1
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A metabolic reaction-diffusion model for PKCα translocation via PIP2 hydrolysis in an endothelial cell. Biochem J 2020; 477:4071-4084. [PMID: 33026061 DOI: 10.1042/bcj20200484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/08/2020] [Accepted: 10/06/2020] [Indexed: 11/17/2022]
Abstract
Hydrolysis of the phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) at the cell membrane induces the release of inositol 1,4,5-trisphosphate (IP3) into the cytoplasm and diffusion of diacylglycerol (DAG) through the membrane, respectively. Release of IP3 subsequently increases Ca2+ levels in the cytoplasm, which results in activation of protein kinase C α (PKCα) by Ca2+ and DAG, and finally the translocation of PKCα from the cytoplasm to the membrane. In this study, we developed a metabolic reaction-diffusion framework to simulate PKCα translocation via PIP2 hydrolysis in an endothelial cell. A three-dimensional cell model, divided into membrane and cytoplasm domains, was reconstructed from confocal microscopy images. The associated metabolic reactions were divided into their corresponding domain; PIP2 hydrolysis at the membrane domain resulted in DAG diffusion at the membrane domain and IP3 release into the cytoplasm domain. In the cytoplasm domain, Ca2+ was released from the endoplasmic reticulum, and IP3, Ca2+, and PKCα diffused through the cytoplasm. PKCα bound Ca2+ at, and diffused through, the cytoplasm, and was finally activated by binding with DAG at the membrane. Using our model, we analyzed IP3 and DAG dynamics, Ca2+ waves, and PKCα translocation in response to a microscopic stimulus. We found a qualitative agreement between our simulation results and our experimental results obtained by live-cell imaging. Interestingly, our results suggest that PKCα translocation is dominated by DAG dynamics. This three-dimensional reaction-diffusion mathematical framework could be used to investigate the link between PKCα activation in a cell and cell function.
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Mikolajewicz N, Sehayek S, Wiseman PW, Komarova SV. Transmission of Mechanical Information by Purinergic Signaling. Biophys J 2019; 116:2009-2022. [PMID: 31053261 DOI: 10.1016/j.bpj.2019.04.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/26/2019] [Accepted: 04/08/2019] [Indexed: 12/27/2022] Open
Abstract
The skeleton constantly interacts and adapts to the physical world. We have previously reported that physiologically relevant mechanical forces lead to small repairable membrane injuries in bone-forming osteoblasts, resulting in release of ATP and stimulation of purinergic (P2) calcium responses in neighboring cells. The goal of this study was to develop a theoretical model describing injury-related ATP and ADP release, their extracellular diffusion and degradation, and purinergic responses in neighboring cells. After validation using experimental data for intracellular free calcium elevations, ATP, and vesicular release after mechanical stimulation of a single osteoblast, the model was scaled to a tissue-level injury to investigate how purinergic signaling communicates information about injuries with varying geometries. We found that total ATP released, peak extracellular ATP concentration, and the ADP-mediated signaling component contributed complementary information regarding the mechanical stimulation event. The total amount of ATP released governed spatial factors, such as the maximal distance from the injury at which purinergic responses were stimulated. The peak ATP concentration reflected the severity of an individual cell injury, allowing to discriminate between minor and severe injuries that released similar amounts of ATP because of differences in injury repair, and determined temporal aspects of the response, such as signal propagation velocity. ADP-mediated signaling became relevant only in larger tissue-level injuries, conveying information about the distance to the injury site and its geometry. Thus, we identified specific features of extracellular ATP and ADP spatiotemporal signals that depend on tissue mechanoresilience and encode the severity, scope, and proximity of the mechanical stimulus.
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Affiliation(s)
- Nicholas Mikolajewicz
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada; Shriners Hospital for Children-Canada, Montreal, Quebec, Canada
| | | | - Paul W Wiseman
- Department of Physics, Montreal, Quebec, Canada; Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - Svetlana V Komarova
- Faculty of Dentistry, McGill University, Montreal, Quebec, Canada; Shriners Hospital for Children-Canada, Montreal, Quebec, Canada.
