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Glycocalyx Sensing with a Mathematical Model of Acoustic Shear Wave Biosensor. BIOENGINEERING (BASEL, SWITZERLAND) 2022; 9:bioengineering9090462. [PMID: 36135008 PMCID: PMC9495919 DOI: 10.3390/bioengineering9090462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/12/2022] [Accepted: 08/22/2022] [Indexed: 11/22/2022]
Abstract
The article deals with an idea of exploiting an acoustic shear wave biosensor for investigating the glycocalyx, a polysaccharide polymer molecule layer on the endothelium of blood vessels that, according to recent studies, plays an important role in protecting against diseases. To test this idea, a mathematical model of an acoustic shear wave sensor and corresponding software developed earlier for proteomic applications are used. In this case, the glycocalyx is treated as a layer homogenized over the thin polymer “villi”. Its material characteristics depend on the density, thickness, and length of the villi and on the viscous properties of the surrounding liquid (blood plasma). It is proved that the model used has a good sensitivity to the above parameters of the villi and blood plasma. Numerical experiments performed using real data collected retrospectively from premature infants show that the use of acoustic shear wave sensors may be a promising approach to investigate properties of glycocalyx-like structures and their role in prematurity.
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Goligorsky MS. OSCILLATORS IN THE MICROVASCULATURE - GLYCOCALYX AND BEYOND. Am J Physiol Cell Physiol 2022; 323:C432-C438. [PMID: 35759436 PMCID: PMC9359649 DOI: 10.1152/ajpcell.00170.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The growing recognition of abundance of oscillating functions in biological systems has motivated this brief overview which narrows down on the microvasculature. Specifically, it encompasses self-sustained oscillations of blood flow, hematocrit and viscosity at bifurcations; their effects on the oscillations of endothelial glycocalyx, mechanotransduction and its termination to prime endothelial cells for the subsequent mechanical signaling event; oscillating affinity of hyaluronan-CD44 binding domain; spontaneous contractility of actomyosin complexes in the cortical actin web, its effects on the tension of the plasma membrane; reversible effects of sirtuin-1 on endothelial glycocalyx; and effects of plasma membrane tension on endo-and exocytosis. Some potential interactions between those oscillators - their coupling - are discussed together with their transition into chaotic movements. Future in-depth understanding of the oscillatory activities in the microvasculature could serve as a guide to its chronotherapy under pathological conditions.
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Affiliation(s)
- Michael S Goligorsky
- Renal Research Institute and Departments of Medicine, Pharmacology and Physiology, New York Medical College at the Touro University, Valhalla, NY
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Molecular dynamics simulation: A new way to understand the functionality of the endothelial glycocalyx. Curr Opin Struct Biol 2022; 73:102330. [DOI: 10.1016/j.sbi.2022.102330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/02/2021] [Accepted: 12/30/2021] [Indexed: 11/22/2022]
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Jiang XZ, Luo KH, Ventikos Y. Understanding the Role of Endothelial Glycocalyx in Mechanotransduction via Computational Simulation: A Mini Review. Front Cell Dev Biol 2021; 9:732815. [PMID: 34485313 PMCID: PMC8415899 DOI: 10.3389/fcell.2021.732815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/27/2021] [Indexed: 11/25/2022] Open
Abstract
Endothelial glycocalyx (EG) is a forest-like structure, covering the lumen side of blood vessel walls. EG is exposed to the mechanical forces of blood flow, mainly shear, and closely associated with vascular regulation, health, diseases, and therapies. One hallmark function of the EG is mechanotransduction, which means the EG senses the mechanical signals from the blood flow and then transmits the signals into the cells. Using numerical modelling methods or in silico experiments to investigate EG-related topics has gained increasing momentum in recent years, thanks to tremendous progress in supercomputing. Numerical modelling and simulation allows certain very specific or even extreme conditions to be fulfilled, which provides new insights and complements experimental observations. This mini review examines the application of numerical methods in EG-related studies, focusing on how computer simulation contributes to the understanding of EG as a mechanotransducer. The numerical methods covered in this review include macroscopic (i.e., continuum-based), mesoscopic [e.g., lattice Boltzmann method (LBM) and dissipative particle dynamics (DPD)] and microscopic [e.g., molecular dynamics (MD) and Monte Carlo (MC) methods]. Accounting for the emerging trends in artificial intelligence and the advent of exascale computing, the future of numerical simulation for EG-related problems is also contemplated.
