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Balraj P, Ambhore NS, Ramakrishnan YS, Borkar NA, Banerjee P, Reza MI, Varadharajan S, Kumar A, Pabelick CM, Prakash YS, Sathish V. Kisspeptin/KISS1R Signaling Modulates Human Airway Smooth Muscle Cell Migration. Am J Respir Cell Mol Biol 2024; 70:507-518. [PMID: 38512807 PMCID: PMC11160419 DOI: 10.1165/rcmb.2023-0469oc] [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] [Received: 12/28/2023] [Accepted: 03/20/2024] [Indexed: 03/23/2024] Open
Abstract
Airway remodeling is a cardinal feature of asthma, associated with increased airway smooth muscle (ASM) cell mass and upregulation of extracellular matrix deposition. Exaggerated ASM cell migration contributes to excessive ASM mass. Previously, we demonstrated the alleviating role of Kp (kisspeptin) receptor (KISS1R) activation by Kp-10 in mitogen (PDGF [platelet-derived growth factor])-induced human ASM cell proliferation in vitro and airway remodeling in vivo in a mouse model of asthma. Here, we examined the mechanisms by which KISS1R activation regulates mitogen-induced ASM cell migration. KISS1R activation using Kp-10 significantly inhibited PDGF-induced ASM cell migration, further confirmed using KISS1R shRNA. Furthermore, KISS1R activation modulated F/G actin dynamics and the expression of promigration proteins like CDC42 (cell division control protein 42) and cofilin. Mechanistically, we observed reduced ASM RhoA-GTPAse with KISS1R activation. The antimigratory effect of KISS1R was abolished by PKA (protein kinase A)-inhibitory peptide. Conversely, KISS1R activation significantly increased cAMP and phosphorylation of CREB (cAMP-response element binding protein) in PDGF-exposed ASM cells. Overall, these results highlight the alleviating properties of Kp-10 in the context of airway remodeling.
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Affiliation(s)
- Premanand Balraj
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota
| | | | | | | | - Priyanka Banerjee
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota
| | - Mohammad Irshad Reza
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota
| | - Subashini Varadharajan
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota
| | - Ashish Kumar
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota
| | - Christina M. Pabelick
- Department of Anesthesiology and Perioperative Medicine, and
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Y. S. Prakash
- Department of Anesthesiology and Perioperative Medicine, and
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Venkatachalem Sathish
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota
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Lee CE, Raduka A, Gao N, Hussain A, Rezaee F. 8-Bromo-cAMP attenuates human airway epithelial barrier disruption caused by titanium dioxide fine and nanoparticles. Tissue Barriers 2024:2300579. [PMID: 38166590 DOI: 10.1080/21688370.2023.2300579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/22/2023] [Indexed: 01/05/2024] Open
Abstract
Titanium dioxide fine particles (TiO2-FPs) and nanoparticles (TiO2-NPs) are the most widely used whitening pigments worldwide. Inhalation of TiO2-FPs and TiO2-NPs can be harmful as it triggers toxicity in the airway epithelial cells. The airway epithelium serves as the respiratory system's first line of defense in which airway epithelial cells are significant targets of inhaled pathogens and environmental particles. Our group previously found that TiO2-NPs lead to a disrupted barrier in the polarized airway epithelial cells. However, the effect of TiO2-FPs on the respiratory epithelial barrier has not been examined closely. In this study, we aimed to compare the effects of TiO2-FPs and TiO2-NPs on the structure and function of the airway epithelial barrier. Additionally, we hypothesized that 8-Bromo-cAMP, a cyclic adenosine monophosphate (cAMP) derivative, would alleviate the disruptive effects of both TiO2-FPs and TiO2-NPs. We observed increased epithelial membrane permeability in both TiO2-FPs and TiO2-NPs after exposure to 16HBE cells. Immunofluorescent labeling showed that both particle sizes disrupted the structural integrity of airway epithelial tight junctions and adherens junctions. TiO2-FPs had a slightly more, but insignificant impact on the epithelial barrier disruption than TiO2-NPs. Treatment with 8-Bromo-cAMP significantly attenuated the barrier-disrupting impact of both TiO2-FPs and TiO2-NPs on cell monolayers. Our study demonstrates that both TiO2-FPs and TiO2-NPs cause comparable barrier disruption and suggests a protective role for cAMP signaling. The observed effects of TiO2-FPs and TiO2-NPs provide a necessary understanding for characterizing the pathways involved in the defensive role of the cAMP pathway on TiO2-induced airway barrier disruption.
