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Kelly RS, Cote MF, Begum S, Lasky-Su J. Pharmacometabolomics of Asthma as a Road Map to Precision Medicine. Handb Exp Pharmacol 2023; 277:247-273. [PMID: 36271166 PMCID: PMC10116407 DOI: 10.1007/164_2022_615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Pharmacometabolomics applies the principles of metabolomics to therapeutics in order to elucidate the biological mechanisms underlying the variation in responses to drugs between groups and individuals. Asthma is associated with broad systemic effects and heterogeneity in treatment response and as such is ideally suited to pharmacometabolomics. In this chapter, we discuss the state of the emerging field of asthma pharmacometabolomics, with a particular focus on studies of steroids, bronchodilators, and leukotriene inhibitors. We also consider those studies concerned with subtyping cases to better understand the pharmacology of those groups and those looking to leverage pharmacometabolomics for asthma prevention. We finish with a discussion of the challenges and opportunities of asthma pharmacometabolomics and reflect upon where this field must go next in order to realize its precision medicine potential.
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Affiliation(s)
- Rachel S Kelly
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Margaret F Cote
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Sofina Begum
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jessica Lasky-Su
- Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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Abstract
Asthma is a heterogeneous inflammatory disease of the airways that is associated with airway hyperresponsiveness and airflow limitation. Although asthma was once simply categorized as atopic or nonatopic, emerging analyses over the last few decades have revealed a variety of asthma endotypes that are attributed to numerous pathophysiological mechanisms. The classification of asthma by endotype is primarily routed in different profiles of airway inflammation that contribute to bronchoconstriction. Many asthma therapeutics target G protein-coupled receptors (GPCRs), which either enhance bronchodilation or prevent bronchoconstriction. Short-acting and long-acting β 2-agonists are widely used bronchodilators that signal through the activation of the β 2-adrenergic receptor. Short-acting and long-acting antagonists of muscarinic acetylcholine receptors are used to reduce bronchoconstriction by blocking the action of acetylcholine. Leukotriene antagonists that block the signaling of cysteinyl leukotriene receptor 1 are used as an add-on therapy to reduce bronchoconstriction and inflammation induced by cysteinyl leukotrienes. A number of GPCR-targeting asthma drug candidates are also in different stages of development. Among them, antagonists of prostaglandin D2 receptor 2 have advanced into phase III clinical trials. Others, including antagonists of the adenosine A2B receptor and the histamine H4 receptor, are in early stages of clinical investigation. In the past decade, significant research advancements in pharmacology, cell biology, structural biology, and molecular physiology have greatly deepened our understanding of the therapeutic roles of GPCRs in asthma and drug action on these GPCRs. This review summarizes our current understanding of GPCR signaling and pharmacology in the context of asthma treatment. SIGNIFICANCE STATEMENT: Although current treatment methods for asthma are effective for a majority of asthma patients, there are still a large number of patients with poorly controlled asthma who may experience asthma exacerbations. This review summarizes current asthma treatment methods and our understanding of signaling and pharmacology of G protein-coupled receptors (GPCRs) in asthma therapy, and discusses controversies regarding the use of GPCR drugs and new opportunities in developing GPCR-targeting therapeutics for the treatment of asthma.
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Affiliation(s)
- Stacy Gelhaus Wendell
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (S.G.W., C.Z.); Bioinformatics Institute, Agency for Science, Technology, and Research, Singapore (H.F.); and Department of Biological Sciences, National University of Singapore, and Center for Computational Biology, DUKE-NUS Medical School, Singapore (H.F.)
| | - Hao Fan
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (S.G.W., C.Z.); Bioinformatics Institute, Agency for Science, Technology, and Research, Singapore (H.F.); and Department of Biological Sciences, National University of Singapore, and Center for Computational Biology, DUKE-NUS Medical School, Singapore (H.F.)
| | - Cheng Zhang
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (S.G.W., C.Z.); Bioinformatics Institute, Agency for Science, Technology, and Research, Singapore (H.F.); and Department of Biological Sciences, National University of Singapore, and Center for Computational Biology, DUKE-NUS Medical School, Singapore (H.F.)
