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Aktories K, Gierschik P, Heringdorf DMZ, Schmidt M, Schultz G, Wieland T. cAMP guided his way: a life for G protein-mediated signal transduction and molecular pharmacology-tribute to Karl H. Jakobs. Naunyn Schmiedebergs Arch Pharmacol 2019; 392:887-911. [PMID: 31101932 DOI: 10.1007/s00210-019-01650-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 04/02/2019] [Indexed: 12/14/2022]
Abstract
Karl H. Jakobs, former editor-in-chief of Naunyn-Schmiedeberg's Archives of Pharmacology and renowned molecular pharmacologist, passed away in April 2018. In this article, his scientific achievements regarding G protein-mediated signal transduction and regulation of canonical pathways are summarized. Particularly, the discovery of inhibitory G proteins for adenylyl cyclase, methods for the analysis of receptor-G protein interactions, GTP supply by nucleoside diphosphate kinases, mechanisms in phospholipase C and phospholipase D activity regulation, as well as the development of the concept of sphingosine-1-phosphate as extra- and intracellular messenger will presented. His seminal scientific and methodological contributions are put in a general and timely perspective to display and honor his outstanding input to the current knowledge in molecular pharmacology.
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Affiliation(s)
- Klaus Aktories
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert Ludwigs University, 79104, Freiburg, Germany
| | - Peter Gierschik
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, 89070, Ulm, Germany
| | - Dagmar Meyer Zu Heringdorf
- Institute of General Pharmacology and Toxicology, University Hospital Frankfurt am Main, Goethe University, 60590, Frankfurt am Main, Germany
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, 9713AV, Groningen, The Netherlands
| | - Günter Schultz
- Department of Pharmacology, Charité University Medical Center Berlin, Campus Benjamin Franklin, 14195, Berlin, Germany
| | - Thomas Wieland
- Experimental Pharmacology Mannheim (EPM), European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13 - 17, 68167, Mannheim, Germany.
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Tóth AD, Schell R, Lévay M, Vettel C, Theis P, Haslinger C, Alban F, Werhahn S, Frischbier L, Krebs-Haupenthal J, Thomas D, Gröne HJ, Avkiran M, Katus HA, Wieland T, Backs J. Inflammation leads through PGE/EP 3 signaling to HDAC5/MEF2-dependent transcription in cardiac myocytes. EMBO Mol Med 2019; 10:emmm.201708536. [PMID: 29907596 PMCID: PMC6034133 DOI: 10.15252/emmm.201708536] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The myocyte enhancer factor 2 (MEF2) regulates transcription in cardiac myocytes and adverse remodeling of adult hearts. Activators of G protein-coupled receptors (GPCRs) have been reported to activate MEF2, but a comprehensive analysis of GPCR activators that regulate MEF2 has to our knowledge not been performed. Here, we tested several GPCR agonists regarding their ability to activate a MEF2 reporter in neonatal rat ventricular myocytes. The inflammatory mediator prostaglandin E2 (PGE2) strongly activated MEF2. Using pharmacological and protein-based inhibitors, we demonstrated that PGE2 regulates MEF2 via the EP3 receptor, the βγ subunit of Gi/o protein and two concomitantly activated downstream pathways. The first consists of Tiam1, Rac1, and its effector p21-activated kinase 2, the second of protein kinase D. Both pathways converge on and inactivate histone deacetylase 5 (HDAC5) and thereby de-repress MEF2. In vivo, endotoxemia in MEF2-reporter mice induced upregulation of PGE2 and MEF2 activation. Our findings provide an unexpected new link between inflammation and cardiac remodeling by de-repression of MEF2 through HDAC5 inactivation, which has potential implications for new strategies to treat inflammatory cardiomyopathies.
