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The role of PGE2 and EP receptors on lung's immune and structural cells; possibilities for future asthma therapy. Pharmacol Ther 2023; 241:108313. [PMID: 36427569 DOI: 10.1016/j.pharmthera.2022.108313] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Revised: 10/06/2022] [Accepted: 11/17/2022] [Indexed: 11/27/2022]
Abstract
Asthma is the most common airway chronic disease with treatments aimed mainly to control the symptoms. Adrenergic receptor agonists, corticosteroids and anti-leukotrienes have been used for decades, and the development of more targeted asthma treatments, known as biological therapies, were only recently established. However, due to the complexity of asthma and the limited efficacy as well as the side effects of available treatments, there is an urgent need for a new generation of asthma therapies. The anti-inflammatory and bronchodilatory effects of prostaglandin E2 in asthma are promising, yet complicated by undesirable side effects, such as cough and airway irritation. In this review, we summarize the most important literature on the role of all four E prostanoid (EP) receptors on the lung's immune and structural cells to further dissect the relevance of EP2/EP4 receptors as potential targets for future asthma therapy.
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Selectively targeting prostanoid E (EP) receptor-mediated cell signalling pathways: Implications for lung health and disease. Pulm Pharmacol Ther 2018; 49:75-87. [DOI: 10.1016/j.pupt.2018.01.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 01/05/2018] [Accepted: 01/25/2018] [Indexed: 12/18/2022]
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3
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Sharma S, Ruffenach G, Umar S, Motayagheni N, Reddy ST, Eghbali M. Role of oxidized lipids in pulmonary arterial hypertension. Pulm Circ 2016; 6:261-73. [PMID: 27683603 DOI: 10.1086/687293] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a multifactorial disease characterized by interplay of many cellular, molecular, and genetic events that lead to excessive proliferation of pulmonary cells, including smooth muscle and endothelial cells; inflammation; and extracellular matrix remodeling. Abnormal vascular changes and structural remodeling associated with PAH culminate in vasoconstriction and obstruction of pulmonary arteries, contributing to increased pulmonary vascular resistance, pulmonary hypertension, and right ventricular failure. The complex molecular mechanisms involved in the pathobiology of PAH are the limiting factors in the development of potential therapeutic interventions for PAH. Over the years, our group and others have demonstrated the critical implication of lipids in the pathogenesis of PAH. This review specifically focuses on the current understanding of the role of oxidized lipids, lipid metabolism, peroxidation, and oxidative stress in the progression of PAH. This review also discusses the relevance of apolipoprotein A-I mimetic peptides and microRNA-193, which are known to regulate the levels of oxidized lipids, as potential therapeutics in PAH.
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Affiliation(s)
- Salil Sharma
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Grégoire Ruffenach
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Soban Umar
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Negar Motayagheni
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Srinivasa T Reddy
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Mansoureh Eghbali
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Milne GL, Dai Q, Roberts LJ. The isoprostanes--25 years later. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1851:433-45. [PMID: 25449649 PMCID: PMC5404383 DOI: 10.1016/j.bbalip.2014.10.007] [Citation(s) in RCA: 226] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 10/13/2014] [Accepted: 10/21/2014] [Indexed: 01/26/2023]
Abstract
Isoprostanes (IsoPs) are prostaglandin-like molecules generated independent of the cyclooxygenase (COX) by the free radical-induced peroxidation of arachidonic acid. The first isoprostane species discovered were isomeric to prostaglandin F2α and were thus termed F2-IsoPs. Since the initial discovery of the F2-IsoPs, IsoPs with differing ring structures have been identified as well as IsoPs from different polyunsaturated fatty acids, including eicosapentaenoic acid and docosahexanenoic acid. The discovery of these molecules in vivo in humans has been a major contribution to the field of lipid oxidation and free radical research over the course of the past 25 years. These molecules have been determined to be both biomarkers and mediators of oxidative stress in numerous disease settings. This review focuses on recent developments in the field with an emphasis on clinical research. Special focus is given to the use of IsoPs as biomarkers in obesity, ischemia-reperfusion injury, the central nervous system, cancer, and genetic disorders. Additionally, attention is paid to diet and lifestyle factors that can affect endogenous levels of IsoPs. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance."