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Yokomizo T, Nakamura M, Shimizu T. Leukotriene receptors as potential therapeutic targets. J Clin Invest 2018; 128:2691-2701. [PMID: 29757196 DOI: 10.1172/jci97946] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Leukotrienes, a class of arachidonic acid-derived bioactive molecules, are known as mediators of allergic and inflammatory reactions and considered to be important drug targets. Although an inhibitor of leukotriene biosynthesis and antagonists of the cysteinyl leukotriene receptor are clinically used for bronchial asthma and allergic rhinitis, these medications were developed before the molecular identification of leukotriene receptors. Numerous studies using cloned leukotriene receptors and genetically engineered mice have unveiled new pathophysiological roles for leukotrienes. This Review covers the recent findings on leukotriene receptors to revisit them as new drug targets.
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Affiliation(s)
- Takehiko Yokomizo
- Department of Biochemistry, Graduate School of Medicine, Juntendo University, Tokyo, Japan
| | - Motonao Nakamura
- Department of Life Science, Graduate School of Science, Okayama University of Science, Okayama, Japan
| | - Takao Shimizu
- Department of Lipidomics, Faculty of Medicine, University of Tokyo, Tokyo, Japan.,Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan
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Selectins and Associated Adhesion Proteins in Inflammatory disorders. ANIMAL LECTINS: FORM, FUNCTION AND CLINICAL APPLICATIONS 2012. [PMCID: PMC7121831 DOI: 10.1007/978-3-7091-1065-2_44] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Inflammation is defined as the normal response of living tissue to injury or infection. It is important to emphasize two components of this definition. First, that inflammation is a normal response and, as such, is expected to occur when tissue is damaged. Infact, if injured tissue does not exhibit signs of inflammation this would be considered abnormal and wounds and infections would never heal without inflammation. Secondly, inflammation occurs in living tissue, hence there is need for an adequate blood supply to the tissues in order to exhibit an inflammatory response. The inflammatory response may be triggered by mechanical injury, chemical toxins, and invasion by microorganisms, and hypersensitivity reactions. Three major events occur during the inflammatory response: the blood supply to the affected area is increased substantially, capillary permeability is increased, and leucocytes migrate from the capillary vessels into the surrounding interstitial spaces to the site of inflammation or injury. The inflammatory response represents a complex biological and biochemical process involving cells of the immune system and a plethora of biological mediators. Cell-to-cell communication molecules such as cytokines play an extremely important role in mediating the process of inflammation. Inflammation and platelet activation are critical phenomena in the setting of acute coronary syndromes. An extensive exposition of this complex phenomenon is beyond the scope of this article (Rankin 2004).
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DiMeo D, Tian J, Zhang J, Narushima S, Berg DJ. Increased interleukin-10 production and Th2 skewing in the absence of 5-lipoxygenase. Immunology 2007; 123:250-62. [PMID: 17894798 PMCID: PMC2433306 DOI: 10.1111/j.1365-2567.2007.02694.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Eicosanoids (prostaglandins and leukotrienes) are important mediators of inflammatory responses. These lipid mediators may also regulate the production of peptide mediators of the immune system. In this study, we investigated the effect of the absence of 5-lipoxygenase (5-LO)-derived leukotrienes on interleukin (IL)-10 production. IL-10 is a key regulator of immune and inflammatory responses, and previous studies have suggested that prostaglandins effect their immunosuppressive functions in part by stimulation of IL-10 production. We therefore investigated whether leukotriene production would have a similar role in regulation of IL-10 production. We have made the striking observation that absence of 5-LO-derived leukotrienes results in increased IL-10 production with a concomitant decrease in the production of pro-inflammatory cytokines, including tumour necrosis factor (TNF)-alpha and IL-12. Moreover, T-cell cytokine production in the absence of 5-LO-derived leukotrienes results in increased IL-4 production and decreased interferon (IFN)-gamma production. This may be in part secondary to increased IL-10 production and its effects on dendritic cell function resulting in altered T-cell differentiation. These findings indicate that, in addition to the central role leukotrienes play in the acute inflammatory response, endogenous leukotrienes are also important regulators of inflammatory cytokine production, via regulation of IL-10 production and in vivo differentiation of T cells.
