1
|
Bayani A, Dunster JL, Crofts JJ, Nelson MR. Spatial considerations in the resolution of inflammation: Elucidating leukocyte interactions via an experimentally-calibrated agent-based model. PLoS Comput Biol 2020; 16:e1008413. [PMID: 33137107 PMCID: PMC7660912 DOI: 10.1371/journal.pcbi.1008413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 11/12/2020] [Accepted: 10/01/2020] [Indexed: 01/13/2023] Open
Abstract
Many common medical conditions (such as cancer, arthritis, chronic obstructive pulmonary disease (COPD), and others) are associated with inflammation, and even more so when combined with the effects of ageing and multimorbidity. While the inflammatory response varies in different tissue types, under disease and in response to therapeutic interventions, it has common interactions that occur between immune cells and inflammatory mediators. Understanding these underlying inflammatory mechanisms is key in progressing treatments and therapies for numerous inflammatory conditions. It is now considered that constituent mechanisms of the inflammatory response can be actively manipulated in order to drive resolution of inflammatory damage; particularly, those mechanisms related to the pro-inflammatory role of neutrophils and the anti-inflammatory role of macrophages. In this article, we describe the assembly of a hybrid mathematical model in which the spatial spread of inflammatory mediators is described through partial differential equations, and immune cells (neutrophils and macrophages) are described individually via an agent-based modelling approach. We pay close attention to how immune cells chemotax toward pro-inflammatory mediators, presenting a model for cell chemotaxis that is calibrated against experimentally observed cell trajectories in healthy and COPD-affected scenarios. We illustrate how variations in key model parameters can drive the switch from resolution of inflammation to chronic outcomes, and show that aberrant neutrophil chemotaxis can move an otherwise healthy outcome to one of chronicity. Finally, we reflect on our results in the context of the on-going hunt for new therapeutic interventions. Inflammation is the body’s primary defence to harmful stimuli such as infections, toxins and tissue strain but also underlies a much broader range of conditions, including asthma, arthritis and cancer. The inflammatory response is key in resolving injury to facilitate recovery, and involves a range of interactions between immune cells (leukocytes, neutrophils and macrophages in particular) and inflammatory mediators. Immune cells are recruited from the blood stream in response to injury. Once in tissue, neutrophils release toxins to kill invading agents and resolve damage; however, if not carefully managed by other immune cells (mainly macrophages), their responses can increase inflammation instead of helping to resolve it. We model these interactions in response to damage using a spatial model, examining how a healthy response can prevent localised inflammation from spreading. We pay close attention to how cells migrate toward the damaged area, as many inflammatory conditions are associated with impairment of this process. We calibrate our model against experimentally-observed cell trajectories from healthy patients and patients with chronic obstructive pulmonary disease. We illustrate that a healthy outcome depends strongly upon efficient cell migration and a delicate balance between the pro- and anti-inflammatory effects of neutrophils and macrophages.
Collapse
Affiliation(s)
- Anahita Bayani
- Department of Physics & Mathematics, Nottingham Trent University, Clifton Campus, Nottingham, NG11 8NS, United Kingdom
| | - Joanne L. Dunster
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, RG6 6AS, United Kingdom
| | - Jonathan J. Crofts
- Department of Physics & Mathematics, Nottingham Trent University, Clifton Campus, Nottingham, NG11 8NS, United Kingdom
| | - Martin R. Nelson
- Department of Physics & Mathematics, Nottingham Trent University, Clifton Campus, Nottingham, NG11 8NS, United Kingdom
- * E-mail:
| |
Collapse
|
2
|
Bayani A, Dunster JL, Crofts JJ, Nelson MR. Mechanisms and Points of Control in the Spread of Inflammation: A Mathematical Investigation. Bull Math Biol 2020; 82:45. [PMID: 32222839 PMCID: PMC7103018 DOI: 10.1007/s11538-020-00709-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/14/2020] [Indexed: 02/07/2023]
Abstract
Understanding the mechanisms that control the body’s response to inflammation is of key importance, due to its involvement in myriad medical conditions, including cancer, arthritis, Alzheimer’s disease and asthma. While resolving inflammation has historically been considered a passive process, since the turn of the century the hunt for novel therapeutic interventions has begun to focus upon active manipulation of constituent mechanisms, particularly involving the roles of apoptosing neutrophils, phagocytosing macrophages and anti-inflammatory mediators. Moreover, there is growing interest in how inflammatory damage can spread spatially due to the motility of inflammatory mediators and immune cells. For example, impaired neutrophil chemotaxis is implicated in causing chronic inflammation under trauma and in ageing, while neutrophil migration is an attractive therapeutic target in ailments such as chronic obstructive pulmonary disease. We extend an existing homogeneous model that captures interactions between inflammatory mediators, neutrophils and macrophages to incorporate spatial behaviour. Through bifurcation analysis and numerical simulation, we show that spatially inhomogeneous outcomes can present close to the switch from bistability to guaranteed resolution in the corresponding homogeneous model. Finally, we show how aberrant spatial mechanisms can play a role in the failure of inflammation to resolve and discuss our results within the broader context of seeking novel inflammatory treatments.