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Affiliation(s)
- Ginger L Milne
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Qi Dai
- Division of Epidemiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - L Jackson Roberts
- Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Davies SS, Guo L. Lipid peroxidation generates biologically active phospholipids including oxidatively N-modified phospholipids. Chem Phys Lipids 2014; 181:1-33. [PMID: 24704586 DOI: 10.1016/j.chemphyslip.2014.03.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 02/28/2014] [Accepted: 03/18/2014] [Indexed: 12/25/2022]
Abstract
Peroxidation of membranes and lipoproteins converts "inert" phospholipids into a plethora of oxidatively modified phospholipids (oxPL) that can act as signaling molecules. In this review, we will discuss four major classes of oxPL: mildly oxygenated phospholipids, phospholipids with oxidatively truncated acyl chains, phospholipids with cyclized acyl chains, and phospholipids that have been oxidatively N-modified on their headgroups by reactive lipid species. For each class of oxPL we will review the chemical mechanisms of their formation, the evidence for their formation in biological samples, the biological activities and signaling pathways associated with them, and the catabolic pathways for their elimination. We will end by briefly highlighting some of the critical questions that remain about the role of oxPL in physiology and disease.
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Affiliation(s)
- Sean S Davies
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University, United States.
| | - Lilu Guo
- Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt University, United States
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Van Ly D, Faiz A, Jenkins C, Crossett B, Black JL, McParland B, Burgess JK, Oliver BGG. Characterising the mechanism of airway smooth muscle β2 adrenoceptor desensitization by rhinovirus infected bronchial epithelial cells. PLoS One 2013; 8:e56058. [PMID: 23457497 PMCID: PMC3574065 DOI: 10.1371/journal.pone.0056058] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 01/04/2013] [Indexed: 11/19/2022] Open
Abstract
Rhinovirus (RV) infections account for approximately two thirds of all virus-induced asthma exacerbations and often result in an impaired response to β2 agonist therapy. Using an in vitro model of RV infection, we investigated the mechanisms underlying RV-induced β2 adrenoceptor desensitization in primary human airway smooth muscle cells (ASMC). RV infection of primary human bronchial epithelial cells (HBEC) for 24 hours produced conditioned medium that caused β2 adrenoceptor desensitization on ASMCs without an effect on ASMCs viability. Less than 3 kDa size fractionation together with trypsin digestion of RV-induced conditioned medium did not prevent β2 adrenoceptor desensitization, suggesting it could potentially be mediated by a small peptide or lipid. RV infection of BECs, ASMCs and fibroblasts produced prostaglandins, of which PGE2, PGF2α and PGI2 had the ability to cause β2 adrenoceptor desensitization on ASMCs. RV-induced conditioned medium from HBECs depleted of PGE2 did not prevent ASMC β2 adrenoceptor desensitization; however this medium induced PGE2 from ASMCs, suggesting that autocrine prostaglandin production may be responsible. Using inhibitors of cyclooxygenase and prostaglandin receptor antagonists, we found that β2 adrenoceptor desensitization was mediated through ASMC derived COX-2 induced prostaglandins. Since ASMC prostaglandin production is unlikely to be caused by RV-induced epithelial derived proteins or lipids we next investigated activation of toll-like receptors (TLR) by viral RNA. The combination of TLR agonists poly I:C and imiquimod induced PGE2 and β2 adrenoceptor desensitization on ASMC as did the RNA extracted from RV-induced conditioned medium. Viral RNA but not epithelial RNA caused β2 adrenoceptor desensitization confirming that viral RNA and not endogenous human RNA was responsible. It was deduced that the mechanism by which β2 adrenoceptor desensitization occurs was by pattern recognition receptor activation of COX-2 induced prostaglandins.
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Affiliation(s)
- David Van Ly
- Woolcock Institute of Medical Research, Sydney, Australia.