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Affiliation(s)
- Claire E Lee
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
- Department of Cognitive Science, College of Arts and Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Andjela Raduka
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Nannan Gao
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Aabid Hussain
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Fariba Rezaee
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
- Center for Pediatric Pulmonary Medicine, Cleveland Clinic Children's, Cleveland, OH, USA
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3
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Kaneda T, Ifadotunnikmah F, Nugroho AE, Koshikawa S, Tadahiro S, Hirasawa Y, Morita H. Calofolic Acid-A from Calophyllum scriblitifolium Bark Has Vasorelaxant Activity via Indirect PKA Activation Caused by PI-3 Kinase Inhibition in Rat Vascular Smooth Muscle Cells. JOURNAL OF NATURAL PRODUCTS 2022; 85:2192-2198. [PMID: 35983865 DOI: 10.1021/acs.jnatprod.2c00502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Previously, we isolated 2R,3S,15R-calofolic acids (CAs) from Calophyllum scriblitifolium bark, which showed vasorelaxant activity on phenylephrine (PE)-precontracted rat aortic rings. Although the effect was suggested to be induced via an extracellular Ca2+-independent manner and mainly acts on vascular smooth muscle, the exact mechanism of action of CAs remained unclear. Thus, this study investigated the detailed mechanism of calofolic acid-A (CA-A) induced vasorelaxation in an aortic ring specimen using rat vascular smooth muscle cells (VSMCs). The levels of PE-induced phosphorylation on MLC Ser19 decreased in VSMCs pretreated with CA-A. CA-A also decreased the phosphorylation of MYPT1 Thr696 and MYPT1 Thr853. On the other hand, CA-A increased the PE-induced phosphorylation of MYPT1 Ser695 and MYPT1 Ser668, which are reported to be phosphorylated by a cAMP-dependent protein kinase (PKA). CA-A slightly increased PKA substrate phosphorylation in a concentration-dependent manner. Furthermore, CA-A enhanced isoproterenol (ISO)-induced cAMP accumulation and PKA substrate phosphorylation. Treatment with PI-3 kinase (PI3K) inhibitor, LY294002, enhanced ISO-induced cAMP accumulation and PKA substrate phosphorylation in the same manner as CA-A treatment. Furthermore, CA-A was found to directly inhibit PI3K enzyme activity in a dose-dependent manner. Taken together, the present study indicated that CA-A induces vasorelaxation through an indirectly activated PKA-MYPT1 pathway caused by inhibition of PI3K activity.
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Affiliation(s)
- Toshio Kaneda
- Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Farida Ifadotunnikmah
- Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Alfarius Eko Nugroho
- Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Sae Koshikawa
- Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Sasaki Tadahiro
- Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Yusuke Hirasawa
- Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Hiroshi Morita
- Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142-8501, Japan
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Beqiraj-Zeqiraj Q, Thaçi Q, Sahiti F, Kovač Z, Raffay TM, Sopi RB. Rho-kinase inhibitors protect against neonatal hyperoxia-induced airway hyperreactivity in a rat pup model: Role of prostaglandin F 2α. Pediatr Pulmonol 2022; 57:1229-1237. [PMID: 35088947 DOI: 10.1002/ppul.25848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 01/06/2022] [Accepted: 01/26/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Oxygen therapy in preterm neonates is associated with airway hyperreactivity. The role of Rho/Rho-kinase smooth muscle signaling in hyperoxia-induced airway hyperreactivity remains understudied. We hypothesized that inhibition of Rho-kinase will attenuate airway hyperreactivity induced by neonatal hyperoxia. METHODS Newborn rats were raised in hyperoxia (>95% O2 ) or ambient air (AA) for 7 days. Subgroups were injected with a Rho-kinase inhibitor: Y-27632 (10 mg·kg-1 ·day-1 ) or fasudil (10 mg·kg-1 ·day-1 ), or a FP receptor antagonist - AS604872 (30 mg·kg-1 ·day-1 ). After exposures, tracheal cylinders were prepared for in vitro wire myography. Contraction to methacholine or PGF2α was measured in the presence or absence of tissue-bath Y-27632, fasudil, or AS604872. Lung PGF2α levels, Rho-kinase protein level and Rho-kinase 1 activity were measured by ELISA. RESULTS Tracheal smooth muscle contraction was significantly greater in hyperoxic compared to AA groups. Both, Y-27632 and fasudil significantly decreased contractility to MCh or PGF2α in hyperoxic groups versus hyperoxic controls (p < 0.001), but did not alter AA group responses. Inhibition of FP receptors attenuated responses to PGF2α . Hyperoxia significantly increased lung PGF2α compared to AA (p < 0.01), but Rho-kinase inhibition did not influence PGF2α level. Rho-kinase protein level (p < 0.001) and activity (p < 0.01), were increased by hyperoxia, but blockade of FP receptor reduced the Rho-kinase 1 activity (p < 0.05) under hyperoxic condition. CONCLUSIONS This study demonstrates an active role of Rho/Rho-kinase signaling on hyperoxia-induced airway hyperreactivity. These findings suggest that Rho-kinase inhibitors might serve as an effective therapy for hyperoxia-induced airway hyperreactivity.
