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Lezoualc'h F, Fazal L, Laudette M, Conte C. Cyclic AMP Sensor EPAC Proteins and Their Role in Cardiovascular Function and Disease. Circ Res 2016; 118:881-97. [PMID: 26941424 DOI: 10.1161/circresaha.115.306529] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
cAMP is a universal second messenger that plays central roles in cardiovascular regulation influencing gene expression, cell morphology, and function. A crucial step toward a better understanding of cAMP signaling came 18 years ago with the discovery of the exchange protein directly activated by cAMP (EPAC). The 2 EPAC isoforms, EPAC1 and EPAC2, are guanine-nucleotide exchange factors for the Ras-like GTPases, Rap1 and Rap2, which they activate independently of the classical effector of cAMP, protein kinase A. With the development of EPAC pharmacological modulators, many reports in the literature have demonstrated the critical role of EPAC in the regulation of various cAMP-dependent cardiovascular functions, such as calcium handling and vascular tone. EPAC proteins are coupled to a multitude of effectors into distinct subcellular compartments because of their multidomain architecture. These novel cAMP sensors are not only at the crossroads of different physiological processes but also may represent attractive therapeutic targets for the treatment of several cardiovascular disorders, including cardiac arrhythmia and heart failure.
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Affiliation(s)
- Frank Lezoualc'h
- From the Department of Cardiac and Renal Remodeling of the Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-1048, Toulouse, France (F.L., L.F., M.L., C.C.); and Université Toulouse III-Paul Sabatier, Toulouse, France (F.L., L.F., M.L., C.C.).
| | - Loubina Fazal
- From the Department of Cardiac and Renal Remodeling of the Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-1048, Toulouse, France (F.L., L.F., M.L., C.C.); and Université Toulouse III-Paul Sabatier, Toulouse, France (F.L., L.F., M.L., C.C.)
| | - Marion Laudette
- From the Department of Cardiac and Renal Remodeling of the Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-1048, Toulouse, France (F.L., L.F., M.L., C.C.); and Université Toulouse III-Paul Sabatier, Toulouse, France (F.L., L.F., M.L., C.C.)
| | - Caroline Conte
- From the Department of Cardiac and Renal Remodeling of the Institute of Metabolic and Cardiovascular Diseases (I2MC), Institut National de la Santé et de la Recherche Médicale (INSERM), UMR-1048, Toulouse, France (F.L., L.F., M.L., C.C.); and Université Toulouse III-Paul Sabatier, Toulouse, France (F.L., L.F., M.L., C.C.)
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152
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Cao S, Bian Z, Zhu X, Shen SR. Effect of Epac1 on pERK and VEGF Activation in Postoperative Persistent Pain in Rats. J Mol Neurosci 2016; 59:554-64. [DOI: 10.1007/s12031-016-0776-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/02/2016] [Indexed: 02/01/2023]
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153
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Domingo-Gonzalez R, Martínez-Colón GJ, Smith AJ, Smith CK, Ballinger MN, Xia M, Murray S, Kaplan MJ, Yanik GA, Moore BB. Inhibition of Neutrophil Extracellular Trap Formation after Stem Cell Transplant by Prostaglandin E2. Am J Respir Crit Care Med 2016; 193:186-97. [PMID: 26417909 DOI: 10.1164/rccm.201501-0161oc] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
RATIONALE Autologous and allogeneic hematopoietic stem cell transplant (HSCT) patients are susceptible to pulmonary infections, including bacterial pathogens, even after hematopoietic reconstitution. We previously reported that murine bone marrow transplant (BMT) neutrophils overexpress cyclooxygenase-2, overproduce prostaglandin E2 (PGE2), and exhibit defective intracellular bacterial killing. Neutrophil extracellular traps (NETs) are DNA structures that capture and kill extracellular bacteria and other pathogens. OBJECTIVES To determine whether NETosis was defective after transplant and if so, whether this was regulated by PGE2 signaling. METHODS Neutrophils isolated from mice and humans (both control and HSCT subjects) were analyzed for NETosis in response to various stimuli in the presence or absence of PGE2 signaling modifiers. MEASUREMENTS AND MAIN RESULTS NETs were visualized by immunofluorescence or quantified by Sytox Green fluorescence. Treatment of BMT or HSCT neutrophils with phorbol 12-myristate 13-acetate or rapamycin resulted in reduced NET formation relative to control cells. NET formation after BMT was rescued both in vitro and in vivo with cyclooxygenase inhibitors. Additionally, the EP2 receptor antagonist (PF-04418948) or the EP4 antagonist (AE3-208) restored NET formation in neutrophils isolated from BMT mice or HSCT patients. Exogenous PGE2 treatment limited NETosis of neutrophils collected from normal human volunteers and naive mice in an exchange protein activated by cAMP- and protein kinase A-dependent manner. CONCLUSIONS Our results suggest blockade of the PGE2-EP2 or EP4 signaling pathway restores NETosis after transplantation. Furthermore, these data provide the first description of a physiologic inhibitor of NETosis.
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Affiliation(s)
| | | | | | - Carolyne K Smith
- 1 Immunology Graduate Program.,3 Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland; and
| | - Megan N Ballinger
- 4 Pulmonary, Allergy, Critical Care and Sleep Division, Department of Internal Medicine, The Ohio State University, Columbus, Ohio
| | - Meng Xia
- 5 Biostatistics Department, School of Public Health
| | - Susan Murray
- 5 Biostatistics Department, School of Public Health
| | - Mariana J Kaplan
- 3 Systemic Autoimmunity Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland; and
| | - Gregory A Yanik
- 6 Department of Pediatrics, Division of Hematology-Oncology, Medical School
| | - Bethany B Moore
- 7 Pulmonary and Critical Care Medicine Division, Department of Internal Medicine, and.,8 Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan
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154
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Lobo MJ, Amaral MD, Zaccolo M, Farinha CM. EPAC1 activation by cAMP stabilizes CFTR at the membrane by promoting its interaction with NHERF1. J Cell Sci 2016; 129:2599-612. [PMID: 27206858 DOI: 10.1242/jcs.185629] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/17/2016] [Indexed: 01/14/2023] Open
Abstract
Cyclic AMP (cAMP) activates protein kinase A (PKA) but also the guanine nucleotide exchange factor 'exchange protein directly activated by cAMP' (EPAC1; also known as RAPGEF3). Although phosphorylation by PKA is known to regulate CFTR channel gating - the protein defective in cystic fibrosis - the contribution of EPAC1 to CFTR regulation remains largely undefined. Here, we demonstrate that in human airway epithelial cells, cAMP signaling through EPAC1 promotes CFTR stabilization at the plasma membrane by attenuating its endocytosis, independently of PKA activation. EPAC1 and CFTR colocalize and interact through protein adaptor NHERF1 (also known as SLC9A3R1). This interaction is promoted by EPAC1 activation, triggering its translocation to the plasma membrane and binding to NHERF1. Our findings identify a new CFTR-interacting protein and demonstrate that cAMP activates CFTR through two different but complementary pathways - the well-known PKA-dependent channel gating pathway and a new mechanism regulating endocytosis that involves EPAC1. The latter might constitute a novel therapeutic target for treatment of cystic fibrosis.
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Affiliation(s)
- Miguel J Lobo
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, Lisboa 1749-016, Portugal Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Margarida D Amaral
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, Lisboa 1749-016, Portugal
| | - Manuela Zaccolo
- Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Carlos M Farinha
- University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, Lisboa 1749-016, Portugal
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155
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Cuíñas A, García-Morales V, Viña D, Gil-Longo J, Campos-Toimil M. Activation of PKA and Epac proteins by cyclic AMP depletes intracellular calcium stores and reduces calcium availability for vasoconstriction. Life Sci 2016; 155:102-9. [PMID: 27142830 DOI: 10.1016/j.lfs.2016.03.059] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/23/2016] [Accepted: 03/03/2016] [Indexed: 12/15/2022]
Abstract
AIMS We investigated the implication of PKA and Epac proteins in the endothelium-independent vasorelaxant effects of cyclic AMP (cAMP). MAIN METHODS Cytosolic Ca(2+) concentration ([Ca(2+)]c) was measured by fura-2 imaging in rat aortic smooth muscle cells (RASMC). Contraction-relaxation experiments were performed in rat aortic rings deprived of endothelium. KEY FINDINGS In extracellular Ca(2+)-free solution, cAMP-elevating agents induced an increase in [Ca(2+)]c in RASMC that was reproduced by PKA and Epac activation and reduced after depletion of intracellular Ca(2+) reservoirs. Arginine-vasopressin (AVP)-evoked increase of [Ca(2+)]c and store-operated Ca(2+) entry (SOCE) were inhibited by cAMP-elevating agents, PKA or Epac activation in these cells. In aortic rings, the contractions induced by phenylephrine in absence of extracellular Ca(2+) were inhibited by cAMP-elevating agents, PKA or Epac activation. In these conditions, reintroduction of Ca(2+) induced a contraction that was inhibited by cAMP-elevating agents, an effect reduced by PKA inhibition and reproduced by PKA or Epac activators. SIGNIFICANCE Our results suggest that increased cAMP depletes intracellular, thapsigargin-sensitive Ca(2+) stores through activation of PKA and Epac in RASMC, thus reducing the amount of Ca(2+) released by IP3-generating agonists during the contraction of rat aorta. cAMP rise also inhibits the contraction induced by depletion of intracellular Ca(2+), an effect mediated by reduction of SOCE after PKA or Epac activation. Both effects participate in the cAMP-induced endothelium-independent vasorelaxation.
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Affiliation(s)
- Andrea Cuíñas
- Farmacología de las Enfermedades Crónicas (CDPHARMA), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Verónica García-Morales
- Farmacología de las Enfermedades Crónicas (CDPHARMA), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Dolores Viña
- Farmacología de las Enfermedades Crónicas (CDPHARMA), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - José Gil-Longo
- Farmacología de las Enfermedades Crónicas (CDPHARMA), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Manuel Campos-Toimil
- Farmacología de las Enfermedades Crónicas (CDPHARMA), Centro de Investigación en Medicina Molecular y Enfermedades Crónicas (CIMUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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156
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Aoyama M, Kawase H, Bando YK, Monji A, Murohara T. Dipeptidyl Peptidase 4 Inhibition Alleviates Shortage of Circulating Glucagon-Like Peptide-1 in Heart Failure and Mitigates Myocardial Remodeling and Apoptosis via the Exchange Protein Directly Activated by Cyclic AMP 1/Ras-Related Protein 1 Axis. Circ Heart Fail 2016; 9:e002081. [PMID: 26721911 DOI: 10.1161/circheartfailure.115.002081] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Ample evidence demonstrates cardiovascular protection by incretin-based therapy using dipeptidyl peptidase 4 inhibitor (DPP4i) and glucagon-like peptide-1 (GLP-1) under either diabetic or nondiabetic condition. Their action on myocardium is mediated by the cyclic AMP (cAMP) signal; however, the pathway remains uncertain. This study was conducted to address the effect of DPP4i/GLP-1/cAMP axis on cardiac dysfunction and remodeling induced by pressure overload (thoracic aortic constriction [TAC]) independently of diabetes mellitus. METHODS AND RESULTS DPP4i (alogliptin, 10 mg/kg per day for 4 weeks) prevented TAC-induced contractile dysfunction, remodeling, and apoptosis of myocardium in a GLP-1 receptor antagonist (exendin [9-39])-sensitive fashion. In TAC, circulating level of GLP-1 (in pmol/L; 0.86 ± 0.10 for TAC versus 2.13 ± 0.54 for sham control) unexpectedly declined and so did the myocardial cAMP concentration (in pmol/mg protein; 33.0 ± 1.4 for TAC versus 42.2 ± 1.5 for sham). Alogliptin restored the decline in the GLP-1/cAMP levels observed in TAC, thereby augmented cAMP signaling effectors (protein kinase A [PKA] and exchange protein directly activated by cAMP 1 [EPAC1]). In vitro assay revealed distinct roles of PKA and EPAC1 in cardiac apoptosis. EPAC1 promoted cardiomyocyte survival via concomitant increase in B cell lymphoma-2 (Bcl-2) expression and activation of small G protein Ras-related protein 1 (Rap1) in a cAMP dose-dependent and PKA-independent fashion. CONCLUSIONS DPP4i restores cardiac remodeling and apoptosis caused by the pathological decline in circulating GLP-1 in response to pressure overload. EPAC1 is essential for cardiomyocyte survival via the cAMP/Rap1 activation independently of PKA.
