scholarly journals Pathophysiological regulation of lung function by the free fatty acid receptor FFA4

2020 ◽  
Vol 12 (557) ◽  
pp. eaaw9009 ◽  
Author(s):  
Rudi Prihandoko ◽  
Davinder Kaur ◽  
Coen H. Wiegman ◽  
Elisa Alvarez-Curto ◽  
Chantal Donovan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Ex Vivo ◽  
Smooth Muscle Relaxation ◽  
Chronic Obstructive ◽  
Prostaglandin E ◽  
Omega 3 ◽  
Airway Diseases

Increased prevalence of inflammatory airway diseases including asthma and chronic obstructive pulmonary disease (COPD) together with inadequate disease control by current frontline treatments means that there is a need to define therapeutic targets for these conditions. Here, we investigate a member of the G protein–coupled receptor family, FFA4, that responds to free circulating fatty acids including dietary omega-3 fatty acids found in fish oils. We show that FFA4, although usually associated with metabolic responses linked with food intake, is expressed in the lung where it is coupled to Gq/11 signaling. Activation of FFA4 by drug-like agonists produced relaxation of murine airway smooth muscle mediated at least in part by the release of the prostaglandin E2 (PGE2) that subsequently acts on EP2 prostanoid receptors. In normal mice, activation of FFA4 resulted in a decrease in lung resistance. In acute and chronic ozone models of pollution-mediated inflammation and house dust mite and cigarette smoke–induced inflammatory disease, FFA4 agonists acted to reduce airway resistance, a response that was absent in mice lacking expression of FFA4. The expression profile of FFA4 in human lung was similar to that observed in mice, and the response to FFA4/FFA1 agonists similarly mediated human airway smooth muscle relaxation ex vivo. Our study provides evidence that pharmacological targeting of lung FFA4, and possibly combined activation of FFA4 and FFA1, has in vivo efficacy and might have therapeutic value in the treatment of bronchoconstriction associated with inflammatory airway diseases such as asthma and COPD.

scholarly journals Pathophysiological regulation of lung function by the free fatty acid receptor FFA4

2020 ◽  
Author(s):  
Rudi Prihandoko ◽  
Davinder Kaur ◽  
Coen H. Wiegman ◽  
Elisa Alvarez-Curto ◽  
Chantal Donovan ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Muscle Relaxation ◽  
Smooth Muscle Relaxation ◽  
Chronic Obstructive ◽  
Omega 3 ◽  
Airway Diseases ◽  
Number Of Patients

AbstractIncreased prevalence of inflammatory airway diseases including asthma and chronic obstructive pulmonary disease (COPD) together with a significant number of patients being inadequately controlled by current frontline treatments means that there is a need to define novel therapeutic targets for these conditions1. Here we investigate a member of the G protein-coupled receptor (GPCR) family, FFA4, which responds to free circulating fatty acids, including dietary omega-3 fatty acids found in fish oils2–4. Although usually associated with metabolic responses linked with food intake, we show that FFA4 is expressed in the lung where it is coupled to Gq/11-signalling. Activation of FFA4 by drug-like agonists produced relaxation of murine airway smooth muscle mediated, at least in part, by the release of the prostaglandin PGE2 that subsequently acts on EP2 prostanoid receptors. In normal mice, activation of FFA4 resulted in a decrease in lung resistance. Importantly, in acute and chronic ozone models of pollution-mediated inflammation, and in house-dust mite and cigarette smoke-induced inflammatory disease, FFA4 agonists acted to reduce airway resistance, whilst this response was absent in mice lacking expression of FFA4. The expression profile of FFA4 in human lung was very similar to that observed in mice and the response to FFA4/FFA1 agonists similarly mediated human airway smooth muscle relaxation. Hence, our study provides evidence that pharmacological targeting of lung FFA4, and possibly combined activation of FFA4 and FFA1, has in vivo efficacy that might have therapeutic value in the treatment of bronchoconstriction associated with inflammatory airway diseases such as asthma and COPD.

scholarly journals The GABAA agonist muscimol attenuates induced airway constriction in guinea pigs in vivo

2009 ◽  
Vol 106 (4) ◽  
pp. 1257-1263 ◽  
Author(s):  
Neil R. Gleason ◽  
George Gallos ◽  
Yi Zhang ◽  
Charles W. Emala
Keyword(s):  
Smooth Muscle ◽  
Cell Membrane ◽  
Airway Smooth Muscle ◽  
Guinea Pigs ◽  
Neural Control ◽  
Chronic Obstructive ◽  
Airway Smooth Muscle Cells ◽  
Membrane Hyperpolarization ◽  
Airway Constriction