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Affiliation(s)
- András D Tóth
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Richard Schell
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Department of Cardiology, Heidelberg University, Heidelberg, Germany
| | - Magdolna Lévay
- DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Experimental Pharmacology, European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Christiane Vettel
- DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Experimental Pharmacology, European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Philipp Theis
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Clemens Haslinger
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Felix Alban
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Stefanie Werhahn
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Lina Frischbier
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Jutta Krebs-Haupenthal
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Dominique Thomas
- Institute of Clinical Pharmacology, Goethe University Frankfurt, Frankfurt, Germany
| | - Hermann-Josef Gröne
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany
| | - Metin Avkiran
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, UK
| | - Hugo A Katus
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
| | - Thomas Wieland
- DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Experimental Pharmacology, European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Johannes Backs
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany .,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
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Longman MR, Ranieri A, Avkiran M, Snabaitis AK. Regulation of PP2AC carboxylmethylation and cellular localisation by inhibitory class G-protein coupled receptors in cardiomyocytes. PLoS One 2014; 9:e86234. [PMID: 24475092 PMCID: PMC3903491 DOI: 10.1371/journal.pone.0086234] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 12/09/2013] [Indexed: 12/25/2022] Open
Abstract
The enzymatic activity of the type 2A protein phosphatase (PP2A) holoenzyme, a major serine/threonine phosphatase in the heart, is conferred by its catalytic subunit (PP2AC). PP2AC activity and subcellular localisation can be regulated by reversible carboxylmethylation of its C-terminal leucine309 (leu309) residue. Previous studies have shown that the stimulation of adenosine type 1 receptors (A1.Rs) induces PP2AC carboxylmethylation and altered subcellular distribution in adult rat ventricular myocytes (ARVM). In the current study, we show that the enzymatic components that regulate the carboxylmethylation status of PP2AC, leucine carboxylmethyltransferase-1 (LCMT-1) and phosphatase methylesterase-1 (PME-1) are abundantly expressed in, and almost entirely localised in the cytoplasm of ARVM. The stimulation of Gi-coupled A1.Rs with N6-cyclopentyladenosine (CPA), and of other Gi-coupled receptors such as muscarinic M2 receptors (stimulated with carbachol) and angiotensin II AT2 receptors (stimulated with CGP42112) in ARVM, induced PP2AC carboxylmethylation at leu309 in a concentration-dependent manner. Exposure of ARVM to 10 µM CPA increased the cellular association between PP2AC and its methyltransferase LCMT-1, but not its esterase PME-1. Stimulation of A1.Rs with 10 µM CPA increased the phosphorylation of protein kinase B at ser473, which was abolished by the PI3K inhibitor LY294002 (20 µM), thereby confirming that PI3K activity is upregulated in response to A1.R stimulation by CPA in ARVM. A1.R-induced PP2AC translocation to the particulate fraction was abrogated by adenoviral expression of the alpha subunit (Gαt1) coupled to the transducin G-protein coupled receptor. A similar inhibitory effect on A1.R-induced PP2AC translocation was also seen with LY294002 (20 µM). These data suggest that in ARVM, A1.R-induced PP2AC translocation to the particulate fraction occurs through a GiPCR-Gβγ-PI3K mediated intracellular signalling pathway, which may involve elevated PP2AC carboxylmethylation at leu309.
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Affiliation(s)
- Michael R. Longman
- School of Pharmacy and Chemistry, Faculty of Science, Engineering and Computing, Kingston University, Kingston-upon-Thames, Surrey, United Kingdom
| | - Antonella Ranieri
- King's College London British Heart Foundation Centre, Cardiovascular Division, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Metin Avkiran
- King's College London British Heart Foundation Centre, Cardiovascular Division, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
| | - Andrew K. Snabaitis
- School of Pharmacy and Chemistry, Faculty of Science, Engineering and Computing, Kingston University, Kingston-upon-Thames, Surrey, United Kingdom
- King's College London British Heart Foundation Centre, Cardiovascular Division, The Rayne Institute, St Thomas' Hospital, London, United Kingdom
- * E-mail:
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Carbajo-Lozoya J, Lutz S, Feng Y, Kroll J, Hammes HP, Wieland T. Angiotensin II modulates VEGF-driven angiogenesis by opposing effects of type 1 and type 2 receptor stimulation in the microvascular endothelium. Cell Signal 2012; 24:1261-9. [PMID: 22374305 DOI: 10.1016/j.cellsig.2012.02.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 02/14/2012] [Accepted: 02/14/2012] [Indexed: 11/19/2022]
Abstract