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Affiliation(s)
- Morihiko Aoyama
- From the Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Haruya Kawase
- From the Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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157
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Wang Z, Liu D, Varin A, Nicolas V, Courilleau D, Mateo P, Caubere C, Rouet P, Gomez AM, Vandecasteele G, Fischmeister R, Brenner C. A cardiac mitochondrial cAMP signaling pathway regulates calcium accumulation, permeability transition and cell death. Cell Death Dis 2016; 7:e2198. [PMID: 27100892 PMCID: PMC4855650 DOI: 10.1038/cddis.2016.106] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/17/2016] [Accepted: 03/21/2016] [Indexed: 12/19/2022]
Abstract
Although cardiac cytosolic cyclic 3',5'-adenosine monophosphate (cAMP) regulates multiple processes, such as beating, contractility, metabolism and apoptosis, little is known yet on the role of this second messenger within cardiac mitochondria. Using cellular and subcellular approaches, we demonstrate here the local expression of several actors of cAMP signaling within cardiac mitochondria, namely a truncated form of soluble AC (sACt) and the exchange protein directly activated by cAMP 1 (Epac1), and show a protective role for sACt against cell death, apoptosis as well as necrosis in primary cardiomyocytes. Upon stimulation with bicarbonate (HCO3(-)) and Ca(2+), sACt produces cAMP, which in turn stimulates oxygen consumption, increases the mitochondrial membrane potential (ΔΨm) and ATP production. cAMP is rate limiting for matrix Ca(2+) entry via Epac1 and the mitochondrial calcium uniporter and, as a consequence, prevents mitochondrial permeability transition (MPT). The mitochondrial cAMP effects involve neither protein kinase A, Epac2 nor the mitochondrial Na(+)/Ca(2+) exchanger. In addition, in mitochondria isolated from failing rat hearts, stimulation of the mitochondrial cAMP pathway by HCO3(-) rescued the sensitization of mitochondria to Ca(2+)-induced MPT. Thus, our study identifies a link between mitochondrial cAMP, mitochondrial metabolism and cell death in the heart, which is independent of cytosolic cAMP signaling. Our results might have implications for therapeutic prevention of cell death in cardiac pathologies.
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Affiliation(s)
- Z Wang
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - D Liu
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - A Varin
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - V Nicolas
- UMS-IPSIT, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - D Courilleau
- UMS-IPSIT, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - P Mateo
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - C Caubere
- INSERM I2MC, UMR 1048, Université Paul Sabatier, Toulouse, France
| | - P Rouet
- INSERM I2MC, UMR 1048, Université Paul Sabatier, Toulouse, France
| | - A-M Gomez
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - G Vandecasteele
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - R Fischmeister
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France.,UMS-IPSIT, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - C Brenner
- INSERM UMR-S 1180, Faculté de Pharmacie, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France.,UMS-IPSIT, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
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158
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Zhang X, Huang X, Fang C, Li Q, Cui J, Sun J, Li L. miR-124 Regulates the Expression of BACE1 in the Hippocampus Under Chronic Cerebral Hypoperfusion. Mol Neurobiol 2016; 54:2498-2506. [DOI: 10.1007/s12035-016-9845-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/09/2016] [Indexed: 12/21/2022]
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159
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Poudyal H. Mechanisms for the cardiovascular effects of glucagon-like peptide-1. Acta Physiol (Oxf) 2016; 216:277-313. [PMID: 26384481 DOI: 10.1111/apha.12604] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 07/25/2015] [Accepted: 09/10/2015] [Indexed: 12/16/2022]
Abstract
Over the past three decades, at least 10 hormones secreted by the enteroendocrine cells have been discovered, which directly affect the cardiovascular system through their innate receptors expressed in the heart and blood vessels or through a neural mechanism. Glucagon-like peptide-1 (GLP-1), an important incretin, is perhaps best studied of these gut-derived hormones with important cardiovascular effects. In this review, I have discussed the mechanism of GLP-1 release from the enteroendocrine L-cells and its physiological effects on the cardiovascular system. Current evidence suggests that GLP-1 has positive inotropic and chronotropic effects on the heart and may be important in preserving left ventricular structure and function by direct and indirect mechanisms. The direct effects of GLP-1 in the heart may be mediated through GLP-1R expressed in atria as well as arteries and arterioles in the left ventricle and mainly involve in the activation of multiple pro-survival kinases and enhanced energy utilization. There is also good evidence to support the involvement of a second, yet to be identified, GLP-1 receptor. Further, GLP-1(9-36)amide, which was previously thought to be the inactive metabolite of the active GLP-1(7-36)amide, may also have direct cardioprotective effects. GLP-1's action on GLP-1R expressed in the central nervous system, kidney, vasculature and the pancreas may indirectly contribute to its cardioprotective effects.
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Affiliation(s)
- H. Poudyal
- Department of Diabetes, Endocrinology and Nutrition; Graduate School of Medicine and Hakubi Centre for Advanced Research; Kyoto University; Kyoto Japan
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160
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Critical role for Epac1 in inflammatory pain controlled by GRK2-mediated phosphorylation of Epac1. Proc Natl Acad Sci U S A 2016; 113:3036-41. [PMID: 26929333 DOI: 10.1073/pnas.1516036113] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
cAMP signaling plays a key role in regulating pain sensitivity. Here, we uncover a previously unidentified molecular mechanism in which direct phosphorylation of the exchange protein directly activated by cAMP 1 (EPAC1) by G protein kinase 2 (GRK2) suppresses Epac1-to-Rap1 signaling, thereby inhibiting persistent inflammatory pain. Epac1(-/-) mice are protected against inflammatory hyperalgesia in the complete Freund's adjuvant (CFA) model. Moreover, the Epac-specific inhibitor ESI-09 inhibits established CFA-induced mechanical hyperalgesia without affecting normal mechanical sensitivity. At the mechanistic level, CFA increased activity of the Epac target Rap1 in dorsal root ganglia of WT, but not of Epac1(-/-), mice. Using sensory neuron-specific overexpression of GRK2 or its kinase-dead mutant in vivo, we demonstrate that GRK2 inhibits CFA-induced hyperalgesia in a kinase activity-dependent manner. In vitro, GRK2 inhibits Epac1-to-Rap1 signaling by phosphorylation of Epac1 at Ser-108 in the Disheveled/Egl-10/pleckstrin domain. This phosphorylation event inhibits agonist-induced translocation of Epac1 to the plasma membrane, thereby reducing Rap1 activation. Finally, we show that GRK2 inhibits Epac1-mediated sensitization of the mechanosensor Piezo2 and that Piezo2 contributes to inflammatory mechanical hyperalgesia. Collectively, these findings identify a key role of Epac1 in chronic inflammatory pain and a molecular mechanism for controlling Epac1 activity and chronic pain through phosphorylation of Epac1 at Ser-108. Importantly, using the Epac inhibitor ESI-09, we validate Epac1 as a potential therapeutic target for chronic pain.
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161
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Abstract
A multitude of physiological processes regulated by G protein-coupled receptors (GPCRs) signaling are accomplished by the participation of active rearrangements of the cytoskeleton. In general, it is common that a cross talk occurs among networks of microfilaments, microtubules, and intermediate filaments in order to reach specific cell responses. In particular, actin-cytoskeleton dynamics regulate processes such as cell shape, cell division, cell motility, and cell polarization, among others. This chapter describes the current knowledge about the regulation of actin-cytoskeleton dynamic by diverse GPCR signaling pathways, and also includes some protocols combining immunofluorescence and confocal microscopy for the visualization of the different rearrangements of the actin-cytoskeleton. We report how both the S1P-GPCR/G12/13/Rho/ROCK and glucagon-GPCR/Gs/cAMP axes induce differential actin-cytoskeleton rearrangements in epithelial cells. We also show that specific actin-binding molecules, like phalloidin and LifeAct, are very useful to analyze F-actin reorganization by confocal microscopy, and also that both molecules show similar results in fixed cells, whereas the anti-actin antibody is useful to detect both the G- and F-actin, as well as their compartmentalization. Thus, it is highly recommended to utilize different approaches to investigate the regulation of actin dynamics by GPCR signaling, with the aim to get a better picture of the phenomenon under study.
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162
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Lewis AE, Aesoy R, Bakke M. Role of EPAC in cAMP-Mediated Actions in Adrenocortical Cells. Front Endocrinol (Lausanne) 2016; 7:63. [PMID: 27379015 PMCID: PMC4904129 DOI: 10.3389/fendo.2016.00063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 05/30/2016] [Indexed: 12/31/2022] Open
Abstract
Adrenocorticotropic hormone regulates adrenal steroidogenesis mainly via the intracellular signaling molecule cAMP. The effects of cAMP are principally relayed by activating protein kinase A (PKA) and the more recently discovered exchange proteins directly activated by cAMP 1 and 2 (EPAC1 and EPAC2). While the intracellular roles of PKA have been extensively studied in steroidogenic tissues, those of EPACs are only emerging. EPAC1 and EPAC2 are encoded by the genes RAPGEF3 and RAPGEF4, respectively. Whereas EPAC1 is ubiquitously expressed, the expression of EPAC2 is more restricted, and typically found in endocrine tissues. Alternative promoter usage of RAPGEF4 gives rise to three different isoforms of EPAC2 that vary in their N-termini (EPAC2A, EPAC2B, and EPAC2C) and that exhibit distinct expression patterns. EPAC2A is expressed in the brain and pancreas, EPAC2B in steroidogenic cells of the adrenal gland and testis, and EPAC2C has until now only been found in the liver. In this review, we discuss current knowledge on EPAC expression and function with focus on the known roles of EPAC in adrenal gland physiology.
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Affiliation(s)
- Aurélia E. Lewis
- Department of Molecular Biology, University of Bergen, Bergen, Norway
- *Correspondence: Aurélia E. Lewis,
| | - Reidun Aesoy
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Marit Bakke
- Department of Biomedicine, University of Bergen, Bergen, Norway
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163
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New pharmacologic interventions to increase cardiac contractility: challenges and opportunities. Curr Opin Cardiol 2015; 30:285-91. [PMID: 25807221 DOI: 10.1097/hco.0000000000000165] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW The most extensively studied inotropic agents in patients with heart failure are phosphodiesterase (PDE) 3 inhibitors, which increase contractility by raising intracellular cyclic adenosine monophosphate content. In clinical trials, the inotropic benefits of these agents have been outweighed by an increase in sudden cardiac death. Here, I review recent findings that help explain what are likely to be distinct mechanisms involved in the beneficial and adverse effects of PDE3 inhibition. RECENT FINDINGS The proapoptotic consequences of PDE3 inhibition are becoming more apparent. Moreover, it has also become clear that individual PDE3 isoforms in cardiac myocytes are selectively regulated to interact with different proteins in different intracellular compartments. The beneficial and adverse effects of PDE3 inhibition may thus be attributable to the inhibition of different isoforms in different intracellular domains. In particular, PDE3A1 has been shown to interact directly with sarcoplasmic/endoplasmic reticulum Ca ATPase (SERCA2) in the sarcoplasmic reticulum through a phosphorylation of a site in its unique N-terminal domain, making it possible that this isoform can be selectively targeted to increase intracellular Ca cycling. SUMMARY Conventional PDE3 inhibitors target several functionally distinct isoforms of these enzymes. Isoform-selective and/or compartment-selective targeting of PDE3, through its protein-protein interactions, may produce the inotropic benefits of PDE3 inhibition without the adverse consequences.