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A simple mechanochemical model for calcium signalling in embryonic epithelial cells. J Math Biol 2019; 78:2059-2092. [PMID: 30826846 PMCID: PMC6560504 DOI: 10.1007/s00285-019-01333-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 11/14/2018] [Indexed: 12/17/2022]
Abstract
Calcium signalling is one of the most important mechanisms of information propagation in the body. In embryogenesis the interplay between calcium signalling and mechanical forces is critical to the healthy development of an embryo but poorly understood. Several types of embryonic cells exhibit calcium-induced contractions and many experiments indicate that calcium signals and contractions are coupled via a two-way mechanochemical feedback mechanism. We present a new analysis of experimental data that supports the existence of this coupling during apical constriction. We then propose a simple mechanochemical model, building on early models that couple calcium dynamics to the cell mechanics and we replace the hypothetical bistable calcium release with modern, experimentally validated calcium dynamics. We assume that the cell is a linear, viscoelastic material and we model the calcium-induced contraction stress with a Hill function, i.e. saturating at high calcium levels. We also express, for the first time, the "stretch-activation" calcium flux in the early mechanochemical models as a bottom-up contribution from stretch-sensitive calcium channels on the cell membrane. We reduce the model to three ordinary differential equations and analyse its bifurcation structure semi-analytically as two bifurcation parameters vary-the [Formula: see text] concentration, and the "strength" of stretch activation, [Formula: see text]. The calcium system ([Formula: see text], no mechanics) exhibits relaxation oscillations for a certain range of [Formula: see text] values. As [Formula: see text] is increased the range of [Formula: see text] values decreases and oscillations eventually vanish at a sufficiently high value of [Formula: see text]. This result agrees with experimental evidence in embryonic cells which also links the loss of calcium oscillations to embryo abnormalities. Furthermore, as [Formula: see text] is increased the oscillation amplitude decreases but the frequency increases. Finally, we also identify the parameter range for oscillations as the mechanical responsiveness factor of the cytosol increases. This work addresses a very important and not well studied question regarding the coupling between chemical and mechanical signalling in embryogenesis.
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Sera T, Komine S, Arai M, Sunaga Y, Yokota H, Kudo S. Three-dimensional model of intracellular and intercellular Ca 2+ waves propagation in endothelial cells. Biochem Biophys Res Commun 2018; 505:781-786. [PMID: 30293682 DOI: 10.1016/j.bbrc.2018.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 10/01/2018] [Indexed: 12/21/2022]
Abstract
Intracellular and intercellular Ca2+ waves play key roles in cellular functions, and focal stimulation triggers Ca2+ wave propagation from stimulation points to neighboring cells, involving localized metabolism reactions and specific diffusion processes. Among these, inositol 1,4,5-trisphosphate (IP3) is produced at membranes and diffuses into the cytoplasm to release Ca2+ from endoplasmic reticulum (ER). In this study, we developed a three-dimensional (3D) simulation model for intercellular and intracellular Ca2+ waves in endothelial cells (ECs). 3D model of 2 cells was reconstructed from confocal microscopic images and was connected via gap junctions. Cells have membrane and cytoplasm domains, and metabolic reactions were divided into each domain. Finally, the intracellular and intercellular Ca2+ wave propagations were induced using microscopic stimulation and were compared between numerical simulations and experiments. The experiments showed that initial sharp increases in intracellular Ca2+ occurred approximately 0.3 s after application of stimuli. In addition, Ca2+ wave speeds remained constant in cells, with intracellular and intercellular speeds of approximately 35 and 15 μm/s, respectively. Simulations indicated initial increases in Ca2+ concentrations at points of stimulation, and these were then propagated across stimulated and neighboring cells. In particular, initial rapid increases in intracellular Ca2+ were delayed and subsequent intracellular and intercellular Ca2+ wave speeds were approximately 25 and 12 μm/s, respectively. Simulation results were in agreement with those from cell culture experiments, indicating the utility of our 3D model for investigations of intracellular and intercellular messaging in ECs.
