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Heng Y, Zheng X, Xu Y, Yan J, Li Y, Sun L, Yang H. Microfluidic device featuring micro-constrained channels for multi-parametric assessment of cellular biomechanics and high-precision mechanical phenotyping of gastric cells. Anal Chim Acta 2024; 1301:342472. [PMID: 38553127 DOI: 10.1016/j.aca.2024.342472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 03/12/2024] [Accepted: 03/12/2024] [Indexed: 04/02/2024]
Abstract
BACKGROUND Cellular biomechanics plays a significant role in the regulation of cellular physiological and pathological processes. In recent years, multiple methods have been developed to evaluate cellular biomechanics, such as atomic force microscopy (AFM), micropipette aspiration, and magnetic tweezers. However, most of these methods only focus on a single parameter and cannot automate the process at a high-efficiency level. A novel microfluidic method is necessary to achieve the simultaneous multi-parametric measurement of cellular biomechanics and high-precision cellular mechanical phenotyping at high throughput. RESULTS To tackle the issue concerning the low-throughput and cellular single-parameter evaluation, we designed and fabricated a microfluidic chip featuring multiple micro-constrained channels structure, providing a simultaneous multi-parametric assessment of cellular biomechanics, including elastic modulus, recovery capability, and deformability. We compared the biomechanical properties of normal human gastric mucosal epithelial cells (GES-1) and human gastric cancer cells (AGS and MKN-45) by the chip. Results demonstrated that the elastic modulus of GES-1, AGS, and MKN-45 cells decreased sequentially, which was the opposite of their invasiveness and metastasis potential, suggesting the inverse correlation between cellular elastic modulus and malignancy. Meanwhile, the recovery capability and deformability of GES-1, AGS, and MKN-45 cells increased sequentially, demonstrating the positive correlation between cellular deformability and malignancy. Furthermore, multiple parameters were used to distinguish gastric cancer cells from normal gastric cells via machine learning. An accuracy of over 94.8% for identifying gastric cancer cells was achieved. SIGNIFICANCE This study provides a deep insight into the biophysical mechanism of gastric cancer metastasis at the single-cell level and possesses great potential to function as a valuable tool for single-cell analysis, thereby facilitating high-precision and high-throughput discrimination of cellular phenotypes that are not easily discernible through single-marker analysis.
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Affiliation(s)
- Yang Heng
- Robotics and Microsystems Center, School of Mechanical and Electrical Engineering, Soochow University, Suzhou, 215000, China
| | - Xinyu Zheng
- Suzhou Medical College of Soochow University, Suzhou, 215000, China; Department of Hematology and Oncology, Children's Hospital of Soochow University, Suzhou, 215025, China
| | - Youyuan Xu
- Robotics and Microsystems Center, School of Mechanical and Electrical Engineering, Soochow University, Suzhou, 215000, China
| | - Jiaqi Yan
- Robotics and Microsystems Center, School of Mechanical and Electrical Engineering, Soochow University, Suzhou, 215000, China
| | - Ying Li
- Department of Mechanical and Electrical Engineering, Shenzhen Polytechnic University, Shenzhen, 518055, China.
| | - Lining Sun
- Robotics and Microsystems Center, School of Mechanical and Electrical Engineering, Soochow University, Suzhou, 215000, China
| | - Hao Yang
- Robotics and Microsystems Center, School of Mechanical and Electrical Engineering, Soochow University, Suzhou, 215000, China.