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164
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Lucchesi O, Ruete MC, Bustos MA, Quevedo MF, Tomes CN. The signaling module cAMP/Epac/Rap1/PLCε/IP3 mobilizes acrosomal calcium during sperm exocytosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:544-61. [PMID: 26704387 DOI: 10.1016/j.bbamcr.2015.12.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 11/23/2015] [Accepted: 12/14/2015] [Indexed: 12/29/2022]
Abstract
Exocytosis of the sperm's single secretory granule, or acrosome, is a regulated exocytosis triggered by components of the egg's investments. In addition to external calcium, sperm exocytosis (termed the acrosome reaction) requires cAMP synthesized endogenously and calcium mobilized from the acrosome through IP3-sensitive channels. The relevant cAMP target is Epac. In the first part of this paper, we present a novel tool (the TAT-cAMP sponge) to investigate cAMP-related signaling pathways in response to progesterone as acrosome reaction trigger. The TAT-cAMP sponge consists of the cAMP-binding sites of protein kinase A regulatory subunit RIβ fused to the protein transduction domain TAT of the human immunodeficiency virus-1. The sponge permeated into sperm, sequestered endogenous cAMP, and blocked exocytosis. Progesterone increased the population of sperm with Rap1-GTP, Rab3-GTP, and Rab27-GTP in the acrosomal region; pretreatment with the TAT-cAMP sponge prevented the activation of all three GTPases. In the second part of this manuscript, we show that phospholipase Cε (PLCε) is required for the acrosome reaction downstream of Rap1 and upstream of intra-acrosomal calcium mobilization. Last, we present direct evidence that cAMP, Epac, Rap1, and PLCε are necessary for calcium mobilization from sperm's secretory granule. In summary, we describe here a pathway that connects cAMP to calcium mobilization from the acrosome during sperm exocytosis. Never before had direct evidence for each step of the cascade been put together in the same study.
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Affiliation(s)
- Ornella Lucchesi
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
| | - María C Ruete
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
| | - Matías A Bustos
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
| | - María F Quevedo
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
| | - Claudia N Tomes
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología, IHEM-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina.
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165
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Simon K, Hennen S, Merten N, Blättermann S, Gillard M, Kostenis E, Gomeza J. The Orphan G Protein-coupled Receptor GPR17 Negatively Regulates Oligodendrocyte Differentiation via Gαi/o and Its Downstream Effector Molecules. J Biol Chem 2015; 291:705-18. [PMID: 26620557 DOI: 10.1074/jbc.m115.683953] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Indexed: 01/08/2023] Open
Abstract
Recent studies have recognized G protein-coupled receptors as important regulators of oligodendrocyte development. GPR17, in particular, is an orphan G protein-coupled receptor that has been identified as oligodendroglial maturation inhibitor because its stimulation arrests primary mouse oligodendrocytes at a less differentiated stage. However, the intracellular signaling effectors transducing its activation remain poorly understood. Here, we use Oli-neu cells, an immortalized cell line derived from primary murine oligodendrocytes, and primary rat oligodendrocyte cultures as model systems to identify molecular targets that link cell surface GPR17 to oligodendrocyte maturation blockade. We demonstrate that stimulation of GPR17 by the small molecule agonist MDL29,951 (2-carboxy-4,6-dichloro-1H-indole-3-propionic acid) decreases myelin basic protein expression levels mainly by triggering the Gαi/o signaling pathway, which in turn leads to reduced activity of the downstream cascade adenylyl cyclase-cAMP-PKA-cAMP response element-binding protein (CREB). In addition, we show that GPR17 activation also diminishes myelin basic protein abundance by lessening stimulation of the exchange protein directly activated by cAMP (EPAC), thus uncovering a previously unrecognized role for EPAC to regulate oligodendrocyte differentiation. Together, our data establish PKA and EPAC as key downstream effectors of GPR17 that inhibit oligodendrocyte maturation. We envisage that treatments augmenting PKA and/or EPAC activity represent a beneficial approach for therapeutic enhancement of remyelination in those demyelinating diseases where GPR17 is highly expressed, such as multiple sclerosis.
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Affiliation(s)
- Katharina Simon
- From the Institute of Pharmaceutical Biology, Section Molecular, Cellular, and Pharmacobiology, University of Bonn, 53115 Bonn, Germany and
| | - Stephanie Hennen
- From the Institute of Pharmaceutical Biology, Section Molecular, Cellular, and Pharmacobiology, University of Bonn, 53115 Bonn, Germany and
| | - Nicole Merten
- From the Institute of Pharmaceutical Biology, Section Molecular, Cellular, and Pharmacobiology, University of Bonn, 53115 Bonn, Germany and
| | - Stefanie Blättermann
- From the Institute of Pharmaceutical Biology, Section Molecular, Cellular, and Pharmacobiology, University of Bonn, 53115 Bonn, Germany and
| | | | - Evi Kostenis
- From the Institute of Pharmaceutical Biology, Section Molecular, Cellular, and Pharmacobiology, University of Bonn, 53115 Bonn, Germany and
| | - Jesus Gomeza
- From the Institute of Pharmaceutical Biology, Section Molecular, Cellular, and Pharmacobiology, University of Bonn, 53115 Bonn, Germany and
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166
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Wang SY, Freeman MR, Sathish V, Thompson MA, Pabelick CM, Prakash YS. Sex Steroids Influence Brain-Derived Neurotropic Factor Secretion From Human Airway Smooth Muscle Cells. J Cell Physiol 2015; 231:1586-92. [PMID: 26566264 DOI: 10.1002/jcp.25254] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 12/15/2022]
Abstract
Brain derived neurotropic factor (BDNF) is emerging as an important player in airway inflammation, remodeling, and hyperreactivity. Separately, there is increasing evidence that sex hormones contribute to pathophysiology in the lung. BDNF and sex steroid signaling are thought to be intricately linked in the brain. There is currently little information on BDNF and sex steroid interactions in the airway but is relevant to understanding growth factor signaling in the context of asthma in men versus women. In this study, we assessed the effect of sex steroids on BDNF expression and secretion in human airway smooth muscle (ASM). Human ASM was treated with estrogen (E2 ) or testosterone (T, 10 nM each) and intracellular BDNF and secreted BDNF measured. E2 and T significantly reduced secretion of BDNF; effects prevented by estrogen and androgen receptor inhibitor, ICI 182,780 (1 μM), and flutamide (10 μM), respectively. Interestingly, no significant changes were observed in intracellular BDNF mRNA or protein expression. High affinity BDNF receptor, TrkB, was not altered by E2 or T. E2 (but not T) significantly increased intracellular cyclic AMP levels. Notably, Epac1 and Epac2 expression were significantly reduced by E2 and T. Furthermore, SNARE complex protein SNAP25 was decreased. Overall, these novel data suggest that physiologically relevant concentrations of E2 or T inhibit BDNF secretion in human ASM, suggesting a potential interaction of sex steroids with BDNF in the airway that is different from brain. The relevance of sex steroid-BDNF interactions may lie in their overall contribution to airway diseases such as asthma.
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Affiliation(s)
- Sheng-Yu Wang
- Department of Respiratory Medicine, First Affiliated Hospital of Xi'an Medical University, Xi'an, Shaanxi, PR China.,Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota
| | | | - Venkatachalem Sathish
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | | | - Christina M Pabelick
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Y S Prakash
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
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167
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Yang Y, Yang F, Wu X, Lv X, Li J. EPAC activation inhibits acetaldehyde-induced activation and proliferation of hepatic stellate cell via Rap1. Can J Physiol Pharmacol 2015; 94:498-507. [PMID: 26854595 DOI: 10.1139/cjpp-2015-0437] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hepatic stellate cells (HSCs) activation represents an essential event during alcoholic liver fibrosis (ALF). Previous studies have demonstrated that the rat HSCs could be significantly activated after exposure to 200 μmol/L acetaldehyde for 48 h, and the cAMP/PKA signaling pathways were also dramatically upregulated in activated HSCs isolated from alcoholic fibrotic rat liver. Exchange protein activated by cAMP (EPAC) is a family of guanine nucleotide exchange factors (GEFs) for the small Ras-like GTPases Rap, and is being considered as a vital mediator of cAMP signaling in parallel with the principal cAMP target protein kinase A (PKA). Our data showed that both cAMP/PKA and cAMP/EPAC signaling pathways were involved in acetaldehyde-induced HSCs. Acetaldehyde could reduce the expression of EPAC1 while enhancing the expression of EPAC2. The cAMP analog Me-cAMP, which stimulates the EPAC/Rap1 pathway, could significantly decrease the proliferation and collagen synthesis of acetaldehyde-induced HSCs. Furthermore, depletion of EPAC2, but not EPAC1, prevented the activation of HSC measured as the production of α-SMA and collagen type I and III, indicating that EPAC1 appears to have protective effects on acetaldehyde-induced HSCs. Curiously, activation of PKA or EPAC perhaps has opposite effects on the synthesis of collagen and α-SMA: EPAC activation by Me-cAMP increased the levels of GTP-bound (activated) Rap1 while PKA activation by Phe-cAMP had no significant effects on such binding. These results suggested that EPAC activation could inhibit the activation and proliferation of acetaldehyde-induced HSCs via Rap1.
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Affiliation(s)
- Yan Yang
- a School of Pharmacy, Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China.,b Institute for Liver Disease of Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China
| | - Feng Yang
- a School of Pharmacy, Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China.,b Institute for Liver Disease of Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China
| | - Xiaojuan Wu
- a School of Pharmacy, Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China.,b Institute for Liver Disease of Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China
| | - Xiongwen Lv
- a School of Pharmacy, Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China.,b Institute for Liver Disease of Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China
| | - Jun Li
- a School of Pharmacy, Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China.,b Institute for Liver Disease of Anhui Medical University, Meishan Road, Hefei, Anhui Province 230032, China
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168
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Shariati B, Thompson EL, Nicol GD, Vasko MR. Epac activation sensitizes rat sensory neurons through activation of Ras. Mol Cell Neurosci 2015; 70:54-67. [PMID: 26596174 DOI: 10.1016/j.mcn.2015.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/04/2015] [Accepted: 11/16/2015] [Indexed: 10/24/2022] Open
Abstract
Guanine nucleotide exchange factors directly activated by cAMP (Epacs) have emerged as important signaling molecules mediating persistent hypersensitivity in animal models of inflammation, by augmenting the excitability of sensory neurons. Although Epacs activate numerous downstream signaling cascades, the intracellular signaling which mediates Epac-induced sensitization of capsaicin-sensitive sensory neurons remains unknown. Here, we demonstrate that selective activation of Epacs with 8-CPT-2'-O-Me-cAMP-AM (8CPT-AM) increases the number of action potentials (APs) generated by a ramp of depolarizing current and augments the evoked release of calcitonin gene-related peptide (CGRP) from isolated rat sensory neurons. Internal perfusion of capsaicin-sensitive sensory neurons with GDP-βS, substituted for GTP, blocks the ability of 8CPT-AM to increase AP firing, demonstrating that Epac-induced sensitization is G-protein dependent. Treatment with 8CPT-AM activates the small G-proteins Rap1 and Ras in cultures of sensory neurons. Inhibition of Rap1, by internal perfusion of a Rap1-neutralizing antibody or through a reduction in the expression of the protein using shRNA does not alter the Epac-induced enhancement of AP generation or CGRP release, despite the fact that in most other cell types, Epacs act as Rap-GEFs. In contrast, inhibition of Ras through expression of a dominant negative Ras (DN-Ras) or through internal perfusion of a Ras-neutralizing antibody blocks the increase in AP firing and attenuates the increase in the evoked release of CGRP induced by Epac activation. Thus, in this subpopulation of nociceptive sensory neurons, it is the novel interplay between Epacs and Ras, rather than the canonical Epacs and Rap1 pathway, that is critical for mediating Epac-induced sensitization.