Vascular endothelial growth factor (VEGF) is a main stimulator of pathological vessel formation. Nevertheless, increasing evidence suggests that Angiotensin II (Ang II) can play an augmentory role in this process. We thus analyzed the contribution of the two Ang II receptor types, AT(1)R and AT(2)R, in a mouse model of VEGF-driven angiogenesis, i.e. oxygen-induced proliferative retinopathy. Application of the AT(1)R antagonist telmisartan but not the AT(2)R antagonist PD123,319 largely attenuated the pathological response. A direct effect of Ang II on endothelial cells (EC) was analyzed by assessing angiogenic responses in primary bovine retinal and immortalized rat microvascular EC. Selective stimulation of the AT(1)R by Ang II in the presence of PD123,319 revealed a pro-angiogenic activity which further increased VEGF-driven EC sprouting and migration. In contrast, selective stimulation of the AT(2)R by either CGP42112A or Ang II in the presence of telmisartan inhibited the VEGF-driven angiogenic response. Using specific inhibitors (pertussis toxin, RGS proteins, kinase inhibitors) we identified G(12/13) and G(i) dependent signaling pathways as the mediators of the AT(1)R-induced angiogenesis and the AT(2)R-induced inhibition, respectively. As AT(1)R and AT(2)R stimulation displays opposing effects on the activity of the monomeric GTPase RhoA and pro-angiogenic responses to Ang II and VEGF requires activation of Rho-dependent kinase (ROCK), we conclude that the opposing effects of the Ang II receptors on VEGF-driven angiogenesis converge on the regulation of activity of RhoA-ROCK-dependent EC migration.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin Receptor Antagonists/pharmacology
- Animals
- Cattle
- Cell Movement
- Cells, Cultured
- Endothelial Cells/cytology
- Endothelial Cells/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/growth & development
- Endothelium, Vascular/metabolism
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- Mice
- Mice, Inbred C57BL
- Microvessels/cytology
- Microvessels/growth & development
- Microvessels/metabolism
- Neovascularization, Pathologic
- Neovascularization, Physiologic
- Rats
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 2/metabolism
- Retina/pathology
- Retina/ultrastructure
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Javier Carbajo-Lozoya
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Maybachstrasse 14, D-68169 Mannheim, Germany
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Hu T, Liu Z, Shen X. Roles of phospholipase D in phorbol myristate acetate-stimulated neutrophil respiratory burst. J Cell Mol Med 2011; 15:647-53. [PMID: 20158570 PMCID: PMC3922386 DOI: 10.1111/j.1582-4934.2010.01035.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The phorbol myristate acetate (PMA) stimulated nutrophil respiratory burst has been considered to simply involve the activation of protein kinase C (PKC). However, the PLD activity was also increased by 10-fold in human neutrophils stimulated with 100 nM PMA. Unexpectedly, U73122, an inhibitor of phospholipase C, was found to significantly inhibit PMA-stimulated respiratory burst in human neutrophils. U73122 at the concentrations, which were sufficient to inhibit the respiratory burst completely, caused partial inhibition of the PLD activity but no inhibition on PKC translocation and activation, suggesting that PLD activity is also required in PMA-stimulated respiratory burst. Using 1-butanol, a PLD substrate, to block phosphatidic acid (PA) generation, the PMA-stimulated neutrophil respiratory burst was also partially inhibited, further indicating that PLD activation, possibly its hydrolytic product PA and diacylglycerol (DAG), is involved in PMA-stimulated respiratory burst. Since GF109203X, an inhibitor of PKC that could completely inhibit the respiratory burst in PMA-stimulated neutrophils, also caused certain suppression of PLD activation, it may suggest that PLD activation in PMA-stimulated neutrophils might be, to some extent, PKC dependent. To further study whether PLD contributes to the PMA stimulated respiratory burst through itself or its hydrolytic product, 1,2-dioctanoyl-sn-glycerol, an analogue of DAG , was used to prime cells at low concentration, and it reversed the inhibition of PMA-stimulated respiratory burst by U73122. The results indicate that U73122 may act as an inhibitor of PLD, and PLD activation is required in PMA-stimulated respiratory burst.
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Affiliation(s)
- Tianhui Hu
- Cancer Research Center, Xiamen University Medical College, Xiamen, China.
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6
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First report on the effect of thrombin and factor Xa on cardiomyocytes in a three-dimensional cell culture model. Thromb Res 2009; 124:375-6. [DOI: 10.1016/j.thromres.2008.11.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 10/31/2008] [Accepted: 11/23/2008] [Indexed: 11/23/2022]
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7
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Nishimaru K, Arimoto T, Takeishi Y, Kubota I, Ishii K, Endoh M. Overexpression of diacylglycerol kinase zeta inhibits endothelin-1-induced decreases in Ca2+ transients and cell shortening in mouse ventricular myocytes. J Mol Cell Cardiol 2008; 44:520-6. [PMID: 18275971 DOI: 10.1016/j.yjmcc.2007.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 12/13/2007] [Accepted: 12/14/2007] [Indexed: 10/22/2022]
Abstract
Endothelin-1 (ET-1) is released in various cardiovascular disorders including congestive heart failure, and may modulate significantly the disease process by its potent action on vascular and cardiac muscle cell function and gene regulation. In adult mouse ventricular cardiomyocytes loaded with indo-1, ET-1 induced a sustained negative inotropic effect (NIE) in association with decreases in Ca(2+) transients. The ET-1-induced effects on Ca(2+) transients and cell shortening were abolished in diacylglycerol (DAG) kinase zeta-overexpressing mouse ventricular myocytes. A nonselective protein kinase C (PKC) inhibitor, GF109203X, inhibited the ET-1-induced decreases in Ca(2+) transients and cell shortening in concentration-dependent manners, whereas a selective Ca(2+)-dependent PKC inhibitor, Gö6976, did not affect the ET-1-induced effects. A phospholipase Cbeta inhibitor, U73122, and an inhibitor of phospholipase D, C(2)-ceramide, partially, but significantly, attenuated the ET-1-induced effects. Derivatives of the respective inhibitors with no specific effects, U73343 and dihydro-C(2)-ceramide, did not affect the ET-1-induced effects. Taken together, these results indicate that activation of a Ca(2+)-independent PKC isozyme by 1,2-DAG, which is generated by phospholipase Cbeta and phospholipase D activation and inactivated by phosphorylation via DAG kinase, is responsible for the ET-1-induced decreases in Ca(2+) transients and cell shortening in mouse ventricular cardiomyocytes.
