51
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Massullo P, Sumoza-Toledo A, Bhagat H, Partida-Sánchez S. TRPM channels, calcium and redox sensors during innate immune responses. Semin Cell Dev Biol 2006; 17:654-66. [PMID: 17178241 DOI: 10.1016/j.semcdb.2006.11.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Melastatin-related TRPM ion channels have emerged as novel therapeutic targets due to their potential ability to modulate the function and fate of immune cells during inflammation, innate, and adaptive immunity. Four family members, TRPM1, TRPM2, TRPM4 and TRPM7 have a strong presence in the immune system. TRPM channels regulate ion-homeostasis by sensing cellular redox status and cytoplasmic calcium levels. TRPM2 for example, is highly expressed in phagocytes. This channel is activated by intracellular ADP-ribose upon exposure to oxidative stress and induces cell death. Here we will review the functional links between TRPM-mediated ion conductance, chemotaxis, apoptosis, and innate immunity.
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Affiliation(s)
- Pam Massullo
- Columbus Children's Research Institute, Center for Microbial Pathogenesis, The Ohio State University, Columbus, OH 43205, USA
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52
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Johnson JD, Ford EL, Bernal-Mizrachi E, Kusser KL, Luciani DS, Han Z, Tran H, Randall TD, Lund FE, Polonsky KS. Suppressed insulin signaling and increased apoptosis in CD38-null islets. Diabetes 2006; 55:2737-46. [PMID: 17003338 DOI: 10.2337/db05-1455] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CD38 is a multifunctional enzyme capable of generating metabolites that release Ca2+ from intracellular stores, including nicotinic acid adenine dinucleotide phosphate (NAADP). A number of studies have led to the controversial proposal that CD38 mediates an alternate pathway for glucose-stimulated insulin release and contributes to the pathogenesis of diabetes. It has recently been shown that NAADP mediates Ca2+ mobilization by insulin in human pancreatic beta-cells. In the present study, we report altered Ca2+ homeostasis and reduced responsiveness to insulin, but not glucose, in Cd38-/- beta-cells. In keeping with the antiapoptotic role of insulin signaling, Cd38-/- islets were significantly more susceptible to apoptosis compared with islets isolated from littermate controls. This finding correlated with disrupted islet architecture and reduced beta-cell mass in Cd38-/- mice, both in the context of a normal lab diet and a high-fat diet. Nevertheless, we did not find robust differences in glucose homeostasis in vivo or glucose signaling in vitro in Cd38-/- mice on the C57BL/6 genetic background, in contrast to previous studies by others of Cd38 knockout mice on the ICR background. Thus, our results suggest that CD38 plays a role in novel antiapoptotic signaling pathways but does not directly control glucose signaling in pancreatic beta-cells.
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Affiliation(s)
- James D Johnson
- Division of Metabolism, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
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53
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Abstract
Cyclic ADP-ribose (cADPR) is a novel Ca(2+) mobilizing second messenger, which is capable of inducing Ca(2+) release from the sarcoplasmic reticulum (SR) via activation of ryanodine receptors (RyR) in vascular cells. This signaling nucleotide has also been reported to participate in generation or modulation of intracellular Ca(2+) sparks, Ca(2+) waves or oscillations, Ca(2+)- induced Ca(2+) release (CICR) and spontaneous transient outward currents (STOCs) in vascular smooth muscle cells (VSMCs). With respect to the role of cADPR-mediated signaling in mediation of vascular responses to different stimuli, there is accumulating evidence showing that cADPR is importantly involved in the Ca(2+) response of vascular endothelial cells (ECs) and VSMCs to various chemical factors such as vasoactive agonists acetylcholine, oxotremorine, endothelin, and physical stimuli such as stretch, electrical depolarization and sheer stress. This cADPR-RyR-mediated Ca(2+) signaling is now recognized as a fundamental mechanism regulating vascular function. Here we reviewed the literature regarding this cADPR signaling pathway in vascular cells with a major focus on the production of cADPR and its physiological roles in the control of vascular tone and vasomotor response. We also summarized some publish results that unveil the underlying mechanisms mediating the actions of cADPR in vascular cells. Given the importance of Ca(2+) in the regulation of vascular function, the results summarized in this brief review will provide new insights into vascular physiology and circulatory regulation.