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Affiliation(s)
- Behzad Shariati
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Eric L Thompson
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Grant D Nicol
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Michael R Vasko
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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169
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Thompson MA, Britt RD, Kuipers I, Stewart A, Thu J, Pandya HC, MacFarlane P, Pabelick CM, Martin RJ, Prakash YS. cAMP-mediated secretion of brain-derived neurotrophic factor in developing airway smooth muscle. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1853:2506-14. [PMID: 26112987 PMCID: PMC4558218 DOI: 10.1016/j.bbamcr.2015.06.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/28/2015] [Accepted: 06/20/2015] [Indexed: 01/12/2023]
Abstract
Moderate hyperoxic exposure in preterm infants contributes to subsequent airway dysfunction and to risk of developing recurrent wheeze and asthma. The regulatory mechanisms that can contribute to hyperoxia-induced airway dysfunction are still under investigation. Recent studies in mice show that hyperoxia increases brain-derived neurotrophic factor (BDNF), a growth factor that increases airway smooth muscle (ASM) proliferation and contractility. We assessed the mechanisms underlying effects of moderate hyperoxia (50% O2) on BDNF expression and secretion in developing human ASM. Hyperoxia increased BDNF secretion, but did not alter endogenous BDNF mRNA or intracellular protein levels. Exposure to hyperoxia significantly increased [Ca2+]i responses to histamine, an effect blunted by the BDNF chelator TrkB-Fc. Hyperoxia also increased ASM cAMP levels, associated with reduced PDE4 activity, but did not alter protein kinase A (PKA) activity or adenylyl cyclase mRNA levels. However, 50% O2 increased expression of Epac2, which is activated by cAMP and can regulate protein secretion. Silencing RNA studies indicated that Epac2, but not Epac1, is important for hyperoxia-induced BDNF secretion, while PKA inhibition did not influence BDNF secretion. In turn, BDNF had autocrine effects of enhancing ASM cAMP levels, an effect inhibited by TrkB and BDNF siRNAs. Together, these novel studies suggest that hyperoxia can modulate BDNF secretion, via cAMP-mediated Epac2 activation in ASM, resulting in a positive feedback effect of BDNF-mediated elevation in cAMP levels. The potential functional role of this pathway is to sustain BDNF secretion following hyperoxic stimulus, leading to enhanced ASM contractility and proliferation.
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Affiliation(s)
| | - Rodney D Britt
- Department of Anesthesiology Mayo Clinic, Rochester, MN, USA
| | - Ine Kuipers
- Department of Anesthesiology Mayo Clinic, Rochester, MN, USA
| | - Alecia Stewart
- Department of Anesthesiology Mayo Clinic, Rochester, MN, USA
| | - James Thu
- Department of Anesthesiology Mayo Clinic, Rochester, MN, USA
| | - Hitesh C Pandya
- Department Pediatrics, University of Leicester, Leicester, UK
| | - Peter MacFarlane
- Department of Pediatrics, Division of Neonatology, Rainbow Babies Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Christina M Pabelick
- Department of Anesthesiology Mayo Clinic, Rochester, MN, USA; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Richard J Martin
- Department of Pediatrics, Division of Neonatology, Rainbow Babies Children's Hospital, Case Western Reserve University, Cleveland, OH, USA
| | - Y S Prakash
- Department of Anesthesiology Mayo Clinic, Rochester, MN, USA; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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170
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Sugawara K, Shibasaki T, Takahashi H, Seino S. Structure and functional roles of Epac2 (Rapgef4). Gene 2015; 575:577-83. [PMID: 26390815 DOI: 10.1016/j.gene.2015.09.029] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/13/2015] [Accepted: 09/15/2015] [Indexed: 10/24/2022]
Abstract
Epac (exchange protein activated by cyclic-AMP) 2 is a direct target of 3'-5'-cyclic adenosine monophosphate (cAMP) and is involved in cAMP-mediated signal transduction through activation of the Ras-like small GTPase Rap. Crystallographic analyses revealed that activation of Epac2 by cAMP is accompanied by dynamic structural changes. Epac2 is expressed mainly in brain, neuroendocrine and endocrine tissues, and is involved in diverse cellular functions in the tissues. In this review, we summarize the structure and function of Epac2. We also discuss the physiological and pathophysiological roles of Epac2, and the possibility of Epac2 as a therapeutic target.
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Affiliation(s)
- Kenji Sugawara
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tadao Shibasaki
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
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171
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Abstract
Cell division relies on coordinated regulation of the cell cycle. A process including a well-defined series of strictly regulated molecular mechanisms involving cyclin-dependent kinases, retinoblastoma protein, and polo-like kinases. Dysfunctions in cell cycle regulation are associated with disease such as cancer, diabetes, and neurodegeneration. Compartmentalization of cellular signaling is a common strategy used to ensure the accuracy and efficiency of cellular responses. Compartmentalization of intracellular signaling is maintained by scaffolding proteins, such as A-kinase anchoring proteins (AKAPs). AKAPs are characterized by their ability to anchor the regulatory subunits of protein kinase A (PKA), and thereby achieve guidance to different cellular locations via various targeting domains. Next to PKA, AKAPs also associate with several other signaling elements including receptors, ion channels, protein kinases, phosphatases, small GTPases, and phosphodiesterases. Taking the amount of possible AKAP signaling complexes and their diverse localization into account, it is rational to believe that such AKAP-based complexes regulate several critical cellular events of the cell cycle. In fact, several AKAPs are assigned as tumor suppressors due to their vital roles in cell cycle regulation. Here, we first briefly discuss the most important players of cell cycle progression. After that, we will review our recent knowledge of AKAPs linked to the regulation and progression of the cell cycle, with special focus on AKAP12, AKAP8, and Ezrin. At last, we will discuss this specific AKAP subset in relation to diseases with focus on a diverse subset of cancer.
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Affiliation(s)
- B Han
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands. .,Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands.
| | - W J Poppinga
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands.,Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
| | - M Schmidt
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands.,Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
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172
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Ye N, Zhu Y, Chen H, Liu Z, Mei FC, Wild C, Chen H, Cheng X, Zhou J. Structure-Activity Relationship Studies of Substituted 2-(Isoxazol-3-yl)-2-oxo-N'-phenyl-acetohydrazonoyl Cyanide Analogues: Identification of Potent Exchange Proteins Directly Activated by cAMP (EPAC) Antagonists. J Med Chem 2015; 58:6033-47. [PMID: 26151319 DOI: 10.1021/acs.jmedchem.5b00635] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Exchange proteins directly activated by cAMP (EPAC) as guanine nucleotide exchange factors mediate the effects of the pivotal second messenger cAMP, thereby regulating a wide variety of intracellular physiological and pathophysiological processes. A series of novel 2-(isoxazol-3-yl)-2-oxo-N'-phenyl-acetohydrazonoyl cyanide EPAC antagonists was synthesized and evaluated in an effort to optimize properties of the previously identified high-throughput (HTS) hit 1 (ESI-09). Structure-activity relationship (SAR) analysis led to the discovery of several more active EPAC antagonists (e.g., 22 (HJC0726), 35 (NY0123), and 47 (NY0173)) with low micromolar inhibitory activity. These inhibitors may serve as valuable pharmacological probes to facilitate our efforts in elucidating the biological functions of EPAC and developing potential novel therapeutics against human diseases. Our SAR results have also revealed that further modification at the 3-, 4-, and 5-positions of the phenyl ring as well as the 5-position of the isoxazole moiety may allow for the development of more potent EPAC antagonists.
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Affiliation(s)
- Na Ye
- †Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Yingmin Zhu
- ‡Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, Texas 77030, United States
| | - Haijun Chen
- †Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Zhiqing Liu
- †Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Fang C Mei
- ‡Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, Texas 77030, United States
| | - Christopher Wild
- †Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Haiying Chen
- †Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Xiaodong Cheng
- ‡Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, Texas 77030, United States
| | - Jia Zhou
- †Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, Texas 77555, United States
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173
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Raymer B, Ebner D. Small molecule and peptide therapies for chronic heart failure: a patent review (2011 - 2014). Expert Opin Ther Pat 2015; 25:1175-90. [PMID: 26173447 DOI: 10.1517/13543776.2015.1061997] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Chronic heart failure (CHF) is the long-term inability of the heart to meet circulatory demands under normal conditions. Effects of CHF can include increased blood volume, increased vascular resistance and compromised contractility leading to fluid retention, dyspnea and fatigue. Current standard of care for chronic systolic heart failure is directed towards managing hypoperfusion through the renin-angiotensin-aldosterone and sympathetic nervous systems. Treatment may also involve reversal of maladaptive cardiac remodeling and prevention of life-threatening arrhythmias. AREAS COVERED This review highlights small molecule and peptidic agents for the treatment of CHF with patents published between 2011 and 2014. Targets are subdivided into inotropic agents, ventricular remodeling, diuretics and the renin-angiotensin-aldosterone system. EXPERT OPINION CHF represents a large, unmet medical need where improved therapies are needed. The renin-angiotensin-aldosterone system pathway continues to be a major source of new therapies for CHF with new inotropic therapies emerging. Promising initial clinical results for a few approaches combined with the expectation of additional clinical results in the near future make this an exciting time in the pursuit of new treatments for CHF.
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Affiliation(s)
- Brian Raymer
- a Cardiovascular, Metabolic, and Endocrine Diseases Chemistry, Pfizer Worldwide Research and Development , Cambridge, MA, USA +1 617 551 3414 ; +1 617 551 3082 ;
| | - David Ebner
- a Cardiovascular, Metabolic, and Endocrine Diseases Chemistry, Pfizer Worldwide Research and Development , Cambridge, MA, USA +1 617 551 3414 ; +1 617 551 3082 ;
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174
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Banerjee U, Cheng X. Exchange protein directly activated by cAMP encoded by the mammalian rapgef3 gene: Structure, function and therapeutics. Gene 2015; 570:157-67. [PMID: 26119090 PMCID: PMC4556420 DOI: 10.1016/j.gene.2015.06.063] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 06/23/2015] [Indexed: 01/08/2023]
Abstract
Mammalian exchange protein directly activated by cAMP isoform 1 (EPAC1), encoded by the RAPGEF3 gene, is one of the two-membered family of cAMP sensors that mediate the intracellular functions of cAMP by acting as guanine nucleotide exchange factors for the Ras-like Rap small GTPases. Extensive studies have revealed that EPAC1-mediated cAMP signaling is highly coordinated spatiotemporally through the formation of dynamic signalosomes by interacting with a diverse array of cellular partners. Recent functional analyses of genetically engineered mouse models further suggest that EPAC1 functions as an important stress response switch and is involved in pathophysiological conditions of cardiac stresses, chronic pain, cancer and infectious diseases. These findings, coupled with the development of EPAC specific small molecule modulators, validate EPAC1 as a promising target for therapeutic interventions. Human gene RAPGEF3 encodes for EPAC1 protein. Along with PKA, CNG & HCN, EPAC is an important cAMP sensor. Selective modulators of EPAC1 have been developed for use as pharmacological probes. Formation of EPAC1 signalosomes allows spatiotemporal control of cAMP signaling. EPAC1 is implicated in major pathophysiological conditions and is an attractive therapeutic target.
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Affiliation(s)
- Upasana Banerjee
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, University of Health Science Center, Houston, TX 77030, United States
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, University of Health Science Center, Houston, TX 77030, United States.
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175
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Abstract
Epacs (exchange proteins directly activated by cAMP) act as guanine-nucleotide-exchange factors for the Ras-like small G-proteins Rap1 and Rap2, and are now recognized as incontrovertible factors leading to complex and diversified cAMP signalling pathways. Given the critical role of cAMP in the regulation of cardiac function, several studies have investigated the functional role of Epacs in the heart, providing evidence that Epacs modulate intracellular Ca2+ and are involved in several cardiac pathologies such as cardiac hypertrophy and arrhythmia. The present review summarizes recent data on the Epac signalling pathway and its role in cardiac pathophysiology. We also discuss recent advances in the discovery of novel pharmacological modulators of Epacs that were identified by high-throughput screening and their therapeutic potential for the treatment of cardiac disorders.