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Affiliation(s)
- Toshihiro Sera
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Japan. //
| | - Shingo Komine
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Japan
| | - Masataka Arai
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Japan
| | - Yasuhiro Sunaga
- Advanced Center for Computing and Communication, RIKEN, Japan
| | - Hideo Yokota
- Image Processing Research Team, RIKEN Center for Advanced Photonics, RIKEN, Japan
| | - Susumu Kudo
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Japan
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5
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Xing F, Zhang P, Jiang P, Chen Z, Yang J, Hu F, Drevenšek-Olenik I, Zhang X, Pan L, Xu J. Spatiotemporal Characteristics of Intercellular Calcium Wave Communication in Micropatterned Assemblies of Single Cells. ACS APPLIED MATERIALS & INTERFACES 2018; 10:2937-2945. [PMID: 29283550 DOI: 10.1021/acsami.7b15759] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Micropatterned substrates offer a unique possibility to define and control spatial organization of biological cells at the microscale, which greatly facilitates investigations of the cell-to-cell communication in vitro. Here, we developed a simple micropatterning strategy to resolve various spatiotemporal characteristics of intercellular calcium wave (ICW) communication among isolated BV-2 microglial cells. By using a single-ring assembly, we found that the direction of the initial transmitter secretion was strongly correlated with the site of the cell at which the mechanical stimulus triggering the ICWs was imposed. By using multiring assemblies, we observed that the response ratio of the same outmost cells 160 μm away from the center increased from 0% in the single-ring assembly to 9.6% in the four-ring assembly. This revealed that cells located in the interring acted as regenerative amplifiers for the ICWs generated by the central cell. By using a special oval-type micropattern, we found that calcium mobilization in lamellipodia of a fusiform BV-2 microglia cell occurred 2.9 times faster than that in the middle part of the cell, demonstrating a higher region-specific sensitivity of lamellipodia to the transmitter. Taken together, our micropatterning strategy opened up new experimental prospects to study ICWs and revealed novel spatiotemporal characteristics of ICW communication including stimulation site-dependent secretion, regenerative propagation, and region-specific cell sensitivity.
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Affiliation(s)
| | | | | | | | | | | | - Irena Drevenšek-Olenik
- Faculty of Mathematics and Physics, University of Ljubljana, and J. Stefan Institute , Ljubljana SI1000, Slovenia
| | | | | | - Jingjun Xu
- Collaborative Innovation Center of Extreme Optics, Shanxi University , Taiyuan, Shanxi 030006, China
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Wang C, Fu KK, Dai J, Lacey SD, Yao Y, Pastel G, Xu L, Zhang J, Hu L. Inverted battery design as ion generator for interfacing with biosystems. Nat Commun 2017; 8:15609. [PMID: 28737174 PMCID: PMC5527283 DOI: 10.1038/ncomms15609] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 04/12/2017] [Indexed: 11/09/2022] Open
Abstract
In a lithium-ion battery, electrons are released from the anode and go through an external electronic circuit to power devices, while ions simultaneously transfer through internal ionic media to meet with electrons at the cathode. Inspired by the fundamental electrochemistry of the lithium-ion battery, we envision a cell that can generate a current of ions instead of electrons, so that ions can be used for potential applications in biosystems. Based on this concept, we report an 'electron battery' configuration in which ions travel through an external circuit to interact with the intended biosystem whereas electrons are transported internally. As a proof-of-concept, we demonstrate the application of the electron battery by stimulating a monolayer of cultured cells, which fluoresces a calcium ion wave at a controlled ionic current. Electron batteries with the capability to generate a tunable ionic current could pave the way towards precise ion-system control in a broad range of biological applications.
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Affiliation(s)
- Chengwei Wang
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
| | - Kun Kelvin Fu
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
| | - Jiaqi Dai
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
| | - Steven D Lacey
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
| | - Yonggang Yao
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
| | - Glenn Pastel
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
| | - Lisha Xu
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
| | - Jianhua Zhang
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Liangbing Hu
- Department of Materials Science and Engineering, University of Maryland College Park, College Park, Maryland 20742, USA
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Handly LN, Wollman R. Wound-induced Ca 2+ wave propagates through a simple release and diffusion mechanism. Mol Biol Cell 2017; 28:1457-1466. [PMID: 28404746 PMCID: PMC5449146 DOI: 10.1091/mbc.e16-10-0695] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 04/07/2017] [Accepted: 04/07/2017] [Indexed: 01/10/2023] Open
Abstract
Damage-associated molecular patterns (DAMPs) are critical mediators of information concerning tissue damage from damaged cells to neighboring healthy cells. ATP acts as an effective DAMP when released into extracellular space from damaged cells. Extracellular ATP receptors monitor tissue damage and activate a Ca2+ wave in the surrounding healthy cells. How the Ca2+ wave propagates through cells after a wound is unclear. Ca2+ wave activation can occur extracellularly via external receptors or intracellularly through GAP junctions. Three potential mechanisms to propagate the Ca2+ wave are source and sink, amplifying wave, and release and diffusion. Both source and sink and amplifying wave regulate ATP levels using hydrolysis or secretion, respectively, whereas release and diffusion relies on dilution. Here we systematically test these hypotheses using a microfluidics assay to mechanically wound an epithelial monolayer in combination with direct manipulation of ATP hydrolysis and release. We show that a release and diffusion model sufficiently explains Ca2+-wave propagation after an epithelial wound. A release and diffusion model combines the benefits of fast activation at short length scales with a self-limiting response to prevent unnecessary inflammatory responses harmful to the organism.