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Affiliation(s)
- Andrew Y Zhang
- Department of Pharmacology & Toxicology, Medical College of Virginia, Virginia Commonwealth UniversityVA, USA
| | - Pin - Lan Li
- Department of Pharmacology & Toxicology, Medical College of Virginia, Virginia Commonwealth UniversityVA, USA
- * Correspondence to: Pin-Lan LI, M.D, Ph.D. Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 410 N 12th, Richmond, VA 23298, USA. Tel.: (804) 828-4793; Fax: (804) 828-2117 E-mail:
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54
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Guedes AGP, Paulin J, Rivero-Nava L, Kita H, Lund FE, Kannan MS. CD38-deficient mice have reduced airway hyperresponsiveness following IL-13 challenge. Am J Physiol Lung Cell Mol Physiol 2006; 291:L1286-93. [PMID: 16891391 DOI: 10.1152/ajplung.00187.2006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The transmembrane glycoprotein CD38 in airway smooth muscle is the source of cyclic-ADP ribose, an intracellular calcium-releasing molecule, and is subject to regulatory effects of cytokines such as interleukin (IL)-13, a cytokine implicated in asthma. We investigated the role of CD38 in airway hyperresponsiveness using a mouse model of IL-13-induced airway disease. Wild-type (WT) and CD38-deficient (CD38KO) mice were intranasally challenged with 5 microg of IL-13 three times on alternate days under isoflurane anesthesia. Lung resistance (R(L)) in response to inhaled methacholine was measured 24 h after the last challenge in pentobarbital-anesthetized, tracheostomized, and mechanically ventilated mice. Bronchoalveolar cytokines, bronchoalveolar and parenchymal inflammation, and smooth muscle contractility and relaxation using tracheal segments were also evaluated. Changes in methacholine-induced R(L) were significantly greater in the WT than in the CD38KO mice following intranasal IL-13 challenges. Airway reactivity after IL-13 exposure, as measured by the slope of the methacholine dose-response curve, was significantly higher in the WT than in the CD38KO mice. The rate of isometric force generation in tracheal segments (e.g., smooth muscle reactivity) was greater in the WT than in the CD38KO mice following incubation with IL-13. IL-13 treatment reduced isoproterenol-induced relaxations to similar magnitudes in tracheal segments obtained from WT and CD38KO mice. Both WT and CD38KO mice developed significant bronchoalveolar and parenchymal inflammation after IL-13 challenges compared with naïve controls. The results indicate that CD38 contributes to airway hyperresponsiveness in lungs exposed to IL-13 at least partly by increasing airway smooth muscle reactivity to contractile agonists.
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Affiliation(s)
- Alonso G P Guedes
- Department of Veterinary Clinicial Sciences, University of Minnesota, St. Paul, MN 55108, USA
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55
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Kip SN, Smelter M, Iyanoye A, Chini EN, Prakash YS, Pabelick CM, Sieck GC. Agonist-induced cyclic ADP ribose production in airway smooth muscle. Arch Biochem Biophys 2006; 452:102-7. [PMID: 16846589 DOI: 10.1016/j.abb.2006.06.014] [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] [Received: 02/14/2006] [Revised: 06/08/2006] [Accepted: 06/10/2006] [Indexed: 11/22/2022]
Abstract
Cyclic ADP-ribose (cADPR) triggers sarcoplasmic reticulum (SR) Ca(2+) release in airway smooth muscle (ASM). SR Ca(2+) release is an important component of the intracellular Ca(2+) ([Ca(2+)](i)) response of ASM to agonists. Whether cADPR is endogenously produced in ASM during agonist stimulation has not been established. In this study, cADPR production was examined in acutely dissociated porcine ASM cells. ACh stimulation (> or = 1 microM) significantly increased cADPR levels, peaking between 30s and 1 min. This effect was inhibited by M(2) and M(3) muscarinic receptor antagonists. Histamine ((> or = 5 microM) increased cADPR levels to a greater extent than ACh, while diphenhydramine blocked histamine-induced cADPR elevation. Both bradykinin (100 nM) and endothelin-1 (100 nM) also increased cADPR levels to a greater extent than ACh or histamine. These results indicate that in porcine ASM, certain agonists acting via receptors increase cADPR levels. Furthermore, the extent of cADPR responses to agonist varies, possibly reflecting differences in G-protein coupling.