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Affiliation(s)
- Qendresa Beqiraj-Zeqiraj
- Department of Pathophysiology, Faculty of Medicine, University of Prishtina, Prishtina, Kosovo.,Pediatric Clinic, University Clinical Centre of Kosovo, Prishtina, Kosovo
| | - Qëndrim Thaçi
- Department of Premedical Courses, Faculty of Medicine, University of Prishtina, Prishtina, Kosovo
| | - Floran Sahiti
- Department of Premedical Courses, Faculty of Medicine, University of Prishtina, Prishtina, Kosovo.,Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
| | - Zdenko Kovač
- Department of Pathophysiology, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Thomas M Raffay
- Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ramadan B Sopi
- Department of Premedical Courses, Faculty of Medicine, University of Prishtina, Prishtina, Kosovo
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Yadav SK, Sharma P, Shah SD, Panettieri RA, Kambayashi T, Penn RB, Deshpande DA. Autocrine regulation of airway smooth muscle contraction by diacylglycerol kinase. J Cell Physiol 2022; 237:603-616. [PMID: 34278583 PMCID: PMC8763953 DOI: 10.1002/jcp.30528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 01/03/2023]
Abstract
Diacylglycerol kinase (DGK), a lipid kinase, catalyzes the conversion of diacylglycerol (DAG) to phosphatidic acid, thereby terminating DAG-mediated signaling by Gq-coupled receptors that regulate contraction of airway smooth muscle (ASM). A previous study from our laboratory demonstrated that DGK inhibition or genetic ablation leads to reduced ASM contraction and provides protection for allergen-induced airway hyperresponsiveness. However, the mechanism by which DGK regulates contractile signaling in ASM is not well established. Herein, we investigated the role of prorelaxant cAMP-protein kinase A (PKA) signaling in DGK-mediated regulation of ASM contraction. Pretreatment of human ASM cells with DGK inhibitor I activated PKA as demonstrated by the phosphorylation of PKA substrates, VASP, Hsp20, and CREB, which was abrogated when PKA was inhibited pharmacologically or molecularly using overexpression of the PKA inhibitor peptide, PKI. Furthermore, inhibition of DGK resulted in induction of cyclooxygenase (COX) and generation of prostaglandin E2 (PGE2 ) with concomitant activation of Gs-cAMP-PKA signaling in ASM cells in an autocrine/paracrine fashion. Inhibition of protein kinase C (PKC) or extracellular-signal-regulated kinase (ERK) attenuated DGK-mediated production of PGE2 and activation of cAMP-PKA signaling in human ASM cells, suggesting that inhibition of DGK activates the COX-PGE2 pathway in a PKC-ERK-dependent manner. Finally, DGK inhibition-mediated attenuation of contractile agonist-induced phosphorylation of myosin light chain 20 (MLC-20), a marker of ASM contraction, involves COX-mediated cAMP production and PKA activation in ASM cells. Collectively these findings establish a novel mechanism by which DGK regulates ASM contraction and further advances DGK as a potential therapeutic target to provide effective bronchoprotection in asthma.