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Dekkers BGJ, Racké K, Schmidt M. Distinct PKA and Epac compartmentalization in airway function and plasticity. Pharmacol Ther 2012; 137:248-65. [PMID: 23089371 DOI: 10.1016/j.pharmthera.2012.10.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 10/09/2012] [Indexed: 12/15/2022]
Abstract
Asthma and chronic obstructive pulmonary disease (COPD) are obstructive lung diseases characterized by airway obstruction, airway inflammation and airway remodelling. Next to inflammatory cells and airway epithelial cells, airway mesenchymal cells, including airway smooth muscle cells and (myo)fibroblasts, substantially contribute to disease features by the release of inflammatory mediators, smooth muscle contraction, extracellular matrix deposition and structural changes in the airways. Current pharmacological treatment of both diseases intends to target the dynamic features of the endogenous intracellular suppressor cyclic AMP (cAMP). This review will summarize our current knowledge on cAMP and will emphasize on key discoveries and paradigm shifts reflecting the complex spatio-temporal nature of compartmentalized cAMP signalling networks in health and disease. As airway fibroblasts and airway smooth muscle cells are recognized as central players in the development and progression of asthma and COPD, we will focus on the role of cAMP signalling in their function in relation to airway function and plasticity. We will recapture on the recent identification of cAMP-sensing multi-protein complexes maintained by cAMP effectors, including A-kinase anchoring proteins (AKAPs), proteins kinase A (PKA), exchange protein directly activated by cAMP (Epac), cAMP-elevating seven-transmembrane (7TM) receptors and phosphodiesterases (PDEs) and we will report on findings indicating that the pertubation of compartmentalized cAMP signalling correlates with the pathopysiology of obstructive lung diseases. Future challenges include studies on cAMP dynamics and compartmentalization in the lung and the development of novel drugs targeting these systems for therapeutic interventions in chronic obstructive inflammatory diseases.
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Affiliation(s)
- Bart G J Dekkers
- Department of Molecular Pharmacology, University Center of Pharmacy, University of Groningen, The Netherlands.
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Chen JX, O’Mara PW, Poole SD, Brown N, Ehinger NJ, Slaughter JC, Paria BC, Aschner JL, Reese J. Isoprostanes as physiological mediators of transition to newborn life: novel mechanisms regulating patency of the term and preterm ductus arteriosus. Pediatr Res 2012; 72:122-8. [PMID: 22565502 PMCID: PMC3586272 DOI: 10.1038/pr.2012.58] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Increased oxygen tension at birth regulates physiologic events that are essential to postnatal survival, but the accompanying oxidative stress may also generate isoprostanes. We hypothesized that isoprostanes regulate ductus arteriosus (DA) function during postnatal vascular transition. METHODS Isoprostanes were measured by gas chromatography-mass spectrometry. DA tone was assessed by pressure myography. Gene expression was measured by quantitative PCR. RESULTS Oxygen exposure was associated with increased 8-iso-prostaglandin (PG)F2α in newborn mouse lungs. Both 8-iso-PGE2 and 8-iso-PGF2α induced concentration-dependent constriction of the isolated term DA, which was reversed by the thromboxane A2 (TxA2) receptor antagonist SQ29548. SQ29548 pretreatment unmasked an isoprostane-induced DA dilation mediated by the EP4 PG receptor. Exposure of the preterm DA to 8-iso-PGE2 caused unexpected DA relaxation that was reversed by EP4 antagonism. In contrast, exposure to 8-iso-PGF2α caused preterm DA constriction via TxA2 receptor activation. Further investigation revealed the predominance of the TxA2 receptor at term, whereas the EP4 receptor was expressed and functionally active from mid-gestation onward. CONCLUSION This study identifies a novel physiological role for isoprostanes during postnatal vascular transition and provide evidence that oxidative stress may act on membrane lipids to produce vasoactive mediators that stimulate physiological DA closure at birth or induce pathological patency of the preterm DA.
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Affiliation(s)
- Jian-Xiong Chen
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Patrick W. O’Mara
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Stanley D. Poole
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Naoko Brown
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Noah J. Ehinger
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - James C. Slaughter
- Department of Biostatistics, Vanderbilt University, Nashville, Tennessee
| | - Bibhash C. Paria
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Judy L. Aschner
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee
| | - Jeff Reese
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee;,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
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β2-Adrenoceptor agonist-induced RGS2 expression is a genomic mechanism of bronchoprotection that is enhanced by glucocorticoids. Proc Natl Acad Sci U S A 2011; 108:19713-8. [PMID: 22080612 DOI: 10.1073/pnas.1110226108] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In asthma and chronic obstructive pulmonary disease, activation of G(q)-protein-coupled receptors causes bronchoconstriction. In each case, the management of moderate-to-severe disease uses inhaled corticosteroid (glucocorticoid)/long-acting β(2)-adrenoceptor agonist (LABA) combination therapies, which are more efficacious than either monotherapy alone. In primary human airway smooth muscle cells, glucocorticoid/LABA combinations synergistically induce the expression of regulator of G-protein signaling 2 (RGS2), a GTPase-activating protein that attenuates G(q) signaling. Functionally, RGS2 reduced intracellular free calcium flux elicited by histamine, methacholine, leukotrienes, and other spasmogens. Furthermore, protection against spasmogen-increased intracellular free calcium, following treatment for 6 h with LABA plus corticosteroid, was dependent on RGS2. Finally, Rgs2-deficient mice revealed enhanced bronchoconstriction to spasmogens and an absence of LABA-induced bronchoprotection. These data identify RGS2 gene expression as a genomic mechanism of bronchoprotection that is induced by glucocorticoids plus LABAs in human airway smooth muscle and provide a rational explanation for the clinical efficacy of inhaled corticosteroid (glucocorticoid)/LABA combinations in obstructive airways diseases.