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Affiliation(s)
- Daniel DiMeo
- Department of Pediatrics, University of Iowa College of Medicine, Iowa City, IA, USA
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Cui S, Shibamoto T, Liu W, Takano H, Kurata Y. Effects of platelet-activating factor, thromboxane A2 and leukotriene D4 on isolated perfused rat liver. Prostaglandins Other Lipid Mediat 2006; 80:35-45. [PMID: 16846785 DOI: 10.1016/j.prostaglandins.2006.03.004] [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] [Received: 01/21/2006] [Revised: 03/17/2006] [Accepted: 03/30/2006] [Indexed: 01/05/2023]
Abstract
Vasoconstrictive lipid mediators, thromboxane A(2) (TxA(2)), platelet-activating factor (PAF) and leukotriene D(4) (LTD(4)) have been implicated as mediators of liver diseases. There are species differences in the primary site of hepatic vasoconstriction in response to these mediators. We determined the effects of a TxA(2) analogue (U-46619), PAF and LTD(4) on the vascular resistance distribution, weight and oxygen consumption of isolated rat livers portally perfused with blood. The sinusoidal pressure was measured by the double occlusion pressure (P(do)), and was used to determine the pre- (R(pre)) and post-sinusoidal (R(post)) resistances. All these three mediators increased the hepatic total vascular resistance (R(t)). The responsiveness to PAF was 100 times greater than that to U-46619 or LTD(4). Both of PAF and U-46619 predominantly increased R(pre) over R(post). At the comparable increased R(t) levels, U-46619 more preferentially increased R(pre) than PAF. In contrast, LTD(4) increased both the R(pre) and R(post) to similar extent. U-46619 caused liver weight loss, while high concentrations of either LTD(4) or PAF produced liver weight gain, which was caused by substantial post-sinusoidal constriction and increased P(do). PAF and U-46619 decreased hepatic oxygen consumption while LTD(4) induced biphasic change of an initial transient decrease followed by an increase. In conclusion, PAF is the most potent vasoconstrictor of rat hepatic vessels among these three mediators. Both TxA(2) and PAF constrict the pre-sinusoidal veins predominantly. TxA(2) more preferentially constricts the pre-sinusoids than PAF, resulting in liver weight loss. However LTD(4) constricts both the pre- and post-sinusoidal veins similarly. High concentrations of LTD(4) and PAF cause liver weight gain by substantial post-sinusoidal constriction. PAF and TxA(2) decrease hepatic oxygen consumption, whereas LTD(4) causes a biphasic change of it.
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Affiliation(s)
- Sen Cui
- Department of Physiology, Kanazawa Medical University, Uchinada 920-0293, Japan
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Lin SJ, Chang LY, Yan DC, Huang YJ, Lin TJ, Lin TY. Decreased intercellular adhesion molecule-1 (CD54) and L-selectin (CD62L) expression on peripheral blood natural killer cells in asthmatic children with acute exacerbation. Allergy 2003; 58:67-71. [PMID: 12580810 DOI: 10.1034/j.1398-9995.2003.t01-1-23697.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND The capacity of inflammatory cells to adhere involves an array of adhesion molecules, and is critical to the inflammatory responses seen in childhood asthma. We aimed to determine the changes of intercellular adhesion molecule-1 (ICAM-1) and L-selectin expressed on peripheral blood (PB) T lymphocytes and natural killer (NK) cells in asthmatic children with acute exacerbation and after prednisolone therapy. METHODS Flow cytometric analysis was performed to determine the expression of ICAM-1 (CD54) and L-selectin (CD62L) on T (CD3+) cells and NK (CD3-/CD56+) cells of PB from children with allergic asthma with acute exacerbation and in a stable condition after prednisolone therapy. Atopic subjects without asthma and age-matched controls were also included for comparison. RESULTS Percentages of PB non-CD3, CD56+ NK cells, but not CD3+ T cells, increased in asthmatic children with acute exacerbation, compared to those assessed in a stable condition after a course of prednisolone. However, significant decrease of ICAM-1 (P = 0.01) and L-selectin (P = 0.01) expression on PB NK cells, but not on T cells, were found in children with acute asthma compared to those in a stable condition. NK cells in children with acute asthma showed minimal expression of CD69 and CD25. CONCLUSIONS Results suggests that either NK cells expressing ICAM-1 and L-selectin selectively migrated into inflamed lung tissues, or subsets of NK cells not expressing ICAM-1/L-selectin were expanded during acute exacerbation of childhood asthma.