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Tervonen A, Korpela S, Nymark S, Hyttinen J, Ihalainen TO. The Effect of Substrate Stiffness on Elastic Force Transmission in the Epithelial Monolayers over Short Timescales. Cell Mol Bioeng 2023; 16:475-495. [PMID: 38099211 PMCID: PMC10716100 DOI: 10.1007/s12195-023-00772-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 06/26/2023] [Indexed: 12/17/2023] Open
Abstract
Purpose The importance of mechanical forces and microenvironment in guiding cellular behavior has been widely accepted. Together with the extracellular matrix (ECM), epithelial cells form a highly connected mechanical system subjected to various mechanical cues from their environment, such as ECM stiffness, and tensile and compressive forces. ECM stiffness has been linked to many pathologies, including tumor formation. However, our understanding of the effect of ECM stiffness and its heterogeneities on rapid force transduction in multicellular systems has not been fully addressed. Methods We used experimental and computational methods. Epithelial cells were cultured on elastic hydrogels with fluorescent nanoparticles. Single cells were moved by a micromanipulator, and epithelium and substrate deformation were recorded. We developed a computational model to replicate our experiments and quantify the force distribution in the epithelium. Our model further enabled simulations with local stiffness gradients. Results We found that substrate stiffness affects the force transduction and the cellular deformation following an external force. Also, our results indicate that the heterogeneities, e.g., gradients, in the stiffness can substantially influence the strain redistribution in the cell monolayers. Furthermore, we found that the cells' apico-basal elasticity provides a level of mechanical isolation between the apical cell-cell junctions and the basal focal adhesions. Conclusions Our simulation results show that increased ECM stiffness, e.g., due to a tumor, can mechanically isolate cells and modulate rapid mechanical signaling between cells over distances. Furthermore, the developed model has the potential to facilitate future studies on the interactions between epithelial monolayers and elastic substrates. Supplementary Information The online version of this article (10.1007/s12195-023-00772-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aapo Tervonen
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520 Tampere, Finland
- Department of Biological and Environmental Science, Faculty of Mathematics and Science, University of Jyväskylä, Survontie 9 C, 40500 Jyväskylä, Finland
| | - Sanna Korpela
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520 Tampere, Finland
| | - Soile Nymark
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520 Tampere, Finland
| | - Jari Hyttinen
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520 Tampere, Finland
| | - Teemu O. Ihalainen
- BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520 Tampere, Finland
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Xin Y, Li K, Huang M, Liang C, Siemann D, Wu L, Tan Y, Tang X. Biophysics in tumor growth and progression: from single mechano-sensitive molecules to mechanomedicine. Oncogene 2023; 42:3457-3490. [PMID: 37864030 PMCID: PMC10656290 DOI: 10.1038/s41388-023-02844-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 09/08/2023] [Accepted: 09/15/2023] [Indexed: 10/22/2023]
Abstract
Evidence from physical sciences in oncology increasingly suggests that the interplay between the biophysical tumor microenvironment and genetic regulation has significant impact on tumor progression. Especially, tumor cells and the associated stromal cells not only alter their own cytoskeleton and physical properties but also remodel the microenvironment with anomalous physical properties. Together, these altered mechano-omics of tumor tissues and their constituents fundamentally shift the mechanotransduction paradigms in tumorous and stromal cells and activate oncogenic signaling within the neoplastic niche to facilitate tumor progression. However, current findings on tumor biophysics are limited, scattered, and often contradictory in multiple contexts. Systematic understanding of how biophysical cues influence tumor pathophysiology is still lacking. This review discusses recent different schools of findings in tumor biophysics that have arisen from multi-scale mechanobiology and the cutting-edge technologies. These findings range from the molecular and cellular to the whole tissue level and feature functional crosstalk between mechanotransduction and oncogenic signaling. We highlight the potential of these anomalous physical alterations as new therapeutic targets for cancer mechanomedicine. This framework reconciles opposing opinions in the field, proposes new directions for future cancer research, and conceptualizes novel mechanomedicine landscape to overcome the inherent shortcomings of conventional cancer diagnosis and therapies.
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Grants
- R35 GM150812 NIGMS NIH HHS
- This work was financially supported by National Natural Science Foundation of China (Project no. 11972316, Y.T.), Shenzhen Science and Technology Innovation Commission (Project no. JCYJ20200109142001798, SGDX2020110309520303, and JCYJ20220531091002006, Y.T.), General Research Fund of Hong Kong Research Grant Council (PolyU 15214320, Y. T.), Health and Medical Research Fund (HMRF18191421, Y.T.), Hong Kong Polytechnic University (1-CD75, 1-ZE2M, and 1-ZVY1, Y.T.), the Cancer Pilot Research Award from UF Health Cancer Center (X. T.), the National Institute of General Medical Sciences of the National Institutes of Health under award number R35GM150812 (X. T.), the National Science Foundation under grant number 2308574 (X. T.), the Air Force Office of Scientific Research under award number FA9550-23-1-0393 (X. T.), the University Scholar Program (X. T.), UF Research Opportunity Seed Fund (X. T.), the Gatorade Award (X. T.), and the National Science Foundation REU Site at UF: Engineering for Healthcare (Douglas Spearot and Malisa Sarntinoranont). We are deeply grateful for the insightful discussions with and generous support from all members of Tang (UF)’s and Tan (PolyU)’s laboratories and all staff members of the MAE/BME/ECE/Health Cancer Center at UF and BME at PolyU.