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Role of prostanoid production and receptors in the regulation of retinal endogenous amino acid neurotransmitters by 8-isoprostaglandin E2, ex vivo. Neurochem Res 2011; 34:2170-80. [PMID: 19513831 DOI: 10.1007/s11064-009-0013-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2009] [Indexed: 12/11/2022]
Abstract
The role of enzymes and receptors of the prostanoid pathway in the inhibitory effect of 8-isoprostaglandin E2 (8-isoPGE2) on endogenous amino acid neurotransmitter levels was examined, ex vivo. Freshly isolated bovine eyeballs were injected intravitreally with IsoPs, incubated in Krebs buffer for 30 min and retina prepared for HPLC-ECD detection of amino acids. 8-isoPGE2 attenuated retinal glutamate and its metabolite, glutamine and glycine in a concentration-dependent manner. The nonselective cyclooxygenase (COX)-inhibitor, flurbiprofen, COX-2 selective inhibitor, NS-398 and thromboxane (Tx) synthase inhibitor, furegrelate had no effect on both basal amino acid levels and the inhibitory effects of 8-isoPGE2 (1-100 μM) on the retinal amino acids. Whereas the TP-receptor antagonist SQ-29548(10 μM) exhibited no effect, SC-19220(EP1; 30 μM), AH-6809(EP(1-3); 30 μM) and AH-23848(EP4; 30 μM) reversed the inhibitory effects of 8-isoPGE2 (0.01-100 μM) on glutamate, glutamine and glycine levels. We conclude that prostanoid EP-receptors regulate the inhibitory effect of 8-isoPGE2 on basal levels of endogenous amino acids in bovine retina, ex vivo.
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Isoprostanes and asthma. Biochim Biophys Acta Gen Subj 2011; 1810:1091-5. [PMID: 21596100 DOI: 10.1016/j.bbagen.2011.04.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 04/06/2011] [Accepted: 04/28/2011] [Indexed: 12/12/2022]
Abstract
Isoprostanes are prostaglandin (PG)-like compounds generated in vivo following oxidative stress by non-enzymatic peroxidation of polyunsaturated fatty acids, including arachidonic acid. They are named based on their prostane ring structure and by the localization of hydroxyl groups on the carbon side chain; these structural differences result in a broad array of isoprostane molecules with varying biological properties. Generation of specific isoprostanes is also regulated by host cell redox conditions; reducing conditions favor F₂-isoprostane production while under conditions with deficient antioxidant capacity, D₂- and E₂-isoprostanes are formed. F₂-isoprostanes (F₂-isoP) are considered reliable markers of oxidative stress in pulmonary diseases including asthma. Importantly, F₂-isoP and other isoprostanes function as ligands for PG receptors, and potentially other receptors that have not yet been identified. They have been reported to have important biological properties in many organs. In the lung, isoprostanes regulate cellular processes affecting airway smooth muscle tone, neural secretion, epithelial ion flux, endothelial cell adhesion and permeability, and macrophage adhesion and function. In this review, we will summarize the evidence that F₂-isoP functions as a marker of oxidative stress in asthma, and that F₂-isoP and other isoprostanes exert biological effects that contribute to the pathogenesis of asthma. This article is part of a Special Issue entitled Biochemistry of Asthma.