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Affiliation(s)
- Santosh K. Yadav
- Center for Translational Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA 19107
| | - Pawan Sharma
- Center for Translational Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA 19107
| | - Sushrut D. Shah
- Center for Translational Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA 19107
| | - Reynold A. Panettieri
- Rutgers Institute for Translational Medicine & Science, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901
| | - Taku Kambayashi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Raymond B. Penn
- Center for Translational Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA 19107
| | - Deepak A. Deshpande
- Center for Translational Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, Jane & Leonard Korman Respiratory Institute, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA 19107.,Corresponding author Deepak Deshpande, PhD, Professor, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, PA, USA 19107,
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6
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O’Sullivan MJ, Gabriel E, Panariti A, Park CY, Ijpma G, Fredberg JJ, Lauzon AM, Martin JG. Epithelial Cells Induce a Cyclo-Oxygenase-1-Dependent Endogenous Reduction in Airway Smooth Muscle Contractile Phenotype. Am J Respir Cell Mol Biol 2017; 57:683-691. [PMID: 28708434 PMCID: PMC5765417 DOI: 10.1165/rcmb.2016-0427oc] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 06/29/2017] [Indexed: 12/11/2022] Open
Abstract
Airway smooth muscle cells (ASMCs) are phenotypically regulated to exist in either a proliferative or a contractile state. However, the influence of other airway structural cell types on ASMC phenotype is largely unknown. Although epithelial cells are known to drive ASM proliferation, their effects on the contractile phenotype are uncertain. In the current study, we tested the hypothesis that epithelial cells reduce the contractile phenotype of ASMCs. To do so, we measured force production by traction microscopy, gene and protein expression, as well as calcium release by Fura-2 ratiometric imaging. ASMCs incubated with epithelial-derived medium produced less force after histamine stimulation. We observed reduced expression of myocardin, α-smooth muscle actin, and calponin within ASMCs after coculture with epithelial cells. Peak calcium release in response to histamine was diminished, and depended on the synthesis of cyclo-oxygenase-1 products by ASM and on prostaglandin E receptors 2 and 4. Together, these in vitro results demonstrate that epithelial cells have the capacity to coordinately reduce ASM contraction by functional antagonism and by reduction of the expression of certain contractile proteins.
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Affiliation(s)
- Michael J. O’Sullivan
- Meakins-Christie Laboratories, McGill University Health Centre, Montreal, Quebec, Canada; and
| | - Elizabeth Gabriel
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Alice Panariti
- Meakins-Christie Laboratories, McGill University Health Centre, Montreal, Quebec, Canada; and
| | - Chan Y. Park
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Gijs Ijpma
- Meakins-Christie Laboratories, McGill University Health Centre, Montreal, Quebec, Canada; and
| | - Jeffrey J. Fredberg
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts
| | - Anne-Marie Lauzon
- Meakins-Christie Laboratories, McGill University Health Centre, Montreal, Quebec, Canada; and
| | - James G. Martin
- Meakins-Christie Laboratories, McGill University Health Centre, Montreal, Quebec, Canada; and
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Levay M, Krobert KA, Wittig K, Voigt N, Bermudez M, Wolber G, Dobrev D, Levy FO, Wieland T. NSC23766, a Widely Used Inhibitor of Rac1 Activation, Additionally Acts as a Competitive Antagonist at Muscarinic Acetylcholine Receptors. J Pharmacol Exp Ther 2013; 347:69-79. [DOI: 10.1124/jpet.113.207266] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Billington CK, Ojo OO, Penn RB, Ito S. cAMP regulation of airway smooth muscle function. Pulm Pharmacol Ther 2013; 26:112-20. [PMID: 22634112 PMCID: PMC3574867 DOI: 10.1016/j.pupt.2012.05.007] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 05/14/2012] [Accepted: 05/17/2012] [Indexed: 12/11/2022]
Abstract
Agonists activating β(2)-adrenoceptors (β(2)ARs) on airway smooth muscle (ASM) are the drug of choice for rescue from acute bronchoconstriction in patients with both asthma and chronic obstructive pulmonary disease (COPD). Moreover, the use of long-acting β-agonists combined with inhaled corticosteroids constitutes an important maintenance therapy for these diseases. β-Agonists are effective bronchodilators due primarily to their ability to antagonize ASM contraction. The presumed cellular mechanism of action involves the generation of intracellular cAMP, which in turn can activate the effector molecules cAMP-dependent protein kinase (PKA) and Epac. Other agents such as prostaglandin E(2) and phosphodiesterase inhibitors that also increase intracellular cAMP levels in ASM, can also antagonize ASM contraction, and inhibit other ASM functions including proliferation and migration. Therefore, β(2)ARs and cAMP are key players in combating the pathophysiology of airway narrowing and remodeling. However, limitations of β-agonist therapy due to drug tachyphylaxis related to β(2)AR desensitization, and recent findings regarding the manner in which β(2)ARs and cAMP signal, have raised new and interesting questions about these well-studied molecules. In this review we discuss current concepts regarding β(2)ARs and cAMP in the regulation of ASM cell functions and their therapeutic roles in asthma and COPD.