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176
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GPCR signaling and cardiac function. Eur J Pharmacol 2015; 763:143-8. [PMID: 25981298 DOI: 10.1016/j.ejphar.2015.05.019] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 03/30/2015] [Accepted: 05/11/2015] [Indexed: 12/27/2022]
Abstract
G protein-coupled receptors (GPCRs), such as β-adrenergic and angiotensin II receptors, located in the membranes of all three major cardiac cell types, i.e. myocytes, fibroblasts and endothelial cells, play crucial roles in regulating cardiac function and morphology. Their importance in cardiac physiology and disease is reflected by the fact that, collectively, they represent the direct targets of over a third of the currently approved cardiovascular drugs used in clinical practice. Over the past few decades, advances in elucidation of their structure, function and the signaling pathways they elicit, specifically in the heart, have led to identification of an increasing number of new molecular targets for heart disease therapy. Here, we review these signaling modalities employed by GPCRs known to be expressed in the cardiac myocyte membranes and to directly modulate cardiac contractility. We also highlight drugs and drug classes that directly target these GPCRs to modulate cardiac function, as well as molecules involved in cardiac GPCR signaling that have the potential of becoming novel drug targets for modulation of cardiac function in the future.
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177
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Petersen TS, Kristensen SG, Jeppesen JV, Grøndahl ML, Wissing ML, Macklon KT, Andersen CY. Distribution and function of 3',5'-Cyclic-AMP phosphodiesterases in the human ovary. Mol Cell Endocrinol 2015; 403:10-20. [PMID: 25578602 DOI: 10.1016/j.mce.2015.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 01/03/2015] [Accepted: 01/05/2015] [Indexed: 12/29/2022]
Abstract
The concentration of the important second messenger cAMP is regulated by phosphodiesterases (PDEs) and hence an attractive drug target. However, limited human data are available about the PDEs in the ovary. The aim of the present study was to describe and characterise the PDEs in the human ovary. Results were obtained by analysis of mRNA microarray data from follicles and granulosa cells (GCs), combined RT-PCR and enzymatic activity analysis in GCs, immunohistochemical analysis of ovarian sections and by studying the effect of PDE inhibitors on progesterone production from cultured GCs. We found that PDE3, PDE4, PDE7 and PDE8 are the major families present while PDE11A was not detected. PDE8B was differentially expressed during folliculogenesis. In cultured GCs, inhibition of PDE7 and PDE8 increased basal progesterone secretion while PDE4 inhibition increased forskolin-stimulated progesterone secretion. In conclusion, we identified PDE3, PDE4, PDE7 and PDE8 as the major PDEs in the human ovary.
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Affiliation(s)
- T S Petersen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark; Medical Department, LEO Pharma, Ballerup 2750, Denmark.
| | - S G Kristensen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
| | - J V Jeppesen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
| | - M L Grøndahl
- The Fertility Clinic, Herlev Hospital, Copenhagen University Hospital, Copenhagen University, Herlev 2730, Denmark
| | - M L Wissing
- The Fertility Clinic, Holbæk Sygehus, Holbæk 4300, Denmark
| | - K T Macklon
- The Fertility Clinic, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
| | - C Y Andersen
- Laboratory of Reproductive Biology, The Juliane Marie Centre for Women, Children, and Reproduction - Copenhagen University Hospital, Copenhagen University, Copenhagen 2100, Denmark
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178
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Poppinga WJ, Heijink IH, Holtzer LJ, Skroblin P, Klussmann E, Halayko AJ, Timens W, Maarsingh H, Schmidt M. A-kinase-anchoring proteins coordinate inflammatory responses to cigarette smoke in airway smooth muscle. Am J Physiol Lung Cell Mol Physiol 2015; 308:L766-75. [PMID: 25637608 DOI: 10.1152/ajplung.00301.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 01/29/2015] [Indexed: 01/13/2023] Open
Abstract
β2-Agonist inhibitors can relieve chronic obstructive pulmonary disease (COPD) symptoms by stimulating cyclic AMP (cAMP) signaling. A-kinase-anchoring proteins (AKAPs) compartmentalize cAMP signaling by establishing protein complexes. We previously reported that the β2-agonist fenoterol, direct activation of protein kinase A (PKA), and exchange factor directly activated by cAMP decrease cigarette smoke extract (CSE)-induced release of neutrophil attractant interleukin-8 (IL-8) from human airway smooth muscle (ASM) cells. In the present study, we tested the role of AKAPs in CSE-induced IL-8 release from ASM cells and assessed the effect of CSE on the expression levels of different AKAPs. We also studied mRNA and protein expression of AKAPs in lung tissue from patients with COPD. Our data show that CSE exposure of ASM cells decreases AKAP5 and AKAP12, both capable of interacting with β2-adrenoceptors. In lung tissue of patients with COPD, mRNA levels of AKAP5 and AKAP12 were decreased compared with lung tissue from controls. Using immunohistochemistry, we detected less AKAP5 protein in ASM of patients with COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II compared with control subjects. St-Ht31, which disrupts AKAP-PKA interactions, augmented CSE-induced IL-8 release from ASM cells and diminished its suppression by fenoterol, an effect mediated by disturbed ERK signaling. The modulatory role of AKAP-PKA interactions in the anti-inflammatory effects of fenoterol in ASM cells and the decrease in expression of AKAP5 and AKAP12 in response to cigarette smoke and in lungs of patients with COPD suggest that cigarette smoke-induced changes in AKAP5 and AKAP12 in patients with COPD may affect efficacy of pharmacotherapy.
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Affiliation(s)
- Wilfred J Poppinga
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands; Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany;
| | - Irene H Heijink
- University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, The Netherlands
| | - Laura J Holtzer
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | | | - Enno Klussmann
- Max-Delbrück-Centrum für Molekulare Medizin, Berlin, Germany
| | - Andrew J Halayko
- University of Manitoba, Departments of Physiology and Pathophysiology, and Internal Medicine, Winnipeg, Manitoba, Canada
| | - Wim Timens
- University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Pathology and Medical Biology, Groningen, The Netherlands
| | - Harm Maarsingh
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands; Palm Beach Atlantic University, Lloyd L. Gregory School of Pharmacy, Department of Pharmaceutical Sciences, West Palm Beach, Florida
| | - Martina Schmidt
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
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179
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Michel MC, Seifert R. Selectivity of pharmacological tools: implications for use in cell physiology. A review in the theme: Cell signaling: proteins, pathways and mechanisms. Am J Physiol Cell Physiol 2015; 308:C505-20. [PMID: 25631871 DOI: 10.1152/ajpcell.00389.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/24/2015] [Indexed: 01/08/2023]
Abstract
Pharmacological inhibitors are frequently used to identify the receptors, receptor subtypes, and associated signaling pathways involved in physiological cell responses. Based on the effects of such inhibitors conclusions are drawn about the involvement of their assumed target or lack thereof. While such inhibitors can be useful tools for a better physiological understanding, their uncritical use can lead to incorrect conclusions. This article reviews the concept of inhibitor selectivity and its implication for cell physiology. Specifically, we discuss the implications of using inhibitor vs. activator approaches, issues of direct vs. indirect pathway modulation, implications of inverse agonism and biased signaling, and those of orthosteric vs. allosteric, competitive vs. noncompetitive, and reversible vs. irreversible inhibition. Additional problems can result from inconsistent estimates of inhibitor potency and differences in potency between cell-free systems and intact cells. These concepts are illustrated by several examples of inhibitors displaying affinity for related but distinct targets or even unrelated targets. Of note, many of the issues being addressed are also applicable to genetic inhibition strategies. The main practical conclusion following from these concepts is that investigators should be critical in the choice of inhibitor, its concentrations, and its mode of application. When this advice is adhered to, small-molecule pharmacological inhibitors can be important experimental tools in the hand of physiologists.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany; and
| | - Roland Seifert
- Department of Pharmacology, Hannover Medical School, Hannover, Germany
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180
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Mohan S, Narumiya S, Doré S. Neuroprotective role of prostaglandin PGE2 EP2 receptor in hemin-mediated toxicity. Neurotoxicology 2015; 46:53-9. [PMID: 25451967 PMCID: PMC4681391 DOI: 10.1016/j.neuro.2014.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 10/18/2014] [Accepted: 10/23/2014] [Indexed: 01/01/2023]
Abstract
Heme (Fe(2+) protoporphyrin IX) and hemin (Fe(3+)), the prosthetic group of hemoprotein, are cytotoxic due to their ability to contribute to the production of reactive oxygen species, increased intracellular calcium levels, and stimulate glutamate-mediated excitotoxicity. Previous work by our group showed that blockade of the prostaglandin E2 (PGE2)-EP1 receptor reduced hemin-induced cytotoxicity in primary cortical neuronal cultures. However, the role of the prostaglandin E2 (PGE2)-EP2 receptor in hemin neurotoxicity remains unclear. Activation of the EP2 receptor in neurons results in increased cyclic AMP (cAMP) and protein kinase A signaling; therefore, we hypothesized that the activation of the EP2 receptor decreases hemin neurotoxicity. Using postnatal primary cortical neurons cultured from wildtype-control (WT) and EP2(-/-) mice, we investigated the role of the EP2 receptor in hemin neurotoxicity by monitoring cell survival with the Calcein-AM live-cell and lactate dehydrogenase assays. MitoTracker staining was also performed to determine how mitochondria were affected by hemin. Hemin neurotoxicity in EP2(-/-) neurons was 37.2 ± 17.0% greater compared to WT neurons. Of interest, cotreatment with the EP2 receptor agonist, butaprost (1 and 10 μM), significantly attenuated hemin neurotoxicity by 55.7 ± 21.1% and 60.1 ± 14.8%, respectively. To further investigate signaling mechanisms related to EP2 receptor mediating cytoprotection, neurons were cotreated with hemin and activators/inhibitors of both the cAMP-protein kinase A/exchange protein directly activated by cAMP (Epac) pathways. Forskolin, a cAMP activator, and 8-pCPT-cAMP, an Epac activator, both attenuated hemin neurotoxicity by 78.8 ± 22.2% and 58.4 ± 9.8%, respectively, as measured using the lactate dehydrogenase assay. Together, the results reveal that activation of the EP2 receptor is protective against hemin neurotoxicity in vitro and these findings suggest that neuroprotection occurs through the cAMP-Epac pathway in neuronal cultures. Therefore, activation of the EP2 receptor could be used to minimize neuronal damage following exposure to supraphysiological levels of hemin.
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MESH Headings
- Adjuvants, Immunologic/pharmacology
- Alprostadil/analogs & derivatives
- Alprostadil/pharmacology
- Analysis of Variance
- Animals
- Animals, Newborn
- Cell Survival/drug effects
- Cerebral Cortex/cytology
- Colforsin/pharmacology
- Cyclic AMP/analogs & derivatives
- Cyclic AMP/pharmacology
- Dose-Response Relationship, Drug
- Excitatory Amino Acid Agonists/pharmacology
- Glutamic Acid/pharmacology
- Hemin/toxicity
- L-Lactate Dehydrogenase/metabolism
- Mice
- Mice, Knockout
- Neurons/drug effects
- Neuroprotective Agents/pharmacology
- Receptors, Prostaglandin E, EP2 Subtype/agonists
- Receptors, Prostaglandin E, EP2 Subtype/genetics
- Receptors, Prostaglandin E, EP2 Subtype/metabolism
- Thionucleotides/pharmacology
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Affiliation(s)
- Shekher Mohan
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA
| | - Shuh Narumiya
- Department of Pharmacology, Kyoto University, Kyoto, Japan
| | - Sylvain Doré
- Department of Anesthesiology, University of Florida, Gainesville, FL, USA; Departments of Neurology, Psychiatry, and Neuroscience, University of Florida, Gainesville, FL, USA.
