1
|
Facchinetti F, Civelli M, Singh D, Papi A, Emirova A, Govoni M. Tanimilast, A Novel Inhaled Pde4 Inhibitor for the Treatment of Asthma and Chronic Obstructive Pulmonary Disease. Front Pharmacol 2021; 12:740803. [PMID: 34887752 PMCID: PMC8650159 DOI: 10.3389/fphar.2021.740803] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 11/01/2021] [Indexed: 12/12/2022] Open
Abstract
Chronic respiratory diseases are the third leading cause of death, behind cardiovascular diseases and cancer, affecting approximately 550 million of people all over the world. Most of the chronic respiratory diseases are attributable to asthma and chronic obstructive pulmonary disease (COPD) with this latter being the major cause of deaths. Despite differences in etiology and symptoms, a common feature of asthma and COPD is an underlying degree of airways inflammation. The nature and severity of this inflammation might differ between and within different respiratory conditions and pharmacological anti-inflammatory treatments are unlikely to be effective in all patients. A precision medicine approach is needed to selectively target patients to increase the chance of therapeutic success. Inhibitors of the phosphodiesterase 4 (PDE4) enzyme like the oral PDE4 inhibitor roflumilast have shown a potential to reduce inflammatory-mediated processes and the frequency of exacerbations in certain groups of COPD patients with a chronic bronchitis phenotype. However, roflumilast use is dampened by class related side effects as nausea, diarrhea, weight loss and abdominal pain, resulting in both substantial treatment discontinuation in clinical practice and withdrawal from clinical trials. This has prompted the search for PDE4 inhibitors to be given by inhalation to reduce the systemic exposure (and thus optimize the systemic safety) and maximize the therapeutic effect in the lung. Tanimilast (international non-proprietary name of CHF6001) is a novel highly potent and selective inhaled PDE4 inhibitor with proven anti-inflammatory properties in various inflammatory cells, including leukocytes derived from asthma and COPD patients, as well as in experimental rodent models of pulmonary inflammation. Inhaled tanimilast has reached phase III clinical development by showing promising pharmacodynamic results associated with a good tolerability and safety profile, with no evidence of PDE4 inhibitors class-related side effects. In this review we will discuss the main outcomes of preclinical and clinical studies conducted during tanimilast development, with particular emphasis on the characterization of the pharmacodynamic profile that led to the identification of target populations with increased therapeutic potential in inflammatory respiratory diseases.
Collapse
Affiliation(s)
| | | | - Dave Singh
- Medicines Evaluation Unit, Manchester University NHS Foundation Hospital Trust, Manchester, United Kingdom
| | - Alberto Papi
- Respiratory Medicine, Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Aida Emirova
- Global Clinical Development, Chiesi, Parma, Italy
| | - Mirco Govoni
- Global Clinical Development, Chiesi, Parma, Italy
| |
Collapse
|
2
|
Bayraktutan Z, Dincer B, Keskin H, Kose D, Bilen A, Toktay E, Sirin B, Halici Z. Roflumilast as a Potential Therapeutic Agent for Cecal Ligation and Puncture-Induced Septic Lung Injury. J INVEST SURG 2021; 35:605-613. [PMID: 33843406 DOI: 10.1080/08941939.2021.1908462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE/AIMS This study focused on delineating the possible effects of roflumilast (ROF), a selective phosphodiesterase 4 (PDE4) inhibitor, in rats with cecal ligation and puncture (CLP)-induced polymicrobial sepsis, and investigated whether ROF can act as a protective agent in sepsis-induced lung damage. MATERIAL AND METHODS Four experimental groups were organized, each comprising eight rats: Control, Sepsis, Sepsis + ROF 0.5 mgkg-1, and Sepsis + ROF 1 mgkg-1 groups. A polymicrobial sepsis model was induced in the rats by cecal ligation and puncture under anesthesia. Twelve hours after sepsis induction, the lungs were obtained for biochemical, molecular, and histopathological analyses. RESULTS In the sepsis group's lungs, the TNF-α, IL-1β, and IL-6 mRNA expression levels peaked in the sepsis group's lung tissues, and ROF significantly decreased these levels compared with the sepsis group dose-dependently. ROF also significantly decreased MDA levels in septic lungs and increased antioxidant parameters (SOD and GSH) compared with the sepsis group. Histopathological analysis results supported biochemical and molecular results. CONCLUSIONS ROF, a PDE4 inhibitor, suppressed the expression levels of pro-inflammatory cytokines, alleviated lung damage (probably by blocking neutrophil infiltration), and increased the capacity of the antioxidant system.