GABAA channels are ubiquitously expressed on neuronal cells and act via an inward chloride current to hyperpolarize the cell membrane of mature neurons. Expression and function of GABAA channels on airway smooth muscle cells has been demonstrated in vitro. Airway smooth muscle cell membrane hyperpolarization contributes to relaxation. We hypothesized that muscimol, a selective GABAA agonist, could act on endogenous GABAA channels expressed on airway smooth muscle to attenuate induced increases in airway pressures in anesthetized guinea pigs in vivo. In an effort to localize muscimol's effect to GABAA channels expressed on airway smooth muscle, we pretreated guinea pigs with a selective GABAA antagonist (gabazine) or eliminated lung neural control from central parasympathetic, sympathetic, and nonadrenergic, noncholinergic (NANC) nerves before muscimol treatment. Pretreatment with intravenous muscimol alone attenuated intravenous histamine-, intravenous acetylcholine-, or vagal nerve-stimulated increases in peak pulmonary inflation pressure. Pretreatment with the GABAA antagonist gabazine blocked muscimol's effect. After the elimination of neural input to airway tone by central parasympathetic nerves, peripheral sympathetic nerves, and NANC nerves, intravenous muscimol retained its ability to block intravenous acetylcholine-induced increases in peak pulmonary inflation pressures. These findings demonstrate that the GABAA agonist muscimol acting specifically via GABAA channel activation attenuates airway constriction independently of neural contributions. These findings suggest that therapeutics directed at the airway smooth muscle GABAA channel may be a novel therapy for airway constriction following airway irritation and possibly more broadly in diseases such as asthma and chronic obstructive pulmonary disease.

The effects of repeated allergen challenge on airway smooth muscle structural and molecular remodeling in a rat model of allergic asthma

2009 ◽  
Vol 297 (4) ◽  
pp. L698-L705 ◽  
Author(s):  
Isabelle Labonté ◽  
Muhannad Hassan ◽  
Paul-André Risse ◽  
Kimitake Tsuchiya ◽  
Michel Laviolette ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Ex Vivo ◽  
Mrna Level ◽  
Allergen Challenge ◽  
Airway Responsiveness ◽  
Brown Norway ◽  
Contractile Phenotype ◽  
The Relationship

The effects of remodeling of airway smooth muscle (SM) by hyperplasia on airway SM contractility in vivo are poorly explored. The aim of this study was to investigate the relationship between allergen-induced airway SM hyperplasia and its contractile phenotype. Brown Norway rats were sensitized with ovalbumin (OVA) or saline on day 0 and then either OVA-challenged once on day 14 and killed 24 h later or OVA-challenged 3 times (on days 14, 19, and 24) and killed 2 or 7 days later. Changes in SM mass, expression of total myosin, SM myosin heavy chain fast isoform (SM-B) and myosin light chain kinase (MLCK), tracheal contractions ex vivo, and airway responsiveness to methacholine (MCh) in vivo were assessed. One day after a single OVA challenge, the number of SM cells positive for PCNA was greater than for control animals, whereas the SM mass, contractile phenotype, and tracheal contractility were unchanged. Two days after three challenges, SM mass and PCNA immunoreactive cells were increased (3- and 10-fold, respectively; P < 0.05), but airway responsiveness to MCh was unaffected. Lower expression in total myosin, SM-B, and MLCK was observed at the mRNA level ( P < 0.05), and total myosin and MLCK expression were lower at the protein level ( P < 0.05) after normalization for SM mass. Normalized tracheal SM force generation was also significantly lower 2 days after repeated challenges ( P < 0.05). Seven days after repeated challenges, features of remodeling were restored toward control levels. Allergen-induced hyperplasia of SM cells was associated with a loss of contractile phenotype, which was offset by the increase in mass.

scholarly journals A novel GABAA receptor ligand MIDD0301 with limited blood-brain barrier penetration relaxes airway smooth muscle ex vivo and in vivo

2019 ◽  
Vol 316 (2) ◽  
pp. L385-L390 ◽  
Author(s):  
Gene T. Yocum ◽  
Jose F. Perez-Zoghbi ◽  
Jennifer Danielsson ◽  
Aisha S. Kuforiji ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Ex Vivo ◽  
Drug Candidate ◽  
Organ Bath ◽  
Forced Oscillation Technique ◽  
Gaba A ◽  
Peripheral Airways ◽  
Trace Concentrations