- National Natural Science Foundation of China (National Science Foundation of China)
- Shenzhen Science and Technology Innovation Commission
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Affiliation(s)
- Ying Xin
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Keming Li
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Miao Huang
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, USA
| | - Chenyu Liang
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, USA
| | - Dietmar Siemann
- UF Health Cancer Center, University of Florida, Gainesville, FL, USA
| | - Lizi Wu
- UF Health Cancer Center, University of Florida, Gainesville, FL, USA
| | - Youhua Tan
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
- Research Institute of Smart Ageing, The Hong Kong Polytechnic University, Hong Kong, China.
| | - Xin Tang
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, USA.
- UF Health Cancer Center, University of Florida, Gainesville, FL, USA.
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, FL, USA.
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Wang X, Li N, Zhang Z, Qin K, Zhang H, Shao S, Liu B. Visualization of Cell Membrane Tension Regulated by the Microfilaments as a "Shock Absorber" in Micropatterned Cells. BIOLOGY 2023; 12:889. [PMID: 37372173 DOI: 10.3390/biology12060889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 06/17/2023] [Indexed: 06/29/2023]
Abstract
The extracellular stress signal transmits along the cell membrane-cytoskeleton-focal adhesions (FAs) complex, regulating the cell function through membrane tension. However, the mechanism of the complex regulating membrane tension is still unclear. This study designed polydimethylsiloxane stamps with specific shapes to change the actin filaments' arrangement and FAs' distribution artificially in live cells, visualized the membrane tension in real time, and introduced the concept of information entropy to describe the order degree of the actin filaments and plasma membrane tension. The results showed that the actin filaments' arrangement and FAs' distribution in the patterned cells were changed significantly. The hypertonic solution resulted in the plasma membrane tension of the pattern cell changing more evenly and slowly in the zone rich in cytoskeletal filaments than in the zone lacking filaments. In addition, the membrane tension changed less in the adhesive area than in the non-adhesive area when destroying the cytoskeletal microfilaments. This suggested that patterned cells accumulated more actin filaments in the zone where FAs were difficult to generate to maintain the stability of the overall membrane tension. The actin filaments act as shock absorbers to cushion the alternation in membrane tension without changing the final value of membrane tension.
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Affiliation(s)
- Xianmeng Wang
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
| | - Na Li
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
- Liaoning Key Laboratory of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China
| | - Zhengyao Zhang
- School of Life and Pharmaceutical Sciences, Dalian University of Technology, Panjin 124221, China
| | - Kairong Qin
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
| | - Hangyu Zhang
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
- Liaoning Key Laboratory of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China
| | - Shuai Shao
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
- Liaoning Key Laboratory of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China
| | - Bo Liu
- School of Biomedical Engineering, Faculty of Medicine, Dalian University of Technology, Dalian 116024, China
- Liaoning Key Laboratory of Integrated Circuit and Biomedical Electronic System, Dalian University of Technology, Dalian 116024, China
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Xie N, Xiao C, Shu Q, Cheng B, Wang Z, Xue R, Wen Z, Wang J, Shi H, Fan D, Liu N, Xu F. Cell response to mechanical microenvironment cues via Rho signaling: From mechanobiology to mechanomedicine. Acta Biomater 2023; 159:1-20. [PMID: 36717048 DOI: 10.1016/j.actbio.2023.01.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/10/2023] [Accepted: 01/17/2023] [Indexed: 01/30/2023]
Abstract
Mechanical cues in the cell microenvironment such as those from extracellular matrix properties, stretching, compression and shear stress, play a critical role in maintaining homeostasis. Upon sensing mechanical stimuli, cells can translate these external forces into intracellular biochemical signals to regulate their cellular behaviors, but the specific mechanisms of mechanotransduction at the molecular level remain elusive. As a subfamily of the Ras superfamily, Rho GTPases have been recognized as key intracellular mechanotransduction mediators that can regulate multiple cell activities such as proliferation, migration and differentiation as well as biological processes such as cytoskeletal dynamics, metabolism, and organ development. However, the upstream mechanosensors for