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Hossain MMN, Hu NW, Kazempour A, Murfee WL, Balogh P. Hemodynamic Characteristics of a Tortuous Microvessel Using High-Fidelity Red Blood Cell Resolved Simulations. Microcirculation 2024; 31:e12875. [PMID: 38989907 PMCID: PMC11471383 DOI: 10.1111/micc.12875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 06/09/2024] [Accepted: 06/29/2024] [Indexed: 07/12/2024]
Abstract
OBJECTIVE Tortuous microvessels are characteristic of microvascular remodeling associated with numerous physiological and pathological scenarios. Three-dimensional (3D) hemodynamics in tortuous microvessels influenced by red blood cells (RBCs), however, are largely unknown, and important questions remain. Is blood viscosity influenced by vessel tortuosity? How do RBC dynamics affect wall shear stress (WSS) patterns and the near-wall cell-free layer (CFL) over a range of conditions? The objective of this work was to parameterize hemodynamic characteristics unique to a tortuous microvessel. METHODS RBC-resolved simulations were performed using an immersed boundary method-based 3D fluid dynamics solver. A representative tortuous microvessel was selected from a stimulated angiogenic network obtained from imaging of the rat mesentery and digitally reconstructed for the simulations. The representative microvessel was a venule with a diameter of approximately 20 μm. The model assumes a constant diameter along the vessel length and does not consider variations due to endothelial cell shapes or the endothelial surface layer. RESULTS Microvessel tortuosity was observed to increase blood apparent viscosity compared to a straight tube by up to 26%. WSS spatial variations in high curvature regions reached 23.6 dyne/cm2 over the vessel cross-section. The magnitudes of WSS and CFL thickness variations due to tortuosity were strongly influenced by shear rate and negligibly influenced by tube hematocrit levels. CONCLUSIONS New findings from this work reveal unique tortuosity-dependent hemodynamic characteristics over a range of conditions. The results provide new thought-provoking information to better understand the contribution of tortuous vessels in physiological and pathological processes and help improve reduced-order models.
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Affiliation(s)
- Mir Md Nasim Hossain
- Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, New Jersey, USA
| | - Nien-Wen Hu
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Ali Kazempour
- Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, New Jersey, USA
| | - Walter L Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Peter Balogh
- Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, New Jersey, USA
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2
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Hossain MMN, Hu NW, Abdelhamid M, Singh S, Murfee WL, Balogh P. Angiogenic Microvascular Wall Shear Stress Patterns Revealed Through Three-dimensional Red Blood Cell Resolved Modeling. FUNCTION 2023; 4:zqad046. [PMID: 37753184 PMCID: PMC10519277 DOI: 10.1093/function/zqad046] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 09/28/2023] Open
Abstract
The wall shear stress (WSS) exerted by blood flowing through microvascular capillaries is an established driver of new blood vessel growth, or angiogenesis. Such adaptations are central to many physiological processes in both health and disease, yet three-dimensional (3D) WSS characteristics in real angiogenic microvascular networks are largely unknown. This marks a major knowledge gap because angiogenesis, naturally, is a 3D process. To advance current understanding, we model 3D red blood cells (RBCs) flowing through rat angiogenic microvascular networks using state-of-the-art simulation. The high-resolution fluid dynamics reveal 3D WSS patterns occurring at sub-endothelial cell (EC) scales that derive from distinct angiogenic morphologies, including microvascular loops and vessel tortuosity. We identify the existence of WSS hot and cold spots caused by angiogenic surface shapes and RBCs, and notably enhancement of low WSS regions by RBCs. Spatiotemporal characteristics further reveal how fluctuations follow timescales of RBC "footprints." Altogether, this work provides a new conceptual framework for understanding how shear stress might regulate EC dynamics in vivo.