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Affiliation(s)
- Sertac N Kip
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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56
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Lazaar AL, Panettieri RA. Airway smooth muscle as a regulator of immune responses and bronchomotor tone. Clin Chest Med 2006; 27:53-69, vi. [PMID: 16543052 DOI: 10.1016/j.ccm.2005.10.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The traditional view of airway smooth muscle (ASM) in asthma, as a purely contractile tissue, seems to be inadequate. Compelling evidence now suggests that ASM plays an important role in regulating bronchomotor tone, in perpetuating airway inflammation, and in remodeling of the airways. This article reviews three distinct functions of ASM cells: the process of excitation-contraction coupling, with a particular focus on the role of cytokines in modulating calcium responses; the processes of smooth muscle cell proliferation and migration; and the synthetic and immunomodulatory function of ASM cells. This article also discusses how altered synthetic function contributes to airway remodeling.
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Affiliation(s)
- Aili L Lazaar
- Pulmonary, Allergy, and Critical Care Division, University of Pennsylvania Medical Center, BRB II/III, 421 Curie Boulevard, Philadelphia, PA 19104-6160, USA.
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57
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Lund FE, Muller-Steffner H, Romero-Ramirez H, Moreno-García ME, Partida-Sánchez S, Makris M, Oppenheimer NJ, Santos-Argumedo L, Schuber F. CD38 induces apoptosis of a murine pro-B leukemic cell line by a tyrosine kinase-dependent but ADP-ribosyl cyclase- and NAD glycohydrolase-independent mechanism. Int Immunol 2006; 18:1029-42. [PMID: 16720618 DOI: 10.1093/intimm/dxl037] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cross-linking of CD38 on hematopoietic cells induces activation, proliferation and differentiation of mature T and B cells and mediates apoptosis of myeloid and lymphoid progenitor cells. In addition to acting as a signaling receptor, CD38 is also an enzyme capable of producing several calcium-mobilizing metabolites, including cyclic adenosine diphosphate ribose (cADPR). It has been previously postulated that the calcium-mobilizing metabolites produced by CD38 may regulate its receptor-based activities. To test this hypothesis, we examined whether the enzyme activity of CD38 controls the apoptosis of an anti-CD38-stimulated leukemic B cell. We show that anti-CD38-induced apoptosis of Ba/F3 cells, a murine pro-B cell line, is not affected by blocking the calcium-mobilizing activity of cADPR or by inhibiting intracellular or extracellular calcium mobilization. In addition, we demonstrate that blocking CD38 enzyme activity with 2'-deoxy-2'-fluoro-nicotinamide arabinoside adenine dinucleotide has no effect on apoptosis and that Ba/F3 cells expressing catalytically inactive mutant forms of CD38 still undergo apoptosis upon CD38 cross-linking. Instead, we find that anti-CD38-induced apoptosis is dependent on tyrosine kinase and caspase activation, and that this process appears to be potentiated by the presence of membrane microdomains. Thus, the receptor-mediated functions of CD38 can be separated from its enzyme activity in a murine leukemic cell line, suggesting that CD38 plays multiple, but independent, biologic roles.