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MESH Headings
- Acute Disease
- Antigens, CD/biosynthesis
- Antigens, CD/blood
- Antigens, CD/drug effects
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/blood
- Antigens, Differentiation, T-Lymphocyte/drug effects
- Asthma/blood
- Asthma/drug therapy
- Asthma/metabolism
- Biomarkers/blood
- CD3 Complex/biosynthesis
- CD3 Complex/blood
- CD3 Complex/drug effects
- Child
- Child Welfare
- Child, Preschool
- Glucocorticoids/therapeutic use
- Humans
- Intercellular Adhesion Molecule-1/biosynthesis
- Intercellular Adhesion Molecule-1/blood
- Intercellular Adhesion Molecule-1/drug effects
- Killer Cells, Natural/drug effects
- Killer Cells, Natural/metabolism
- L-Selectin/biosynthesis
- L-Selectin/blood
- L-Selectin/drug effects
- Lectins, C-Type
- Prednisolone/therapeutic use
- Receptors, Interleukin-2/biosynthesis
- Receptors, Interleukin-2/blood
- Receptors, Interleukin-2/drug effects
- T-Lymphocytes/drug effects
- T-Lymphocytes/metabolism
- Taiwan
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Affiliation(s)
- S-J Lin
- Division of Allergy, Asthma and Rheumatology, Chang Gung Children's Hospital, Taoyuan, Taiwan
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8
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Affiliation(s)
- G Passalacqua
- Allergy and Respiratory Diseases, Department of Internal Medicine, University of Genoa, Italy
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9
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Jolly S, Thomas C, Genicot B, Dessy-Doizé CE, Coignoul FL, Desmecht D. Effect of intravenous platelet-activating factor on bovine pulmonary mast cells. J Comp Pathol 2001; 125:81-9. [PMID: 11578122 DOI: 10.1053/jcpa.2001.0480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The effect of platelet-activating factor (PAF) on bovine pulmonary mast cells (MCs) was investigated in calves aged 1-4 months. PAF was administered over a 5-min period at a rate of 50 ng/kg/min to six animals, which were killed approximately 10 min later. No macroscopical lesions were observed in the lung tissue of five control calves. On semi-thin toluidine-blue stained sections, MC cytoplasm showed profuse deep-blue granulation. In the lung tissues of PAF-treated calves, striking interstitial, alveolar and interlobular oedema and emphysema were observed. MC granules occurred at the periphery of the cytoplasm and MC nuclei were easily detectable. Moreover, the number of granules in the MC cytoplasm was remarkably low. A few granules with some metachromatic material were sometimes detected outside the cell limits. Ultrastructurally, the matrix pattern of the MC granules in lung tissues of control calves was either amorphous or granular. In lung tissues of the PAF-treated calves, the granular matrix pattern was pronounced, varying from fine- to coarse-grained, and the MCs were of reduced size, with many filiform processes and exocytotic vesicles. These findings indicate that pulmonary MC degranulation was induced by PAF in healthy calves.
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Affiliation(s)
- S Jolly
- Department of Anatomy, Faculty of Veterinary Medicine, University of Liège, Sart Tilman B-43, B-4000 Liège, Belgium
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Abstract
Asthma is common and becoming more so in childhood. Although mild asthma may incur low average annual costs per child, these estimates need to be viewed in the context of the very large numbers of affected individuals. Whereas asthma and wheezing illness in childhood had in the past been broadly subdivided into asthma (often associated with atopy) and wheezy bronchitis (wheeze only, with associated upper respiratory tract infection), this distinction was lost during the 1970s in view of the demonstrated underdiagnosis and undertreatment of symptomatic school-age children. The acceptance of asthma as a chronic inflammatory disease and evidence for airway remodeling and progressive deterioration in airway function in association with symptoms and atopy have led to earlier use of topical steroids at higher starting doses delivered by improved age-appropriate devices. Treating all children as if they were destined to become atopic asthmatics and at risk of airway remodeling may not be rational, particularly in those whose symptoms will subsequently resolve. However, there are as yet no screening tests which can clearly identify individuals at risk of long-term chronic airway inflammation and airway remodeling. The large number of infants and young children with current symptoms suggestive of asthma and in whom resolution is likely in the majority poses problems for the clinician in deciding the best initial therapy. There is an urgent need to develop simple and reliable measures that can identify the early manifestations of atopic airway sensitisation and to establish the place of early intervention with nonsteroidal drugs, including leukotriene antigonists.
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Affiliation(s)
- P J Helms
- University of Aberdeen Medical School, Aberdeen, Scotland, UK.