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Affiliation(s)
- Kazuhide Nishimaru
- Department of Cardiovascular Pharmacology, Yamagata University School of Medicine, 2-2-2 Iida-nishi, Yamagata, 990-9585 Japan
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Allahdadi KJ, Duling LC, Walker BR, Kanagy NL. Eucapnic intermittent hypoxia augments endothelin-1 vasoconstriction in rats: role of PKCdelta. Am J Physiol Heart Circ Physiol 2007; 294:H920-7. [PMID: 18083893 DOI: 10.1152/ajpheart.01264.2007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We reported previously that simulating sleep apnea by exposing rats to eucapnic intermittent hypoxia (E-IH) causes endothelin-dependent hypertension and increases constrictor sensitivity to endothelin-1 (ET-1). In addition, augmented ET-1-induced constriction in small mesenteric arteries (sMA) is mediated by increased Ca(2+) sensitization independent of Rho-associated kinase. We hypothesized that exposing rats to E-IH augments ET-1-mediated vasoconstriction by increasing protein kinase C (PKC)-dependent Ca(2+) sensitization. In sMA, the nonselective PKC inhibitor GF-109203x (3 microM) significantly inhibited ET-1-stimulated constriction in E-IH arteries but did not affect ET-1-stimulated constriction in sham arteries. Phospholipase C inhibitor U-73122 (1 microM) also inhibited constriction by ET-1 in E-IH but not sham sMA. In contrast, the classical PKC (cPKC) inhibitor Gö-6976 (1 microM) had no effect on ET-1-mediated vasoconstriction in either group, but a PKCdelta-selective inhibitor (rottlerin, 3 microM) significantly decreased ET-1-mediated constriction in E-IH but not in sham sMA. ET-1 increased PKCdelta phosphorylation in E-IH but not sham sMA. In contrast, ET-1 constriction in thoracic aorta from both sham and E-IH rats was inhibited by Gö-6976 but not by rottlerin. These observations support our hypothesis that E-IH exposure significantly increases ET-1-mediated constriction of sMA through PKCdelta activation and modestly augments ET-1 contraction in thoracic aorta through activation of one or more cPKC isoforms. Therefore, upregulation of a PKC pathway may contribute to elevated ET-1-dependent vascular resistance in this model of hypertension.
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Affiliation(s)
- Kyan J Allahdadi
- Deparment of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM 87131, USA
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9
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Grodnitzky JA, Syed N, Kimber MJ, Day TA, Donaldson JG, Hsu WH. Somatostatin receptors signal through EFA6A-ARF6 to activate phospholipase D in clonal beta-cells. J Biol Chem 2007; 282:13410-8. [PMID: 17353194 DOI: 10.1074/jbc.m701940200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Somatostatin (SS) is a peptide hormone that inhibits insulin secretion in beta-cells by activating its G(i/o)-coupled receptors. Our previous work indicated that a betagamma-dimer of G(i/o) coupled to SS receptors can activate phospholipase D1 (PLD1) (Cheng, H., Grodnitzky, J. A., Yibchok-anun, S., Ding, J., and Hsu, W. H. (2005) Mol. Pharmacol. 67, 2162-2172). The aim of the present study was to elucidate the mechanisms underlying SS-induced PLD activation. We demonstrated the presence of ADP-ribosylation factor Arf1 and Arf6 in clonal beta-cells, HIT-T15. We also determined that the activation of PLD1 was mediated through Arf6. Overexpression of dominant-negative (dn) Arf6 mutant, Arf6(T27N), and suppression of mRNA levels using siRNA, both abolished SS-induced PLD activation, while overexpression of wild type Arf6 further enhanced this PLD activation. In contrast, overexpression of dn-Arf1 mutant Arf1(T31N) or dn-Arf5 mutant Arf5(T31N) failed to reduce SS-induced PLD activation. These findings suggested that Arf6, but not Arf1 or Arf5, mediates the effect of SS. We further determined the involvement of the Arf6 guanine nucleotide exchange factor (GEF) EFA6A, a GEF previously thought to be found predominantly in the brain, in the activation of PLD1 in HIT-T15 cells. Using Northern and Western blot analyses, both mRNA and protein of EFA6A were found in these cells. Overexpression of dn-EFA6A mutant, EFA6A(E242K), and suppression of mRNA levels using siRNA, both abolished SS-induced PLD activation, whereas overexpression of dn-EFA6B mutant, EFA6B(E651K), failed to reduce SS-induced PLD activation. In addition, overexpression of dn-ARNO mutant, ARNO(E156K), another GEF of Arf6, had no effect on SS-induced activation of PLD. Taken together, these results suggest that SS signals through EFA6A to activate Arf6-PLD cascade.
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Affiliation(s)
- Justin A Grodnitzky
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
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Oude Weernink PA, López de Jesús M, Schmidt M. Phospholipase D signaling: orchestration by PIP2 and small GTPases. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2007; 374:399-411. [PMID: 17245604 PMCID: PMC2020506 DOI: 10.1007/s00210-007-0131-4] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2006] [Accepted: 12/20/2006] [Indexed: 11/12/2022]
Abstract
Hydrolysis of phosphatidylcholine by phospholipase D (PLD) leads to the generation of the versatile lipid second messenger, phosphatidic acid (PA), which is involved in fundamental cellular processes, including membrane trafficking, actin cytoskeleton remodeling, cell proliferation and cell survival. PLD activity can be dramatically stimulated by a large number of cell surface receptors and is elaborately regulated by intracellular factors, including protein kinase C isoforms, small GTPases of the ARF, Rho and Ras families and, particularly, by the phosphoinositide, phosphatidylinositol 4,5-bisphosphate (PIP(2)). PIP(2) is well known as substrate for the generation of second messengers by phospholipase C, but is now also understood to recruit and/or activate a variety of actin regulatory proteins, ion channels and other signaling proteins, including PLD, by direct interaction. The synthesis of PIP(2) by phosphoinositide 5-kinase (PIP5K) isoforms is tightly regulated by small GTPases and, interestingly, by PA as well, and the concerted formation of PIP(2) and PA has been shown to mediate receptor-regulated cellular events. This review highlights the regulation of PLD by membrane receptors, and describes how the close encounter of PLD and PIP5K isoforms with small GTPases permits the execution of specific cellular functions.