Collapse
Affiliation(s)
| | - Busra Dincer
- Department of Pharmacology, Erzincan Binali Yildirim University, Erzincan, Turkey
| | - Halil Keskin
- Department of Child Health and Diseases, Ataturk University, Erzurum, Turkey
| | - Duygu Kose
- Department of Pharmacology, Ataturk University, Erzurum, Turkey
| | - Arzu Bilen
- Department of Internal Medicine, Ataturk University, Erzurum, Turkey
| | - Erdem Toktay
- Department of Histology and Embryology, Kafkas University, Kars, Turkey
| | - Busra Sirin
- Clinical Research, Development and Design Application and Research Center, Ataturk University, Erzurum, Turkey
| | - Zekai Halici
- Department of Pharmacology, Ataturk University, Erzurum, Turkey.,Department of Internal Medicine, Ataturk University, Erzurum, Turkey.,Department of Histology and Embryology, Kafkas University, Kars, Turkey.,Clinical Research, Development and Design Application and Research Center, Ataturk University, Erzurum, Turkey
| |
Collapse
|
3
|
Joshi R, Hamed O, Yan D, Michi AN, Mostafa MM, Wiehler S, Newton R, Giembycz MA. Prostanoid Receptors of the EP 4-Subtype Mediate Gene Expression Changes in Human Airway Epithelial Cells with Potential Anti-Inflammatory Activity. J Pharmacol Exp Ther 2020; 376:161-180. [PMID: 33158942 DOI: 10.1124/jpet.120.000196] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 11/03/2020] [Indexed: 11/22/2022] Open
Abstract
There is a clear, unmet clinical need to identify new drugs to treat individuals with asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF) in whom current medications are either inactive or suboptimal. In preclinical models, EP4-receptor agonists display efficacy, but their mechanism of action is unclear. In this study, using human bronchial epithelial cells as a therapeutically relevant drug target, we hypothesized that changes in gene expression may play an important role. Several prostanoid receptor mRNAs were detected in BEAS-2B cells, human primary bronchial epithelial cells (HBECs) grown in submersion culture and HBECs grown at an air-liquid interface with PTGER4 predominating. By using the activation of a cAMP response element reporter in BEAS-2B cells as a surrogate of gene expression, Schild analysis determined that PTGER4 mRNAs encoded functional EP4-receptors. Moreover, inhibitors of phosphodiesterase 4 (roflumilast N-oxide [RNO]) and cAMP-dependent protein kinase augmented and attenuated, respectively, reporter activation induced by 2-[3-[(1R,2S,3R)-3-hydroxy-2-[(E,3S)-3-hydroxy-5-[2-(methoxymethyl)phenyl]pent-1-enyl]-5-oxo-cyclopentyl]sulphanylpropylsulphanyl] acetic acid (ONO-AE1-329), a selective EP4-receptor agonist. ONO-AE1-329 also enhanced dexamethasone-induced activation of a glucocorticoid response element reporter in BEAS-2B cells, which was similarly potentiated by RNO. In each airway epithelial cell variant, numerous genes that may impart therapeutic benefit in asthma, COPD, and/or IPF were differentially expressed by ONO-AE1-329, and those changes were often augmented by RNO and/or dexamethasone. We submit that an EP4-receptor agonist, either alone or as a combination therapy, may be beneficial in individuals with chronic lung diseases in whom current treatment options are inadequate. SIGNIFICANCE STATEMENT: Using human bronchial epithelial cells as a therapeutically relevant drug target, we report that EP4-receptor activation promoted gene expression changes that could provide therapeutic benefit in individuals with asthma, COPD, and IPF in whom current treatment options are ineffective or suboptimal.
Collapse
Affiliation(s)
- Radhika Joshi
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Omar Hamed
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Dong Yan
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Aubrey N Michi
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Mahmoud M Mostafa
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Shahina Wiehler
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert Newton
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Mark A Giembycz
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
4
|
Rhee CK, Kim DK. Role of phosphodiesterase-4 inhibitors in chronic obstructive pulmonary disease. Korean J Intern Med 2020; 35:276-283. [PMID: 32131571 PMCID: PMC7061018 DOI: 10.3904/kjim.2020.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 02/22/2020] [Indexed: 12/18/2022] Open
Abstract
Phosphodiesterase-4 inhibitors (PDE4Is) are potent anti-inf lammatory agents and roflumilast has been used to prevent acute exacerbation of chronic obstructive pulmonary disease (COPD). Roflumilast decreases neutrophil migration, restores cystic fibrosis transmembrane conductance regulator activity, and recovers glucocorticoid effects. A forced expiratory volume in 1 second of < 50%, a chronic bronchitis phenotype, high blood eosinophil levels, and a history of hospitalization are biomarkers for predicting responses to roflumilast. Adverse effects are common in clinical practice. An inhaled PDE4I has recently been developed and is under clinical trial. CHF6001 and RPL554 exhibit promise and may be future treatment options for COPD.