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Abstract
Based on the studies that have used human subjects and materials, and a much larger body of data from animal and in vitro experiments, one can conclude that the LTs are potent bronchoconstrictors in normal and asthmatic subjects. A major part of their action is mediated directly via the cysLT-1 receptor on airway smooth muscle. There is also evidence for an effect on airway hyperresponsiveness probably via eosinophil recruitment and activation, airway edema, and possibly airway nerves. Taken together, these studies support a key role for the leukotrienes in asthma. However, additional studies are needed to further define their effects on the airway inflammatory response.
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Mulder A, Gauvreau GM, Watson RM, O'byrne PM. Effect of inhaled leukotriene D4 on airway eosinophilia and airway hyperresponsiveness in asthmatic subjects. Am J Respir Crit Care Med 1999; 159:1562-7. [PMID: 10228127 DOI: 10.1164/ajrccm.159.5.9810095] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Inhaled cysteinyl leukotrienes may cause recruitment of eosinophils into asthmatic airways. We compared the effects of inhaled leukotriene D4 (LTD4), methacholine, and allergen on airway eosinophils in 10 nonsmoking, atopic, mildly asthmatic subjects in a double-blind, diluent-controlled, randomized crossover study. Concentrations of LTD4, methacholine, and allergen resulting in a 30% decrease in FEV1, and diluent controls (ethanol and saline), were inhaled with at least 7 d between challenges. Spirometry was conducted for 4 h after inhalation challenge, and airway hyperresponsiveness (AHR) to methacholine was measured before and 24 h after challenge. Sputum was induced before and 4 h, 7 h, and 24 h after challenge. The maximum decrease in FEV1 was 31.4 +/- 1.8% with LTD4, 39.4 +/- 2.8% with methacholine, and 30.1 +/- 3.4% with allergen. AHR to methacholine, at the provocative concentration causing a 20% decrease in FEV1 (PC20), was enhanced 24 h after allergen challenge, but remained unchanged 24 h after LTD4 and methacholine (p > 0.05). The percentage of eosinophils in sputum was increased after inhalation of allergen at 7 h and 24 h (p = 0.003), but not after LTD4 or methacholine (p = 0.70). We demonstrated that neither inhalation of LTD4 nor of methacholine at concentrations causing submaximal bronchoconstriction increases the number of sputum eosinophils in the airways of mildly asthmatic subjects. However, LTD4 may still be an important cofactor for eosinophil recruitment in asthma.
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Affiliation(s)
- A Mulder
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
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Shamsuddin M, Chen E, Anderson J, Smith LJ. Regulation of leukotriene and platelet-activating factor synthesis in human alveolar macrophages. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1997; 130:615-26. [PMID: 9422335 DOI: 10.1016/s0022-2143(97)90111-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It has been suggested that phospholipase A2 (PLA2) contributes to the regulation of leukotriene (LT) and platelet-activating factor (PAF) synthesis by controlling the release of their precursors, arachidonic acid (AA) and lysophosphatidylcholine (lysoPC), from membrane phospholipids. In rat alveolar macrophages (AMs), PLA2 appears to have a major role in LT synthesis but a more limited role in PAF synthesis. The present study was designed to define the role of PLA2 in LT and PAF synthesis in human AMs and determine whether differences exist between AMs obtained from normal subjects and those from patients with asthma. In the normal subjects, the calcium ionophore A23187 (Cal) increased AM PAF synthesis (percent incorporation of tritiated acetate) by 135% (p < 0.01) and LTB4 synthesis 88-fold (p < 0.001). Phorbol myristate acetate (PMA) had little effect alone, but it had a synergistic effect with Cal, increasing PAF synthesis by 466% and LTB4 synthesis to 229-fold above the control values (p < 0.001 for both). Ro 25-4331, a combined cytosolic (c) and secretory (s) PLA2 inhibitor, had little effect on the Cal-stimulated PAF synthesis, but it completely blocked the effect of PMA. It also blocked the Cal- and Cal+PMA-stimulated LTB4 synthesis. AACOCF3, a cPLA2 inhibitor, had no effect on either Cal or Cal+PMA-stimulated PAF synthesis. It reduced LTB4 synthesis, but it did so less effectively than Ro 25-4331. CoA-independent transacylase (CoAI-TA) activity in the AMs increased after stimulation and exposure to Ro 25-4331. SK&F 45905, a CoAI-TA inhibitor, reduced stimulated PAF synthesis by 30% to 40%. Patients with asthma had similar results except that cPLA2 had a greater role in stimulated LTB4 synthesis. These data indicate that PLA2 plays a direct role in human AM LT synthesis; both the cytosolic and secretory forms contribute to LT synthesis; PLA2 appears to have a more limited role in PAF synthesis, although it mediates the synergistic effect of PMA, probably via sPLA2; and CoAI-TA contributes to PAF synthesis during PLA2 inhibition. With the exception of the greater role for cPLA2 in stimulated LTB4 synthesis in the patients with asthma, the contributions of PLA2 and CoAI-TA to AM LT and PAF synthesis appear to be similar in normal subjects and patients with asthma.