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Affiliation(s)
- Xi Zhuo Jiang
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, China
| | - Kai H Luo
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Yiannis Ventikos
- Department of Mechanical Engineering, University College London, London, United Kingdom
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Cross talk between endothelial and red blood cell glycocalyces via near-field flow. Biophys J 2021; 120:3180-3191. [PMID: 34197803 PMCID: PMC8392098 DOI: 10.1016/j.bpj.2021.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 04/09/2021] [Accepted: 06/03/2021] [Indexed: 02/06/2023] Open
Abstract
Vascular endothelial cells and circulating red blood cell (RBC) surfaces are both covered by a layer of bushy glycocalyx. The interplay between these glycocalyx layers is hardly measurable and insufficiently understood. This study aims to investigate and qualify the possible interactions between the glycocalyces of RBCs and endothelial cells using mathematical modeling and numerical simulation. Dissipative particle dynamics (DPD) simulations are conducted to investigate the response of the endothelial glycocalyx (EG) to varying ambient conditions. A two-compartment model including EG and flow and a three-compartment model comprising EG, RBC glycocalyx, and flow are established. The two-compartment analysis shows that a relatively fast flow is associated with a predominantly bending motion of the EG, whereas oscillatory motions are predominant in a relatively slow flow. Results show that circulating RBCs cause the contactless deformation of EG. Its deformation is dependent on the chain layout, chain length, bending stiffness, RBC-to-EG distance, and RBC velocities. Specifically, shorter EG chains or RBC-to-EG distance leads to greater relative deflections of EG. Deformation of EG is enhanced when the EG chains are rarefied or RBCs move faster. The bending stiffness maintains stretching conformation of EG. Moreover, a compact EG chain layout and shedding EG chains disturb the neighboring flow field, causing disordered flow velocity distributions. In contrast, the movement of EG chains on RBC surfaces exerts a marginal driving force on RBCs. The DPD method is used for the first time, to our knowledge, in the three-compartment system to explore the cross talk between EG and RBC glycocalyx. This study suggests that RBCs drive the EG deformation via the near-field flow, whereas marginal propulsion of RBCs by the EG is observed. These new, to our knowledge, findings provide a new angle to understand the roles of glycocalyx in mechanotransduction and microvascular permeability and their perturbations under idealized pathophysiologic conditions associated with EG degradation.
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Structure and elasticity of bush and brush-like models of the endothelial glycocalyx. Sci Rep 2018; 8:240. [PMID: 29321567 PMCID: PMC5762753 DOI: 10.1038/s41598-017-18577-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/14/2017] [Indexed: 12/12/2022] Open
Abstract
The endothelial glycocalyx (EG), a sugar-rich layer that lines the luminal surface of blood vessels, is an important constituent of the vascular system. Although the chemical composition of the EG is fairly well known, there is no consensus regarding its ultrastructure. While previous experiments probed the properties of the layer at the continuum level, they did not provide sufficient insight into its molecular organisation. In this work, we investigate the EG mechanics using two simple brush and bush-like simulation models, and use these models to describe its molecular structure and elastic response to indentation. We analyse the relationship between the mechanical properties of the EG layer and several molecular parameters, including the filament bending rigidity, grafting density, and the type of ultrastructure . We show that variations in the glycan density determine the elasticity of the EG for small deformations, and that the normal stress may be effectively dampened by the EG layer, preventing the stress from being transferred to the cell membrane. Furthermore, our bush-like model allows us to evaluate the forces and energies required to overcome the mechanical resistance of the EG.
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O'Connor J, Day P, Mandal P, Revell A. Computational fluid dynamics in the microcirculation and microfluidics: what role can the lattice Boltzmann method play? Integr Biol (Camb) 2016; 8:589-602. [PMID: 27068565 DOI: 10.1039/c6ib00009f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Patient-specific simulations, efficient parametric analyses, and the study of complex processes that are otherwise experimentally intractable are facilitated through the use of Computational Fluid Dynamics (CFD) to study biological flows. This review discusses various CFD methodologies that have been applied across different biological scales, from cell to organ level. Through this discussion the lattice Boltzmann method (LBM) is highlighted as an emerging technique capable of efficiently simulating fluid problems across the midrange of scales; providing a practical analytical tool compared to methods more attuned to the extremities of scale. Furthermore, the merits of the LBM are highlighted through examples of previous applications and suggestions for future research are made. The review focusses on applications in the midrange bracket, such as cell-cell interactions, the microcirculation, and microfluidic devices; wherein the inherent mesoscale nature of the LBM renders it well suited to the incorporation of fluid-structure interaction effects, molecular/particle interactions and interfacial dynamics. The review demonstrates that the LBM has the potential to become a valuable tool across a range of emerging areas in bio-CFD, such as understanding and predicting disease, designing lab-on-a-chip devices, and elucidating complex biological processes.
