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Pybus HJ, O'Dea RD, Brook BS. A dynamical model of TGF-β activation in asthmatic airways. MATHEMATICAL MEDICINE AND BIOLOGY : A JOURNAL OF THE IMA 2023; 40:238-265. [PMID: 37285178 DOI: 10.1093/imammb/dqad004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 05/30/2023] [Accepted: 06/05/2023] [Indexed: 06/08/2023]
Abstract
Excessive activation of the regulatory cytokine transforming growth factor $\beta $ (TGF-$\beta $) via contraction of airway smooth muscle (ASM) is associated with the development of asthma. In this study, we develop an ordinary differential equation model that describes the change in density of the key airway wall constituents, ASM and extracellular matrix (ECM), and their interplay with subcellular signalling pathways leading to the activation of TGF-$\beta $. We identify bistable parameter regimes where there are two positive steady states, corresponding to either reduced or elevated TGF-$\beta $ concentration, with the latter leading additionally to increased ASM and ECM density. We associate the former with a healthy homeostatic state and the latter with a diseased (asthmatic) state. We demonstrate that external stimuli, inducing TGF-$\beta $ activation via ASM contraction (mimicking an asthmatic exacerbation), can perturb the system irreversibly from the healthy state to the diseased one. We show that the properties of the stimuli, such as their frequency or strength, and the clearance of surplus active TGF-$\beta $, are important in determining the long-term dynamics and the development of disease. Finally, we demonstrate the utility of this model in investigating temporal responses to bronchial thermoplasty, a therapeutic intervention in which ASM is ablated by applying thermal energy to the airway wall. The model predicts the parameter-dependent threshold damage required to obtain irreversible reduction in ASM content, suggesting that certain asthma phenotypes are more likely to benefit from this intervention.
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Affiliation(s)
- Hannah J Pybus
- Department of Bioengineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Reuben D O'Dea
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Bindi S Brook
- School of Mathematical Sciences, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
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Montaño LM, Flores-Soto E, Reyes-García J, Díaz-Hernández V, Carbajal-García A, Campuzano-González E, Ramírez-Salinas GL, Velasco-Velázquez MA, Sommer B. Testosterone induces hyporesponsiveness by interfering with IP 3 receptors in guinea pig airway smooth muscle. Mol Cell Endocrinol 2018; 473:17-30. [PMID: 29275169 DOI: 10.1016/j.mce.2017.12.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 12/15/2017] [Accepted: 12/18/2017] [Indexed: 10/18/2022]
Abstract
Asthma symptoms have been associated with sex steroids. During childhood, this illness seems more frequent in boys than in girls and this tendency reverts in puberty when it is more severe in women. Testosterone (TES), at supraphysiological concentrations, relaxed pre-contracted airway smooth muscle, but its effects at physiological concentrations have not been thoroughly studied. We explored this possibility in guinea pig tracheal smooth muscle. In myocytes TES (10 nM) abolished carbachol (CCh)-induced intracellular Ca2+ concentration ([Ca2+]i) increment. Ca2+ responses to ATP were partially modified by TES while histamine's were not. These results indicate that inositol 1,4,5-trisphosphate (IP3) signaling pathway might be involved. Photolysis of caged-IP3 increased [Ca2+]i and TES abolished this effect. TES diminished reactivity of the smooth muscle to CCh and this effect was non-genomic since it was unchanged by flutamide. In tracheal smooth muscle, mRNA for each IP3 receptor (ITPR) isoform was found and, by immunofluorescence, ITPR1 and ITPR3 seems to be the main isoforms observed while ITPR2 was less prominent. Comparing the amino acid sequence of ITPR1 and the sequence of the TES binding site on the androgen receptor, we found that they share a short sequence. This domain could be responsible for the TES binding to the ITPR1 and probably for its blocking effect. We conclude that TES modifies ITPR1 function in airway smooth muscle, turning this tissue less reactive to contractile agonists that act through PLCβ-IP3 signaling cascade. These results might be related to the low asthma prevalence in males from puberty to adulthood.