Airway smooth muscle (ASM) cells express GABA A receptors (GABAARs), and previous reports have demonstrated that GABAAR activators relax ASM. However, given the activity of GABAARs in central nervous system inhibitory neurotransmission, concern exists that these activators may lead to undesirable sedation. MIDD0301 is a novel imidazobenzodiazepine and positive allosteric modulator of the GABAAR with limited brain distribution, thus eliminating the potential for sedation. Here, we demonstrate that MIDD0301 relaxes histamine-contracted guinea pig ( P < 0.05, n = 6–9) and human ( P < 0.05, n = 6–10) tracheal smooth muscle ex vivo in organ bath experiments, dilates mouse peripheral airways ex vivo in precision-cut lung-slice experiments ( P < 0.001, n = 16 airways from three mice), and alleviates bronchoconstriction in vivo in mice, as assessed by the forced-oscillation technique ( P < 0.05, n = 6 mice). Only trace concentrations of the compound were detected in the brains of mice after inhalation of nebulized 5 mM MIDD0301. Given its favorable pharmacokinetic properties and demonstrated ability to relax ASM in a number of clinically relevant experimental paradigms, MIDD0301 is a promising drug candidate for bronchoconstrictive diseases, such as asthma.

scholarly journals Attenuation of airway smooth muscle contractility via flavonol-mediated inhibition of phospholipase-Cβ

2016 ◽  
Vol 310 (8) ◽  
pp. L747-L758 ◽  
Author(s):  
Amy Brown ◽  
Jennifer Danielsson ◽  
Elizabeth A. Townsend ◽  
Yi Zhang ◽  
Jose F. Perez-Zoghbi ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Inositol Phosphates ◽  
Ex Vivo ◽  
Treatment Options ◽  
Smooth Muscle Contractility ◽  
Phosphodiesterase 4 ◽  
Naturally Occurring ◽  
Pharmacological Method

Enhanced contractility of airway smooth muscle (ASM) is a major pathophysiological characteristic of asthma. Expanding the therapeutic armamentarium beyond β-agonists that target ASM hypercontractility would substantially improve treatment options. Recent studies have identified naturally occurring phytochemicals as candidates for acute ASM relaxation. Several flavonoids were evaluated for their ability to acutely relax human and murine ASM ex vivo and murine airways in vivo and were evaluated for their ability to inhibit procontractile signaling pathways in human ASM (hASM) cells. Two members of the flavonol subfamily, galangin and fisetin, significantly relaxed acetylcholine-precontracted murine tracheal rings ex vivo ( n = 4 and n = 5, respectively, P < 0.001). Galangin and fisetin also relaxed acetylcholine-precontracted hASM strips ex vivo ( n = 6–8, P < 0.001). Functional respiratory in vivo murine studies demonstrated that inhaled galangin attenuated the increase in lung resistance induced by inhaled methacholine ( n = 6, P < 0.01). Both flavonols, galangin and fisetin, significantly inhibited purified phosphodiesterase-4 (PDE4) ( n = 7, P < 0.05; n = 7, P < 0.05, respectively), and PLCβ enzymes ( n = 6, P < 0.001 and n = 6, P < 0.001, respectively) attenuated procontractile Gq agonists' increase in intracellular calcium ( n = 11, P < 0.001), acetylcholine-induced increases in inositol phosphates, and CPI-17 phosphorylation ( n = 9, P < 0.01) in hASM cells. The prorelaxant effect retained in these structurally similar flavonols provides a novel pharmacological method for dual inhibition of PLCβ and PDE4 and therefore may serve as a potential treatment option for acute ASM constriction.