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Giembycz MA, Newton R. Harnessing the clinical efficacy of phosphodiesterase 4 inhibitors in inflammatory lung diseases: dual-selective phosphodiesterase inhibitors and novel combination therapies. Handb Exp Pharmacol 2011:415-446. [PMID: 21695651 DOI: 10.1007/978-3-642-17969-3_18] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Phosphodiesterase (PDE) 4 inhibitors have been in development as a novel anti-inflammatory therapy for more than 20 years, with asthma and chronic obstructive pulmonary disease (COPD) being primary indications. Despite initial optimism, only one selective PDE4 inhibitor, roflumilast (Daxas (®)), has been approved for use in humans and available in Canada and the European Union in 2011 for the treatment of a specific population of patients with severe COPD. In many other cases, the development of PDE4 inhibitors of various structural classes has been discontinued due to lack of efficacy and/or dose-limiting adverse events. Indeed, for many of these compounds, it is likely that the maximum tolerated dose is either subtherapeutic or at the very bottom of the efficacy dose-response curve. Thus, a significant ongoing challenge that faces the pharmaceutical industry is to synthesize compounds with therapeutic ratios that are superior to roflumilast. Several strategies are being considered, but clinically effective compounds with an optimal pharmacophore have not, thus far, been reported. In this chapter, alternative means of harnessing the clinical efficacy of PDE4 inhibitors are described. These concepts are based on the assumption that additive or synergistic anti-inflammatory effects can be produced with inhibitors that target either two or more PDE families or with a PDE4 inhibitor in combination with other anti-inflammatory drugs such as a glucocorticoid.
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Affiliation(s)
- Mark A Giembycz
- Airways Inflammation Research Group, Departments of Physiology and Pharmacology, Institute of Infection, Immunity and Inflammation, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4N1, Canada.
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Clarke DL, Dakshinamurti S, Larsson AK, Ward JE, Yamasaki A. Lipid metabolites as regulators of airway smooth muscle function. Pulm Pharmacol Ther 2008; 22:426-35. [PMID: 19114116 DOI: 10.1016/j.pupt.2008.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 11/18/2008] [Accepted: 12/10/2008] [Indexed: 02/02/2023]
Abstract
Compelling evidence identifies airway smooth muscle (ASM) not only as a target but also a cellular source for a diverse range of mediators underlying the processes of airway narrowing and airway hyperresponsiveness in diseases such as asthma. These include the growing family of plasma membrane phospholipid-derived polyunsaturated fatty acids broadly characterised by the prostaglandins, leukotrienes, lipoxins, isoprostanes and lysophospholipids. In this review, we describe the enzymatic and non-enzymatic biosynthetic pathways of these lipid mediators and how these are influenced by drug treatment, oxidative stress and airways disease. Additionally, we outline their cognate receptors, many of which are expressed by ASM. We describe potential deleterious and protective roles for these lipid mediators in airway inflammatory and remodelling processes by describing their effects on diverse functions of ASM in asthma that have the potential to contribute to asthma pathogenesis and symptoms. These functions include contractile tone development, cytokine and extracellular matrix production, and cellular proliferation and migration.
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Affiliation(s)
- Deborah L Clarke
- Respiratory Pharmacology, National Heart and Lung Institute, Imperial College, London, UK
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15
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Kaur M, Holden NS, Wilson SM, Sukkar MB, Chung KF, Barnes PJ, Newton R, Giembycz MA. Effect of beta2-adrenoceptor agonists and other cAMP-elevating agents on inflammatory gene expression in human ASM cells: a role for protein kinase A. Am J Physiol Lung Cell Mol Physiol 2008; 295:L505-14. [PMID: 18586957 DOI: 10.1152/ajplung.00046.2008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In diseases such as asthma, airway smooth muscle (ASM) cells play a synthetic role by secreting inflammatory mediators such as granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, or IL-8 and by expressing surface adhesion molecules, including ICAM-1. In the present study, PGE(2), forskolin, and short-acting (salbutamol) and long-acting (salmeterol and formoterol) beta(2)-adrenoceptor agonists reduced the expression of ICAM-1 and the release of GM-CSF evoked by IL-1beta in ASM cells. IL-1beta-induced IL-8 release was also repressed by PGE(2) and forskolin, whereas the beta(2)-adrenoceptor agonists were ineffective. In each case, repression of these inflammatory indexes was prevented by adenoviral overexpression of PKIalpha, a highly selective PKA inhibitor. These data indicate a PKA-dependent mechanism of repression and suggest that agents that elevate intracellular cAMP, and thereby activate PKA, may have a widespread anti-inflammatory effect in ASM cells. Since ICAM-1 and GM-CSF are highly NF-kappaB-dependent genes, we used an adenoviral-delivered NF-kappaB-dependent luciferase reporter to examine the effects of forskolin and the beta(2)-adrenoceptor agonists on NF-kappaB activation. There was no effect on luciferase activity measured in the presence of forskolin or beta(2)-adrenoceptor agonists. This finding is consistent with the observation that IL-1beta-induced expression of IL-6, a known NF-kappaB-dependent gene in ASM, was also unaffected by beta(2)-adrenoceptor agonists, forskolin, PGE(2), 8-bromo-cAMP, or rolipram. Collectively, these results indicate that repression of IL-1beta-induced ICAM-1 expression and GM-CSF release by cAMP-elevating agents, including beta(2)-adrenoceptor agonists, may not occur through a generic effect on NF-kappaB.