Collapse
Affiliation(s)
- Chin Kook Rhee
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Deog Kyeom Kim
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Korea
- Correspondence to Deog Kyeom Kim, M.D. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, 20 Boramae-ro 5-gil, Dongjak-gu, Seoul 07061, Korea Tel: +82-2-870-2228 Fax: +82-2-831-0714 E-mail:
| |
Collapse
|
5
|
Joshi R, Yan D, Hamed O, Mostafa MM, Joshi T, Newton R, Giembycz MA. Impact of Phosphodiesterase 4 Inhibition on the Operational Efficacy, Response Maxima, and Kinetics of Indacaterol-Induced Gene Expression Changes in BEAS-2B Airway Epithelial Cells: A Global Transcriptomic Analysis. Mol Pharmacol 2019; 96:56-72. [DOI: 10.1124/mol.118.115311] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 04/25/2019] [Indexed: 12/26/2022] Open
|
6
|
Dunne AE, Kawamatawong T, Fenwick PS, Davies CM, Tullett H, Barnes PJ, Donnelly LE. Direct Inhibitory Effect of the PDE4 Inhibitor Roflumilast on Neutrophil Migration in Chronic Obstructive Pulmonary Disease. Am J Respir Cell Mol Biol 2019; 60:445-453. [DOI: 10.1165/rcmb.2018-0065oc] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Amy E. Dunne
- Airway Disease, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Theerasuk Kawamatawong
- Airway Disease, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter S. Fenwick
- Airway Disease, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Ceri M. Davies
- Airway Disease, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Hannah Tullett
- Airway Disease, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter J. Barnes
- Airway Disease, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Louise E. Donnelly
- Airway Disease, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| |
Collapse
|
7
|
Joshi T, Yan D, Hamed O, Tannheimer SL, Phillips GB, Wright CD, Kim M, Salmon M, Newton R, Giembycz MA. GS-5759, a Bifunctional β2-Adrenoceptor Agonist and Phosphodiesterase 4 Inhibitor for Chronic Obstructive Pulmonary Disease with a Unique Mode of Action: Effects on Gene Expression in Human Airway Epithelial Cells. J Pharmacol Exp Ther 2016; 360:324-340. [DOI: 10.1124/jpet.116.237743] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/05/2016] [Indexed: 12/31/2022] Open
|
8
|
Newton R, Giembycz MA. Understanding how long-acting β 2 -adrenoceptor agonists enhance the clinical efficacy of inhaled corticosteroids in asthma - an update. Br J Pharmacol 2016; 173:3405-3430. [PMID: 27646470 DOI: 10.1111/bph.13628] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/19/2016] [Accepted: 08/21/2016] [Indexed: 12/18/2022] Open
Abstract
In moderate-to-severe asthma, adding an inhaled long-acting β2 -adenoceptor agonist (LABA) to an inhaled corticosteroid (ICS) provides better disease control than simply increasing the dose of ICS. Acting on the glucocorticoid receptor (GR, gene NR3C1), ICSs promote anti-inflammatory/anti-asthma gene expression. In vitro, LABAs synergistically enhance the maximal expression of many glucocorticoid-induced genes. Other genes, including dual-specificity phosphatase 1(DUSP1) in human airways smooth muscle (ASM) and epithelial cells, are up-regulated additively by both drug classes. Synergy may also occur for LABA-induced genes, as illustrated by the bronchoprotective gene, regulator of G-protein signalling 2 (RGS2) in ASM. Such effects cannot be produced by either drug alone and may explain the therapeutic efficacy of ICS/LABA combination therapies. While the molecular basis of synergy remains unclear, mechanistic interpretations must accommodate gene-specific regulation. We explore the concept that each glucocorticoid-induced gene is an independent signal transducer optimally activated by a specific, ligand-directed, GR conformation. In addition to explaining partial agonism, this realization provides opportunities to identify novel GR ligands that exhibit gene expression bias. Translating this into improved therapeutic ratios requires consideration of GR density in target tissues and further understanding of gene function. Similarly, the ability of a LABA to interact with a glucocorticoid may be suboptimal due to low β2 -adrenoceptor density or biased β2 -adrenoceptor signalling. Strategies to overcome these limitations include adding-on a phosphodiesterase inhibitor and using agonists of other Gs-coupled receptors. In all cases, the rational design of ICS/LABA, and derivative, combination therapies requires functional knowledge of induced (and repressed) genes for therapeutic benefit to be maximized.