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Affiliation(s)
- M Shamsuddin
- Pulmonary Division, Northwestern University Medical School, Veterans Affairs Lakeside Medical Center, Chicago, IL 60611-3053, USA
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Shindo K, Koide K, Fukumura M. Enhancement of leukotriene B4 release in stimulated asthmatic neutrophils by platelet activating factor. Thorax 1997; 52:1024-9. [PMID: 9516893 PMCID: PMC1758460 DOI: 10.1136/thx.52.12.1024] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The role of platelet activating factor (PAF) in asthma remains controversial. The priming effect of PAF on leukotriene B4 (LTB4) release, 5-lipoxygenase activity, and intracellular calcium levels in asthmatic neutrophils was examined. METHODS LTB4 and other lipoxygenase metabolites in neutrophils obtained from 17 asthmatic patients and 15 control subjects were measured by reverse phase-high performance liquid chromatography (RP-HPLC). Intracellular calcium levels were monitored using the fluorescent probe fura-2. RESULTS The mean (SD) basal LTB4, release from neutrophils was not significantly different between the two groups (0.05 (0.01) vs 0.03 (0.02) ng/10(6) cells); however, when stimulated with calcium ionophore A23187 (2.5 microM), neutrophils from asthma patients released more LTB4 than cells from control subjects (15.7 (1.2) vs 9.9 (1.6) ng/10(6) cells). Although PAF alone did not alter LTB4 release, it enhanced the response to subsequent A23187 stimulation. This effect was observed following treatment for five minutes with PAF at concentrations > 1.0 microM. The maximal effect was seen with 5.0 microM PAF + 2.5 microM A23187 (62.7 (2.2) vs 18.6 (2.3) ng/10(6) cells). Pretreatment with PAF also increased 5-lipoxygenase activity and intracellular calcium levels in neutrophils from asthmatic patients to a greater extent than in those from non-asthmatic patients. CONCLUSIONS These findings indicate that, in neutrophils from asthmatic patients, PAF enhances LTB4 release and increases 5-lipoxygenase activity and intracellular calcium to a greater extent than in neutrophils from non-asthmatic patients.
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Affiliation(s)
- K Shindo
- First Department of Internal Medicine, Yokohama City University School of Medicine, Japan
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Smith LJ, Shamsuddin M, Sporn PH, Denenberg M, Anderson J. Reduced superoxide dismutase in lung cells of patients with asthma. Free Radic Biol Med 1997; 22:1301-7. [PMID: 9098106 DOI: 10.1016/s0891-5849(96)00550-3] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lung cells recovered from symptomatic patients with asthma generate increased amounts of reactive oxygen species (ROS). Animal and in vitro studies indicate that ROS can reproduce many of the features of asthma. The ability of ROS to produce the clinical features of asthma may depend on an individual's lung antioxidant defenses. Patients with asthma are reported to have reduced antioxidant defenses in peripheral blood, but little is known about the antioxidant defenses of their lung cells. To define lung cell antioxidant defenses in asthma, the glutathione concentration and the glutathione reductase, glutathione peroxidase, catalase, and superoxide dismutase (SOD) activities were measured in cells recovered by bronchoalveolar lavage (BAL cells) and by bronchial brushing (bronchial epithelial cells, HBEC) from normal subjects and patients with asthma. Superoxide dismutase activity was reduced 25% in BAL cells (p < .05) and nearly 50% in HBEC (p < .02) from patients with asthma. Alterations in the other antioxidants were not identified. A direct relationship was found between airway reactivity to methacholine, measured as PC(20)FEV(1), and HBEC SOD activity (r2 = 89; p < .005), but not between airway reactivity and the other antioxidants. The finding of reduced SOD activity in lung cells of patients with asthma suggests that diminished SOD activity serves as a marker of the inflammation characterizing asthma. Alternatively, it may play a role in the development or severity of the disease.