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Affiliation(s)
- Manminder Kaur
- Dept. of Cell Biology & Anatomy, Faculty of Medicine, Univ. of Calgary, 3330 Hospital Dr. NW, Calgary, AB, Canada T2N 4N1
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Paredes C, Tazzeo T, Janssen LJ. E-ring isoprostane augments cholinergic neurotransmission in bovine trachealis via FP prostanoid receptors. Am J Respir Cell Mol Biol 2007; 37:739-47. [PMID: 17630320 DOI: 10.1165/rcmb.2007-0022oc] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Isoprostanes are prostaglandin-like molecules that accumulate in oxidative stress and also exert powerful biological effects on a wide variety of tissues. We investigated the effects of several different isoprostanes on contractions evoked by electrical field stimulation (EFS) in bovine trachealis, finding only 15-E2t-IsoP to augment those responses. Many others have shown that isoprostanes act on prostanoid receptors, usually those of the thromboxane-selective prostanoid receptor (TP) subtype, although some describe actions through prostaglandin E2-selective prostanoid receptor (EP) or less frequently through prostaglandin F2alpha-selective prostanoid receptors (FP). We used an extensive panel of highly selective agonists and antagonists of prostanoid receptors to characterize the ones through which 15-E2t-IsoP was acting here. Pretreatment with the FP-selective AL-8810 significantly inhibited the augmentation, whereas TP- and EP-selective blockers did not. On the other hand, the augmentation exerted by 15-E2t-IsoP was mimicked by submicromolar concentrations of the FP-selective agonists PGF2alpha and fluprostenol, as well as by micromolar concentrations of the TP-selective agonist U46619. The concentration-response relationship for exogenously added acetylcholine was not significantly affected by 15-E2t-IsoP, confirming that the effect of the latter on EFS-evoked responses was exerted prejunctionally (i.e., to enhance release of Ach from nerve endings), rather than a direct postjunctional effect via a receptor on the smooth muscle. Finally, we investigated whether the inhibitory (adrenergic) innervation was also modulated by 15-E2t-IsoP, finding EFS-evoked relaxations to be unaffected by the isoprostane. We conclude that 15-E2t-IsoP acts upon an FP receptor on the cholinergic nerve endings, leading to enhanced neurotransmission.
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Affiliation(s)
- Christine Paredes
- Firestone Institute for Respiratory Health, St. Joseph's Healthcare, and Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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17
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Li R, Mouillesseaux KP, Montoya D, Cruz D, Gharavi N, Dun M, Koroniak L, Berliner JA. Identification of Prostaglandin E2 Receptor Subtype 2 As a Receptor Activated by OxPAPC. Circ Res 2006; 98:642-50. [PMID: 16456101 DOI: 10.1161/01.res.0000207394.39249.fc] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (OxPAPC), which has been shown to accumulate in atherosclerotic lesions and other sites of chronic inflammation, activates endothelial cells (EC) to bind monocytes by activation of endothelial beta1 integrin and subsequent deposition of fibronectin on the apical surface. Our previous studies suggest this function of OxPAPC is mediated via a Gs protein-coupled receptor (GPCR). PEIPC (1-palmitoyl-2-epoxyisoprostane E2-sn-glycero-3-phosphorylcholine) is the most active lipid in OxPAPC that activates this pathway. We screened a number of candidate GPCRs for their interaction with OxPAPC and PEIPC, using a reporter gene assay; we identified prostaglandin E2 receptor EP2 and prostaglandin D2 receptor DP as responsive to OxPAPC. We focused on EP2, which is expressed in ECs, monocytes, and macrophages. OxPAPC component PEIPC, but not POVPC, activated EP2 with an EC50 of 108.6 nmol/L. OxPAPC and PEIPC were also able to compete with PGE2 for binding to EP2 in a ligand-binding assay. The EP2 specific agonist butaprost was shown to mimic the effect of OxPAPC on the activation of beta1 integrin and the stimulation of monocyte binding to endothelial cells. Butaprost also mimicked the effect of OxPAPC on the regulation of tumor necrosis factor-alpha and interleukin-10 in monocyte-derived cells. EP2 antagonist AH6809 blocked the activation of EP2 by OxPAPC in HEK293 cells and blocked the interleukin-10 response to PEIPC in monocytic THP-1 cells. These results suggest that EP2 functions as a receptor for OxPAPC and PEIPC, either as the phospholipid ester or the released fatty acid, in both endothelial cells and macrophages.