Collapse
Affiliation(s)
- Robert Newton
- Department of Cell Biology and Anatomy, Airways Inflammation Research Group, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Mark A Giembycz
- Department of Physiology and Pharmacology, Airways Inflammation Research Group, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
9
|
Leigh R, Mostafa MM, King EM, Rider CF, Shah S, Dumonceaux C, Traves SL, McWhae A, Kolisnik T, Kooi C, Slater DM, Kelly MM, Bieda M, Miller-Larsson A, Newton R. An inhaled dose of budesonide induces genes involved in transcription and signaling in the human airways: enhancement of anti- and proinflammatory effector genes. Pharmacol Res Perspect 2016; 4:e00243. [PMID: 28116096 PMCID: PMC5242176 DOI: 10.1002/prp2.243] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/03/2016] [Indexed: 12/27/2022] Open
Abstract
Although inhaled glucocorticoids, or corticosteroids (ICS), are generally effective in asthma, understanding their anti‐inflammatory actions in vivo remains incomplete. To characterize glucocorticoid‐induced modulation of gene expression in the human airways, we performed a randomized placebo‐controlled crossover study in healthy male volunteers. Six hours after placebo or budesonide inhalation, whole blood, bronchial brushings, and endobronchial biopsies were collected. Microarray analysis of biopsy RNA, using stringent (≥2‐fold, 5% false discovery rate) or less stringent (≥1.25‐fold, P ≤ 0.05) criteria, identified 46 and 588 budesonide‐induced genes, respectively. Approximately two third of these genes are transcriptional regulators (KLF9, PER1, TSC22D3, ZBTB16), receptors (CD163, CNR1, CXCR4, LIFR, TLR2), or signaling genes (DUSP1, NFKBIA, RGS1, RGS2, ZFP36). Listed genes were qPCR verified. Expression of anti‐inflammatory and other potentially beneficial genes is therefore confirmed and consistent with gene ontology (GO) terms for negative regulation of transcription and gene expression. However, GO terms for transcription, signaling, metabolism, proliferation, inflammatory responses, and cell movement were also associated with the budesonide‐induced genes. The most enriched functional cluster indicates positive regulation of proliferation, locomotion, movement, and migration. Moreover, comparison with the budesonide‐induced expression profile in primary human airway epithelial cells shows considerable cell type specificity. In conclusion, increased expression of multiple genes, including the transcriptional repressor, ZBTB16, that reduce inflammatory signaling and gene expression, occurs in the airways and blood and may contribute to the therapeutic efficacy of ICS. This provides a previously lacking insight into the in vivo effects of ICS and should promote strategies to improve glucocorticoid efficacy in inflammatory diseases.
Collapse
Affiliation(s)
- Richard Leigh
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Mahmoud M Mostafa
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Elizabeth M King
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Christopher F Rider
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Suharsh Shah
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Curtis Dumonceaux
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Suzanne L Traves
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Andrew McWhae
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Tyler Kolisnik
- Alberta Children's Hospital Research Institute University of Calgary Calgary Alberta T2N 4Z6
| | - Cora Kooi
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Donna M Slater
- Alberta Children's Hospital Research Institute University of Calgary Calgary Alberta T2N 4Z6
| | - Margaret M Kelly
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| | - Mark Bieda
- Alberta Children's Hospital Research Institute University of Calgary Calgary Alberta T2N 4Z6
| | | | - Robert Newton
- Airways Inflammation Research Group Snyder Institute for Chronic Diseases University of Calgary Calgary Alberta T2N 4Z6
| |
Collapse
|
10
|
Vos W, Hajian B, De Backer J, Van Holsbeke C, Vinchurkar S, Claes R, Hufkens A, Parizel PM, Bedert L, De Backer W. Functional respiratory imaging to assess the interaction between systemic roflumilast and inhaled ICS/LABA/LAMA. Int J Chron Obstruct Pulmon Dis 2016; 11:263-71. [PMID: 26917956 PMCID: PMC4745845 DOI: 10.2147/copd.s93830] [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] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Patients with COPD show a significant reduction of the lobar hyperinflation at the functional residual capacity level in the patients who improved >120 mL in forced expiratory volume in 1 second (FEV1) after 6 months of treatment with roflumilast in addition to inhaled corticosteroids (ICSs)/long-acting beta-2 agonists (LABAs)/long-acting muscarinic antagonists (LAMAs). Methods Functional respiratory imaging was used to quantify lobar hyperinflation, blood vessel density, ventilation, aerosol deposition, and bronchodilation. To investigate the exact mode of action of roflumilast, correlations between lobar and global measures have been tested using a mixed-model approach with nested random factors and Pearson correlation, respectively. Results The reduction in lobar hyperinflation appears to be associated with a larger blood vessel density in the respective lobes (t=−2.154, P=0.040); lobes with a higher percentage of blood vessels reduce more in hyperinflation in the responder group. Subsequently, it can be observed that lobes that reduce in hyperinflation after treatment are better ventilated (t=−5.368, P<0.001). Functional respiratory imaging (FRI)-based aerosol deposition showed that enhanced ventilation leads to more peripheral particle deposition of ICS/LABA/LAMA in the better-ventilated areas (t=2.407, P=0.024). Finally, the study showed that areas receiving more particles have increased FRI-based bronchodilation (t=2.564, P=0.017), leading to an increase in FEV1 (R=0.348, P=0.029). Conclusion The study demonstrated that orally administered roflumilast supports the reduction of regional hyperinflation in areas previously undertreated by inhalation medication. The local reduction in hyperinflation induces a redistribution of ventilation and aerosol deposition, leading to enhanced efficacy of the concomitant ICS/LABA/LAMA therapy. FRI appears to be a sensitive tool to describe the mode of action of novel compounds in chronic obstructive pulmonary disease. Future studies need to confirm the enhanced sensitivity and the potential of FRI parameters to act as surrogates for clinically relevant, but more difficult to measure, end points such as exacerbations.