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Affiliation(s)
- L Naomi Handly
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095.,Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, Los Angeles, CA 90095
| | - Roy Wollman
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095 .,Institute for Quantitative and Computational Biosciences, University of California, Los Angeles, Los Angeles, CA 90095.,Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095
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8
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Kobayashi Y, Kitahata H, Nagayama M. Model for calcium-mediated reduction of structural fluctuations in epidermis. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:022709. [PMID: 26382434 DOI: 10.1103/physreve.92.022709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Indexed: 06/05/2023]
Abstract
We propose a reaction-advection-diffusion model of epidermis consisting of two variables, the degree of differentiation and the calcium ion concentration, where calcium ions enhance differentiation. By analytically and numerically investigating this system, we show that a calcium localization layer formed beneath the stratum corneum helps reduce spatiotemporal fluctuations of the structure of the stratum corneum. In particular, spatially or temporally small-scale fluctuations in the lower structure are suppressed and do not affect the upper structure, due to acceleration of differentiation by calcium ions. Analytical expressions for the reduction rate of fluctuation amplitudes are shown.
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Affiliation(s)
- Yasuaki Kobayashi
- Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan
- JST CREST, Saitama 332-0012, Japan
| | - Hiroyuki Kitahata
- Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
| | - Masaharu Nagayama
- Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan
- JST CREST, Saitama 332-0012, Japan
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9
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Vainio I, Abu Khamidakh A, Paci M, Skottman H, Juuti-Uusitalo K, Hyttinen J, Nymark S. Computational Model of Ca2+ Wave Propagation in Human Retinal Pigment Epithelial ARPE-19 Cells. PLoS One 2015; 10:e0128434. [PMID: 26070134 PMCID: PMC4466493 DOI: 10.1371/journal.pone.0128434] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 04/27/2015] [Indexed: 12/21/2022] Open
Abstract
Objective Computational models of calcium (Ca2+) signaling have been constructed for several cell types. There are, however, no such models for retinal pigment epithelium (RPE). Our aim was to construct a Ca2+ signaling model for RPE based on our experimental data of mechanically induced Ca2+ wave in the in vitro model of RPE, the ARPE-19 monolayer. Methods We combined six essential Ca2+ signaling components into a model: stretch-sensitive Ca2+ channels (SSCCs), P2Y2 receptors, IP3 receptors, ryanodine receptors, Ca2+ pumps, and gap junctions. The cells in our epithelial model are connected to each other to enable transport of signaling molecules. Parameterization was done by tuning the above model components so that the simulated Ca2+ waves reproduced our control experimental data and data where gap junctions were blocked. Results Our model was able to explain Ca2+ signaling in ARPE-19 cells, and the basic mechanism was found to be as follows: 1) Cells near the stimulus site are likely to conduct Ca2+ through plasma membrane SSCCs and gap junctions conduct the Ca2+ and IP3 between cells further away. 2) Most likely the stimulated cell secretes ligand to the extracellular space where the ligand diffusion mediates the Ca2+ signal so that the ligand concentration decreases with distance. 3) The phosphorylation of the IP3 receptor defines the cell’s sensitivity to the extracellular ligand attenuating the Ca2+ signal in the distance. Conclusions The developed model was able to simulate an array of experimental data including drug effects. Furthermore, our simulations predict that suramin may interfere ligand binding on P2Y2 receptors or accelerate P2Y2 receptor phosphorylation, which may partially be the reason for Ca2+ wave attenuation by suramin. Being the first RPE Ca2+ signaling model created based on experimental data on ARPE-19 cell line, the model offers a platform for further modeling of native RPE functions.