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Affiliation(s)
| | | | - Martina Schmidt
- />Department of Molecular Pharmacology, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands
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Oude Weernink PA, Han L, Jakobs KH, Schmidt M. Dynamic phospholipid signaling by G protein-coupled receptors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1768:888-900. [PMID: 17054901 DOI: 10.1016/j.bbamem.2006.09.012] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 09/18/2006] [Accepted: 09/18/2006] [Indexed: 11/19/2022]
Abstract
G protein-coupled receptors (GPCRs) control a variety of fundamental cellular processes by regulating phospholipid signaling pathways. Essential for signaling by a large number of receptors is the hydrolysis of the membrane phosphoinositide PIP(2) by phospholipase C (PLC) into the second messengers IP(3) and DAG. Many receptors also stimulate phospholipase D (PLD), leading to the generation of the versatile lipid, phosphatidic acid. Particular PLC and PLD isoforms take differential positions in receptor signaling and are additionally regulated by small GTPases of the Ras, Rho and ARF families. It is now recognized that the PLC substrate, PIP(2), has signaling capacity by itself and can, by direct interaction, affect the activity and subcellular localization of PLD and several other proteins. As expected, the synthesis of PIP(2) by phosphoinositide 5-kinases is tightly regulated as well. In this review, we present an overview of how these signaling pathways are governed by GPCRs, explain the molecular basis for the spatially and temporally organized, highly dynamic quality of phospholipid signaling, and point to the functional connection of the pathways.
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Affiliation(s)
- Paschal A Oude Weernink
- Institut für Pharmakologie, Universitätsklinikum Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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Snabaitis AK, D'Mello R, Dashnyam S, Avkiran M. A Novel Role for Protein Phosphatase 2A in Receptor-mediated Regulation of the Cardiac Sarcolemmal Na+/H+ Exchanger NHE1. J Biol Chem 2006; 281:20252-62. [PMID: 16707501 DOI: 10.1074/jbc.m600268200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
G(q) protein-coupled receptor stimulation increases sarcolemmal Na(+)/H(+) exchanger (NHE1) activity in cardiac myocytes by an ERK/RSK-dependent mechanism, most likely via RSK-mediated phosphorylation of the NHE1 regulatory domain. Adenosine A(1) receptor stimulation inhibits this response through a G(i) protein-mediated pathway, but the distal inhibitory signaling mechanisms are unknown. In cultured adult rat ventricular myocytes (ARVM), the A(1) receptor agonist cyclopentyladenosine (CPA) inhibited the increase in NHE1 phosphorylation induced by the alpha(1)-adrenoreceptor agonist phenylephrine, without affecting activation of the ERK/RSK pathway. CPA also induced significant accumulation of the catalytic subunit of type 2A protein phosphatase (PP2A(c)) in the particulate fraction, which contained the cellular NHE1 complement; this effect was abolished by pretreatment with pertussis toxin to inactivate G(i) proteins. Confocal immunofluorescence microscopic imaging of CPA-treated ARVM revealed significant co-localization of PP2A(c) and NHE1, in intercalated disc regions. In an in vitro assay, purified PP2A(c) dephosphorylated a GST-NHE1 fusion protein containing aa 625-747 of the NHE1 regulatory domain, which had been pre-phosphorylated by recombinant RSK; such dephosphorylation was inhibited by the PP2A-selective phosphatase inhibitor endothall. In intact ARVM, the ability of CPA to attenuate the phenylephrine-induced increase in NHE1 phosphorylation and activity was lost in the presence of endothall. These studies reveal a novel role for the PP2A holoenzyme in adenosine A(1) receptor-mediated regulation of NHE1 activity in ARVM, the mechanism of which appears to involve G(i) protein-mediated translocation of PP2A(c) and NHE1 dephosphorylation.
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Abstract
Over the last decade, the Rho family GTPases have gained considerable recognition as powerful regulators of actin cytoskeletal organization. As with many high profile signal transducers, these molecules soon attracted the attention of the cardiovascular research community. Shortly thereafter, two prominent members known as RhoA and Rac1 were linked to agonist-induced gene expression and myofilament organization using the isolated cardiomyocyte cell model. Subsequent creation of transgenic mouse lines provided evidence for more complex roles of RhoA and Rac1 signaling. Clues from in vitro and in vivo studies suggest the involvement of numerous downstream targets of RhoA and Rac1 signaling including serum response factor, NF-kappaB, and other transcription factors, myofilament proteins, ion channels, and reactive oxygen species generation. Which of these contribute to the observed phenotypic effects of enhanced RhoA and Rac activation in vivo remain to be determined. Current research efforts with a more translational focus have used statins or Rho kinase blockers to assess RhoA and Rac1 as targets for interventional approaches to blunt hypertrophy or heart failure. Generally, salutary effects on remodeling and ischemic damage are observed, but the broad specificity and multiple cellular targets for these drugs within the myocardium demands caution in interpretation. In this review, we assess the evolution of knowledge related to Rac1 and RhoA in the context of hypertrophy and heart failure and highlight the direction that future exploration will lead.