Collapse
Affiliation(s)
- Wim Vos
- FLUIDDA nv, Groeningenlei, Kontich, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Bita Hajian
- Department of Respiratory Medicine, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Jan De Backer
- FLUIDDA nv, Groeningenlei, Kontich, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Cedric Van Holsbeke
- FLUIDDA nv, Groeningenlei, Kontich, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Samir Vinchurkar
- FLUIDDA nv, Groeningenlei, Kontich, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Rita Claes
- Department of Respiratory Medicine, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Annemie Hufkens
- Department of Respiratory Medicine, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Paul M Parizel
- Department of Radiology, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| | - Lieven Bedert
- Department of Respiratory Medicine, ZNA Middelheim Hospital, Antwerp, Belgium
| | - Wilfried De Backer
- Department of Respiratory Medicine, University Hospital Antwerp, Wilrijkstraat, Edegem, Belgium
| |
Collapse
|
11
|
Eskandari N, Mirmosayyeb O, Bordbari G, Bastan R, Yousefi Z, Andalib A. A short review on structure and role of cyclic-3',5'-adenosine monophosphate-specific phosphodiesterase 4 as a treatment tool. J Res Pharm Pract 2015; 4:175-81. [PMID: 26645022 PMCID: PMC4645128 DOI: 10.4103/2279-042x.167043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) are known as a super-family of enzymes which catalyze the metabolism of the intracellular cyclic nucleotides, cyclic-3',5'-adenosine monophosphate (cAMP), and cyclic-3',5'-guanosine monophosphate that are expressed in a variety of cell types that can exert various functions based on their cells distribution. The PDE4 family has been the focus of vast research efforts over recent years because this family is considered as a prime target for therapeutic intervention in a number of inflammatory diseases such as asthma, chronic obstructive pulmonary disease, and rheumatoid arthritis, and it should be used and researched by pharmacists. This is because the major isoform of PDE that regulates inflammatory cell activity is the cAMP-specific PDE, PDE4. This review discusses the relationship between PDE4 and its inhibitor drugs based on structures, cells distribution, and pharmacological properties of PDE4 which can be informative for all pharmacy specialists.
Collapse
Affiliation(s)
- Nahid Eskandari
- Department of Immunology, Isfahan University of Medical Sciences, Isfahan, Iran ; Applied Physiology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Omid Mirmosayyeb
- Department of Immunology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Gazaleh Bordbari
- Department of Immunology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Reza Bastan
- Department of Human Vaccines, Razi Serum and Vaccine Research Institute, Karaj, Alborz, Iran
| | - Zahra Yousefi
- Department of Immunology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Alireza Andalib
- Department of Immunology, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
12
|
Joshi T, Johnson M, Newton R, Giembycz MA. The long-acting β2 -adrenoceptor agonist, indacaterol, enhances glucocorticoid receptor-mediated transcription in human airway epithelial cells in a gene- and agonist-dependent manner. Br J Pharmacol 2015; 172:2634-53. [PMID: 25598440 DOI: 10.1111/bph.13087] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/11/2014] [Accepted: 01/13/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE Inhaled glucocorticoid (ICS)/long-acting β2 -adrenoceptor agonist (LABA) combination therapy is a recommended treatment option for patients with moderate/severe asthma in whom adequate control cannot be achieved by an ICS alone. Previously, we discovered that LABAs can augment dexamethasone-inducible gene expression and proposed that this effect may explain how these two drugs interact to deliver superior clinical benefit. Herein, we extended that observation by analysing, pharmacodynamically, the effect of the LABA, indacaterol, on glucocorticoid receptor (GR)-mediated gene transcription induced by seven ligands with intrinsic activity values that span the spectrum of full agonism to antagonism. EXPERIMENTAL APPROACH BEAS-2B human airway epithelial cells stably transfected with a 2× glucocorticoid response element luciferase reporter were used to model gene transcription together with an analysis of several glucocorticoid-inducible genes. KEY RESULTS Indacaterol augmented glucocorticoid-induced reporter activation in a manner that was positively related to the intrinsic activity of the GR agonist. This effect was demonstrated by an increase in response maxima without a change in GR agonist affinity or efficacy. Indacaterol also enhanced glucocorticoid-inducible gene expression. However, the magnitude of this effect was dependent on both the GR agonist and the gene of interest. CONCLUSIONS AND IMPLICATIONS These data suggest that indacaterol activates a molecular rheostat, which increases the transcriptional competency of GR in an agonist- and gene-dependent manner without apparently changing the relationship between fractional GR occupancy and response. These findings provide a platform to rationally design ICS/LABA combination therapy that is based on the generation of agonist-dependent gene expression profiles in target and off-target tissues.