Rho proteins and downstream effectors that respond to Rho signal activation have not been well illustrated. Moreover, Rho-mediated mechanical signals in previous studies are highly context-dependent. In this review, we systematically summarize the types of mechanical cues in the cell microenvironment and provide recent advances on the roles of the Rho-based mechanotransduction in various cell activities, physiological processes and diseases. Comprehensive insights into the mechanical roles of Rho GTPase partners would open a new paradigm of mechanomedicine for a variety of diseases. STATEMENT OF SIGNIFICANCE: In this review, we highlight the critical role of Rho GTPases as signal mediators to respond to physical cues in microenvironment. This article will add a distinct contribution to this set of knowledge by intensively addressing the relationship between Rho signaling and mechanobiology/mechanotransduction/mechanomedcine. This topic has not been discussed by the journal, nor has it yet been developed by the field. The comprehensive picture that will develop, from molecular mechanisms and engineering methods to disease treatment strategies, represents an important and distinct contribution to the field. We hope that this review would help researchers in various fields, especially clinicians, oncologists and bioengineers, who study Rho signal pathway and mechanobiology/mechanotransduction, understand the critical role of Rho GTPase in mechanotransduction.
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Affiliation(s)
- Ning Xie
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Cailan Xiao
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Qiuai Shu
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Bo Cheng
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Ziwei Wang
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Runxin Xue
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Zhang Wen
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Jinhai Wang
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Haitao Shi
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Daiming Fan
- State Key Laboratory of Cancer Biology and National Clinical Research Center for Digestive Diseases, Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an Shaanxi 710049, China.
| | - Na Liu
- Department of Gastroenterology, The Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
| | - Feng Xu
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China; The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
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Sahan AZ, Baday M, Patel CB. Biomimetic Hydrogels in the Study of Cancer Mechanobiology: Overview, Biomedical Applications, and Future Perspectives. Gels 2022; 8:gels8080496. [PMID: 36005097 PMCID: PMC9407355 DOI: 10.3390/gels8080496] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/26/2022] [Accepted: 07/02/2022] [Indexed: 11/18/2022] Open
Abstract
Hydrogels are biocompatible polymers that are tunable to the system under study, allowing them to be widely used in medicine, bioprinting, tissue engineering, and biomechanics. Hydrogels are used to mimic the three-dimensional microenvironment of tissues, which is essential to understanding cell–cell interactions and intracellular signaling pathways (e.g., proliferation, apoptosis, growth, and survival). Emerging evidence suggests that the malignant properties of cancer cells depend on mechanical cues that arise from changes in their microenvironment. These mechanobiological cues include stiffness, shear stress, and pressure, and have an impact on cancer proliferation and invasion. The hydrogels can be tuned to simulate these mechanobiological tissue properties. Although interest in and research on the biomedical applications of hydrogels has increased in the past 25 years, there is still much to learn about the development of biomimetic hydrogels and their potential applications in biomedical and clinical settings. This review highlights the application of hydrogels in developing pre-clinical cancer models and their potential for translation to human disease with a focus on reviewing the utility of such models in studying glioblastoma progression.
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Affiliation(s)
- Ayse Z. Sahan
- Biomedical Sciences Graduate Program, Department of Pharmacology, School of Medicine, University California at San Diego, 9500 Gilman Drive, San Diego, CA 92093, USA
| | - Murat Baday
- Department of Neurology and Neurological Sciences, School of Medicine, Stanford University, Stanford, CA 94305, USA
- Precision Health and Integrated Diagnostics Center, School of Medicine, Stanford University, Stanford, CA 94305, USA
- Correspondence: (M.B.); (C.B.P.)
| | - Chirag B. Patel
- Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Neuroscience Graduate Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences (GSBS), Houston, TX 77030, USA
- Cancer Biology Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences (GSBS), Houston, TX 77030, USA
- Correspondence: (M.B.); (C.B.P.)