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181
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Gellersen B, Brosens JJ. Cyclic decidualization of the human endometrium in reproductive health and failure. Endocr Rev 2014; 35:851-905. [PMID: 25141152 DOI: 10.1210/er.2014-1045] [Citation(s) in RCA: 622] [Impact Index Per Article: 62.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Decidualization denotes the transformation of endometrial stromal fibroblasts into specialized secretory decidual cells that provide a nutritive and immunoprivileged matrix essential for embryo implantation and placental development. In contrast to most mammals, decidualization of the human endometrium does not require embryo implantation. Instead, this process is driven by the postovulatory rise in progesterone levels and increasing local cAMP production. In response to falling progesterone levels, spontaneous decidualization causes menstrual shedding and cyclic regeneration of the endometrium. A growing body of evidence indicates that the shift from embryonic to maternal control of the decidual process represents a pivotal evolutionary adaptation to the challenge posed by invasive and chromosomally diverse human embryos. This concept is predicated on the ability of decidualizing stromal cells to respond to individual embryos in a manner that either promotes implantation and further development or facilitates early rejection. Furthermore, menstruation and cyclic regeneration involves stem cell recruitment and renders the endometrium intrinsically capable of adapting its decidual response to maximize reproductive success. Here we review the endocrine, paracrine, and autocrine cues that tightly govern this differentiation process. In response to activation of various signaling pathways and genome-wide chromatin remodeling, evolutionarily conserved transcriptional factors gain access to the decidua-specific regulatory circuitry. Once initiated, the decidual process is poised to transit through distinct phenotypic phases that underpin endometrial receptivity, embryo selection, and, ultimately, resolution of pregnancy. We discuss how disorders that subvert the programming, initiation, or progression of decidualization compromise reproductive health and predispose for pregnancy failure.
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Affiliation(s)
- Birgit Gellersen
- Endokrinologikum Hamburg (B.G.), 20251 Hamburg, Germany; and Division of Reproductive Health (J.J.B.), Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom
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182
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Poppinga WJ, Muñoz-Llancao P, González-Billault C, Schmidt M. A-kinase anchoring proteins: cAMP compartmentalization in neurodegenerative and obstructive pulmonary diseases. Br J Pharmacol 2014; 171:5603-23. [PMID: 25132049 PMCID: PMC4290705 DOI: 10.1111/bph.12882] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/14/2014] [Accepted: 08/10/2014] [Indexed: 12/25/2022] Open
Abstract
The universal second messenger cAMP is generated upon stimulation of Gs protein-coupled receptors, such as the β2 -adreneoceptor, and leads to the activation of PKA, the major cAMP effector protein. PKA oscillates between an on and off state and thereby regulates a plethora of distinct biological responses. The broad activation pattern of PKA and its contribution to several distinct cellular functions lead to the introduction of the concept of compartmentalization of cAMP. A-kinase anchoring proteins (AKAPs) are of central importance due to their unique ability to directly and/or indirectly interact with proteins that either determine the cellular content of cAMP, such as β2 -adrenoceptors, ACs and PDEs, or are regulated by cAMP such as the exchange protein directly activated by cAMP. We report on lessons learned from neurons indicating that maintenance of cAMP compartmentalization by AKAP5 is linked to neurotransmission, learning and memory. Disturbance of cAMP compartments seem to be linked to neurodegenerative disease including Alzheimer's disease. We translate this knowledge to compartmentalized cAMP signalling in the lung. Next to AKAP5, we focus here on AKAP12 and Ezrin (AKAP78). These topics will be highlighted in the context of the development of novel pharmacological interventions to tackle AKAP-dependent compartmentalization.
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Affiliation(s)
- W J Poppinga
- Department of Molecular Pharmacology, University of GroningenGroningen, The Netherlands
- Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of GroningenGroningen, The Netherlands
| | - P Muñoz-Llancao
- Department of Molecular Pharmacology, University of GroningenGroningen, The Netherlands
- Laboratory of Cell and Neuronal Dynamics (Cenedyn), Department of Biology, Faculty of Sciences, Universidad de ChileSantiago, Chile
- Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of GroningenGroningen, The Netherlands
| | - C González-Billault
- Laboratory of Cell and Neuronal Dynamics (Cenedyn), Department of Biology, Faculty of Sciences, Universidad de ChileSantiago, Chile
| | - M Schmidt
- Department of Molecular Pharmacology, University of GroningenGroningen, The Netherlands
- Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of GroningenGroningen, The Netherlands
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183
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Traini M, Quinn CM, Sandoval C, Johansson E, Schroder K, Kockx M, Meikle PJ, Jessup W, Kritharides L. Sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) is a novel nucleotide phosphodiesterase regulated by cholesterol in human macrophages. J Biol Chem 2014; 289:32895-913. [PMID: 25288789 DOI: 10.1074/jbc.m114.612341] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cholesterol-loaded foam cell macrophages are prominent in atherosclerotic lesions and play complex roles in both inflammatory signaling and lipid metabolism, which are underpinned by large scale reprogramming of gene expression. We performed a microarray study of primary human macrophages that showed that transcription of the sphingomyelin phosphodiesterase acid-like 3A (SMPDL3A) gene is up-regulated after cholesterol loading. SMPDL3A protein expression in and secretion from primary macrophages are stimulated by cholesterol loading, liver X receptor ligands, and cyclic AMP, and N-glycosylated SMPDL3A protein is detectable in circulating blood. We demonstrate for the first time that SMPDL3A is a functional phosphodiesterase with an acidic pH optimum. We provide evidence that SMPDL3A is not an acid sphingomyelinase but unexpectedly is active against nucleotide diphosphate and triphosphate substrates at acidic and neutral pH. SMPDL3A is a major source of nucleotide phosphodiesterase activity secreted by liver X receptor-stimulated human macrophages. Extracellular nucleotides such as ATP may activate pro-inflammatory responses in immune cells. Increased expression and secretion of SMPDL3A by cholesterol-loaded macrophage foam cells in lesions may decrease local concentrations of pro-inflammatory nucleotides and potentially represent a novel anti-inflammatory axis linking lipid metabolism with purinergic signaling in atherosclerosis.
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Affiliation(s)
- Mathew Traini
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139,
| | - Carmel M Quinn
- the Centre for Vascular Research, University of New South Wales, Sydney, New South Wales 2052
| | - Cecilia Sandoval
- the Centre for Vascular Research, University of New South Wales, Sydney, New South Wales 2052
| | - Erik Johansson
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139
| | - Kate Schroder
- the Institute for Molecular Bioscience, University of Queensland, Queensland 4072
| | - Maaike Kockx
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139
| | - Peter J Meikle
- the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, and
| | - Wendy Jessup
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139
| | - Leonard Kritharides
- From the Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, New South Wales 2139, the Department of Cardiology, Concord Repatriation General Hospital, Concord, New South Wales 2139, Australia
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184
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Jansen SR, Holman R, Hedemann I, Frankes E, Elzinga CRS, Timens W, Gosens R, de Bont ES, Schmidt M. Prostaglandin E2 promotes MYCN non-amplified neuroblastoma cell survival via β-catenin stabilization. J Cell Mol Med 2014; 19:210-26. [PMID: 25266063 PMCID: PMC4288364 DOI: 10.1111/jcmm.12418] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 08/01/2014] [Indexed: 12/17/2022] Open
Abstract
Amplification of MYCN is the most well-known prognostic marker of neuroblastoma risk classification, but still is only observed in 25% of cases. Recent evidence points to the cyclic adenosine monophosphate (cAMP) elevating ligand prostaglandin E2 (PGE2 ) and β-catenin as two novel players in neuroblastoma. Here, we aimed to define the potential role of PGE2 and cAMP and its potential interplay with β-catenin, both of which may converge on neuroblastoma cell behaviour. Gain and loss of β-catenin function, PGE2 , the adenylyl cyclase activator forskolin and pharmacological inhibition of cyclooxygenase-2 (COX-2) were studied in two human neuroblastoma cell lines without MYCN amplification. Our findings show that PGE2 enhanced cell viability through the EP4 receptor and cAMP elevation, whereas COX-2 inhibitors attenuated cell viability. Interestingly, PGE2 and forskolin promoted glycogen synthase kinase 3β inhibition, β-catenin phosphorylation at the protein kinase A target residue ser675, β-catenin nuclear translocation and TCF-dependent gene transcription. Ectopic expression of a degradation-resistant β-catenin mutant enhances neuroblastoma cell viability and inhibition of β-catenin with XAV939 prevented PGE2 -induced cell viability. Finally, we show increased β-catenin expression in human high-risk neuroblastoma tissue without MYCN amplification. Our data indicate that PGE2 enhances neuroblastoma cell viability, a process which may involve cAMP-mediated β-catenin stabilization, and suggest that this pathway is of relevance to high-risk neuroblastoma without MYCN amplification.
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Affiliation(s)
- Sepp R Jansen
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands; Department of Paediatrics, Department of Pediatric Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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185
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Desman G, Waintraub C, Zippin JH. Investigation of cAMP microdomains as a path to novel cancer diagnostics. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2636-45. [PMID: 25205620 DOI: 10.1016/j.bbadis.2014.08.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/21/2014] [Accepted: 08/26/2014] [Indexed: 12/17/2022]
Abstract
Understanding of cAMP signaling has greatly improved over the past decade. The advent of live cell imaging techniques and more specific pharmacologic modulators has led to an improved understanding of the intricacies by which cAMP is able to modulate such a wide variety of cellular pathways. It is now appreciated that cAMP is able to activate multiple effector proteins at distinct areas in the cell leading to the activation of very different downstream targets. The investigation of signaling proteins in cancer is a common route to the development of diagnostic tools, prognostic tools, and/or therapeutic targets, and in this review we highlight how investigation of cAMP signaling microdomains driven by the soluble adenylyl cyclase in different cancers has led to the development of a novel cancer biomarker. Antibodies directed against the soluble adenylyl cyclase (sAC) are highly specific markers for melanoma especially for lentigo maligna melanoma and are being described as "second generation" cancer diagnostics, which are diagnostics that determine the 'state' of a cell and not just identify the cell type. Due to the wide presence of cAMP signaling pathways in cancer, we predict that further investigation of both sAC and other cAMP microdomains will lead to additional cancer biomarkers. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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Affiliation(s)
- Garrett Desman
- Department of Pathology, Joan and Sanford I. Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA
| | - Caren Waintraub
- Albert Einstein College of Medicine at Yeshiva University, 1300 Morris Park Avenue, Bronx, NY 10461, USA; Department of Dermatology, Joan and Sanford I. Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA
| | - Jonathan H Zippin
- Department of Dermatology, Joan and Sanford I. Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA.
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186
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cAMP signalling in the vasculature: the role of Epac (exchange protein directly activated by cAMP). Biochem Soc Trans 2014; 42:89-97. [PMID: 24450633 DOI: 10.1042/bst20130253] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The second messenger cAMP plays a central role in mediating vascular smooth muscle relaxation in response to vasoactive transmitters and in strengthening endothelial cell-cell junctions that regulate the movement of solutes, cells and macromolecules between the blood and the surrounding tissue. The vasculature expresses three cAMP effector proteins: PKA (protein kinase A), CNG (cyclic-nucleotide-gated) ion channels, and the most recently discovered Epacs (exchange proteins directly activated by cAMP). Epacs are a family of GEFs (guanine-nucleotide-exchange factors) for the small Ras-related GTPases Rap1 and Rap2, and are being increasingly implicated as important mediators of cAMP signalling, both in their own right and in parallel with the prototypical cAMP target PKA. In the present paper, we review what is currently known about the role of Epac within blood vessels, particularly with regard to the regulation of vascular tone, endothelial barrier function and inflammation.
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187
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Brown LM, Rogers KE, Aroonsakool N, McCammon JA, Insel PA. Allosteric inhibition of Epac: computational modeling and experimental validation to identify allosteric sites and inhibitors. J Biol Chem 2014; 289:29148-57. [PMID: 25183009 DOI: 10.1074/jbc.m114.569319] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Epac, a guanine nucleotide exchange factor for the low molecular weight G protein Rap, is an effector of cAMP signaling and has been implicated to have roles in numerous diseases, including diabetes mellitus, heart failure, and cancer. We used a computational molecular modeling approach to predict potential binding sites for allosteric modulators of Epac and to identify molecules that might bind to these regions. This approach revealed that the conserved hinge region of the cyclic nucleotide-binding domain of Epac1 is a potentially druggable region of the protein. Using a bioluminescence resonance energy transfer-based assay (CAMYEL, cAMP sensor using YFP-Epac-Rluc), we assessed the predicted compounds for their ability to bind Epac and modulate its activity. We identified a thiobarbituric acid derivative, 5376753, that allosterically inhibits Epac activity and used Swiss 3T3 and HEK293 cells to test the ability of this compound to modulate the activity of Epac and PKA, as determined by Rap1 activity and vasodilator-stimulated phosphoprotein phosphorylation, respectively. Compound 5376753 selectively inhibited Epac in biochemical and cell migration studies. These results document the utility of a computational approach to identify a domain for allosteric regulation of Epac and a novel compound that prevents the activation of Epac1 by cAMP.