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Affiliation(s)
- Iina Vainio
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
- * E-mail:
| | - Amna Abu Khamidakh
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
| | - Michelangelo Paci
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
| | - Heli Skottman
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland
| | - Kati Juuti-Uusitalo
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland
| | - Jari Hyttinen
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
| | - Soile Nymark
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
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10
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Kobayashi Y, Sanno Y, Sakai A, Sawabu Y, Tsutsumi M, Goto M, Kitahata H, Nakata S, Kumamoto J, Denda M, Nagayama M. Mathematical modeling of calcium waves induced by mechanical stimulation in keratinocytes. PLoS One 2014; 9:e92650. [PMID: 24663805 PMCID: PMC3963930 DOI: 10.1371/journal.pone.0092650] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 02/25/2014] [Indexed: 11/18/2022] Open
Abstract
Recent studies have shown that the behavior of calcium in the epidermis is closely related to the conditions of the skin, especially the differentiation of the epidermal keratinocytes and the permeability barrier function, and therefore a correct understanding of the calcium dynamics is important in explaining epidermal homeostasis. Here we report on experimental observations of in vitro calcium waves in keratinocytes induced by mechanical stimulation, and present a mathematical model that can describe the experimentally observed wave behavior that includes finite-range wave propagation and a ring-shaped pattern. A mechanism of the ring formation hypothesized by our model may be related to similar calcium propagation patterns observed during the wound healing process in the epidermis. We discuss a possible extension of our model that may serve as a tool for investigating the mechanisms of various skin diseases.
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Affiliation(s)
- Yasuaki Kobayashi
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
- CREST, Japan Science and Technology Agency, Tokyo, Japan
| | - Yumi Sanno
- Graduate School of Science and Technology, Kanazawa University, Kanazawa, Japan
| | - Akihiko Sakai
- Graduate School of Science and Technology, Kanazawa University, Kanazawa, Japan
| | - Yusuke Sawabu
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Moe Tsutsumi
- Shiseido Research Center, Shiseido Co., Ltd., Yokohama, Japan
| | - Makiko Goto
- Shiseido Research Center, Shiseido Co., Ltd., Yokohama, Japan
| | - Hiroyuki Kitahata
- Department of Physics, Graduate School of Science, Chiba University, Chiba, Japan
| | - Satoshi Nakata
- Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan
| | - Junichi Kumamoto
- CREST, Japan Science and Technology Agency, Tokyo, Japan
- Shiseido Research Center, Shiseido Co., Ltd., Yokohama, Japan
| | - Mitsuhiro Denda
- CREST, Japan Science and Technology Agency, Tokyo, Japan
- Shiseido Research Center, Shiseido Co., Ltd., Yokohama, Japan
| | - Masaharu Nagayama
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
- CREST, Japan Science and Technology Agency, Tokyo, Japan
- * E-mail:
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11
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Milovic C, Oses C, Villalón M, Uribe S, Lizama C, Prieto C, Andia ME, Irarrazaval P, Tejos C. Calcium (Ca2+) waves data calibration and analysis using image processing techniques. BMC Bioinformatics 2013; 14:162. [PMID: 23679062 PMCID: PMC3667061 DOI: 10.1186/1471-2105-14-162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 05/07/2013] [Indexed: 11/16/2022] Open
Abstract
Background Calcium (Ca2+) propagates within tissues serving as an important information carrier. In particular, cilia beat frequency in oviduct cells is partially regulated by Ca2+ changes. Thus, measuring the calcium density and characterizing the traveling wave plays a key role in understanding biological phenomena. However, current methods to measure propagation velocities and other wave characteristics involve several manual or time-consuming procedures. This limits the amount of information that can be extracted, and the statistical quality of the analysis. Results Our work provides a framework based on image processing procedures that enables a fast, automatic and robust characterization of data from two-filter fluorescence Ca2+ experiments. We calculate the mean velocity of the wave-front, and use theoretical models to extract meaningful parameters like wave amplitude, decay rate and time of excitation. Conclusions Measurements done by different operators showed a high degree of reproducibility. This framework is also extended to a single filter fluorescence experiments, allowing higher sampling rates, and thus an increased accuracy in velocity measurements.
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Affiliation(s)
- Carlos Milovic
- Department of Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile.