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Affiliation(s)
- Mir Md Nasim Hossain
- Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, NJ 07114, USA
| | - Nien-Wen Hu
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Maram Abdelhamid
- Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, NJ 07114, USA
| | - Simerpreet Singh
- Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, NJ 07114, USA
| | - Walter L Murfee
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Peter Balogh
- Mechanical and Industrial Engineering, New Jersey Institute of Technology, Newark, NJ 07114, USA
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3
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Clevenger AJ, McFarlin MK, Collier CA, Sheshadri VS, Madyastha AK, Gorley JPM, Solberg SC, Stratman AN, Raghavan SA. Peristalsis-Associated Mechanotransduction Drives Malignant Progression of Colorectal Cancer. Cell Mol Bioeng 2023; 16:261-281. [PMID: 37811008 PMCID: PMC10550901 DOI: 10.1007/s12195-023-00776-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 07/21/2023] [Indexed: 10/10/2023] Open
Abstract
Introduction In the colorectal cancer (CRC) tumor microenvironment, cancerous and precancerous cells continuously experience mechanical forces associated with peristalsis. Given that mechanical forces like shear stress and strain can positively impact cancer progression, we explored the hypothesis that peristalsis may also contribute to malignant progression in CRC. We defined malignant progression as enrichment of cancer stem cells and the acquisition of invasive behaviors, both vital to CRC progression. Methods We leveraged our peristalsis bioreactor to expose CRC cell lines (HCT116), patient-derived xenograft (PDX1,2) lines, or non-cancerous intestinal cells (HIEC-6) to forces associated with peristalsis in vitro. Cells were maintained in static control conditions or exposed to peristalsis for 24 h prior to assessment of cancer stem cell (CSC) emergence or the acquisition of invasive phenotypes. Results Exposure of HCT116 cells to peristalsis significantly increased the emergence of LGR5+ CSCs by 1.8-fold compared to static controls. Peristalsis enriched LGR5 positivity in several CRC cell lines, notably significant in KRAS mutant lines. In contrast, peristalsis failed to increase LGR5+ in non-cancerous intestinal cells, HIEC-6. LGR5+ emergence downstream of peristalsis was dependent on ROCK and Wnt activity, and not YAP1 activation. Additionally, HCT116 cells adopted invasive morphologies when exposed to peristalsis, with increased filopodia density and epithelial to mesenchymal gene expression, in a Wnt dependent manner. Conclusions Peristalsis associated forces drive malignant progression of CRC via ROCK, YAP1, and Wnt-related mechanotransduction. Supplementary Information The online version contains supplementary material available at 10.1007/s12195-023-00776-w.
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Affiliation(s)
- Abigail J. Clevenger
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
| | - Maygan K. McFarlin
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
| | - Claudia A. Collier
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
| | - Vibha S. Sheshadri
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
| | - Anirudh K. Madyastha
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
| | - John Paul M. Gorley
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
| | - Spencer C. Solberg
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
| | - Amber N. Stratman
- Department of Cell Biology and Physiology, Washington University School of Medicine in St. Louis, St. Louis, MO USA
| | - Shreya A. Raghavan
- Department of Biomedical Engineering, Texas A&M University, 5016 Emerging Technologies Building, 3120 TAMU, College Station, TX 77843 USA
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX USA
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4
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Kotlyarov S. Immune Function of Endothelial Cells: Evolutionary Aspects, Molecular Biology and Role in Atherogenesis. Int J Mol Sci 2022; 23:ijms23179770. [PMID: 36077168 PMCID: PMC9456046 DOI: 10.3390/ijms23179770] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 11/16/2022] Open
Abstract
Atherosclerosis is one of the key problems of modern medicine, which is due to the high prevalence of atherosclerotic cardiovascular diseases and their significant share in the structure of morbidity and mortality in many countries. Atherogenesis is a complex chain of events that proceeds over many years in the vascular wall with the participation of various cells. Endothelial cells are key participants in vascular function. They demonstrate involvement in the regulation of vascular hemodynamics, metabolism, and innate immunity, which act as leading links in the pathogenesis of atherosclerosis. These endothelial functions have close connections and deep evolutionary roots, a better understanding of which will improve the prospects of early diagnosis and effective treatment.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
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5
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Mechanical Forces Govern Interactions of Host Cells with Intracellular Bacterial Pathogens. Microbiol Mol Biol Rev 2022; 86:e0009420. [PMID: 35285720 PMCID: PMC9199418 DOI: 10.1128/mmbr.00094-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
To combat infectious diseases, it is important to understand how host cells interact with bacterial pathogens. Signals conveyed from pathogen to host, and vice versa, may be either chemical or mechanical. While the molecular and biochemical basis of host-pathogen interactions has been extensively explored, relatively less is known about mechanical signals and responses in the context of those interactions. Nevertheless, a wide variety of bacterial pathogens appear to have developed mechanisms to alter the cellular biomechanics of their hosts in order to promote their survival and dissemination, and in turn many host responses to infection rely on mechanical alterations in host cells and tissues to limit the spread of infection. In this review, we present recent findings on how mechanical forces generated by host cells can promote or obstruct the dissemination of intracellular bacterial pathogens. In addition, we discuss how in vivo extracellular mechanical signals influence interactions between host cells and intracellular bacterial pathogens. Examples of such signals include shear stresses caused by fluid flow over the surface of cells and variable stiffness of the extracellular matrix on which cells are anchored. We highlight bioengineering-inspired tools and techniques that can be used to measure host cell mechanics during infection. These allow for the interrogation of how mechanical signals can modulate infection alongside biochemical signals. We hope that this review will inspire the microbiology community to embrace those tools in future studies so that host cell biomechanics can be more readily explored in the context of infection studies.