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Affiliation(s)
| | | | | | - J Andrew McCammon
- From the Departments of Pharmacology, Chemistry and Biochemistry, and the Howard Hughes Medical Institute, University of California at San Diego, La Jolla, California 92093
| | - Paul A Insel
- From the Departments of Pharmacology, Medicine and
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188
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Oldenburger A, Timens W, Bos S, Smit M, Smrcka AV, Laurent AC, Cao J, Hylkema M, Meurs H, Maarsingh H, Lezoualc'h F, Schmidt M. Epac1 and Epac2 are differentially involved in inflammatory and remodeling processes induced by cigarette smoke. FASEB J 2014; 28:4617-28. [PMID: 25103224 DOI: 10.1096/fj.13-248930] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cigarette smoke (CS) induces inflammatory responses characterized by increase of immune cells and cytokine release. Remodeling processes, such as mucus hypersecretion and extracellular matrix protein production, are also directly or indirectly induced by CS. Recently, we showed that activation of the exchange protein directly activated by cAMP (Epac) attenuates CS extract-induced interleukin (IL)-8 release from cultured airway smooth muscle cells. Using an acute, short-term model of CS exposure, we now studied the role of Epac1, Epac2, and the Epac effector phospholipase-Cε (PLCε) in airway inflammation and remodeling in vivo. Compared to wild-type mice exposed to CS, the number of total inflammatory cells, macrophages, and neutrophils and total IL-6 release was lower in Epac2(-/-) mice, which was also the case for neutrophils and IL-6 in PLCε(-/-) mice. Taken together, Epac2, acting partly via PLCε, but not Epac1, enhances CS-induced airway inflammation in vivo. In total lung homogenates of Epac1(-/-) mice, MUC5AC and matrix remodeling parameters (transforming growth factor-β1, collagen I, and fibronectin) were increased at baseline. Our findings suggest that Epac1 primarily is capable of inhibiting remodeling processes, whereas Epac2 primarily increases inflammatory processes in vivo.
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Affiliation(s)
- Anouk Oldenburger
- Department of Molecular Pharmacology and Groningen Research Institute for Asthma and COPD and
| | - Wim Timens
- Groningen Research Institute for Asthma and COPD and Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Sophie Bos
- Department of Molecular Pharmacology and
| | | | - Alan V Smrcka
- Department of Pharmacology and Physiology, School of Medicine, University of Rochester, Rochester, NY, USA
| | - Anne-Coline Laurent
- Institut National de la Recherche Scientifique (INSERM), Unité Mixte de Recherche (UMR) 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, France; Université de Toulouse III, Paul Sabatier, Toulouse, France; and
| | - Junjun Cao
- Groningen Research Institute for Asthma and COPD and Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Machteld Hylkema
- Groningen Research Institute for Asthma and COPD and Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Herman Meurs
- Department of Molecular Pharmacology and Groningen Research Institute for Asthma and COPD and
| | - Harm Maarsingh
- Department of Pharmaceutical Sciences, Lloyd L. Gregory School of Pharmacy, Palm Beach Atlantic University, West Palm Beach, Florida, USA
| | - Frank Lezoualc'h
- Institut National de la Recherche Scientifique (INSERM), Unité Mixte de Recherche (UMR) 1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, France; Université de Toulouse III, Paul Sabatier, Toulouse, France; and
| | - Martina Schmidt
- Department of Molecular Pharmacology and Groningen Research Institute for Asthma and COPD and
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Oldenburger A, van Basten B, Kooistra W, Meurs H, Maarsingh H, Krenning G, Timens W, Schmidt M. Interaction between Epac1 and miRNA-7 in airway smooth muscle cells. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2014; 387:795-7. [PMID: 24994109 DOI: 10.1007/s00210-014-1015-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/26/2014] [Indexed: 12/16/2022]
Affiliation(s)
- Anouk Oldenburger
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands,
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190
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Role of soluble adenylyl cyclase in cell death and growth. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2646-55. [PMID: 25010002 DOI: 10.1016/j.bbadis.2014.06.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 12/13/2022]
Abstract
cAMP signaling is an evolutionarily conserved intracellular communication system controlling numerous cellular functions. Until recently, transmembrane adenylyl cyclase (tmAC) was considered the major source for cAMP in the cell, and the role of cAMP signaling was therefore attributed exclusively to the activity of this family of enzymes. However, increasing evidence demonstrates the role of an alternative, intracellular source of cAMP produced by type 10 soluble adenylyl cyclase (sAC). In contrast to tmAC, sAC produces cAMP in various intracellular microdomains close to specific cAMP targets, e.g., in nucleus and mitochondria. Ongoing research demonstrates involvement of sAC in diverse physiological and pathological processes. The present review is focused on the role of cAMP signaling, particularly that of sAC, in cell death and growth. Although the contributions of sAC to the regulation of these cellular functions have only recently been discovered, current data suggest that sAC plays key roles in mitochondrial bioenergetics and the mitochondrial apoptosis pathway, as well as cell proliferation and development. Furthermore, recent reports suggest the importance of sAC in several pathologies associated with apoptosis as well as in oncogenesis. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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191
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Novel drug targets for asthma and COPD: lessons learned from in vitro and in vivo models. Pulm Pharmacol Ther 2014; 29:181-98. [PMID: 24929072 DOI: 10.1016/j.pupt.2014.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 05/20/2014] [Accepted: 05/31/2014] [Indexed: 12/28/2022]
Abstract
Asthma and chronic obstructive pulmonary disease (COPD) are highly prevalent respiratory diseases characterized by airway inflammation, airway obstruction and airway hyperresponsiveness. Whilst current therapies, such as β-agonists and glucocorticoids, may be effective at reducing symptoms, they do not reduce disease progression. Thus, there is a need to identify new therapeutic targets. In this review, we summarize the potential of novel targets or tools, including anti-inflammatories, phosphodiesterase inhibitors, kinase inhibitors, transient receptor potential channels, vitamin D and protease inhibitors, for the treatment of asthma and COPD.
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192
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Matsumoto JPP, Almeida MG, Castilho-Martins EA, Costa MA, Fior-Chadi DR. Protein kinase A mediates adenosine A2a receptor modulation of neurotransmitter release via synapsin I phosphorylation in cultured cells from medulla oblongata. Neurosci Res 2014; 85:1-11. [PMID: 24912137 DOI: 10.1016/j.neures.2014.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 04/09/2014] [Accepted: 05/07/2014] [Indexed: 01/25/2023]
Abstract
Synaptic transmission is an essential process for neuron physiology. Such process is enabled in part due to modulation of neurotransmitter release. Adenosine is a synaptic modulator of neurotransmitter release in the Central Nervous System, including neurons of medulla oblongata, where several nuclei are involved with neurovegetative reflexes. Adenosine modulates different neurotransmitter systems in medulla oblongata, specially glutamate and noradrenaline in the nucleus tractussolitarii, which are involved in hypotensive responses. However, the intracellular mechanisms involved in this modulation remain unknown. The adenosine A2a receptor modulates neurotransmitter release by activating two cAMP protein effectors, the protein kinase A and the exchange protein activated by cAMP. Therefore, an in vitro approach (cultured cells) was carried out to evaluate modulation of neurotransmission by adenosine A2a receptor and the signaling intracellular pathway involved. Results show that the adenosine A2a receptor agonist, CGS 21680, increases neurotransmitter release, in particular, glutamate and noradrenaline and such response is mediated by protein kinase A activation, which in turn increased synapsin I phosphorylation. This suggests a mechanism of A2aR modulation of neurotransmitter release in cultured cells from medulla oblongata of Wistar rats and suggest that protein kinase A mediates this modulation of neurotransmitter release via synapsin I phosphorylation.
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Affiliation(s)
| | - Marina Gomes Almeida
- Department of Physiology, Institute of Biosciences, University of Sao Paulo, Sao Paulo, Brazil
| | | | - Maisa Aparecida Costa
- Department of Physiology, Institute of Biosciences, University of Sao Paulo, Sao Paulo, Brazil
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193
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Sheppard CL, Lee LCY, Hill EV, Henderson DJP, Anthony DF, Houslay DM, Yalla KC, Cairns LS, Dunlop AJ, Baillie GS, Huston E, Houslay MD. Mitotic activation of the DISC1-inducible cyclic AMP phosphodiesterase-4D9 (PDE4D9), through multi-site phosphorylation, influences cell cycle progression. Cell Signal 2014; 26:1958-74. [PMID: 24815749 DOI: 10.1016/j.cellsig.2014.04.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 04/28/2014] [Accepted: 04/29/2014] [Indexed: 10/25/2022]
Abstract
In Rat-1 cells, the dramatic decrease in the levels of both intracellular cyclic 3'5' adenosine monophosphate (cyclic AMP; cAMP) and in the activity of cAMP-activated protein kinase A (PKA) observed in mitosis was paralleled by a profound increase in cAMP hydrolyzing phosphodiesterase-4 (PDE4) activity. The decrease in PKA activity, which occurs during mitosis, was attributable to PDE4 activation as the PDE4 selective inhibitor, rolipram, but not the phosphodiesterase-3 (PDE3) inhibitor, cilostamide, specifically ablated this cell cycle-dependent effect. PDE4 inhibition caused Rat-1 cells to move from S phase into G2/M more rapidly, to transit through G2/M more quickly and to remain in G1 for a longer period. Inhibition of PDE3 elicited no observable effects on cell cycle dynamics. Selective immunopurification of each of the four PDE4 sub-families identified PDE4D as being selectively activated in mitosis. Subsequent analysis uncovered PDE4D9, an isoform whose expression can be regulated by Disrupted-In-Schizophrenia 1 (DISC1)/activating transcription factor 4 (ATF4) complex, as the sole PDE4 species activated during mitosis in Rat-1 cells. PDE4D9 becomes activated in mitosis through dual phosphorylation at Ser585 and Ser245, involving the combined action of ERK and an unidentified 'switch' kinase that has previously been shown to be activated by H2O2. Additionally, in mitosis, PDE4D9 also becomes phosphorylated at Ser67 and Ser81, through the action of MK2 (MAPKAPK2) and AMP kinase (AMPK), respectively. The multisite phosphorylation of PDE4D9 by all four of these protein kinases leads to decreased mobility (band-shift) of PDE4D9 on SDS-PAGE. PDE4D9 is predominantly concentrated in the perinuclear region of Rat-1 cells but with a fraction distributed asymmetrically at the cell margins. Our investigations demonstrate that the diminished levels of cAMP and PKA activity that characterise mitosis are due to enhanced cAMP degradation by PDE4D9. PDE4D9, was found to locate primarily not only in the perinuclear region of Rat-1 cells but also at the cell margins. We propose that the sequestration of PDE4D9 in a specific complex together with AMPK, ERK, MK2 and the H2O2-activatable 'switch' kinase allows for its selective multi-site phosphorylation, activation and regulation in mitosis.
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Affiliation(s)
- Catherine L Sheppard
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Louisa C Y Lee
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Elaine V Hill
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - David J P Henderson
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Diana F Anthony
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Daniel M Houslay
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Krishna C Yalla
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Lynne S Cairns
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Allan J Dunlop
- Institute of Neuroscience and Psychology, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - George S Baillie
- Institute of Cardiovascular and Medical Sciences, Wolfson Link and Davidson Buildings, University of Glasgow, University Avenue, Glasgow G12 8QQ, Scotland, UK
| | - Elaine Huston
- Institute of Pharmaceutical Science, King's College London, 5th Floor, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | - Miles D Houslay
- Institute of Pharmaceutical Science, King's College London, 5th Floor, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
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194
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Liu S, Moayeri M, Leppla SH. Anthrax lethal and edema toxins in anthrax pathogenesis. Trends Microbiol 2014; 22:317-25. [PMID: 24684968 DOI: 10.1016/j.tim.2014.02.012] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 02/23/2014] [Accepted: 02/26/2014] [Indexed: 10/25/2022]
Abstract
The pathophysiological effects resulting from many bacterial diseases are caused by exotoxins released by the bacteria. Bacillus anthracis, a spore-forming bacterium, is such a pathogen, causing anthrax through a combination of bacterial infection and toxemia. B. anthracis causes natural infection in humans and animals and has been a top bioterrorism concern since the 2001 anthrax attacks in the USA. The exotoxins secreted by B. anthracis use capillary morphogenesis protein 2 (CMG2) as the major toxin receptor and play essential roles in pathogenesis during the entire course of the disease. This review focuses on the activities of anthrax toxins and their roles in initial and late stages of anthrax infection.