Collapse
Affiliation(s)
- T Joshi
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | | | | | | |
Collapse
|
13
|
Gimenez LE, Baameur F, Vayttaden SJ, Clark RB. Salmeterol Efficacy and Bias in the Activation and Kinase-Mediated Desensitization of β2-Adrenergic Receptors. Mol Pharmacol 2015; 87:954-64. [PMID: 25784721 DOI: 10.1124/mol.114.096800] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 03/17/2015] [Indexed: 11/22/2022] Open
Abstract
Salmeterol is a long-acting β2-adrenergic receptor (β2AR) agonist that is widely used as a bronchodilator for the treatment of persistent asthma and chronic obstructive pulmonary disease in conjunction with steroids. Previous studies demonstrated that salmeterol showed weak efficacy for activation of adenylyl cyclase; however, its efficacy in the complex desensitization of the β2AR remains poorly understood. In this work, we provide insights into the roles played by the G protein-coupled receptor kinase/arrestin and protein kinase A in salmeterol-mediated desensitization through bioluminescence resonance energy transfer (BRET) studies of liganded-β2AR binding to arrestin and through kinetic studies of cAMP turnover. First, BRET demonstrated a much reduced efficacy for salmeterol recruitment of arrestin to β2AR relative to isoproterenol. The ratio of BRETISO/BRETSALM after 5-minute stimulation was 20 and decreased to 5 after 35 minutes, reflecting a progressive decline in BRETISO and a stable BRETSALM. Second, to assess salmeterol efficacy for functional desensitization, we examined the kinetics of salmeterol-induced cAMP accumulation (0-30 minutes) in human airway smooth muscle cells in the presence and absence of phosphodiesterase inhibition. Analysis of shaping of cAMP turnover for both agonists demonstrated significant salmeterol desensitization, although it was reduced relative to isoproterenol. Using an isoproterenol rescue protocol after either short-term (10 minutes) or long-term (2 and 14 hours) salmeterol pretreatments, we found that salmeterol progressively depressed isoproterenol stimulation but did not prevent subsequent rescue by isoproterenol and additional isoproterenol-mediated desensitization. Our findings reveal a complex efficacy for functional desensitization, demonstrating that although salmeterol shows weak efficacy for adenylyl cyclase activation and G protein-coupled receptor kinase/arrestin-mediated desensitization, it acts as a strong agonist in highly amplified protein kinase A-mediated events.
Collapse
Affiliation(s)
- Luis E Gimenez
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee (L.E.G.); Division of Internal Medicine, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, Texas (F.B.); and Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas (S.J.V., R.B.C.)
| | - Faiza Baameur
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee (L.E.G.); Division of Internal Medicine, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, Texas (F.B.); and Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas (S.J.V., R.B.C.)
| | - Sharat J Vayttaden
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee (L.E.G.); Division of Internal Medicine, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, Texas (F.B.); and Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas (S.J.V., R.B.C.)
| | - Richard B Clark
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee (L.E.G.); Division of Internal Medicine, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, Texas (F.B.); and Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, Texas (S.J.V., R.B.C.)
| |
Collapse
|
14
|
Joshi T, Johnson M, Newton R, Giembycz M. An analysis of glucocorticoid receptor-mediated gene expression in BEAS-2B human airway epithelial cells identifies distinct, ligand-directed, transcription profiles with implications for asthma therapeutics. Br J Pharmacol 2015; 172:1360-78. [PMID: 25393397 PMCID: PMC4337707 DOI: 10.1111/bph.13014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/08/2014] [Accepted: 11/05/2014] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE International asthma guidelines recommend that inhaled glucocorticoids be used as a monotherapy in all patients with mild to moderate disease because of their ability to suppress airways inflammation. Current evidence suggests that the therapeutic benefit of glucocorticoids is due to the transactivation and transrepression of anti-inflammatory and pro-inflammatory genes respectively. However, the extent to which clinically relevant glucocorticoids are equivalent in their ability to modulate gene expression is unclear. EXPERIMENTAL APPROACH A pharmacodynamics investigation of glucocorticoid receptor (GR)-mediated gene transactivation in BEAS-2B human airway epithelial cells was performed using a glucocorticoid response element luciferase reporter coupled with an analysis of glucocorticoid-inducible genes encoding proteins with anti-inflammatory and adverse-effect potential. KEY RESULTS Using transactivation as a functionally relevant output, a given glucocorticoid displayed a unique, gene expression 'fingerprint' where intrinsic efficacy and GR density were essential determinants. We showed that depending on the gene selected for analysis, a given glucocorticoid can behave as an antagonist, partial agonist, full agonist or even 'super agonist'. In the likely event that different, tissue-dependent gene expression profiles are reproduced in vivo, then the anti-inflammatory and adverse-effect potential of many glucocorticoids currently available as asthma therapeutics may not be equivalent. CONCLUSIONS AND IMPLICATIONS The generation of gene expression 'fingerprints' in target and off-target human tissues could assist the rational design of GR agonists with improved therapeutic ratios. This approach could identify compounds that are useful in the management of severe asthma and other inflammatory disorders where systemic exposure is desirable.