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Affiliation(s)
- Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, USA
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14
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Snabaitis AK, Muntendorf A, Wieland T, Avkiran M. Regulation of the extracellular signal-regulated kinase pathway in adult myocardium: differential roles of G(q/11), Gi and G(12/13) proteins in signalling by alpha1-adrenergic, endothelin-1 and thrombin-sensitive protease-activated receptors. Cell Signal 2005; 17:655-64. [PMID: 15683740 DOI: 10.1016/j.cellsig.2004.10.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Revised: 10/13/2004] [Accepted: 10/13/2004] [Indexed: 11/21/2022]
Abstract
Using adenoviruses encoding RGS2, RGS4 and Lsc (regulator of G protein signalling (RGS) domain of p115 RhoGEF), we investigated the contributions of G(q/11), Gi and G(12/13) proteins to G protein-coupled receptor (GPCR)-mediated activation of the extracellular signal-regulated kinase (ERK) pathway in adult rat ventricular myocytes (ARVM). Exposure to phenylephrine, endothelin-1 (ET-1) or thrombin induced significant activation of ERK1/2 and their downstream target 90 kDa ribosomal S6 kinase (p90RSK), which was abolished by overexpression of RGS4 (inhibits signalling via G(q/11) and Gi) or RGS2 (inhibits signalling via G(q/11)). Pertussis toxin (inhibits signalling via Gi) only partially attenuated the activation of ERK1/2 and p90(RSK) by phenylephrine and ET-1, but abolished such activation by thrombin. Overexpression of Lsc (inhibits signalling via G(12/13)) did not affect the responses to phenylephrine and ET-1, but suppressed the activation of ERK1/2 and p90RSK by thrombin. We conclude that full activation of the ERK pathway in ARVM by alpha1-adrenergic, ET-1 and thrombin receptors requires the activation of distinct families of heterotrimeric G proteins.
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MESH Headings
- Adenoviridae/genetics
- Adrenergic alpha-1 Receptor Agonists
- Adrenergic alpha-Agonists/pharmacology
- Animals
- GTP-Binding Protein alpha Subunits/physiology
- GTP-Binding Protein alpha Subunits, G12-G13/physiology
- GTP-Binding Protein alpha Subunits, Gi-Go/physiology
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- Genetic Vectors
- Guanine Nucleotide Exchange Factors/chemistry
- MAP Kinase Signaling System
- Male
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/metabolism
- Pertussis Toxin/pharmacology
- Phenylephrine/pharmacology
- Protein Structure, Tertiary
- RGS Proteins/genetics
- RGS Proteins/metabolism
- Rats
- Rats, Wistar
- Receptor, Endothelin A/metabolism
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Thrombin/metabolism
- Rho Guanine Nucleotide Exchange Factors
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Affiliation(s)
- Andrew K Snabaitis
- Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital, London, SE1 7EH, United Kingdom
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15
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Riobo NA, Manning DR. Receptors coupled to heterotrimeric G proteins of the G12 family. Trends Pharmacol Sci 2005; 26:146-54. [PMID: 15749160 DOI: 10.1016/j.tips.2005.01.007] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Much regarding the engagement of the G(12) family of heterotrimeric G proteins (G(12) and G(13)) by agonist-activated receptors remains unclear. For example, the identity of receptors that couple unequivocally to G(12) and G(13) and how signals are allocated among these and other G proteins remain open questions. Part of the problem in understanding signaling through G(12) and G(13) is that the activation of these G proteins is rarely demonstrated directly and is instead presumed usually from far removed downstream events. Furthermore, receptors that couple to G(12) and G(13) invariably couple to additional G proteins, and thus few events can be linked unambiguously to one G protein or another. In this article, we document receptors that reportedly couple to G(12), G(13) or both G(12) and G(13), evaluate the methodology used to understand the coupling of these receptors, and discuss the ability of these receptors to couple also to G(q).