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Affiliation(s)
- Charlotte K Billington
- Division of Therapeutics and Molecular Medicine, The University of Nottingham, Nottingham NG7 2UH, UK.
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9
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Pelaia G, Renda T, Gallelli L, Vatrella A, Busceti MT, Agati S, Caputi M, Cazzola M, Maselli R, Marsico SA. Molecular mechanisms underlying airway smooth muscle contraction and proliferation: implications for asthma. Respir Med 2008; 102:1173-81. [PMID: 18579364 DOI: 10.1016/j.rmed.2008.02.020] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 02/26/2008] [Indexed: 11/18/2022]
Abstract
Airway smooth muscle (ASM) plays a key role in bronchomotor tone, as well as in structural remodeling of the bronchial wall. Therefore, ASM contraction and proliferation significantly participate in the development and progression of asthma. Many contractile agonists also behave as mitogenic stimuli, thus contributing to frame a hyperresponsive and hyperplastic ASM phenotype. In this review, the molecular mechanisms and signaling pathways involved in excitation-contraction coupling and ASM cell growth will be outlined. Indeed, the recent advances in understanding the basic aspects of ASM biology are disclosing important cellular targets, currently explored for the implementation of new, more effective anti-asthma therapies.
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Affiliation(s)
- Girolamo Pelaia
- Department of Experimental and Clinical Medicine, University "Magna Graecia" of Catanzaro, Italy
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10
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Oguma T, Kume H, Ito S, Takeda N, Honjo H, Kodama I, Shimokata K, Kamiya K. Involvement of reduced sensitivity to Ca in beta-adrenergic action on airway smooth muscle. Clin Exp Allergy 2006; 36:183-91. [PMID: 16433855 DOI: 10.1111/j.1365-2222.2006.02412.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND It is well known that beta-adrenoceptor agonists (beta-agonists) cause relaxation in airway smooth muscle mediated by a reduction in the concentration of intracellular Ca2+ ([Ca2+](i)). However, little is currently known regarding whether reduced sensitization to Ca2+ is involved in the beta-adrenergic relaxation. OBJECTIVE This study was designed to determine the intracellular mechanisms underlying suppression of Ca2+ sensitization in beta-adrenergic relaxation (Ca(2+)-independent relaxation by beta-agonists). Methods Isometric tension and [Ca2+](i) were simultaneously measured in fura-2-loaded strips isolated from guinea-pig tracheal smooth muscles. The relationships between tension and [Ca2+](i) were examined in the inhibitory action of isoprenaline (ISO) and other cAMP-related agents against methacholine-induced contraction. RESULTS The concentration-inhibition curve for ISO against methacholine in tension was significantly dissociated from the curve for ISO in [Ca2+](i). In ISO-induced relaxation, a reduction in tension was significantly greater than that in [Ca2+](i.) This phenomenon was mimicked by other cAMP-related agents: forskolin and dibutyryl-cAMP. In contrast, the inhibitory action of SKF-96365, a non-selective inhibitor of Ca(2+) channels, was associated with that in [Ca2+](i). In the presence of Rp-cAMPS, an inhibitor of protein kinase A (PKA), ISO caused an equivalent relaxation with less reduction in [Ca2+](i). The effects of ISO were not affected by Y-27632, an inhibitor of Rho-kinase, or by bisindolylmaleimide, an inhibitor of protein kinase C. ISO failed to inhibit contraction elicited by calyculin A, an inhibitor of myosin phosphatase. Conclusion beta-Adrenergic action antagonizes not only Ca2+ mobilization but also Ca2+ sensitization in methacholine-induced contraction. The cAMP/PKA-independent, G(s)-direct action is more potent in Ca(2+)-independent relaxation by beta-agonists than the cAMP/PKA-dependent pathway. Moreover, myosin phosphatase is a fundamentally affected protein in the reduced response to Ca2+ mediated by beta-agonist. Our results may provide evidence that this Ca2+ desensitization is a novel target for a reliever medication using rapid-acting beta-agonists in acute asthma management.