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Fallon ME, Mathews R, Hinds MT. In Vitro Flow Chamber Design for the Study of Endothelial Cell (Patho)Physiology. J Biomech Eng 2022; 144:020801. [PMID: 34254640 PMCID: PMC8628846 DOI: 10.1115/1.4051765] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 07/06/2021] [Indexed: 02/03/2023]
Abstract
In the native vasculature, flowing blood produces a frictional force on vessel walls that affects endothelial cell function and phenotype. In the arterial system, the vasculature's local geometry directly influences variations in flow profiles and shear stress magnitudes. Straight arterial sections with pulsatile shear stress have been shown to promote an athero-protective endothelial phenotype. Conversely, areas with more complex geometry, such as arterial bifurcations and branch points with disturbed flow patterns and lower, oscillatory shear stress, typically lead to endothelial dysfunction and the pathogenesis of cardiovascular diseases. Many studies have investigated the regulation of endothelial responses to various shear stress environments. Importantly, the accurate in vitro simulation of in vivo hemodynamics is critical to the deeper understanding of mechanotransduction through the proper design and use of flow chamber devices. In this review, we describe several flow chamber apparatuses and their fluid mechanics design parameters, including parallel-plate flow chambers, cone-and-plate devices, and microfluidic devices. In addition, chamber-specific design criteria and relevant equations are defined in detail for the accurate simulation of shear stress environments to study endothelial cell responses.
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Affiliation(s)
- Meghan E. Fallon
- Department of Biomedical Engineering, Oregon Health & Science University, 3303 S Bond Ave CH13B, Portland, OR 97239
| | - Rick Mathews
- Department of Biomedical Engineering, Oregon Health & Science University, 3303 S Bond Ave CH13B, Portland, OR 97239
| | - Monica T. Hinds
- Department of Biomedical Engineering, Oregon Health & Science University, 3303 S Bond Ave CH13B, Portland, OR 97239
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7
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Wang X, Fang F, Ni Y, Yu H, Ma J, Deng L, Li C, Shen Y, Liu X. The Combined Contribution of Vascular Endothelial Cell Migration and Adhesion to Stent Re-endothelialization. Front Cell Dev Biol 2021; 9:641382. [PMID: 33748131 PMCID: PMC7969796 DOI: 10.3389/fcell.2021.641382] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/08/2021] [Indexed: 12/12/2022] Open
Abstract
Coronary stent placement inevitably causes mechanical damage to the endothelium, leading to endothelial denudation and in-stent restenosis (ISR). Re-endothelialization depends mainly on the migration of vascular endothelial cells (VECs) adjacent to the damaged intima, as well as the mobilization and adhesion of circulating VECs. To evaluate the combined contribution of VEC migration and adhesion to re-endothelialization under flow and the influence of stent, in vitro models were constructed to simulate various endothelial denudation scales (2 mm/5 mm/10 mm) and stent deployment depths (flat/groove/bulge). Our results showed that (1) in 2 mm flat/groove/bulge models, both VEC migration and adhesion combined completed the percentage of endothelial recovery about 27, 16, and 12%, and migration accounted for about 21, 15, and 7%, respectively. It was suggested that the flat and groove models were in favor of VEC migration. (2) With the augmentation of the injury scales (5 and 10 mm), the contribution of circulating VEC adhesion on endothelial repair increased. Taken together, endothelial restoration mainly depended on the migration of adjacent VECs when the injury scale was 2 mm. The adhered cells contributed to re-endothelialization in an injury scale-dependent way. This study is helpful to provide new enlightenment for surface modification of cardiovascular implants.