Collapse
Affiliation(s)
- T Joshi
- Airways Inflammation Research Group, Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of CalgaryCalgary, AB, Canada
| | - M Johnson
- GlaxoSmithKline Research and DevelopmentUxbridge, Middlesex, UK
| | - R Newton
- Department of Cell Biology and Anatomy, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of CalgaryCalgary, AB, Canada
| | - M Giembycz
- Airways Inflammation Research Group, Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of CalgaryCalgary, AB, Canada
| |
Collapse
|
15
|
Giembycz MA, Newton R. Potential mechanisms to explain how LABAs and PDE4 inhibitors enhance the clinical efficacy of glucocorticoids in inflammatory lung diseases. F1000PRIME REPORTS 2015; 7:16. [PMID: 25750734 PMCID: PMC4335793 DOI: 10.12703/p7-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Inhaled glucocorticoids acting via the glucocorticoid receptor are a mainstay treatment option for individuals with asthma. There is a consensus that the remedial actions of inhaled glucocorticoids are due to their ability to suppress inflammation by modulating gene expression. While inhaled glucocorticoids are generally effective in asthma, there are subjects with moderate-to-severe disease in whom inhaled glucocorticoids fail to provide adequate control. For these individuals, asthma guidelines recommend that a long-acting β2-adrenoceptor agonist (LABA) be administered concurrently with an inhaled glucocorticoid. This so-called “combination therapy” is often effective and clinically superior to the inhaled glucocorticoid alone, irrespective of dose. LABAs, and another class of drug known as phosphodiesterase 4 (PDE4) inhibitors, may also enhance the efficacy of inhaled glucocorticoids in chronic obstructive pulmonary disease (COPD). In both conditions, these drugs are believed to work by elevating the concentration of cyclic adenosine-3',5'-monophosphate (cAMP) in target cells and tissues. Despite the success of inhaled glucocorticoid/LABA combination therapy, it remains unclear how an increase in cAMP enhances the clinical efficacy of an inhaled glucocorticoid. In this report, we provide a state-of-the-art appraisal, including unresolved and controversial issues, of how cAMP-elevating drugs and inhaled glucocorticoids interact at a molecular level to deliver enhanced anti-inflammatory benefit over inhaled glucocorticoid monotherapy. We also speculate on ways to further exploit this desirable interaction. Critical discussion of how these two drug classes regulate gene transcription, often in a synergistic manner, is a particular focus. Indeed, because interplay between glucocorticoid receptor and cAMP signaling pathways may contribute to the superiority of inhaled glucocorticoid/LABA combination therapy, understanding this interaction may provide a logical framework to rationally design these multicomponent therapeutics that was not previously possible.
Collapse
Affiliation(s)
- Mark A. Giembycz
- Department of Physiology & Pharmacology, Snyder Institute of Chronic Diseases, Cumming School of Medicine, University of Calgary3820 Hospital Drive NW, Calgary, AlbertaCanada T2N 1N4
| | - Robert Newton
- Department of Cell Biology & Anatomy, Snyder Institute of Chronic Diseases, Cumming School of Medicine, University of Calgary3820 Hospital Drive NW, Calgary, AlbertaCanada T2N 1N4
| |
Collapse
|
16
|
Cazzola M, Matera MG. Triple combinations in chronic obstructive pulmonary disease – is three better than two? Expert Opin Pharmacother 2014; 15:2475-8. [DOI: 10.1517/14656566.2014.972367] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
17
|
BinMahfouz H, Borthakur B, Yan D, George T, Giembycz MA, Newton R. Superiority of combined phosphodiesterase PDE3/PDE4 inhibition over PDE4 inhibition alone on glucocorticoid- and long-acting β2-adrenoceptor agonist-induced gene expression in human airway epithelial cells. Mol Pharmacol 2014; 87:64-76. [PMID: 25324049 DOI: 10.1124/mol.114.093393] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Glucocorticoids, also known as corticosteroids, induce effector gene transcription as a part of their anti-inflammatory mechanisms of action. Such genomic effects can be significantly enhanced by long-acting β2-adrenoceptor agonists (LABAs) and may contribute to the clinical superiority of inhaled corticosteroid (ICS)/LABA combinations in asthma and chronic obstructive pulmonary disease (COPD) over ICSs alone. Using models of cAMP- and glucocorticoid-induced transcription in human bronchial epithelial BEAS-2B cells, we show that combining inhibitors of phosphodiesterase (PDE) 3 and PDE4 provides greater benefits compared with inhibiting either PDE alone. In respect to cAMP-dependent transcription, inhibitors of PDE3 (siguazodan, cilostazol) and PDE4 (rolipram, GSK256066, roflumilast N-oxide) each sensitized to the LABA, formoterol. This effect was magnified by dual PDE3 and PDE4 inhibition. Siguazodan plus rolipram was also more effective at inducing cAMP-dependent transcription than either inhibitor alone. Conversely, the concentration-response curve describing the enhancement of dexamethasone-induced, glucocorticoid response element-dependent transcription by formoterol was displaced to the left by PDE4, but not PDE3, inhibition. Overall, similar effects were described for bona fide genes, including RGS2, CD200, and CRISPLD2. Importantly, the combination of siguazodan plus rolipram prolonged the duration of gene expression induced by formoterol, dexamethasone, or dexamethasone plus formoterol. This was most apparent for RGS2, a bronchoprotective gene that may also reduce the proinflammatory effects of constrictor mediators. Collectively, these data provide a rationale for the use of PDE3 and PDE4 inhibitors in the treatment of COPD and asthma where they may enhance, sensitize, and prolong the effects of LABA/ICS combination therapies.