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Rens EG, Edelstein-Keshet L. Cellular Tango: how extracellular matrix adhesion choreographs Rac-Rho signaling and cell movement. Phys Biol 2021; 18. [PMID: 34544056 DOI: 10.1088/1478-3975/ac2888] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 09/20/2021] [Indexed: 12/14/2022]
Abstract
The small GTPases Rac and Rho are known to regulate eukaryotic cell shape, promoting front protrusion (Rac) or rear retraction (Rho) of the cell edge. Such cell deformation changes the contact and adhesion of cell to the extracellular matrix (ECM), while ECM signaling through integrin receptors also affects GTPase activity. We develop and investigate a model for this three-way feedback loop in 1D and 2D spatial domains, as well as in a fully deforming 2D cell shapes with detailed adhesion-bond biophysics. The model consists of reaction-diffusion equations solved numerically with open-source software, Morpheus, and with custom-built cellular Potts model simulations. We find a variety of patterns and cell behaviors, including persistent polarity, flipped front-back cell polarity oscillations, spiral waves, and random protrusion-retraction. We show that the observed spatial patterns depend on the cell shape, and vice versa.
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Affiliation(s)
- Elisabeth G Rens
- Delft Institute of Applied Mathematics, Delft University of Technology, Delft, The Netherlands.,Department of Mathematics, University of British Columbia, Vancouver, Canada
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Amar K, Wei F, Chen J, Wang N. Effects of forces on chromatin. APL Bioeng 2021; 5:041503. [PMID: 34661040 PMCID: PMC8516479 DOI: 10.1063/5.0065302] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/27/2021] [Indexed: 12/29/2022] Open
Abstract
Chromatin is a unique structure of DNA and histone proteins in the cell nucleus and the site of dynamic regulation of gene expression. Soluble factors are known to affect the chromatin structure and function via activating or inhibiting specific transcription factors. Forces on chromatin come from exogenous stresses on the cell surface and/or endogenous stresses, which are regulated by substrate mechanics, geometry, and topology. Forces on chromatin involve direct (via adhesion molecules, cytoskeleton, and the linker of nucleoskeleton and cytoskeleton complexes) and indirect (via diffusion and/or translocation processes) signaling pathways to modulate levels of chromatin folding and deformation to regulate transcription, which is controlled by histone modifications and depends on magnitude, direction, rate/frequency, duration, and modes of stresses. The rapid force transmission pathway activates multiple genes simultaneously, and the force may act like a "supertranscription factor." The indirect mechanotransduction pathways and the rapid force transmission pathway together exert sustained impacts on the chromatin, the nucleus, and cell functions.
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Affiliation(s)
- Kshitij Amar
- Department of Mechanical Science and Engineering, The Grainger College of Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Fuxiang Wei
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Junwei Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Ning Wang
- Department of Mechanical Science and Engineering, The Grainger College of Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Chowdhury F, Huang B, Wang N. Cytoskeletal prestress: The cellular hallmark in mechanobiology and mechanomedicine. Cytoskeleton (Hoboken) 2021; 78:249-276. [PMID: 33754478 PMCID: PMC8518377 DOI: 10.1002/cm.21658] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022]
Abstract
Increasing evidence demonstrates that mechanical forces, in addition to soluble molecules, impact cell and tissue functions in physiology and diseases. How living cells integrate mechanical signals to perform appropriate biological functions is an area of intense investigation. Here, we review the evidence of the central role of cytoskeletal prestress in mechanotransduction and mechanobiology. Elevating cytoskeletal prestress increases cell stiffness and reinforces cell stiffening, facilitates long-range cytoplasmic mechanotransduction via integrins, enables direct chromatin stretching and rapid gene expression, spurs embryonic development and stem cell differentiation, and boosts immune cell activation and killing of tumor cells whereas lowering cytoskeletal prestress maintains embryonic stem cell pluripotency, promotes tumorigenesis and metastasis of stem cell-like malignant tumor-repopulating cells, and elevates drug delivery efficiency of soft-tumor-cell-derived microparticles. The overwhelming evidence suggests that the cytoskeletal prestress is the governing principle and the cellular hallmark in mechanobiology. The application of mechanobiology to medicine (mechanomedicine) is rapidly emerging and may help advance human health and improve diagnostics, treatment, and therapeutics of diseases.