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Affiliation(s)
- Xiaoli Wang
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Fei Fang
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Yinghao Ni
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Hongchi Yu
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Jia Ma
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Li Deng
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Chunli Li
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Yang Shen
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
| | - Xiaoheng Liu
- West China School of Basic Medical Sciences and Forensic Medicine, Institute of Biomedical Engineering, Sichuan University, Chengdu, China
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8
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Sonmez UM, Cheng YW, Watkins SC, Roman BL, Davidson LA. Endothelial cell polarization and orientation to flow in a novel microfluidic multimodal shear stress generator. LAB ON A CHIP 2020; 20:4373-4390. [PMID: 33099594 PMCID: PMC7686155 DOI: 10.1039/d0lc00738b] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Endothelial cells (EC) respond to shear stress to maintain vascular homeostasis, and a disrupted response is associated with cardiovascular diseases. To understand how different shear stress modalities affect EC morphology and behavior, we developed a microfluidic device that concurrently generates three different levels of uniform wall shear stress (WSS) and six different WSS gradients (WSSG). In this device, human umbilical vein endothelial cells (HUVECs) exhibited a rapid and robust response to WSS, with the relative positioning of the Golgi and nucleus transitioning from a non-polarized to polarized state in a WSS magnitude- and gradient-dependent manner. By contrast, polarized HUVECs oriented their Golgi and nucleus polarity to the flow vector in a WSS magnitude-dependent manner, with positive WSSG inhibiting and negative WSSG promoting upstream orientation. Having validated this device, this chip can now be used to dissect the mechanisms underlying EC responses to different WSS modalities, including shear stress gradients, and to investigate the influence of flow on a diverse range of cells during development, homeostasis and disease.
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Affiliation(s)
- Utku M. Sonmez
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Ya-Wen Cheng
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Simon C. Watkins
- Department of Cellular Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Beth L. Roman
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA; Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Lance A. Davidson
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Developmental Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
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9
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Li W, Mao S, Khan M, Zhang Q, Huang Q, Feng S, Lin JM. Responses of Cellular Adhesion Strength and Stiffness to Fluid Shear Stress during Tumor Cell Rolling Motion. ACS Sens 2019; 4:1710-1715. [PMID: 31094503 DOI: 10.1021/acssensors.9b00678] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Biochemical and physical factors affect the rolling of tumor cells across the blood vessel. The biochemical factors have been well studied, while the influence of physical factors such as fluid shear stress (FSS) remains poorly understood. Here, human glioma cells (U87 cells) in a straight microfluidic channel were exposed to FSS (0.12, 1.2, and 1.8 dyn/cm2); and their locomotion behaviors from crawling-to-rolling and changes in cellular morphology (concave, elongated, less elongated, and round) were observed. The adhesion strength and stiffness of the cells of different morphologies were analyzed using a live single-cell extractor and atomic force microscopy, respectively. In general, the FSS stimulated cells showed stronger adhesion strength than the cells not exposed to FSS. The cell not exposed to FSS always exhibited greater nuclear stiffness than cortex stiffness, while after FSS treatment the cortex hardened and nucleus softened, where the round-shaped cell had a cortex that was more rigid than its nucleus. These results indicated that FSS influenced the biomechanics of circulating tumor cells, and elucidation of the mechanical responses to FSS might provide a deeper insight for cancer metastasis.
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Affiliation(s)
- Weiwei Li
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Sifeng Mao
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Mashooq Khan
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Qiang Zhang
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Qiushi Huang
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Shuo Feng
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Jin-Ming Lin
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
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10
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Balogh P, Bagchi P. Three-dimensional distribution of wall shear stress and its gradient in red cell-resolved computational modeling of blood flow in in vivo-like microvascular networks. Physiol Rep 2019; 7:e14067. [PMID: 31062494 PMCID: PMC6503071 DOI: 10.14814/phy2.14067] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 01/13/2023] Open
Abstract
Using a high-fidelity, 3D computational model of blood flow in microvascular networks, we provide the full 3D distribution of wall shear stress (WSS), and its gradient (WSSG), and quantify the influence of red blood cells (RBCs) on WSS and WSSG. The deformation and flow dynamics of the individual RBCs are accurately resolved in the model, while physiologically realistic microvascular networks comprised of multiple bifurcations, convergences, and tortuous vessels are considered. A strong heterogeneity in WSS and WSSG is predicted across the networks, with the highest WSS occurring in precapillary bifurcations and capillary vessels. 3D variations of WSS and WSSG are shown to occur due to both network morphology and the influence of RBCs. The RBCs increase the WSS by as much as three times compared to that when no RBCs are present, and the highest increase is observed in venules. WSSG also increases significantly, and high WSSGs occur over wider regions in the presence of RBCs. In most vessels, the circumferential component of WSSG is observed to be greater than the axial component in the presence of RBCs, while the opposite trend is observed when RBCs are not considered. These results underscore the important role of RBCs on WSS and WSSG that cannot be predicted by widely used 1D models of network blood flow. Furthermore, the subendothelium-scale variations of WSS and WSSG predicted by the present model have implications in terms of endothelial cell functions in the microvasculature.