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MESH Headings
- Amino Acid Sequence
- Animals
- Calcium/metabolism
- Calcium Channels/metabolism
- Carbachol/pharmacology
- Genome
- Guinea Pigs
- Histamine/pharmacology
- Humans
- Inositol 1,4,5-Trisphosphate/pharmacology
- Inositol 1,4,5-Trisphosphate Receptors/chemistry
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Intracellular Space/metabolism
- Male
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Protein Isoforms/metabolism
- Receptors, Androgen/chemistry
- Receptors, Androgen/metabolism
- Signal Transduction/drug effects
- Testosterone/pharmacology
- Trachea/drug effects
- Trachea/physiology
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Affiliation(s)
- Luis M Montaño
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico.
| | - Edgar Flores-Soto
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Jorge Reyes-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Verónica Díaz-Hernández
- Departamento de Embriología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Abril Carbajal-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Elías Campuzano-González
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - G Lizbeth Ramírez-Salinas
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico; Cátedras CONACYT, Mexico; Unidad Periférica de Biomedicina Traslacional, (CMN 20 de Noviembre, ISSSTE) Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Marco A Velasco-Velázquez
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico; Unidad Periférica de Biomedicina Traslacional, (CMN 20 de Noviembre, ISSSTE) Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Bettina Sommer
- Departamento de Investigación en Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias, 14080, Ciudad de México, Mexico
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Croisier H, Tan X, Perez-Zoghbi JF, Sanderson MJ, Sneyd J, Brook BS. Activation of store-operated calcium entry in airway smooth muscle cells: insight from a mathematical model. PLoS One 2013; 8:e69598. [PMID: 23936056 PMCID: PMC3723852 DOI: 10.1371/journal.pone.0069598] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 06/10/2013] [Indexed: 11/30/2022] Open
Abstract
Intracellular dynamics of airway smooth muscle cells (ASMC) mediate ASMC contraction and proliferation, and thus play a key role in airway hyper-responsiveness (AHR) and remodelling in asthma. We evaluate the importance of store-operated entry (SOCE) in these dynamics by constructing a mathematical model of ASMC signaling based on experimental data from lung slices. The model confirms that SOCE is elicited upon sufficient depletion of the sarcoplasmic reticulum (SR), while receptor-operated entry (ROCE) is inhibited in such conditions. It also shows that SOCE can sustain agonist-induced oscillations in the absence of other influx. SOCE up-regulation may thus contribute to AHR by increasing the oscillation frequency that in turn regulates ASMC contraction. The model also provides an explanation for the failure of the SERCA pump blocker CPA to clamp the cytosolic of ASMC in lung slices, by showing that CPA is unable to maintain the SR empty of . This prediction is confirmed by experimental data from mouse lung slices, and strongly suggests that CPA only partially inhibits SERCA in ASMC.
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Affiliation(s)
- Huguette Croisier
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail:
| | - Xiahui Tan
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachussetts, United States of America
| | - Jose F. Perez-Zoghbi
- Department of Cell Physiology and Molecular Biophysics, Texas Tech University Health Sciences Center, Lubbock, Texas, United States of America
| | - Michael J. Sanderson
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachussetts, United States of America
| | - James Sneyd
- Department of Mathematics, University of Auckland, Auckland, New Zealand
| | - Bindi S. Brook
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
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Brumen M, Fajmut A, Dobovišek A, Roux E. Mathematical modelling of ca(2+) oscillations in airway smooth muscle cells. J Biol Phys 2013; 31:515-24. [PMID: 23345915 DOI: 10.1007/s10867-005-2409-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The action of different agonists such as acetylcholine on the membrane of airway smooth muscle cells may induce cytosolic Ca(2+) oscillations which can be a part of the Ca(2+) signalling pathway, eventually leading to cell contraction. The aim of the present study is to present a mathematical model of the possible effect of the initial Ca(2+) distribution within the cell on the form and frequency of induced Ca(2+) oscillations. It takes into account intracellular Ca(2+) stores such as sarcoplasmic reticulum and cytosolic proteins as well as Ca(2+) exchange across the plasma membrane. We are able to demonstrate a closer agreement of model predictions with observed Ca(2+) traces for a significantly wider range of parameter values, as was previously reported. We show also that the total cellular Ca(2+) content is an important system parameter especially because of the content in sarcoplasmic reticulum. At a total Ca(2+) increase of about 20%, the oscillation frequency increases by 25%; also, damped oscillations become sustained. Cases are indicated in which such a situation could occur.