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Affiliation(s)
- Farhan Chowdhury
- Department of Mechanical Engineering and Energy ProcessesSouthern Illinois University CarbondaleCarbondaleIllinoisUSA
| | - Bo Huang
- Department of Immunology, Institute of Basic Medical Sciences & State Key Laboratory of Medical Molecular BiologyChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Ning Wang
- Department of Mechanical Science and EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
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Michel JB. Phylogenic Determinants of Cardiovascular Frailty, Focus on Hemodynamics and Arterial Smooth Muscle Cells. Physiol Rev 2020; 100:1779-1837. [DOI: 10.1152/physrev.00022.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The evolution of the circulatory system from invertebrates to mammals has involved the passage from an open system to a closed in-parallel system via a closed in-series system, accompanying the increasing complexity and efficiency of life’s biological functions. The archaic heart enables pulsatile motion waves of hemolymph in invertebrates, and the in-series circulation in fish occurs with only an endothelium, whereas mural smooth muscle cells appear later. The present review focuses on evolution of the circulatory system. In particular, we address how and why this evolution took place from a closed, flowing, longitudinal conductance at low pressure to a flowing, highly pressurized and bifurcating arterial compartment. However, although arterial pressure was the latest acquired hemodynamic variable, the general teleonomy of the evolution of species is the differentiation of individual organ function, supported by specific fueling allowing and favoring partial metabolic autonomy. This was achieved via the establishment of an active contractile tone in resistance arteries, which permitted the regulation of blood supply to specific organ activities via its localized function-dependent inhibition (active vasodilation). The global resistance to viscous blood flow is the peripheral increase in frictional forces caused by the tonic change in arterial and arteriolar radius, which backscatter as systemic arterial blood pressure. Consequently, the arterial pressure gradient from circulating blood to the adventitial interstitium generates the unidirectional outward radial advective conductance of plasma solutes across the wall of conductance arteries. This hemodynamic evolution was accompanied by important changes in arterial wall structure, supported by smooth muscle cell functional plasticity, including contractility, matrix synthesis and proliferation, endocytosis and phagocytosis, etc. These adaptive phenotypic shifts are due to epigenetic regulation, mainly related to mechanotransduction. These paradigms actively participate in cardio-arterial pathologies such as atheroma, valve disease, heart failure, aneurysms, hypertension, and physiological aging.
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Garcia E, Ismail S. Spatiotemporal Regulation of Signaling: Focus on T Cell Activation and the Immunological Synapse. Int J Mol Sci 2020; 21:E3283. [PMID: 32384769 PMCID: PMC7247333 DOI: 10.3390/ijms21093283] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 01/22/2023] Open
Abstract
In a signaling network, not only the functions of molecules are important but when (temporal) and where (spatial) those functions are exerted and orchestrated is what defines the signaling output. To temporally and spatially modulate signaling events, cells generate specialized functional domains with variable lifetime and size that concentrate signaling molecules, enhancing their transduction potential. The plasma membrane is a key in this regulation, as it constitutes a primary signaling hub that integrates signals within and across the membrane. Here, we examine some of the mechanisms that cells exhibit to spatiotemporally regulate signal transduction, focusing on the early events of T cell activation from triggering of T cell receptor to formation and maturation of the immunological synapse.
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Affiliation(s)
- Esther Garcia
- CR-UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Shehab Ismail
- CR-UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
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12
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Bush J, Maruthamuthu V. In situ determination of exerted forces in magnetic pulling cytometry. AIP ADVANCES 2019; 9:035221. [PMID: 30915259 PMCID: PMC6417906 DOI: 10.1063/1.5084261] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/05/2019] [Indexed: 06/09/2023]
Abstract
Localized application of exogenous forces on soft biomaterials and cells is often essential for the study of their response to external mechanical stimuli. Magnetic means of applying forces, particularly those based on permanent magnets and magnetic beads coupled to substrates or cells provide an accessible means of exerting forces of appropriate magnitude. The amount of force exerted, however, is often inferred from calibration performed ex situ, with typically similar but different magnetic beads. Here, we construct a simple magnetic tweezer by coupling a pencil-shaped stainless-steel probe to permanent neodymium magnets using a 3D printed adapter. We then demonstrate the in situ determination of magnetic bead pulling forces on a super-paramagnetic micro-bead coupled to a soft substrate using traction force microscopy. We determine the force exerted on the magnetic bead by the magnet probe - and thus exerted by the magnetic bead on the soft polyacrylamide substrate - as a function of the distance between the probe tip and the magnetic bead. We also show that we can determine the force exerted on a magnetic bead coupled to a cell by the changes in the traction force exerted by the cell on the soft substrate beneath. We thus demonstrate that forces of nanonewton magnitude can be locally exerted on soft substrates or cells and simultaneously determined using traction force microscopy. Application of this method for the in situ measurement of localized exogenous forces exerted on cells can also enable dissection of cellular force transmission pathways.