Angiogenesis is induced by airway smooth muscle strain

2007 ◽  
Vol 293 (4) ◽  
pp. L1059-L1068 ◽  
Author(s):  
Nadia A. Hasaneen ◽  
Stanley Zucker ◽  
Richard Z. Lin ◽  
Gayle G. Vaday ◽  
Reynold A. Panettieri ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Neutralizing Antibodies ◽  
Airway Remodeling ◽  
Mechanical Strain ◽  
Microvascular Endothelial Cell ◽  
Chronic Obstructive ◽  
Vegf Expression

Angiogenesis is an important feature of airway remodeling in both chronic asthma and chronic obstructive pulmonary disease (COPD). Airways in those conditions are exposed to excessive mechanical strain during periods of acute exacerbations. We recently reported that mechanical strain of human airway smooth muscle (HASM) led to an increase in their proliferation and migration. Sustained growth in airway smooth muscle in vivo requires an increase in the nutritional supply to these muscles, hence angiogenesis. In this study, we examined the hypothesis that cyclic mechanical strain of HASM produces factors promoting angiogenic events in the surrounding vascular endothelial cells. Our results show: 1) a significant increase in human lung microvascular endothelial cell (HMVEC-L) proliferation, migration, and tube formation following incubation in conditioned media (CM) from HASM cells exposed to mechanical strain; 2) mechanical strain of HASM cells induced VEGF expression and release; 3) VEGF neutralizing antibodies inhibited the proliferation, migration, and tube formations of HMVEC-L induced by the strained airway smooth muscle CM; 4) mechanical strain of HASM induced a significant increase in hypoxia-inducible factor-1α (HIF-1α) mRNA and protein, a transcription factor required for VEGF gene transcription; and 5) mechanical strain of HASM induced HIF-1α/VEGF through dual phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and ERK pathways. In conclusion, exposing HASM cells to mechanical strain induces signal transduction pathway through PI3K/Akt/mTOR and ERK pathways that lead to an increase in HIF-1α, a transcription factor required for VEGF expression. VEGF release by mechanical strain of HASM may contribute to the angiogenesis seen with repeated exacerbation of asthma and COPD.

TGF-β enhances deposition of perlecan from COPD airway smooth muscle

2012 ◽  
Vol 302 (3) ◽  
pp. L325-L333 ◽  
Author(s):  
Yukikazu Ichimaru ◽  
David I. Krimmer ◽  
Janette K. Burgess ◽  
Judith L. Black ◽  
Brian G. G. Oliver
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Transforming Growth Factor ◽  
Signaling Molecules ◽  
Collagen I ◽  
Chronic Obstructive ◽  
Airway Smooth Muscle Cells ◽  
Organ Systems

Chronic obstructive pulmonary disease (COPD) and asthma are characterized by irreversible remodeling of the airway walls, including thickening of the airway smooth muscle layer. Perlecan is a large, multidomain, proteoglycan that is expressed in the lungs, and in other organ systems, and has been described to have a role in cell adhesion, angiogenesis, and proliferation. This study aimed to investigate functional properties of the different perlecan domains in relation to airway smooth muscle cells (ASMC). Primary human ASMC obtained from donors with asthma ( n = 13), COPD ( n = 12), or other lung disease ( n = 20) were stimulated in vitro with 1 ng/ml transforming growth factor-β1 (TGF-β1) before perlecan deposition and cytokine release were analyzed. In some experiments, inhibitors of signaling molecules were added. Perlecan domains I–V were seeded on tissue culture plates at 10 μg/ml with 1 μg/ml collagen I as a control. ASM was incubated on top of the peptides before being analyzed for attachment, proliferation, and wound healing. TGF-β1 upregulated deposition of perlecan by ASMC from COPD subjects only. TGF-β1 upregulated release of IL-6 into the supernatant of ASMC from all subjects. Inhibitors of SMAD and JNK signaling molecules decreased TGF-β1-induced perlecan deposition by COPD ASMC. Attachment of COPD ASMC was upregulated by collagen I and perlecan domains IV and V, while perlecan domain II upregulated attachment only of asthmatic ASMC. Seeding on perlecan domains did not increase proliferation of any ASMC type. TGF-β1-induced perlecan deposition may enhance attachment of migrating ASMC in vivo and thus may be a mechanism for ASMC layer hypertrophy in COPD.

scholarly journals TAS2R activation promotes airway smooth muscle relaxation despite β2-adrenergic receptor tachyphylaxis

2012 ◽  
Vol 303 (4) ◽  
pp. L304-L311 ◽  
Author(s):  
Steven S. An ◽  
Wayne C. H. Wang ◽  
Cynthia J. Koziol-White ◽  
Kwangmi Ahn ◽  
Danielle Y. Lee ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Intracellular Signaling ◽  
Adrenergic Receptor ◽  
Muscle Relaxation ◽  
Chronic Obstructive Lung Disease ◽  
Cell Stiffness ◽  
Smooth Muscle Relaxation ◽  
Chronic Obstructive ◽  
Intracellular Ca