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Affiliation(s)
- Rongsong Li
- Department of Pathology, University of California, Los Angeles, CA 90095, USA
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Bradbury D, Clarke D, Seedhouse C, Corbett L, Stocks J, Knox A. Vascular endothelial growth factor induction by prostaglandin E2 in human airway smooth muscle cells is mediated by E prostanoid EP2/EP4 receptors and SP-1 transcription factor binding sites. J Biol Chem 2005; 280:29993-30000. [PMID: 15970595 DOI: 10.1074/jbc.m414530200] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prostaglandin E2 (PGE2) can increase endothelial vascular endogrowth factor A (VEGF-A) production but the mechanisms involved are unclear. Here we characterized the transcriptional mechanisms involved in human airway smooth muscle cells (HASMC). PGE2 increased VEGF-A mRNA and protein but not mRNA stability. PGE2 stimulated the activity of a transiently transfected 2068-bp (-2018 to +50) VEGF-A promoter-driven luciferase construct. Functional 5' deletional analysis mapped the PGE2 response element to the 135-bp sequence (-85/+50) of the human VEGF-A promoter. PGE2-induced luciferase activity was reduced in cells transfected with a 135-bp VEGF promoter fragment containing mutated Sp-1 binding sites but not in cells transfected with a construct containing mutated EGR-1 binding sites. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay confirmed binding of Sp-1 to the VEGF promoter. PGE2 increased phosphorylation of Sp-1 and luciferase activity of a transfected Sp-1 reporter construct. PGE receptor agonists EP2 (ONO-AE1 259) and EP4 (ONO-AE1 329) mimicked the effect of PGE2, and reverse transcription-PCR, Western blotting, and flow cytometry confirmed the presence of EP2 and EP4 receptors. VEGF protein release and Sp-1 reporter activity were increased by forskolin and isoproterenol, which increase cytosolic cAMP, and the cAMP analogue, 8-bromoadenosine-3',5'-cyclophosphoric acid. These studies suggest that PGE2 increases VEGF transcriptionally and involves the Sp-1 binding site via a cAMP-dependent mechanism involving EP2 and EP4 receptors.
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MESH Headings
- Base Sequence
- Binding Sites
- Cell Survival
- Cells, Cultured
- Chromatin Immunoprecipitation
- Colforsin/pharmacology
- Cyclic AMP/metabolism
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Dinoprostone/metabolism
- Dose-Response Relationship, Drug
- Gene Deletion
- Humans
- Isoproterenol/pharmacology
- Luciferases/metabolism
- Molecular Sequence Data
- Mutation
- Myocytes, Smooth Muscle/cytology
- Promoter Regions, Genetic
- Protein Binding
- RNA/metabolism
- RNA, Messenger/metabolism
- Receptors, Prostaglandin E/metabolism
- Receptors, Prostaglandin E, EP2 Subtype
- Receptors, Prostaglandin E, EP4 Subtype
- Sp1 Transcription Factor/metabolism
- Time Factors
- Trachea/cytology
- Transcription, Genetic
- Transfection
- Vascular Endothelial Growth Factor A/biosynthesis
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Dawn Bradbury
- Division of Respiratory Medicine, University of Nottingham, City Hospital, Nottingham NG5 1PB, United Kingdom
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