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Affiliation(s)
- Milan Brumen
- Medical Faculty, University of Maribor, Slomškov trg 15, Maribor, Slovenia ; Department of Physics, University of Maribor, Koroška 160, Maribor, Slovenia ; Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia
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Dupont G, Combettes L. Modelling the effect of specific inositol 1,4,5-trisphosphate receptor isoforms on cellular Ca2+ signals. Biol Cell 2012; 98:171-82. [PMID: 16033332 DOI: 10.1042/bc20050032] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION Oscillations of cytosolic Ca2+ are well-known to rely on the regulatory properties of the InsP3R (inositol 1,4,5-trisphosphate receptor). Three isoforms of this channel have been identified. They differ in their regulatory properties by Ca2+ and InsP3. Experiments in different cell types clearly indicate that the relative amounts of each isoform affect the time course of Ca2+ changes after agonist stimulation. In the present study, we investigate whether different steady-state curves for the open probability of the InsP3Rs as a function of Ca2+ imply different dynamical behaviours when these receptors are present in a cellular environment. We therefore describe by a specific phenomenological model the three main types of curves that have been reported: (i) the classical bell-shaped curve, (ii) the bell-shaped curve that is shifted towards higher Ca2+ concentrations when InsP3 is increased, and (iii) a monotonous increasing function of cytosolic Ca2+. RESULTS We show that, although these types of curves can be ascribed to slight differences in the channel regulation by Ca2+ and InsP3, they can indicate important variations as to the receptor role in cellular Ca2+ control. Thus the receptor associated with the classical bell-shaped curve appears to be the most robust Ca2+ oscillator. If the steady-state curve is supposed to be a monotonous increasing function of cytosolic Ca2+, the modelled receptor cannot sustain Ca2+ oscillations in the absence of Ca2+ exchanges with the extracellular medium. When the bell-shaped curve is shifted towards higher Ca2+ concentrations with increasing InsP3 levels, the model predicts that the receptor is less robust to changes in density; this receptor, however, provides a finer control of the steady-state level of Ca2+ when varying the InsP3 concentration. CONCLUSIONS Our model allows us to propose an explanation for the experimental observations about the effect of selectively expressing or down-regulating InsP3R isoforms, as well as to make theoretical predictions.
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Affiliation(s)
- Geneviève Dupont
- Université Libre de Bruxelles, Faculté des Sciences CP231, Boulevard du Triomphe, B-1050 Brussels, Belgium.
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Bai Y, Edelmann M, Sanderson MJ. The contribution of inositol 1,4,5-trisphosphate and ryanodine receptors to agonist-induced Ca(2+) signaling of airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2009; 297:L347-61. [PMID: 19465516 DOI: 10.1152/ajplung.90559.2008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The relative contribution of inositol 1,4,5-trisphosphate (IP(3)) receptors (IP(3)Rs) and ryanodine receptors (RyRs) to agonist-induced Ca(2+) signaling in mouse airway smooth muscle cells (SMCs) was investigated in lung slices with phase-contrast or laser scanning microscopy. At room temperature (RT), methacholine (MCh) or 5-hydroxytryptamine (5-HT) induced Ca(2+) oscillations and an associated contraction in small airway SMCs. The subsequent exposure to an IP(3)R antagonist, 2-aminoethoxydiphenyl borate (2-APB), inhibited the Ca(2+) oscillations and induced airway relaxation in a concentration-dependent manner. 2-APB also inhibited Ca(2+) waves generated by the photolytic release of IP(3). However, the RyR antagonist ryanodine had no significant effect, at any concentration, on airway contraction or agonist- or IP(3)-induced Ca(2+) oscillations or Ca(2+) wave propagation. By contrast, a second RyR antagonist, tetracaine, relaxed agonist-contracted airways and inhibited agonist-induced Ca(2+) oscillations in a concentration-dependent manner. However, tetracaine did not affect IP(3)-induced Ca(2+) release or wave propagation nor the Ca(2+) content of SMC Ca(2+) stores as evaluated by Ca(2+)-release induced by caffeine. Conversely, both ryanodine and tetracaine completely blocked agonist-independent slow Ca(2+) oscillations induced by KCl. The inhibitory effects of 2-APB and absence of an effect of ryanodine on MCh-induced airway contraction or Ca(2+) oscillations of SMCs were also observed at 37 degrees C. In Ca(2+)-permeable SMCs, tetracaine inhibited agonist-induced contraction without affecting intracellular Ca(2+) levels indicating that relaxation also resulted from a reduction in Ca(2+) sensitivity. These results indicate that agonist-induced Ca(2+) oscillations in mouse small airway SMCs are primary mediated via IP(3)Rs and that tetracaine induces relaxation by both decreasing Ca(2+) sensitivity and inhibiting agonist-induced Ca(2+) oscillations via an IP(3)-dependent mechanism.