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Affiliation(s)
- Joseph O'Connor
- School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, UKM13 9PL.
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McGarrity S, Halldórsson H, Palsson S, Johansson PI, Rolfsson Ó. Understanding the Causes and Implications of Endothelial Metabolic Variation in Cardiovascular Disease through Genome-Scale Metabolic Modeling. Front Cardiovasc Med 2016; 3:10. [PMID: 27148541 PMCID: PMC4834436 DOI: 10.3389/fcvm.2016.00010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/03/2016] [Indexed: 01/04/2023] Open
Abstract
High-throughput biochemical profiling has led to a requirement for advanced data interpretation techniques capable of integrating the analysis of gene, protein, and metabolic profiles to shed light on genotype-phenotype relationships. Herein, we consider the current state of knowledge of endothelial cell (EC) metabolism and its connections to cardiovascular disease (CVD) and explore the use of genome-scale metabolic models (GEMs) for integrating metabolic and genomic data. GEMs combine gene expression and metabolic data acting as frameworks for their analysis and, ultimately, afford mechanistic understanding of how genetic variation impacts metabolism. We demonstrate how GEMs can be used to investigate CVD-related genetic variation, drug resistance mechanisms, and novel metabolic pathways in ECs. The application of GEMs in personalized medicine is also highlighted. Particularly, we focus on the potential of GEMs to identify metabolic biomarkers of endothelial dysfunction and to discover methods of stratifying treatments for CVDs based on individual genetic markers. Recent advances in systems biology methodology, and how these methodologies can be applied to understand EC metabolism in both health and disease, are thus highlighted.
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Affiliation(s)
- Sarah McGarrity
- Center for Systems Biology, University of Iceland , Reykjavik , Iceland
| | - Haraldur Halldórsson
- Department of Pharmacology and Toxicology, School of Health Sciences, University of Iceland , Reykjavik , Iceland
| | - Sirus Palsson
- Center for Systems Biology, University of Iceland, Reykjavik, Iceland; Sinopia Biosciences Inc., San Diego, CA, USA
| | - Pär I Johansson
- Section for Transfusion Medicine, Capital Region Blood Bank, Rigshospitalet, University of Copenhagen , Copenhagen , Denmark
| | - Óttar Rolfsson
- Center for Systems Biology, University of Iceland, Reykjavik, Iceland; Department of Biochemistry and Molecular Biology, School of Health Sciences, University of Iceland, Reykjavik, Iceland
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O Connor J, Revell A, Mandal P, Day P. Application of a lattice Boltzmann-immersed boundary method for fluid-filament dynamics and flow sensing. J Biomech 2015; 49:2143-2151. [PMID: 26718062 DOI: 10.1016/j.jbiomech.2015.11.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 11/26/2015] [Indexed: 11/16/2022]
Abstract
Complex fluid-structure interactions between elastic filaments, or cilia, immersed in viscous flows are commonplace in nature and bear important roles. Some biological systems have evolved to interpret flow-induced motion into signals for the purpose of feedback response. Given the challenges associated with extracting meaningful experimental data at this scale, there has been particular focus on the numerical study of these effects. Porous models have proven useful where cilia arrangements are relatively dense, but for more sparse configurations the dynamic interactions of individual structures play a greater role and direct modelling becomes increasingly necessary. The present study reports efforts towards explicit modelling of regularly spaced wall-mounted cilia using a lattice Boltzmann-immersed boundary method. Both steady and forced unsteady 2D channel flows at different Reynolds numbers are investigated, with and without the presence of a periodic array of elastic inextensible filaments. It is demonstrated that the structure response depends significantly on Reynolds number. For low Reynolds flow, the recirculation vortex aft of successive filaments is small relative to the cilia spacing and does not fully bridge the gap, in which case the structure lags the flow. At higher Reynolds number, when this gap is fully bridged the structure and flow move in phase. The trapping of vortices between cilia is associated with relatively lower wall shear stress. At low to intermediate Reynolds, vortex bridging is incomplete and large deflection is still possible, which is reflected in the tip dynamics and wall shear stress profiles.