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Affiliation(s)
- Peter Balogh
- Mechanical and Aerospace Engineering DepartmentRutgers, The State University of New JerseyPiscatawayNew Jersey
| | - Prosenjit Bagchi
- Mechanical and Aerospace Engineering DepartmentRutgers, The State University of New JerseyPiscatawayNew Jersey
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11
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Surya VN, Michalaki E, Fuller GG, Dunn AR. Lymphatic endothelial cell calcium pulses are sensitive to spatial gradients in wall shear stress. Mol Biol Cell 2019; 30:923-931. [PMID: 30811261 PMCID: PMC6589782 DOI: 10.1091/mbc.e18-10-0618] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cytosolic calcium (Ca2+) is a ubiquitous second messenger that influences numerous aspects of cellular function. In many cell types, cytosolic Ca2+ concentrations are characterized by periodic pulses, whose dynamics can influence downstream signal transduction. Here, we examine the general question of how cells use Ca2+ pulses to encode input stimuli in the context of the response of lymphatic endothelial cells (LECs) to fluid flow. Previous work shows that fluid flow regulates Ca2+ dynamics in LECs and that Ca2+-dependent signaling plays a key role in regulating lymphatic valve formation during embryonic development. However, how fluid flow might influence the Ca2+ pulse dynamics of individual LECs has remained, to our knowledge, little explored. We used live-cell imaging to characterize Ca2+ pulse dynamics in LECs exposed to fluid flow in an in vitro flow device that generates spatial gradients in wall shear stress (WSS), such as are found at sites of valve formation. We found that the frequency of Ca2+ pulses was sensitive to the magnitude of WSS, while the duration of individual Ca2+ pulses increased in the presence of spatial gradients in WSS. These observations provide an example of how cells can separately modulate Ca2+ pulse frequency and duration to encode distinct forms of information, a phenomenon that could extend to other cell types.
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Affiliation(s)
- Vinay N Surya
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | | | - Gerald G Fuller
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305
| | - Alexander R Dunn
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305.,Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA 94305
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12
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Surya VN, Michalaki E, Huang EY, Fuller GG, Dunn AR. Sphingosine 1-phosphate receptor 1 regulates the directional migration of lymphatic endothelial cells in response to fluid shear stress. J R Soc Interface 2017; 13:rsif.2016.0823. [PMID: 27974574 DOI: 10.1098/rsif.2016.0823] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 11/17/2016] [Indexed: 01/03/2023] Open
Abstract
The endothelial cells that line blood and lymphatic vessels undergo complex, collective migration and rearrangement processes during embryonic development, and are known to be exquisitely responsive to fluid flow. At present, the molecular mechanisms by which endothelial cells sense fluid flow remain incompletely understood. Here, we report that both the G-protein-coupled receptor sphingosine 1-phosphate receptor 1 (S1PR1) and its ligand sphingosine 1-phosphate (S1P) are required for collective upstream migration of human lymphatic microvascular endothelial cells in an in vitro setting. These findings are consistent with a model in which signalling via S1P and S1PR1 are integral components in the response of lymphatic endothelial cells to the stimulus provided by fluid flow.