Collapse
Affiliation(s)
- A Bayani
- Department of Physics and Mathematics, Nottingham Trent University, Clifton Campus, Nottingham, NG11 8NS, UK
| | - J L Dunster
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, RG6 6AS, UK
| | - J J Crofts
- Department of Physics and Mathematics, Nottingham Trent University, Clifton Campus, Nottingham, NG11 8NS, UK
| | - M R Nelson
- Department of Physics and Mathematics, Nottingham Trent University, Clifton Campus, Nottingham, NG11 8NS, UK.
| |
Collapse
|
3
|
Beentjes CHL, Taylor-King JP, Bayani A, Davis CN, Dunster JL, Jabbari S, Mirams GR, Jenkinson C, Kilby MD, Hewison M, Tamblyn JA. Defining vitamin D status using multi-metabolite mathematical modelling: A pregnancy perspective. J Steroid Biochem Mol Biol 2019; 190:152-160. [PMID: 30926429 PMCID: PMC7614536 DOI: 10.1016/j.jsbmb.2019.03.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 02/11/2019] [Accepted: 03/25/2019] [Indexed: 11/21/2022]
Abstract
Vitamin D deficiency is linked to adverse pregnancy outcomes such as pre-eclampsia (PET) but remains defined by serum measurement of 25-hydroxyvitamin D3 (25(OH)D3) alone. To identify broader changes in vitamin D metabolism during normal and PET pregnancies we developed a relatively simple but fully parametrised mathematical model of the vitamin D metabolic pathway. The data used for parametrisation were serum vitamin D metabolites analysed for a cross-sectional group of women (n = 88); including normal pregnant women at 1 st (NP1, n = 25) and 3rd trimester (NP3, n = 21) and pregnant women with PET (n = 22), as well as non-pregnant female controls (n = 20). To account for the effects various metabolites have upon each other, data were analysed using an ordinary differential equation model of the vitamin D reaction network. Information obtained from the model was then also applied to serum vitamin D metabolome data (n = 50) obtained from a 2nd trimester pregnancy cohort, of which 25 prospectively developed PET. Statistical analysis of the data alone showed no significant difference between NP3 and PET for serum 25(OH)D3 and 24,25(OH)2D3 concentrations. Conversely, a statistical analysis informed by the reaction network model revealed that a better indicator of PET is the ratios of vitamin D metabolites in late pregnancy. Assessing the potential predicative value, no significant difference between NP3 and PET cases at 15 weeks gestation was found. Mathematical modelling offers a novel strategy for defining the impact of vitamin D metabolism on human health. This is particularly relevant within the context of pregnancy, where major changes in vitamin D metabolism occur across gestation, and dysregulated metabolism is evidenced in women with established PET.
Collapse
Affiliation(s)
- C H L Beentjes
- Mathematical Institute, University of Oxford, Oxford, UK
| | - J P Taylor-King
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 OAS, UK; Institute of Molecular Systems Biology, Department of Biology, ETHZ, CH-8093, Zurich, Switzerland
| | - A Bayani
- Department of Physics and Mathematics, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - C N Davis
- MathSys CDT, Mathematics Institute, University of Warwick, Coventry, UK
| | - J L Dunster
- Institute for Cardiovascular and Metabolic Research, University of Reading, UK
| | - S Jabbari
- School of Mathematics and Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - G R Mirams
- Centre for Mathematical Medicine & Biology, Mathematical Sciences, University of Nottingham, UK
| | - C Jenkinson
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - M D Kilby
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK; Centre for Women's & Newborn Health, Birmingham Health Partners, Birmingham Women's & Children's Foundation Hospital, Edgbaston, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK; Fetal Medicine Centre, Birmingham Women's & Children's Foundation Trust, Edgbaston, Birmingham, UK
| | - M Hewison
- Centre for Women's & Newborn Health, Birmingham Health Partners, Birmingham Women's & Children's Foundation Hospital, Edgbaston, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - J A Tamblyn
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK; Centre for Women's & Newborn Health, Birmingham Health Partners, Birmingham Women's & Children's Foundation Hospital, Edgbaston, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK.