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Affiliation(s)
- Frances E Lund
- Trudeau Institute, 154 Algonquin Avenue, Saranac Lake, NY 12983, USA.
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58
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Gosens R, Zaagsma J, Meurs H, Halayko AJ. Muscarinic receptor signaling in the pathophysiology of asthma and COPD. Respir Res 2006; 7:73. [PMID: 16684353 PMCID: PMC1479816 DOI: 10.1186/1465-9921-7-73] [Citation(s) in RCA: 275] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Accepted: 05/09/2006] [Indexed: 12/14/2022] Open
Abstract
Anticholinergics are widely used for the treatment of COPD, and to a lesser extent for asthma. Primarily used as bronchodilators, they reverse the action of vagally derived acetylcholine on airway smooth muscle contraction. Recent novel studies suggest that the effects of anticholinergics likely extend far beyond inducing bronchodilation, as the novel anticholinergic drug tiotropium bromide can effectively inhibit accelerated decline of lung function in COPD patients. Vagal tone is increased in airway inflammation associated with asthma and COPD; this results from exaggerated acetylcholine release and enhanced expression of downstream signaling components in airway smooth muscle. Vagally derived acetylcholine also regulates mucus production in the airways. A number of recent research papers also indicate that acetylcholine, acting through muscarinic receptors, may in part regulate pathological changes associated with airway remodeling. Muscarinic receptor signalling regulates airway smooth muscle thickening and differentiation, both in vitro and in vivo. Furthermore, acetylcholine and its synthesizing enzyme, choline acetyl transferase (ChAT), are ubiquitously expressed throughout the airways. Most notably epithelial cells and inflammatory cells generate acetylcholine, and express functional muscarinic receptors. Interestingly, recent work indicates the expression and function of muscarinic receptors on neutrophils is increased in COPD. Considering the potential broad role for endogenous acetylcholine in airway biology, this review summarizes established and novel aspects of muscarinic receptor signaling in relation to the pathophysiology and treatment of asthma and COPD.
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Affiliation(s)
- Reinoud Gosens
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
- Departments of Physiology & Internal Medicine, University of Manitoba, Winnipeg, MB, Canada
- Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, MB, Canada
| | - Johan Zaagsma
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Herman Meurs
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Andrew J Halayko
- Departments of Physiology & Internal Medicine, University of Manitoba, Winnipeg, MB, Canada
- Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, MB, Canada
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59
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Kang BN, Tirumurugaan KG, Deshpande DA, Amrani Y, Panettieri RA, Walseth TF, Kannan MS. Transcriptional regulation of CD38 expression by tumor necrosis factor-alpha in human airway smooth muscle cells: role of NF-kappaB and sensitivity to glucocorticoids. FASEB J 2006; 20:1000-2. [PMID: 16571778 DOI: 10.1096/fj.05-4585fje] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The transmembrane glycoprotein CD38 catalyzes the synthesis of the calcium mobilizing molecule cyclic ADP-ribose from NAD. In human airway smooth muscle (HASM) cells, the expression and function of CD38 are augmented by the inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha), leading to increased intracellular calcium response to agonists. A glucocorticoid response element in the CD38 gene has been computationally described, providing evidence for transcriptional regulation of its expression. In the present study, we investigated the effects of dexamethasone, a glucocorticoid, on CD38 expression and ADP-ribosyl cyclase activity in HASM cells stimulated with TNF-alpha. In HASM cells, TNF-alpha augmented CD38 expression and ADP-ribosyl cyclase activity, which were attenuated by dexamethasone. TNF-alpha increased NF-kappaB expression and its activation, and dexamethasone partially reversed these effects. TNF-alpha increased the expression of IkappaBalpha, and dexamethasone increased it further. An inhibitor of NF-kappaB activation or transfection of cells with IkappaB mutants decreased TNF-alpha-induced CD38 expression. The results indicate that TNF-alpha-induced CD38 expression involves NF-kappaB expression and its activation and dexamethasone inhibits CD38 expression through NF-kappaB-dependent and -independent mechanisms.