Collapse
Affiliation(s)
- Hawazen BinMahfouz
- Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Bibhusana Borthakur
- Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Dong Yan
- Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Tresa George
- Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Mark A Giembycz
- Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert Newton
- Airways Inflammation Research Group, Snyder Institute for Chronic Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
18
|
Phosphodiesterase Inhibitors for Chronic Obstructive Pulmonary Disease: What Does the Future Hold? Drugs 2014; 74:1983-92. [DOI: 10.1007/s40265-014-0303-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
19
|
Ahmad F, Murata T, Shimizu K, Degerman E, Maurice D, Manganiello V. Cyclic nucleotide phosphodiesterases: important signaling modulators and therapeutic targets. Oral Dis 2014; 21:e25-50. [PMID: 25056711 DOI: 10.1111/odi.12275] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 07/09/2014] [Indexed: 02/06/2023]
Abstract
By catalyzing hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), cyclic nucleotide phosphodiesterases are critical regulators of their intracellular concentrations and their biological effects. As these intracellular second messengers control many cellular homeostatic processes, dysregulation of their signals and signaling pathways initiate or modulate pathophysiological pathways related to various disease states, including erectile dysfunction, pulmonary hypertension, acute refractory cardiac failure, intermittent claudication, chronic obstructive pulmonary disease, and psoriasis. Alterations in expression of PDEs and PDE-gene mutations (especially mutations in PDE6, PDE8B, PDE11A, and PDE4) have been implicated in various diseases and cancer pathologies. PDEs also play important role in formation and function of multimolecular signaling/regulatory complexes, called signalosomes. At specific intracellular locations, individual PDEs, together with pathway-specific signaling molecules, regulators, and effectors, are incorporated into specific signalosomes, where they facilitate and regulate compartmentalization of cyclic nucleotide signaling pathways and specific cellular functions. Currently, only a limited number of PDE inhibitors (PDE3, PDE4, PDE5 inhibitors) are used in clinical practice. Future paths to novel drug discovery include the crystal structure-based design approach, which has resulted in generation of more effective family-selective inhibitors, as well as burgeoning development of strategies to alter compartmentalized cyclic nucleotide signaling pathways by selectively targeting individual PDEs and their signalosome partners.
Collapse
Affiliation(s)
- F Ahmad
- Cardiovascular and Pulmonary Branch, National Heart, Lung and Blood Institute, Bethesda, MD, USA
| | | | | | | | | | | |
Collapse
|
20
|
Giembycz MA, Maurice DH. Cyclic nucleotide-based therapeutics for chronic obstructive pulmonary disease. Curr Opin Pharmacol 2014; 16:89-107. [PMID: 24810285 DOI: 10.1016/j.coph.2014.04.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 04/10/2014] [Accepted: 04/11/2014] [Indexed: 12/18/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) defines a group of chronic inflammatory disorders of the airways that are characterised by a progressive and largely irreversible decline in expiratory airflow. Drugs used to treat COPD through actions mediated by cyclic AMP (cAMP) are restricted to long-acting and short-acting β2-adrenoceptor agonists and, in a subset of patients with chronic bronchitis, a phosphodiesterase 4 inhibitor, roflumilast. These agents relax airway smooth muscle and suppress inflammation. At the molecular level, these effects in the airways are mediated by two cAMP effectors, cAMP-dependent protein kinase and exchange proteins activated by cAMP. The pharmacology of newer agents, acting through these systems, is discussed here with an emphasis on their potential to interact and increase therapeutic effectiveness.
Collapse
Affiliation(s)
- Mark A Giembycz
- Department of Physiology & Pharmacology, Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Donald H Maurice
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.
| |
Collapse
|