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Affiliation(s)
- T Oguma
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
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11
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Bai Y, Sanderson MJ. Airway smooth muscle relaxation results from a reduction in the frequency of Ca2+ oscillations induced by a cAMP-mediated inhibition of the IP3 receptor. Respir Res 2006; 7:34. [PMID: 16504084 PMCID: PMC1459146 DOI: 10.1186/1465-9921-7-34] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Accepted: 02/23/2006] [Indexed: 01/08/2023] Open
Abstract
Background It has been shown that the contractile state of airway smooth muscle cells (SMCs) in response to agonists is determined by the frequency of Ca2+ oscillations occurring within the SMCs. Therefore, we hypothesized that the relaxation of airway SMCs induced by agents that increase cAMP results from the down-regulation or slowing of the frequency of the Ca2+ oscillations. Methods The effects of isoproterenol (ISO), forskolin (FSK) and 8-bromo-cAMP on the relaxation and Ca2+ signaling of airway SMCs contracted with methacholine (MCh) was investigated in murine lung slices with phase-contrast and laser scanning microscopy. Results All three cAMP-elevating agents simultaneously induced a reduction in the frequency of Ca2+ oscillations within the SMCs and the relaxation of contracted airways. The decrease in the Ca2+ oscillation frequency correlated with the extent of airway relaxation and was concentration-dependent. The mechanism by which cAMP reduced the frequency of the Ca2+ oscillations was investigated. Elevated cAMP did not affect the re-filling rate of the internal Ca2+ stores after emptying by repetitive exposure to 20 mM caffeine. Neither did elevated cAMP limit the Ca2+ available to stimulate contraction because an elevation of intracellular Ca2+ concentration induced by exposure to a Ca2+ ionophore (ionomycin) or by photolysis of caged-Ca2+ did not reverse the effect of cAMP. Similar results were obtained with iberiotoxin, a blocker of Ca2+-activated K+ channels, which would be expected to increase Ca2+ influx and contraction. By contrast, the photolysis of caged-IP3 in the presence of agonist, to further elevate the intracellular IP3 concentration, reversed the slowing of the frequency of the Ca2+ oscillations and relaxation of the airway induced by FSK. This result implied that the sensitivity of the IP3R to IP3 was reduced by FSK and this was supported by the reduced ability of IP3 to release Ca2+ in SMCs in the presence of FSK. Conclusion These results indicate that the relaxant effect of cAMP-elevating agents on airway SMCs is achieved by decreasing the Ca2+ oscillation frequency by reducing internal Ca2+ release through IP3 receptors.
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Affiliation(s)
- Yan Bai
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
| | - Michael J Sanderson
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
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12
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Bai Y, Sanderson MJ. Modulation of the Ca2+ sensitivity of airway smooth muscle cells in murine lung slices. Am J Physiol Lung Cell Mol Physiol 2006; 291:L208-21. [PMID: 16461427 DOI: 10.1152/ajplung.00494.2005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To investigate the phenomenon of Ca(2+) sensitization, we developed a new intact airway and arteriole smooth muscle cell (SMC) "model" by treating murine lung slices with ryanodine-receptor antagonist, ryanodine (50 microM), and caffeine (20 mM). A sustained elevation in intracellular Ca(2+) concentration ([Ca(2+)](i)) was induced in both SMC types by the ryanodine-caffeine treatment due to the depletion of internal Ca(2+) stores and the stimulation of a persistent influx of Ca(2+). Arterioles responded to this sustained increase in [Ca(2+)](i) with a sustained contraction. By contrast, airways responded to sustained high [Ca(2+)](i) with a transient contraction followed by relaxation. Subsequent exposure to methacholine (MCh) induced a sustained concentration-dependent contraction of the airway without a change in the [Ca(2+)](i). During sustained MCh-induced contraction, Y-27632 (a Rho-kinase inhibitor) and GF-109203X (a protein kinase C inhibitor) induced a concentration-dependent relaxation without changing the [Ca(2+)](i). The cAMP-elevating agents, forskolin (an adenylyl cyclase activator), IBMX (a phosphodiesterase inhibitor), and caffeine (also acting as a phosphodiesterase inhibitor), exerted similar relaxing effects. These results indicate that 1) ryanodine-caffeine treatment is a valuable tool for investigating the contractile mechanisms of SMCs while avoiding nonspecific effects due to cell permeabilization, 2) in the absence of agonist, sustained high [Ca(2+)](i) has a differential time-dependent effect on the Ca(2+) sensitivity of airway and arteriole SMCs, 3) MCh facilitates the contraction of airway SMCs by inducing Ca(2+) sensitization via the activation of Rho-kinase and protein kinase C, and 4) cAMP-elevating agents contribute to the relaxation of airway SMCs through Ca(2+) desensitization.