Recently, bitter taste receptors (TAS2Rs) were found in the lung and act to relax airway smooth muscle (ASM) via intracellular Ca2+ concentration signaling generated from restricted phospholipase C activation. As potential therapy, TAS2R agonists could be add-on treatment when patients fail to achieve adequate bronchodilation with chronic β-agonists. The β2-adrenergic receptor (β2AR) of ASM undergoes extensive functional desensitization. It remains unknown whether this desensitization affects TAS2R function, by cross talk at the receptors or distal common components in the relaxation machinery. We studied intracellular signaling and cell mechanics using isolated human ASM, mouse tracheal responses, and human bronchial responses to characterize TAS2R relaxation in the context of β2AR desensitization. In isolated human ASM, magnetic twisting cytometry revealed >90% loss of isoproterenol-promoted decrease in cell stiffness after 18-h exposure to albuterol. Under these same conditions of β2AR desensitization, the TAS2R agonist chloroquine relaxation response was unaffected. TAS2R-mediated stimulation of intracellular Ca2+ concentration in human ASM was unaltered by albuterol pretreatment, in contrast to cAMP signaling, which was desensitized by >90%. In mouse trachea, β2AR desensitization by β-agonist amounted to 92 ± 6.0% ( P < 0.001), while, under these same conditions, TAS2R desensitization was not significant (11 ± 3.5%). In human lung slices, chronic β-agonist exposure culminated in 64 ± 5.7% ( P < 0.001) desensitization of β2AR-mediated dilation of carbachol-constricted airways that was reversed by chloroquine. We conclude that there is no evidence for physiologically relevant cross-desensitization of TAS2R-mediated ASM relaxation from chronic β-agonist treatment. These findings portend a favorable therapeutic profile for TAS2R agonists for the treatment of bronchospasm in asthma or chronic obstructive lung disease.

scholarly journals Glucagon induces airway smooth muscle relaxation by nitric oxide and prostaglandin E2

2015 ◽  
Vol 225 (3) ◽  
pp. 205-217 ◽  
Author(s):  
Daniella B R Insuela ◽  
Julio B Daleprane ◽  
Luciana P Coelho ◽  
Adriana R Silva ◽  
Patrícia M R e Silva ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Airway Obstruction ◽  
Airway Smooth Muscle ◽  
Airway Hyperreactivity ◽  
Whole Body ◽  
Smooth Muscle Relaxation ◽  
Prostaglandin E ◽  
Organ Bath ◽  
Cox 1

Glucagon is a hyperglycemic pancreatic hormone that has been shown to provide a beneficial effect against asthmatic bronchospasm. We investigated the role of this hormone on airway smooth muscle contraction and lung inflammation using bothin vitroandin vivoapproaches. The action of glucagon on mouse cholinergic tracheal contraction was studied in a conventional organ bath system, and its effect on airway obstruction was also investigated using the whole-body pletysmographic technique in mice. We also tested the effect of glucagon on lipopolysaccharide (LPS)-induced airway hyperreactivity (AHR) and inflammation. The expression of glucagon receptor (GcgR), CREB, phospho-CREB, nitric oxide synthase (NOS)-3, pNOS-3 and cyclooxygenase (COX)-1 was evaluated by western blot, while prostaglandin E2(PGE2) and tumour necrosis factor-α were quantified by enzyme-linked immunoassay and ELISA respectively. Glucagon partially inhibited carbachol-induced tracheal contraction in a mechanism clearly sensitive to des-His1-[Glu9]-glucagon amide, a GcgR antagonist. Remarkably, GcgR was more expressed in the lung and trachea with intact epithelium than in the epithelium-denuded trachea. In addition, the glucagon-mediated impairment of carbachol-induced contraction was prevented by either removing epithelial cells or blocking NOS (l-NAME), COX (indomethacin) or COX-1 (SC-560). In contrast, inhibitors of either heme oxygenase or COX-2 were inactive. Intranasal instillation of glucagon inhibited methacholine-induced airway obstruction by a mechanism sensitive to pretreatment withl-NAME, indomethacin and SC-560. Glucagon induced CREB and NOS-3 phosphorylation and increased PGE2levels in the lung tissue without altering COX-1 expression. Glucagon also inhibited LPS-induced AHR and bronchoalveolar inflammation. These findings suggest that glucagon possesses airway-relaxing properties that are mediated by epithelium-NOS-3-NO- and COX-1-PGE2-dependent mechanisms.

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