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Affiliation(s)
- Bit-Na Kang
- Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Ave., St. Paul, Minnesota 55108, USA
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60
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Bergner A, Kellner J, Kemp da Silva A, Gamarra F, Huber RM. Ca2+-signaling in airway smooth muscle cells is altered in T-bet knock-out mice. Respir Res 2006; 7:33. [PMID: 16504082 PMCID: PMC1395308 DOI: 10.1186/1465-9921-7-33] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2005] [Accepted: 02/23/2006] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Airway smooth muscle cells (ASMC) play a key role in bronchial hyperresponsiveness (BHR). A major component of the signaling cascade leading to ASMC contraction is calcium. So far, agonist-induced Ca2+-signaling in asthma has been studied by comparing innate properties of inbred rat or mouse strains, or by using selected mediators known to be involved in asthma. T-bet knock-out (KO) mice show key features of allergic asthma such as a shift towards TH2-lymphocytes and display a broad spectrum of asthma-like histological and functional characteristics. In this study, we aimed at investigating whether Ca2+-homeostasis of ASMC is altered in T-bet KO-mice as an experimental model of asthma. METHODS Lung slices of 100 to 200 microm thickness were obtained from T-bet KO- and wild-type mice. Airway contraction in response to acetylcholine (ACH) was measured by video-microscopy and Ca2+-signaling in single ASMC of lung slices was assessed using two-photon-microscopy. RESULTS Airways from T-bet KO-mice showed increased baseline airway tone (BAT) and BHR compared to wild-type mice. This could be mimicked by incubation of lung slices from wild-type mice with IL-13. The increased BAT was correlated with an increased incidence of spontaneous changes in intracellular Ca2+-concentrations, whereas BHR correlated with higher ACH-induced Ca2+-transients and an increased proportion of ASMC showing Ca2+-oscillations. Emptying intracellular Ca2+-stores using caffeine or cyclopiazonic acid induced higher Ca2+-elevations in ASMC from T-bet KO- compared to wild-type mice. CONCLUSION Altered Ca2+-homeostasis of ASMC contributes to increased BAT and BHR in lung slices from T-bet KO-mice as a murine asthma model. We propose that a higher Ca2+-content of the intracellular Ca2+-stores is involved in the pathophysiology of these changes.
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Affiliation(s)
- Albrecht Bergner
- Pneumology, Medizinische Klinik-Innenstadt, Ludwig-Maximilians-University, Munich, Germany
| | - Julia Kellner
- Pneumology, Medizinische Klinik-Innenstadt, Ludwig-Maximilians-University, Munich, Germany
| | - Anita Kemp da Silva
- Pneumology, Medizinische Klinik-Innenstadt, Ludwig-Maximilians-University, Munich, Germany
| | - Fernando Gamarra
- Pneumology, Medizinische Klinik-Innenstadt, Ludwig-Maximilians-University, Munich, Germany
| | - Rudolf M Huber
- Pneumology, Medizinische Klinik-Innenstadt, Ludwig-Maximilians-University, Munich, Germany
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61
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Kang BN, Deshpande DA, Tirumurugaan KG, Panettieri RA, Walseth TF, Kannan MS. Adenoviral mediated anti-sense CD38 attenuates TNF-alpha-induced changes in calcium homeostasis of human airway smooth muscle cells. Can J Physiol Pharmacol 2006; 83:799-804. [PMID: 16333382 DOI: 10.1139/y05-081] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CD38 is a membrane-bound protein involved in the synthesis and degradation of cyclic-ADP-ribose (cADPR). cADPR mobilizes calcium from intracellular stores in airway smooth muscle cells. To determine the role of CD38/cADPR signaling in calcium regulation in human airway smooth muscle (HASM) cells, we downregulated CD38 expression using a recombinant replication-defective adenovirus with anti-sense human CD38 (Ad-asCD38). CD38 expression was determined by RT-PCR and real-time quantitative PCR, and ADP-ribosyl cyclase (cyclase) activity was determined by competitive binding assay. In HASM cells infected with Ad-asCD38, TNF-alpha-induced, augmented-CD38 expression and cyclase activity were significantly lower than in TNF-alpha-treated cells. The net intracellular calcium responses to 10 nmol/L bradykinin were measured in HASM cells by fluorescence imaging. In cells infected with Ad-asCD38 in the presence of TNF-alpha, the net intracellular Ca2+ responses were significantly lower than in cells treated with TNF-alpha in the presence of the control vector (p < 0.001). These results provide evidence for the feasibility of using adenoviral vectors for gene transfer to down regulate gene expression, and confirm the role of CD38 in calcium homeostatis in ASM cells.