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Affiliation(s)
- Joshua Bush
- Mechanical & Aerospace Engineering, Old Dominion University, Kaufman 238e, 1 Old Dominion University, Norfolk, Virginia 23529, USA
| | - Venkat Maruthamuthu
- Mechanical & Aerospace Engineering, Old Dominion University, Kaufman 238e, 1 Old Dominion University, Norfolk, Virginia 23529, USA
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13
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FRET biosensor allows spatio-temporal observation of shear stress-induced polar RhoGDIα activation. Commun Biol 2018; 1:224. [PMID: 30564745 PMCID: PMC6288100 DOI: 10.1038/s42003-018-0232-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 11/14/2018] [Indexed: 12/25/2022] Open
Abstract
Rho GDP-dissociation inhibitor α (RhoGDIα) is a known negative regulator of the Rho family that shuts off GDP/GTP cycling and cytoplasm/membrane translocation to regulate cell migration. However, to our knowledge, no reports are available that focus on how the RhoGDIα-Rho GTPases complex is activated by laminar flow through exploring the activation of RhoGDIα itself. Here, we constructed a new biosensor using fluorescence resonance energy transfer (FRET) technology to measure the spatio-temporal activation of RhoGDIα in its binding with Rho GTPases in living HeLa cells. Using this biosensor, we find that the dissociation of the RhoGDIα-Rho GTPases complex is increased by shear stress, and its dissociation rate varies with subcellular location. Moreover, this process is mediated by membrane fluidity, cytoskeleton and Src activity, which indicates that the regulation of RhoGDIα activation under shear stress application represents a relatively separate pathway from the shear stress-induced Rho pathway. Shuai Shao, Xiaoling Liao et al. present a new FRET biosensor for measuring the spatio-temporal activation of RhoGDIα upon binding Rho GTPases. They find that dissociation of the RhoGDIα-Rho GTPase complex is increased by shear stress and varies with subcellular location.
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14
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Basoli F, Giannitelli SM, Gori M, Mozetic P, Bonfanti A, Trombetta M, Rainer A. Biomechanical Characterization at the Cell Scale: Present and Prospects. Front Physiol 2018; 9:1449. [PMID: 30498449 PMCID: PMC6249385 DOI: 10.3389/fphys.2018.01449] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 09/24/2018] [Indexed: 12/12/2022] Open
Abstract
The rapidly growing field of mechanobiology demands for robust and reproducible characterization of cell mechanical properties. Recent achievements in understanding the mechanical regulation of cell fate largely rely on technological platforms capable of probing the mechanical response of living cells and their physico–chemical interaction with the microenvironment. Besides the established family of atomic force microscopy (AFM) based methods, other approaches include optical, magnetic, and acoustic tweezers, as well as sensing substrates that take advantage of biomaterials chemistry and microfabrication techniques. In this review, we introduce the available methods with an emphasis on the most recent advances, and we discuss the challenges associated with their implementation.