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12
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Sun GX, Wang LJ, Xiang C, Qin KR. A dynamic model for intracellular calcium response in fibroblasts induced by electrical stimulation. Math Biosci 2013; 244:47-57. [PMID: 23624256 DOI: 10.1016/j.mbs.2013.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 04/13/2013] [Accepted: 04/15/2013] [Indexed: 11/27/2022]
Abstract
Regulation of intracellular calcium ion concentration ([Ca(2+)]in) in fibroblasts induced by exogenous electrical stimulation could be applied to control gene expressions selectively which in turn modulate the function of the fibroblasts. Regarding the mechanism for electric-field-induced Ca(2+) influx via voltage-gated Ca(2+) channels and/or stretch-activated cation channels in the fibroblasts, a dynamic mathematical model is proposed to quantify the [Ca(2+)]in dynamics in response to direct current or alternating current electric fields. Simulation results demonstrate that the changes in [Ca(2+)]in predicted by our dynamic model are consistent with the experimental data in the literature. The proposed dynamic model could provide not only more insights into the electric-field-induced intracellular Ca(2+) response but also a quantitative way to regulate the [Ca(2+)]in dynamics by controlling the external electrical stimulation.
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Affiliation(s)
- Guo-Xin Sun
- Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, No. 2, Linggong Rd., Dalian 116024, China
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13
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A mechanochemical model for auto-regulation of lung airway surface layer volume. J Theor Biol 2013; 325:42-51. [PMID: 23415939 DOI: 10.1016/j.jtbi.2013.01.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 01/26/2013] [Accepted: 01/29/2013] [Indexed: 01/23/2023]
Abstract
We develop a proof-of-principle model for auto-regulation of water volume in the lung airway surface layer (ASL) by coupling biochemical kinetics, transient ASL volume, and homeostatic mechanical stresses. The model is based on the hypothesis that ASL volume is sensed through soluble mediators and phasic stresses generated by beating cilia and air drag forces. Model parameters are fit based on the available data on human bronchial epithelial cell cultures. Simulations then demonstrate that homeostatic volume regulation is a natural consequence of the processes described. The model maintains ASL volume within a physiological range that modulates with phasic stress frequency and amplitude. Next, we show that the model successfully reproduces the responses of cell cultures to significant isotonic and hypotonic challenges, and to hypertonic saline, an effective therapy for mucus hydration in cystic fibrosis patients. These results compel an advanced airway hydration model with therapeutic value that will necessitate detailed kinetics of multiple molecular pathways, feedback to ASL viscoelasticity properties, and stress signaling from the ASL to the cilia and epithelial cells.
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14
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Abstract
Intercellular calcium (Ca(2+)) waves (ICWs) represent the propagation of increases in intracellular Ca(2+) through a syncytium of cells and appear to be a fundamental mechanism for coordinating multicellular responses. ICWs occur in a wide diversity of cells and have been extensively studied in vitro. More recent studies focus on ICWs in vivo. ICWs are triggered by a variety of stimuli and involve the release of Ca(2+) from internal stores. The propagation of ICWs predominately involves cell communication with internal messengers moving via gap junctions or extracellular messengers mediating paracrine signaling. ICWs appear to be important in both normal physiology as well as pathophysiological processes in a variety of organs and tissues including brain, liver, retina, cochlea, and vascular tissue. We review here the mechanisms of initiation and propagation of ICWs, the key intra- and extracellular messengers (inositol 1,4,5-trisphosphate and ATP) mediating ICWs, and the proposed physiological functions of ICWs.
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Affiliation(s)
- Luc Leybaert
- Department of Basic Medical Sciences, Physiology Group, Faculty of Medicine & Health Sciences, Ghent University, Ghent, Belgium.
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15
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Abstract
Motile cilia in the airway epithelium are the engine for mucociliary clearance, the mechanism responsible for cleaning the airways from inhaled particles. Human airway epithelial cilia appear to have a slow constitutive rate of beating, driven by inherent and spontaneous dynein ATPase activity. Additionally, cilia can increase their beating frequency by activation of several different control mechanisms. One of these controllers is calcium. Its intracellular concentration is regulated by purinergic and acetylcholine receptors. Besides the rate regulatory effect of calcium on ciliary beat, calcium is also involved in synchronizing the beat among cilia of one single cell as well as between cilia on different cells. This article gives an overview of the complex effects of calcium on the beating of motile cilia in the airways.