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Affiliation(s)
- Bit Na Kang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA
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62
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Du W, Stiber JA, Rosenberg PB, Meissner G, Eu JP. Ryanodine receptors in muscarinic receptor-mediated bronchoconstriction. J Biol Chem 2005; 280:26287-94. [PMID: 15894801 DOI: 10.1074/jbc.m502905200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ryanodine receptors (RyRs), intracellular calcium release channels essential for skeletal and cardiac muscle contraction, are also expressed in various types of smooth muscle cells. In particular, recent studies have suggested that in airway smooth muscle cells (ASMCs) provoked by spasmogens, stored calcium release by the cardiac isoform of RyR (RyR2) contributes to the calcium response that leads to airway constriction (bronchoconstriction). Here we report that mouse ASMCs also express the skeletal muscle and brain isoforms of RyRs (RyR1 and RyR3, respectively). In these cells, RyR1 is localized to the periphery near the cell membrane, whereas RyR3 is more centrally localized. Moreover, RyR1 and/or RyR3 in mouse airway smooth muscle also appear to mediate bronchoconstriction caused by the muscarinic receptor agonist carbachol. Inhibiting all RyR isoforms with > or = 200 microM ryanodine attenuated the graded carbachol-induced contractile responses of mouse bronchial rings and calcium responses of ASMCs throughout the range of carbachol used (50 nM to > or = 3 microM). In contrast, inhibiting only RyR1 and RyR3 with 25 microM dantrolene attenuated these responses caused by high (>500 nM) but not by low concentrations of carbachol. These data suggest that, as the stimulation of muscarinic receptor in the airway smooth muscle increases, RyR1 and/or RyR3 also mediate the calcium response and thus bronchoconstriction. Our findings provide new insights into the complex calcium signaling in ASMCs and suggest that RyRs are potential therapeutic targets in bronchospastic disorders such as asthma.
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MESH Headings
- Animals
- Brain/metabolism
- Bronchi/metabolism
- Bronchi/pathology
- Bronchi/physiology
- Calcium/metabolism
- Carbachol/metabolism
- Carbachol/pharmacology
- Cell Membrane/metabolism
- Cell Nucleus/metabolism
- Cholinergic Agonists/pharmacology
- Dantrolene/pharmacology
- Dose-Response Relationship, Drug
- Immunoblotting
- Male
- Mice
- Mice, Inbred C57BL
- Microscopy, Confocal
- Microscopy, Fluorescence
- Models, Biological
- Muscle Contraction
- Muscle Relaxants, Central/pharmacology
- Muscle, Skeletal/metabolism
- Muscle, Smooth/drug effects
- Muscle, Smooth/metabolism
- Protein Isoforms
- Receptors, Muscarinic/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Ryanodine/pharmacology
- Ryanodine Receptor Calcium Release Channel/biosynthesis
- Ryanodine Receptor Calcium Release Channel/chemistry
- Ryanodine Receptor Calcium Release Channel/metabolism
- Signal Transduction
- Tissue Distribution
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Affiliation(s)
- Wanglei Du
- Division of Pulmonary, Allergy and Critical Care Medicine, Duke University, Medical Center, Durham, North Carolina, 27710, USA
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