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Affiliation(s)
- Natalia A Riobo
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6084, USA
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16
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Dent MR, Singal T, Dhalla NS, Tappia PS. Expression of phospholipase D isozymes in scar and viable tissue in congestive heart failure due to myocardial infarction. J Cell Mol Med 2005; 8:526-36. [PMID: 15601581 PMCID: PMC6740262 DOI: 10.1111/j.1582-4934.2004.tb00477.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The phospholipase D (PLD) associated with the cardiac sarcolemmal (SL) membrane hydrolyses phosphatidylcholine to produce phosphatidic acid, an important phospholipid signaling molecule known to influence cardiac function. The present study was undertaken to examine PLD isozyme mRNA expression, protein contents and activities in congestive heart failure (CHF) subsequent to myocardial infarction (MI). MI was induced in rats by occlusion of the left anterior descending coronary artery. At 8 weeks after the surgical procedure, hemodynamic assessment revealed that these experimental rats were at a moderate stage of CHF. Semi-quantitative reverse transcriptase-polymerase chain reaction revealed that PLD1 and PLD2 mRNA amounts were unchanged in viable left ventricular (LV) tissue of the failing heart. Furthermore, this technique demonstrated the presence of PLD1 and PLD2 mRNA in the scar tissue. While SL PLD1 and PLD2 protein contents were elevated in the viable LV tissue of the failing heart, SL PLD1 activity was significantly decreased, whereas SL PLD2 activity was significantly increased. On the other hand, although PLD1 protein was undetectable, PLD2 protein and activity were detected in the scar tissue. Our findings suggest that differential changes in PLD isozymes may contribute to the pathophysiology of CHF and may also be involved in the processes of scar remodeling.
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Affiliation(s)
- Melissa R Dent
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, 351 Tache Avenue, Winnipeg, Manitoba, Canada, R2H 2A6
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17
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Brostrom MA, Pan Z, Meiners S, Drumm C, Ahmed I, Brostrom CO. Ca2+ dynamics of thrombin-stimulated rat heart-derived embryonic myocytes: relationship to protein synthesis and cell growth. Int J Biochem Cell Biol 2003; 35:1573-87. [PMID: 12824066 DOI: 10.1016/s1357-2725(03)00132-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Various cell types respond to the serum protease, thrombin, with increased proliferation rates. In non-dividing postnatal mammalian cardiomyocytes, however, thrombin induces cellular hypertrophy. Both growth responses are associated with early Ca2+ signaling. The present study was conducted to characterize Ca2+ dynamics in thrombin stimulated, dividing embryonic cardiomyocytes, and to ascertain whether such dynamics support hypertrophic or hyperplastic growth. H9c2 rat cardiomyoblasts responded to thrombin with immediate, large increments in free Ca2+ that arose principally from the release of S(E)R sequestered Ca2+ and that persisted for only a few min. Ca2+ stores were refilled within 1h. Thrombin also increased rates of overall protein synthesis for several hours. This translational up-regulation, which required gene transcription, was abolished if cells were incubated at low extracellular Ca2+ during the first hour with thrombin. The protease conferred protective effects against toxicity resulting from serum deprivation and doxorubicin treatment. However, thrombin induced neither cellular hypertrophy, as is seen with arginine vasopressin, nor hyperplasia, as is observed with platelet-derived growth factor (PDGF-BB), in H9c2 cardiomyocytes. In comparison with vasopressin or PDGF-BB, thrombin promoted brief Ca2+ signaling, little cation movement to the extracellular fluid, and more rapid refilling of the S(E)R. It is concluded that the Ca2+ signaling generated by thrombin and the translational stimulation shown in this report to depend on this Ca2+ signaling are insufficient to sustain a major growth response in these embryonic cardiomyocytes.
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Affiliation(s)
- Margaret A Brostrom
- Department of Pharmacologya, U.M.D.N.J.-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA.
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18
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Liu S, Premont RT, Kontos CD, Huang J, Rockey DC. Endothelin-1 activates endothelial cell nitric-oxide synthase via heterotrimeric G-protein betagamma subunit signaling to protein jinase B/Akt. J Biol Chem 2003; 278:49929-35. [PMID: 14523027 DOI: 10.1074/jbc.m306930200] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Endothelin-1 has dual vasoactive effects, mediating vasoconstriction via ETA receptor activation of vascular smooth muscle cells and vasorelaxation via ETB receptor activation of endothelial cells. Although it is commonly accepted that endothelin-1 binding to endothelial cell ETB receptors stimulates nitric oxide (NO) synthesis and subsequent smooth muscle relaxation, the signaling pathways downstream of ETB receptor activation are unknown. Here, using a model in which we have utilized isolated primary endothelial cells, we demonstrate that ET-1 binding to sinusoidal endothelial cell ETB receptors led to increased protein kinase B/Akt phosphorylation, endothelial cell nitric-oxide synthase (eNOS) phosphorylation, and NO synthesis. Furthermore, eNOS activation was not dependent on tyrosine phosphorylation, and pretreatment of endothelial cells with pertussis toxin as well as overexpression of a dominant negative G-protein-coupled receptor kinase construct that sequesters betagamma subunits inhibited Akt phosphorylation and NO synthesis. Taken together, the data elucidate a G-protein-coupled receptor signaling pathway for ETB receptor-mediated NO production and call attention to the absolute requirement for heterotrimeric G-protein betagamma subunits in this cascade.