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Affiliation(s)
- Vinay N Surya
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Eleftheria Michalaki
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Eva Y Huang
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Gerald G Fuller
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Alexander R Dunn
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA .,Stanford Cardiovascular Institute, Stanford University, Stanford, CA 94305, USA
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13
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Inukai N, Tanaka K, Takizawa T. A convenient technique for live-cell observation on the surface of polytetrafluoroethylene with a phase-contrast microscope. Microscopy (Oxf) 2017; 66:136-142. [PMID: 28423411 DOI: 10.1093/jmicro/dfw042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 09/02/2016] [Indexed: 11/14/2022] Open
Abstract
Phase-contrast microscopy is a convenient technique for live-cell observation on the surface of materials with high optical transmittance. Here, we demonstrate a novel technique to observe living cells on the surface of materials with low optical transmittance, such as polytetrafluoroethylene (PTFE), which are widely used in biomaterials for blood-contacting devices. The surface of a cover glass was coated with a thin PTFE layer with sufficient transmittance, thereby enabling the observation of living cells on the PTFE surface with a phase-contrast microscope.
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Affiliation(s)
- Naoto Inukai
- Graduate School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.,Nihon Chemical Coat Co. Ltd., 8-17-25 Seishin, Chuo-ku, Sagamihara, Kanagawa 252-0216, Japan
| | - Kazuaki Tanaka
- Graduate School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Tatsuya Takizawa
- Graduate School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
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Nakayama KH, Surya VN, Gole M, Walker T, Yang W, Lai ES, Ostrowski M, Fuller GG, Dunn AR, Huang NF. Nanoscale Patterning of Extracellular Matrix Alters Endothelial Function under Shear Stress. NANO LETTERS 2016; 16:410-419. [PMID: 26670737 PMCID: PMC4758680 DOI: 10.1021/acs.nanolett.5b04028] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The role of nanotopographical extracellular matrix (ECM) cues in vascular endothelial cell (EC) organization and function is not well-understood, despite the composition of nano- to microscale fibrillar ECMs within blood vessels. Instead, the predominant modulator of EC organization and function is traditionally thought to be hemodynamic shear stress, in which uniform shear stress induces parallel-alignment of ECs with anti-inflammatory function, whereas disturbed flow induces a disorganized configuration with pro-inflammatory function. Since shear stress acts on ECs by applying a mechanical force concomitant with inducing spatial patterning of the cells, we sought to decouple the effects of shear stress using parallel-aligned nanofibrillar collagen films that induce parallel EC alignment prior to stimulation with disturbed flow resulting from spatial wall shear stress gradients. Using real time live-cell imaging, we tracked the alignment, migration trajectories, proliferation, and anti-inflammatory behavior of ECs when they were cultured on parallel-aligned or randomly oriented nanofibrillar films. Intriguingly, ECs cultured on aligned nanofibrillar films remained well-aligned and migrated predominantly along the direction of aligned nanofibrils, despite exposure to shear stress orthogonal to the direction of the aligned nanofibrils. Furthermore, in stark contrast to ECs cultured on randomly oriented films, ECs on aligned nanofibrillar films exposed to disturbed flow had significantly reduced inflammation and proliferation, while maintaining intact intercellular junctions. This work reveals fundamental insights into the importance of nanoscale ECM interactions in the maintenance of endothelial function. Importantly, it provides new insight into how ECs respond to opposing cues derived from nanotopography and mechanical shear force and has strong implications in the design of polymeric conduits and bioengineered tissues.
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Affiliation(s)
- Karina H. Nakayama
- Stanford Cardiovascular Institute, Stanford, CA
- Department of Cardiothoracic Surgery, Stanford School of Medicine, Stanford, CA
- Veterans Affairs Palo Alto Health Care System, Palo Alto
| | - Vinay N. Surya
- Stanford Cardiovascular Institute, Stanford, CA
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, CA
| | - Monica Gole
- Veterans Affairs Palo Alto Health Care System, Palo Alto
| | - Travis Walker
- Department of Chemical Engineering, Oregon State University, Corvallis, OR
| | - Weiguang Yang
- Department of Pediatrics, Stanford School of Medicine, Stanford, CA
| | - Edwina S. Lai
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, CA
| | - Maggie Ostrowski
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, CA
| | - Gerald G. Fuller
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, CA
| | - Alexander R. Dunn
- Stanford Cardiovascular Institute, Stanford, CA
- Department of Chemical Engineering, Stanford University School of Engineering, Stanford, CA
| | - Ngan F. Huang
- Stanford Cardiovascular Institute, Stanford, CA
- Department of Cardiothoracic Surgery, Stanford School of Medicine, Stanford, CA
- Veterans Affairs Palo Alto Health Care System, Palo Alto
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