been extensively used to study and understand the physiology and cell biology of neuronal cells. Here, we show that differentiation of N1E-115 neuroblastoma cells is more pronounced upon exposure of a chemical analog of cyclic AMP (cAMP), db-cAMP. We next analysed the expression of key microtubule-regulating proteins in differentiated cells and the expression and activation of key cAMP players such as EPAC, PKA and AKAP79/150. Most of the microtubule-promoting factors were up regulated during differentiation of N1E-115 cells, while microtubule-destabilizing proteins were down regulated. We observed an increase in tubulin post-translational modifications related to microtubule stability. As expected, db-cAMP increased PKA- and EPAC-dependent signalling. Consistently, pharmacological modulation of EPAC activity instructed cell differentiation, number of neurites, and neurite length in N1E-115 cells. Moreover, disruption of the PKA-AKAP interaction reduced these morphometric parameters. Interestingly, PKA and EPAC act synergistically to induce neuronal differentiation in N1E-115. Altogether these results show that the changes observed in the differentiation of N1E-115 cells proceed by regulating several microtubule-stabilizing factors, and the acquisition of a neuronal phenotype is a process involving concerted although independent functions of EPAC and PKA.
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Affiliation(s)
- Pablo Muñoz-Llancao
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile.,Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Cristian de Gregorio
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile
| | - Macarena Las Heras
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile
| | - Christopher Meinohl
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Kevin Noorman
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Erik Boddeke
- Department of Medical Physiology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, USA
| | - Frank Lezoualc'h
- Inserm UMR-1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, France.,Université de Toulouse III, Paul Sabatier, Toulouse, France
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, The Netherlands
| | - Christian Gonzalez-Billault
- Laboratory of Cell and Neuronal Dynamics, Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago, Chile.,Geroscience Center for Brain Health and Metabolism (GERO), Santiago, Chile.,The Buck Institute for Research on Aging, Novato, USA
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50
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Abstract
The recently identified mechanically activated Piezo1 and Piezo2 channels play major roles in various aspects of mechanosensation in mammals, and their mutations are associated with human diseases. Recent reports show that activation of cell surface receptors coupled to heterotrimeric Gq proteins increase the sensitivity of Piezo2 channels to mechanical stimuli. Activation of the cyclic adenosine monophosphate pathway was also shown to potentiate Piezo2 channel activity. This phenomenon may play a role in mechanical allodynia or hyperalgesia during inflammation. Both Piezo1 and Piezo2 channels are inhibited upon depletion of plasma membrane phosphoinositides, in response to phospholipase C activation by Ca2+ influx via the transient receptor potential vanilloid 1 channels. This review will discuss current knowledge on regulation of Piezo channels by these intracellular signaling pathways.
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Affiliation(s)
- I Borbiro
- Rutgers, New Jersey Medical School, Newark, NJ, United States
| | - T Rohacs
- Rutgers, New Jersey Medical School, Newark, NJ, United States
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