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Affiliation(s)
- Shihui Liu
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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195
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Dale PR, Cernecka H, Schmidt M, Dowling MR, Charlton SJ, Pieper MP, Michel MC. The pharmacological rationale for combining muscarinic receptor antagonists and β-adrenoceptor agonists in the treatment of airway and bladder disease. Curr Opin Pharmacol 2014; 16:31-42. [PMID: 24682092 PMCID: PMC4071415 DOI: 10.1016/j.coph.2014.03.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/03/2014] [Accepted: 03/04/2014] [Indexed: 02/07/2023]
Abstract
Muscarinic receptors increase smooth muscle tone in airways and urinary bladder. β-Adrenoceptors relax smooth muscle tone and oppose muscarinic contraction. Opposition involves transmitter release, signal transduction and receptor expression. This supports the combined use of muscarinic antagonists and β-adrenoceptor agonists.
Muscarinic receptor antagonists and β-adrenoceptor agonists are used in the treatment of obstructive airway disease and overactive bladder syndrome. Here we review the pharmacological rationale for their combination. Muscarinic receptors and β-adrenoceptors are physiological antagonists for smooth muscle tone in airways and bladder. Muscarinic agonism may attenuate β-adrenoceptor-mediated relaxation more than other contractile stimuli. Chronic treatment with one drug class may regulate expression of the target receptor but also that of the opposing receptor. Prejunctional β2-adrenoceptors can enhance neuronal acetylcholine release. Moreover, at least in the airways, muscarinic receptors and β-adrenoceptors are expressed in different locations, indicating that only a combined modulation of both systems may cause dilatation along the entire bronchial tree. While all of these factors contribute to a rationale for a combination of muscarinic receptor antagonists and β-adrenoceptor agonists, the full value of such combination as compared to monotherapy can only be determined in clinical studies.
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Affiliation(s)
- Philippa R Dale
- Department of Pharmacology, Cambridge University, Cambridge, UK
| | - Hana Cernecka
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
| | - Martina Schmidt
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
| | - Mark R Dowling
- Department of Molecular Pharmacology, Respiratory Diseases, Novartis Institutes for Biomedical Research, Horsham, UK
| | - Steven J Charlton
- Department of Molecular Pharmacology, Respiratory Diseases, Novartis Institutes for Biomedical Research, Horsham, UK
| | - Michael P Pieper
- Respiratory Diseases Research and Department of Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH, Ingelheim, Germany
| | - Martin C Michel
- Respiratory Diseases Research and Department of Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH, Ingelheim, Germany; Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
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196
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Oldenburger A, Poppinga WJ, Kos F, de Bruin HG, Rijks WF, Heijink IH, Timens W, Meurs H, Maarsingh H, Schmidt M. A-kinase anchoring proteins contribute to loss of E-cadherin and bronchial epithelial barrier by cigarette smoke. Am J Physiol Cell Physiol 2014; 306:C585-97. [PMID: 24452374 DOI: 10.1152/ajpcell.00183.2013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Airway epithelium, which forms the first barrier towards environmental insults, is disturbed by cigarette smoking, a major risk factor for developing chronic obstructive pulmonary disease (COPD). A-kinase anchoring proteins (AKAP) maintain endothelial barrier function and coordinate subcellular localization of protein kinase A (PKA). However, the role of AKAPs in epithelial barrier function is unknown. We studied the role of AKAPs in regulating human bronchial epithelial (Hogg JC, Timens W. Annu Rev Pathol 4: 435-459, 2009; HBE) barrier. Cigarette smoke extract (CSE) reduced barrier function in 16HBE cells and the expression of the adhesion molecule E-cadherin specifically at the cell membrane. In addition, CSE reduced the protein expression of the AKAP family member AKAP9 at the cell membrane. The expression of AKAP5 and AKAP12 was unaffected by CSE. AKAP9 interacted and colocalized with E-cadherin at the cell membrane, suggesting that the reduction of both proteins may be related. Interestingly, disruption of AKAP-PKA interactions by st-Ht31 prevented the CSE-induced reduction of E-cadherin and AKAP9 protein expression and subsequent loss of barrier function. Silencing of AKAP9 reduced the functional epithelial barrier and prevented the ability of st-Ht31 to restore membrane localization of E-cadherin. Our data suggest the possibility of a specific role for AKAP9 in the maintenance of the epithelial barrier. E-cadherin, but not AKAP9, protein expression was reduced in lung tissue from COPD patients compared with controls. However, AKAP9 mRNA expression was decreased in primary bronchial epithelial cells from current smokers compared with non/ex-smokers. In conclusion, our results indicate that AKAP proteins, most likely AKAP9, maintain the bronchial epithelial barrier by regulating the E-cadherin expression at the cell membrane.
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Affiliation(s)
- Anouk Oldenburger
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands
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197
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Prakash YS, Martin RJ. Brain-derived neurotrophic factor in the airways. Pharmacol Ther 2014; 143:74-86. [PMID: 24560686 DOI: 10.1016/j.pharmthera.2014.02.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 02/10/2014] [Indexed: 12/13/2022]
Abstract
In addition to their well-known roles in the nervous system, there is increasing recognition that neurotrophins such as brain derived neurotrophic factor (BDNF) as well as their receptors are expressed in peripheral tissues including the lung, and can thus potentially contribute to both normal physiology and pathophysiology of several diseases. The relevance of this family of growth factors lies in emerging clinical data indicating altered neurotrophin levels and function in a range of diseases including neonatal and adult asthma, sinusitis, influenza, and lung cancer. The current review focuses on 1) the importance of BDNF expression and signaling mechanisms in early airway and lung development, critical to both normal neonatal lung function and also its disruption in prematurity and insults such as inflammation and infection; 2) how BDNF, potentially derived from airway nerves modulate neurogenic control of airway tone, a key aspect of airway reflexes as well as dysfunctional responses to allergic inflammation; 3) the emerging idea that local BDNF production by resident airway cells such as epithelium and airway smooth muscle can contribute to normal airway structure and function, and to airway hyperreactivity and remodeling in diseases such as asthma. Furthermore, given its pleiotropic effects in the airway, BDNF may be a novel and appealing therapeutic target.
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Affiliation(s)
- Y S Prakash
- Department of Anesthesiology, Mayo Clinic College of Medicine, Rochester, MN 55905, United States; Department of Physiology & Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, United States.
| | - Richard J Martin
- Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, OH 44106, United States
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198
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Almahariq M, Mei FC, Cheng X. Cyclic AMP sensor EPAC proteins and energy homeostasis. Trends Endocrinol Metab 2014; 25:60-71. [PMID: 24231725 PMCID: PMC3946731 DOI: 10.1016/j.tem.2013.10.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 09/30/2013] [Accepted: 10/11/2013] [Indexed: 12/16/2022]
Abstract
The pleiotropic second-messenger cAMP plays a crucial role in mediating the effects of various hormones on metabolism. The major intracellular functions of cAMP are transduced by protein kinase A (PKA) and by exchange proteins directly activated by cAMP (EPACs). The latter act as guanine-nucleotide exchange factors for the RAS-like small G proteins Rap1 and Rap2. Although the role of PKA in regulating energy balance has been extensively studied, the impact of EPACs remains relatively enigmatic. This review summarizes recent genetic and pharmacological studies concerning EPAC involvement in glucose homeostasis and energy balance via the regulation of leptin and insulin signaling pathways. In addition, the development of small-molecule EPAC-specific modulators and their therapeutic potential for the treatment of diabetes and obesity are discussed.
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Affiliation(s)
- Muayad Almahariq
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, Texas 77555-0615, USA
| | - Fang C Mei
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, Texas 77555-0615, USA; Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Xiaodong Cheng
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, Texas 77555-0615, USA; Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center, Houston, Texas 77030, USA.
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199
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Rieg T, Kohan DE. Regulation of nephron water and electrolyte transport by adenylyl cyclases. Am J Physiol Renal Physiol 2014; 306:F701-9. [PMID: 24477683 DOI: 10.1152/ajprenal.00656.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adenylyl cyclases (AC) catalyze formation of cAMP, a critical component of G protein-coupled receptor signaling. So far, nine distinct membrane-bound AC isoforms (AC1-9) and one soluble AC (sAC) have been identified and, except for AC8, all of them are expressed in the kidney. While the role of ACs in renal cAMP formation is well established, we are just beginning to understand the function of individual AC isoforms, particularly with regard to hormonal regulation of transporter and channel phosphorylation, membrane abundance, and trafficking. This review focuses on the role of different AC isoforms in regulating renal water and electrolyte transport in health as well as potential pathological implications of disordered AC isoform function. In particular, we focus on modulation of transporter and channel abundance, activity, and phosphorylation, with an emphasis on studies employing genetically modified animals. As will be described, it is now evident that specific AC isoforms can exert unique effects in the kidney that may have important implications in our understanding of normal physiology as well as disease pathogenesis.
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Affiliation(s)
- Timo Rieg
- Dept. of Medicine, Div. of Nephrology/Hypertension, Univ. of California San Diego and VA San Diego Healthcare System; 3350 La Jolla Village Dr. (9151 San Diego, CA 92161.
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200
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García-Morales V, Cuíñas A, Elíes J, Campos-Toimil M. PKA and Epac activation mediates cAMP-induced vasorelaxation by increasing endothelial NO production. Vascul Pharmacol 2014; 60:95-101. [PMID: 24469067 DOI: 10.1016/j.vph.2014.01.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 01/13/2014] [Accepted: 01/17/2014] [Indexed: 12/15/2022]
Abstract
Vascular relaxation induced by 3',5'-cyclic adenosine monophosphate (cAMP) is both endothelium-dependent and endothelium-independent, although the underlying signaling pathways are not fully understood. Aiming to uncover potential mechanisms, we performed contraction-relaxation experiments on endothelium-denuded and intact rat aorta rings and measured NO levels in isolated human endothelial cells using single cell fluorescence imaging. The vasorelaxant effect of forskolin, an adenylyl cyclase activator, was decreased after selective inhibitor of protein kinase A (PKA), a cAMP-activated kinase, or L-NAME, an endothelial nitric oxide synthase (eNOS) inhibitor, only in intact aortic rings. Both selective activation of PKA with 6-Bnz-cAMP and exchange protein directly activated by cAMP (Epac) with 8-pCPT-2'-O-Me-cAMP significantly relaxed phenylephrine-induced contractions. The vasorelaxant effect of the Epac activator, but not that of the PKA activator, was reduced by endothelium removal. Forskolin, dibutyryl cAMP (a cAMP analogue), 6-Bnz-cAMP and 8-pCPT-2'-O-Me-cAMP increased NO levels in endothelial cells and the forskolin effect was significantly inhibited by inactivation of both Epac and PKA, and eNOS inhibition. Our results indicate that the endothelium-dependent component of forskolin/cAMP-induced vasorelaxation is partially mediated by an increase in endothelial NO release due to an enhanced eNOS activity through PKA and Epac activation in endothelial cells.
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Affiliation(s)
- Verónica García-Morales
- Farmacología Cardiovascular y Plaquetaria, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Andrea Cuíñas
- Farmacología Cardiovascular y Plaquetaria, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Jacobo Elíes
- Farmacología Cardiovascular y Plaquetaria, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Manuel Campos-Toimil
- Farmacología Cardiovascular y Plaquetaria, Centro de Investigación en Medicina Molecular y Enfermedades Crónicas, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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