| |
Collapse
|
4
|
Bayani A, Jafari S, Sprott JC, Hatef B. A chaotic model of migraine headache considering the dynamical transitions of this cyclic disease. ACTA ACUST UNITED AC 2018. [DOI: 10.1209/0295-5075/123/10006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
5
|
Travasso RDM, Sampaio Dos Aidos F, Bayani A, Abranches P, Salvador A. Localized redox relays as a privileged mode of cytoplasmic hydrogen peroxide signaling. Redox Biol 2017; 12:233-245. [PMID: 28279943 PMCID: PMC5339411 DOI: 10.1016/j.redox.2017.01.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/18/2016] [Accepted: 01/03/2017] [Indexed: 12/31/2022] Open
Abstract
Hydrogen peroxide (H2O2) is a key signaling agent. Its best characterized signaling actions in mammalian cells involve the early oxidation of thiols in cytoplasmic phosphatases, kinases and transcription factors. However, these redox targets are orders of magnitude less H2O2-reactive and abundant than cytoplasmic peroxiredoxins. How can they be oxidized in a signaling time frame? Here we investigate this question using computational reaction-diffusion models of H2O2 signaling. The results show that at H2O2 supply rates commensurate with mitogenic signaling a H2O2 concentration gradient with a length scale of a few tenths of μm is established. Even near the supply sites H2O2 concentrations are far too low to oxidize typical targets in an early mitogenic signaling time frame. Furthermore, any inhibition of the peroxiredoxin or increase in H2O2 supply able to drastically increase the local H2O2 concentration would collapse the concentration gradient and/or cause an extensive oxidation of the peroxiredoxins I and II, inconsistent with experimental observations. In turn, the local concentrations of peroxiredoxin sulfenate and disulfide forms exceed those of H2O2 by several orders of magnitude. Redox targets reacting with these forms at rate constants much lower than that for, say, thioredoxin could be oxidized within seconds. Moreover, the spatial distribution of the concentrations of these peroxiredoxin forms allows them to reach targets within 1 μm from the H2O2 sites while maintaining signaling localized. The recruitment of peroxiredoxins to specific sites such as caveolae can dramatically increase the local concentrations of the sulfenic and disulfide forms, thus further helping these species to outcompete H2O2 for the oxidation of redox targets. Altogether, these results suggest that H2O2 signaling is mediated by localized redox relays whereby peroxiredoxins are oxidized to sulfenate and disulfide forms at H2O2 supply sites and these forms in turn oxidize the redox targets near these sites. 2-Cys peroxiredoxins impose strong cytoplasmic and transmembrane H2O2 gradients. Maximal cytoplasmic H2O2 concentrations are insufficient to oxidize Tyr phosphatases. Prx inhibition modestly increases maximal H2O2 concentration, blunts gradients. Sulfenate and disulfide Prx strongly exceed H2O2 concentrations, are also localized. Prx recruitment causes modest local H2O2 depletion, helps Prx outcompete H2O2.
Collapse
Affiliation(s)
- Rui D M Travasso
- Centro de Física da Universidade de Coimbra (CFisUC), Department of Physics, University of Coimbra, Coimbra, Portugal.
| | - Fernando Sampaio Dos Aidos
- Centro de Física da Universidade de Coimbra (CFisUC), Department of Physics, University of Coimbra, Coimbra, Portugal
| | - Anahita Bayani
- Department of Physics & Mathematics, School of Science & Technology, Nottingham Trent University, UK
| | - Pedro Abranches
- Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Armindo Salvador
- Center for Neuroscience and Cell Biology, University of Coimbra, Portugal; CQC, Department of Chemistry, University of Coimbra, Portugal.
| |
Collapse
|
6
|
|