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Affiliation(s)
- L J Smith
- Pulmonary Division, Northwestern University Medical School and VA Lakeside Medical Center, Chicago, IL 60611, USA
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Affiliation(s)
- C Denzlinger
- Medizinische Klinik III, Klinikum Grosshadern, Ludwig-Maximilians Universität München, Germany
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Hogg JC. Airway behavior and its regulation: how do structural changes affect airway behavior? Am J Respir Crit Care Med 1996; 153:S16-8. [PMID: 8646375 DOI: 10.1164/ajrccm/153.6_pt_2.s16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Hubbard NE, Erickson KL. Role of 5'-lipoxygenase metabolites in the activation of peritoneal macrophages for tumoricidal function. Cell Immunol 1995; 160:115-22. [PMID: 7842477 DOI: 10.1016/0008-8749(95)80016-c] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Metabolites of arachidonic acid have been shown to be potent biological modulators of macrophage function. While the role of cyclooxygenase metabolites of arachidonic acid have been well studied, metabolites of lipoxygenase have not. In this report, we evaluate the role that select 5'-lipoxygenase (5'-LO) products may play in macrophage activation for select tumoricidal functions. When thioglycollate-elicited macrophages were treated with inhibitors of 5'-LO during activation, cytolytic capacity, nitric oxide production, and tumor necrosis factor-alpha production were significantly inhibited. Moreover, both an inhibitor of the 5'-LO-activating protein and an inhibitor of glutathione-s-transferase (GST) significantly decreased macrophage tumoricidal function. The activating agents used were able to stimulate 5'-LO activity which was measured by quantitating secreted LTC4. Increased production of PGE2 by shunting could have been the cause for decreased macrophage tumoricidal function. However, treatment of macrophages with inhibitors of 5'-LO during lipopolysaccharide stimulation did not increase formation of PGE2. When select 5'-LO metabolites were added to cultures during activation and 5'-LO inhibition, tumoricidal activity could not be restored, even when the metabolites were encapsulated in liposomes. These results suggest that the activity of 5'-LO and GST are important for macrophage activation. However, the specific role of 5'-LO metabolites has not been completely established.
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Affiliation(s)
- N E Hubbard
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis 95616-8643
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Restrick LJ, Sampson AP, Piper PJ, Costello JF. Reduction in leukotriene B4 generation by bronchoalveolar lavage cells in asthma. Thorax 1995; 50:67-73. [PMID: 7886653 PMCID: PMC473713 DOI: 10.1136/thx.50.1.67] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Leukotrienes are inflammatory mediators implicated in the pathogenesis of asthma. The capacity of inflammatory cells within the airways to generate leukotrienes may be altered in asthma. This hypothesis was tested using bronchoalveolar lavage (BAL) to sample cells within the airways from atopic asthmatic and normal subjects, and by measuring their capacity to generate leukotriene B4 (LTB4) and leukotriene C4 (LTC4) in response to A23187, a potent stimulus of leukotriene generation. METHODS Bronchoalveolar lavage was performed in 12 mild asymptomatic atopic asthmatic patients and 12 normal subjects. Mixed BAL cell aliquots (approximately 80% alveolar macrophages) were incubated with 0-20 microM A23187 for 10 minutes and with 4 microM A23187 for 0-30 minutes, and leukotrienes were measured by radioimmunoassay and high performance liquid chromatography. RESULTS Mixed BAL cells from asthmatic subjects generated less LTB4 than cells from normal subjects in dose response and time course experiments (area under the curve 81.5 (0.0-228.5) ng.min.10(-6) cells in asthmatic subjects and 197.9 (13.9-935.6) ng.min.10(-6) cells in normal subjects. There were no differences in LTC4 generation between BAL cells from asthmatic and normal subjects. CONCLUSIONS Generation of LTB4 by BAL cells from atopic asthmatic subjects in response to A23187 was reduced. As the alveolar macrophage is the major source of LTB4 in BAL cells, these results probably reflect reduced generation of LTB4 by alveolar macrophages from asthmatic patients. This may be a consequence of monocyte migration into the lung, or altered alveolar macrophage function in asthma, or both.
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Affiliation(s)
- L J Restrick
- Department of Thoracic Medicine, King's College School of Medicine and Dentistry, London
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