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Warren NJ, Tawhai MH, Crampin EJ. The effect of intracellular calcium oscillations on fluid secretion in airway epithelium. J Theor Biol 2010; 265:270-7. [PMID: 20488194 DOI: 10.1016/j.jtbi.2010.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 05/07/2010] [Accepted: 05/07/2010] [Indexed: 11/19/2022]
Abstract
Airway epithelium has been shown to elicit fluid secretion after a rise in intracellular calcium. This rise in intracellular calcium has been shown to display complex oscillations in many species after the binding of particular agonists to extracellular receptors. Fluid secreted by the airway epithelium is used to maintain the depth of the periciliary liquid (PCL) above the apical membrane of the epithelial cells lining the bronchial airways. Previous mathematical models have been published which separately consider the electrophysiology involved in regulating periciliary liquid depth, and the transmission of intracellular calcium waves in airway epithelial tissue. In this paper we present a mathematical model that combines these previous models and allows the effect of oscillations in intracellular calcium on fluid secretion by airway epithelial cells to be investigated. We show that an oscillatory calcium response produces different fluid secretion properties to that elicited by a tonic rise in intracellular calcium. These differences are shown to be due to saturation of the Ca(2+) activated ion channels.
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Affiliation(s)
- N J Warren
- Auckland Bioengineering Institute, Level 6, 70 Symond St, Auckland, New Zealand
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Warren NJ, Crampin EJ, Tawhai MH. The role of airway epithelium in replenishment of evaporated airway surface liquid from the human conducting airways. Ann Biomed Eng 2010; 38:3535-49. [PMID: 20596780 DOI: 10.1007/s10439-010-0111-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2010] [Accepted: 06/21/2010] [Indexed: 11/26/2022]
Abstract
This article presents a multi-scale computational model describing the transport of water vapor and heat within the human conducting airways and its interaction with cellular fluid transport kinetics. This tight coupling between the cell and the evaporative flux allows the periciliary liquid (PCL) depth to be investigated within the context of a geometric framework of the human conducting airways with spatial and temporal variations. Within the in vivo airway, the epithelium is not the only source of fluid available for hydration of the PCL, and fluid may also be supplied from submucosal glands (SMGs) or via axial transport of the PCL. The model predicts that without fluid supplied by either SMGs or via PCL transport, significant dehydration would occur under normal breathing conditions. Previous studies have suggested that PCL transport from the periphery to the trachea would require absorption of the fluid by the epithelium; here we show that this can theoretically be sustained by the evaporative load under normal breathing conditions. SMGs could also provide a significant supply of fluid for airway hydration, a hypothesis which is corroborated by comparing the distribution of SMGs as a function of airway generation with the distribution of airway evaporative flux.
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Affiliation(s)
- N J Warren
- Auckland Bioengineering Institute, University of Auckland, New Zealand.
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Palk L, Sneyd J, Shuttleworth TJ, Yule DI, Crampin EJ. A dynamic model of saliva secretion. J Theor Biol 2010; 266:625-40. [PMID: 20600135 DOI: 10.1016/j.jtbi.2010.06.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 06/12/2010] [Accepted: 06/21/2010] [Indexed: 10/19/2022]
Abstract
We construct a mathematical model of the parotid acinar cell with the aim of investigating how the distribution of K(+) and Cl(-) channels affects saliva production. Secretion of fluid is initiated by Ca(2+) signals acting on Ca(2+) dependent K(+) and Cl(-) channels. The opening of these channels facilitates the movement of Cl(-) ions into the lumen which water follows by osmosis. We use recent results into both the release of Ca(2+) from internal stores via the inositol (1,4,5)-trisphosphate receptor (IP(3)R) and IP(3) dynamics to create a physiologically realistic Ca(2+) model which is able to recreate important experimentally observed behaviours seen in parotid acinar cells. We formulate an equivalent electrical circuit diagram for the movement of ions responsible for water flow which enables us to calculate and include distinct apical and basal membrane potentials to the model. We show that maximum saliva production occurs when a small amount of K(+) conductance is located at the apical membrane, with the majority in the basal membrane. The maximum fluid output is found to coincide with a minimum in the apical membrane potential. The traditional model whereby all Cl(-) channels are located in the apical membrane is shown to be the most efficient Cl(-) channel distribution.
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Affiliation(s)
- Laurence Palk
- Department of Mathematics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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