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Affiliation(s)
- Songling Liu
- Duke University Liver Center, Duke University Medical Center, Durham, North Carolina 27710, USA
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19
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Ouyang YS, Tu Y, Barker SA, Yang F. Regulators of G-protein signaling (RGS) 4, insertion into model membranes and inhibition of activity by phosphatidic acid. J Biol Chem 2003; 278:11115-22. [PMID: 12538649 DOI: 10.1074/jbc.m212606200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulators of G-protein signaling (RGS) proteins are critical for attenuating G protein-coupled signaling pathways. The membrane association of RGS4 has been reported to be crucial for its regulatory activity in reconstituted vesicles and physiological roles in vivo. In this study, we report that RGS4 initially binds onto the surface of anionic phospholipid vesicles and subsequently inserts into, but not through, the membrane bilayer. Phosphatidic acid, one of anionic phospholipids, could dramatically inhibit the ability of RGS4 to accelerate GTPase activity in vitro. Phosphatidic acid is an effective and potent inhibitor of RGS4 in a G alpha(i1)-[gamma-(32)P]GTP single turnover assay with an IC(50) approximately 4 microm and maximum inhibition of over 90%. Furthermore, phosphatidic acid was the only phospholipid tested that inhibited RGS4 activity in a receptor-mediated, steady-state GTP hydrolysis assay. When phosphatidic acid (10 mol %) was incorporated into m1 acetylcholine receptor-G alpha(q) vesicles, RGS4 GAP activity was markedly inhibited by more than 70% and the EC(50) of RGS4 was increased from 1.5 to 7 nm. Phosphatidic acid also induced a conformational change in the RGS domain of RGS4 measured by acrylamide-quenching experiments. Truncation of the N terminus of RGS4 (residues 1-57) resulted in the loss of both phosphatidic acid binding and lipid-mediated functional inhibition. A single point mutation in RGS4 (Lys(20) to Glu) permitted its binding to phosphatidic acid-containing vesicles but prevented lipid-induced conformational changes in the RGS domain and abolished the inhibition of its GAP activity. We speculate that the activation of phospholipase D or diacylglycerol kinase via G protein-mediated signaling cascades will increase the local concentration of phosphatidic acid, which in turn block RGS4 GAP activity in vivo. Thus, RGS4 may represent a novel effector of phosphatidic acid, and this phospholipid may function as a feedback regulator in G protein-mediated signaling pathways.
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Affiliation(s)
- Ying-Shi Ouyang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
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20
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Wieland T, Mittmann C. Regulators of G-protein signalling: multifunctional proteins with impact on signalling in the cardiovascular system. Pharmacol Ther 2003; 97:95-115. [PMID: 12559385 DOI: 10.1016/s0163-7258(02)00326-1] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Regulator of G-protein signalling (RGS) proteins form a superfamily of at least 25 proteins, which are highly diverse in structure, expression patterns, and function. They share a 120 amino acid homology domain (RGS domain), which exhibits GTPase accelerating activity for alpha-subunits of heterotrimeric G-proteins, and thus, are negative regulators of G-protein-mediated signalling. Based on the organisation of the Rgs genes, structural similarities, and differences in functions, they can be divided into at least six subfamilies of RGS proteins and three more families of RGS-like proteins. Many of these proteins regulate signalling processes within cells, not only via interaction with G-protein alpha-subunits, but are G-protein-regulated effectors, Gbetagamma scavenger, or scaffolding proteins in signal transduction complexes as well. The expression of at least 16 different RGS proteins in the mammalian or human myocardium have been described. A subgroup of at least eight was detected in a single atrial myocyte. The exact functions of these proteins remain mostly elusive, but RGS proteins such as RGS4 are involved in the regulation of G(i)-protein betagamma-subunit-gated K(+) channels. An up-regulation of RGS4 expression has been consistently found in human heart failure and some animal models. Evidence is increasing that the enhanced RGS4 expression counter-regulates the G(q/11)-induced signalling caused by hypertrophic stimuli. In the vascular system, RGS5 seems to be an important signalling regulator. It is expressed in vascular endothelial cells, but not in cultured smooth muscle cells. Its down-regulation, both in a model of capillary morphogenesis and in an animal model of stroke, render it a candidate gene, which may be involved in the regulation of capillary growth, angiogenesis, and in the pathophysiology of stroke.
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Affiliation(s)
- Thomas Wieland
- Institut für Pharmakologie und Toxikologie, Fakultät für Klinische Medizin Mannheim der Universität Heidelberg, Maybachstrasse 14-16, D-68169 Mannheim, Germany.
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Maas R, Schwedhelm E, Albsmeier J, Böger RH. The pathophysiology of erectile dysfunction related to endothelial dysfunction and mediators of vascular function. Vasc Med 2002; 7:213-25. [PMID: 12553745 DOI: 10.1191/1358863x02vm429ra] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The incidence of erectile dysfunction increases with diabetes, hypertension, hypercholesterolaemia, cardiovascular disease and renal failure. All these conditions are associated with endothelial dysfunction. This review addresses the pathophysiology of erectile dysfunction with a special focus on new insights into nitric oxide (NO)-mediated pathways, oxidative stress and parallels to endothelial dysfunction. NO appears to be the key mediator promoting endothelium-derived vasodilation and penile erection. The possibility is discussed that elevated plasma concentrations of asymmetrical dimethylarginine (ADMA), an endogenous NO synthase inhibitor, may provide an additional pathomechanism for various forms of erectile dysfunction associated with cardiovascular risk factors and disease. Likewise, the role of endothelium-derived factors mediating NO-independent pathways is evaluated.
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Affiliation(s)
- Renke Maas
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany.
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