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Affiliation(s)
- Yan Bai
- Department of Physiology, University of Massachusetts Medical School, Worcester, 01655, USA
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Li SJ, Sun NL. Regulation of intracellular Ca2+ and calcineurin by NO/PKG in proliferation of vascular smooth muscle cells. Acta Pharmacol Sin 2005; 26:323-8. [PMID: 15715928 DOI: 10.1111/j.1745-7254.2005.00049.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIM To determine whether Ca2+/calcineurin mediated the inhibitory effects of nitric oxide /cGMP-dependent protein kinase (NO/PKG) on the proliferation of vascular smooth muscle cells (VSMC). METHODS Proliferation and viability of primary VSMC from rat aorta were measured using [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) assay and acridine orange and ethidium bromide staining, respectively. Cytosolic Ca2+ was determined by Fluo-3/AM. Calcineurin protein and its activity were assayed using immunoblotting and free inorganic phosphate analysis, respectively. RESULTS (+/-)-S-nitroso-N-acetyl-penicillamine (SNAP) and Sp-8-(4-chlorophenylthio)-guanosine-3',5'-cyclic monophosphorothioate (Sp-8-pCPT-cGMPS) decreased phenylephrine (PE)-induced proliferation of VSMC by 27.3% and 36.6%, respectively, but Rp-8-[(4-chlorophenyl)thio]-guanosine-3',5'-cyclic monophosphorothioate (Rp-8-pCPT-cGMPS) increased PE-induced proliferation of VSMC. SNAP, Sp-8-pCPT-cGMPS, and Rp-8-pCPT-cGMPS did not affect the viability of VSMC. Calcineurin protein was decreased by 63.1% and its activity was decreased by 59.7% in smooth muscle cells (SMC) pretreated with verapamil (Ver) and then stimulated by PE. In SMC pretreated with Ver, the absorbance of cells stimulated by PE decreased by 22.0% and was further inhibited by the additional treatment of SNAP and Sp-8-pCPT-cGMPS. In SMC pretreated with cyclosporin A (CsA), the absorbance of cells stimulated by PE decreased by 36.7%, but could not be further altered by the additional treatment of SNAP, Sp-8-pCPT-cGMPS, and Rp-8-pCPT-cGMPS. In addition, Ver inhibited PE-induced intracellular Ca2+ variations, which could be further inhibited by SNAP and Sp-8-pCPT-cGMPS, but not by Rp-8-pCPT-cGMPS. Moreover, the increase in calcineurin activity induced by PE was inhibited by SNAP and Sp-8-pCPT-cGMPS, but was promoted by Rp-8-pCPT-cGMPS. CONCLUSION NO/PKG regulates calcineurin activity via the modulation of intracellular Ca2+ concentration, and thus partially inhibits the proliferation of VSMC without affecting their viability.
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Affiliation(s)
- Shi-jun Li
- Department of Cardiology, People's Hospital, Peking University, Beijing 100044, China.
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Sylvester JT. The tone of pulmonary smooth muscle: ROK and Rho music? Am J Physiol Lung Cell Mol Physiol 2004; 287:L624-30. [PMID: 15355859 DOI: 10.1152/ajplung.00215.2004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- J T Sylvester
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA.
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