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Affiliation(s)
- Joseph O Connor
- School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK.
| | - Alistair Revell
- School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Parthasarathi Mandal
- School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Philip Day
- Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7ND, UK
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Peters W, Kusche-Vihrog K, Oberleithner H, Schillers H. Cystic fibrosis transmembrane conductance regulator is involved in polyphenol-induced swelling of the endothelial glycocalyx. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 11:1521-30. [PMID: 25881741 DOI: 10.1016/j.nano.2015.03.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/15/2015] [Accepted: 03/23/2015] [Indexed: 12/21/2022]
Abstract
UNLABELLED Previous studies show that polyphenol-rich compounds can induce a swelling of the endothelial glycocalyx (eGC). Our goal was to reveal the mechanism behind the eGC-swelling. As polyphenols are potent modulators of fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel, the hypothesis was tested whether polyphenol-induced increase in CFTR activity is responsible for the eGC-swelling. The impact of the polyphenols resveratrol, (-)-epicatechin, and quercetin on nanomechanics of living endothelial GM7373 cells was monitored by AFM-nanoindentation. The tested polyphenols lead to eGC-swelling with a simultaneous decrease in cortical stiffness. EGC-swelling, but not the change in cortical stiffness, was prevented by the inhibition of CFTR. Polyphenol-induced eGC-swelling could be mimicked by cytochalasin D, an actin-depolymerizing agent. Thus, in the vascular endothelium, polyphenols induce eGC-swelling by softening cortical actin and activating CFTR. Our findings imply that CFTR plays an important role in the maintenance of vascular homeostasis and may explain the vasoprotective properties of polyphenols. FROM THE CLINICAL EDITOR Many vascular problems clinically can be attributed to a dysregulation of endothelial glycocalyx (eGC). The underlying mechanism however remains unclear. In this article, the authors used nanoindentation and showed that polyphenols could swell the endothelial glycocalyx and alter its function. This investigative method can lead to further mechanistic studies of other molecular pathways.
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Affiliation(s)
- Wladimir Peters
- Institute of Physiology II, University of Münster, Münster, Germany
| | | | | | - Hermann Schillers
- Institute of Physiology II, University of Münster, Münster, Germany.
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Omori T, Imai Y, Kikuchi K, Ishikawa T, Yamaguchi T. Hemodynamics in the microcirculation and in microfluidics. Ann Biomed Eng 2014; 43:238-57. [PMID: 25398331 DOI: 10.1007/s10439-014-1180-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 11/04/2014] [Indexed: 12/20/2022]
Abstract
Hemodynamics in microcirculation is important for hemorheology and several types of circulatory disease. Although hemodynamics research has a long history, the field continues to expand due to recent advancements in numerical and experimental techniques at the micro-and nano-scales. In this paper, we review recent computational and experimental studies of blood flow in microcirculation and microfluidics. We first focus on the computational studies of red blood cell (RBC) dynamics, from the single cellular level to mesoscopic multiple cellular flows, followed by a review of recent computational adhesion models for white blood cells, platelets, and malaria-infected RBCs, in which the cell adhesion to the vascular wall is essential for cellular function. Recent developments in optical microscopy have enabled the observation of flowing blood cells in microfluidics. Experimental particle image velocimetry and particle tracking velocimetry techniques are described in this article. Advancements in micro total analysis system technologies have facilitated flowing cell separation with microfluidic devices, which can be used for biomedical applications, such as a diagnostic tool for breast cancer or large intestinal tumors. In this paper, cell-separation techniques are reviewed for microfluidic devices, emphasizing recent advances and the potential of this fast-evolving research field in the near future.
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Affiliation(s)
- Toshihiro Omori
- Department of Bioengineering and Robotics, Tohoku University, Aoba 6-6-01, Sendai, Miyagi, Japan,
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Abstract
The mechanical characteristics of endothelial cells reveal four distinct compartments, namely glycocalyx, cell cortex, cytoplasm and nucleus. There is accumulating evidence that endothelial nanomechanics of these individual compartments control vascular physiology. Depending on protein composition, filament formation and interaction with cross-linker proteins, these four compartments determine endothelial stiffness. Structural organization and mechanical properties directly influence physiological processes such as endothelial barrier function, nitric oxide release and gene expression. This review will focus on endothelial nanomechanics and its impact on vascular function.
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