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Affiliation(s)
- Yan Bai
- Dept. of Physiology, Univ. of Massachusetts Medical School, Worcester, 01655, USA
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Marhl M, Perc M, Schuster S. A minimal model for decoding of time-limited Ca2+ oscillations. Biophys Chem 2006; 120:161-7. [PMID: 16338050 DOI: 10.1016/j.bpc.2005.11.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 11/14/2005] [Accepted: 11/15/2005] [Indexed: 10/25/2022]
Abstract
Calcium oscillations regulate several cellular processes by activating particular proteins. Most theoretical studies focused on the idealized situation of infinitely long oscillations. Here we analyze information transfer by time-limited calcium spike trains. We show that proteins can be selectively activated in a resonance-like manner by time-limited spike trains of different frequencies, while infinitely long oscillations do not show this resonance phenomenon. We found that proteins are activated more specifically by shorter oscillatory signals with narrower spikes.
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Affiliation(s)
- Marko Marhl
- Department of Physics, Faculty of Education, University of Maribor, Koroska cesta 160, SI-2000 Maribor, Slovenia.
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Roux E, Noble PJ, Noble D, Marhl M. Modelling of calcium handling in airway myocytes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2005; 90:64-87. [PMID: 15982722 DOI: 10.1016/j.pbiomolbio.2005.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Airway myocytes are the primary effectors of airway reactivity which modulates airway resistance and hence ventilation. Stimulation of airway myocytes results in an increase in the cytosolic Ca(2+) concentration ([Ca(2+)](i)) and the subsequent activation of the contractile apparatus. Many contractile agonists, including acetylcholine, induce [Ca(2+)](i) increase via Ca(2+) release from the sarcoplasmic reticulum through InsP(3) receptors. Several models have been developed to explain the characteristics of InsP(3)-induced [Ca(2+)](i) responses, in particular Ca(2+) oscillations. The article reviews the modelling of the major structures implicated in intracellular Ca(2+) handling, i.e., InsP(3) receptors, SERCAs, mitochondria and Ca(2+)-binding cytosolic proteins. We developed theoretical models specifically dedicated to the airway myocyte which include the major mechanisms responsible for intracellular Ca(2+) handling identified in these cells. These biocomputations pointed out the importance of the relative proportion of InsP(3) receptor isoforms and the respective role of the different mechanisms responsible for cytosolic Ca(2+) clearance in the pattern of [Ca(2+)](i) variations. We have developed a theoretical model of membrane conductances that predicts the variations in membrane potential and extracellular Ca(2+) influx. Stimulation of this model by simulated increase in [Ca(2+)](i) predicts membrane depolarisation, but not great enough to trigger a significant opening of voltage-dependant Ca(2+) channels. This may explain why airway contraction induced by cholinergic stimulation does not greatly depend on extracellular calcium. The development of such models of airway myocytes is important for the understanding of the cellular mechanisms of airway reactivity and their possible modulation by pharmacological agents.
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Affiliation(s)
- Etienne Roux
- Laboratoire de Physiologie Cellulaire Respiratoire, INSERM E 356, Université Victor Segalen Bordeaux 2, 146 rue Léo-Saignat, 33076 Bordeaux cedex, France.
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