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Affiliation(s)
- Francesco Basoli
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | | | - Manuele Gori
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Pamela Mozetic
- Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital, Brno, Czechia
| | - Alessandra Bonfanti
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Marcella Trombetta
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Alberto Rainer
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy.,Institute for Photonics and Nanotechnologies, National Research Council, Rome, Italy
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15
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Li W, Yu X, Xie F, Zhang B, Shao S, Geng C, Aziz AUR, Liao X, Liu B. A Membrane-Bound Biosensor Visualizes Shear Stress-Induced Inhomogeneous Alteration of Cell Membrane Tension. iScience 2018; 7:180-190. [PMID: 30267679 PMCID: PMC6153118 DOI: 10.1016/j.isci.2018.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/10/2018] [Accepted: 09/03/2018] [Indexed: 01/10/2023] Open
Abstract
Cell membrane is the first medium from where a cell senses and responds to external stress stimuli. Exploring the tension changes in cell membrane will help us to understand intracellular force transmission. Here, a biosensor (named MSS) based on fluorescence resonance energy transfer is developed to visualize cell membrane tension. Validity of the biosensor is first verified for the detection of cell membrane tension. Results show a shear stress-induced heterogeneous distribution of membrane tension with the biosensor, which is strengthened by the disruption of microfilaments or enhancement of membrane fluidity, but weakened by the reduction of membrane fluidity or disruption of microtubules. These findings suggest that the MSS biosensor is a beneficial tool to visualize the changes and distribution of cell membrane tension. Besides, cell membrane tension does not display obvious polar distribution, indicating that cellular polarity changes do not first occur on the cell membrane during mechanical transmission. A FRET-based biosensor (named MSS) is developed to study cell membrane tension MSS is a beneficial tool to visualize the distribution of membrane tension Membrane tension is inhomogeneous in response to shear stress Membrane tension does not display polar distribution during mechanotransduction
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Affiliation(s)
- Wang Li
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China
| | - Xinlei Yu
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China
| | - Fei Xie
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China
| | - Baohong Zhang
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China
| | - Shuai Shao
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China
| | - Chunyang Geng
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China
| | - Aziz Ur Rehman Aziz
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China
| | - Xiaoling Liao
- Biomaterials and Live Cell Imaging Institute, Chongqing University of Science and Technology, Chongqing 400030, China
| | - Bo Liu
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, Dalian 116024, China.
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16
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Koride S, Loza AJ, Sun SX. Epithelial vertex models with active biochemical regulation of contractility can explain organized collective cell motility. APL Bioeng 2018; 2:031906. [PMID: 31069315 PMCID: PMC6324211 DOI: 10.1063/1.5023410] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 06/14/2018] [Indexed: 01/22/2023] Open
Abstract
Collective motions of groups of cells are observed in many biological settings such as embryo development, tissue formation, and cancer metastasis. To effectively model collective cell movement, it is important to incorporate cell specific features such as cell size, cell shape, and cell mechanics, as well as active behavior of cells such as protrusion and force generation, contractile forces, and active biochemical signaling mechanisms that regulate cell behavior. In this paper, we develop a comprehensive model of collective cell migration in confluent epithelia based on the vertex modeling approach. We develop a method to compute cell-cell viscous friction based on the vertex model and incorporate RhoGTPase regulation of cortical myosin contraction. Global features of collective cell migration are examined by computing the spatial velocity correlation function. As active cell force parameters are varied, we found rich dynamical behavior. Furthermore, we find that cells exhibit nonlinear phenomena such as contractile waves and vortex formation. Together our work highlights the importance of active behavior of cells in generating collective cell movement. The vertex modeling approach is an efficient and versatile approach to rigorously examine cell motion in the epithelium.
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Affiliation(s)
- Sarita Koride
- Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Andrew J Loza
- Department of Cell Biology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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17
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Kim Y, Meade SM, Chen K, Feng H, Rayyan J, Hess-Dunning A, Ereifej ES. Nano-Architectural Approaches for Improved Intracortical Interface Technologies. Front Neurosci 2018; 12:456. [PMID: 30065623 PMCID: PMC6056633 DOI: 10.3389/fnins.2018.00456] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/14/2018] [Indexed: 12/19/2022] Open
Abstract
Intracortical microelectrodes (IME) are neural devices that initially were designed to function as neuroscience tools to enable researchers to understand the nervous system. Over the years, technology that aids interfacing with the nervous system has allowed the ability to treat patients with a wide range of neurological injuries and diseases. Despite the substantial success that has been demonstrated using IME in neural interface applications, these implants eventually fail due to loss of quality recording signals. Recent strategies to improve interfacing with the nervous system have been inspired by methods that mimic the native tissue. This review focusses on one strategy in particular, nano-architecture, a term we introduce that encompasses the approach of roughening the surface of the implant. Various nano-architecture approaches have been hypothesized to improve the biocompatibility of IMEs, enhance the recording quality, and increase the longevity of the implant. This review will begin by introducing IME technology and discuss the challenges facing the clinical deployment of IME technology. The biological inspiration of nano-architecture approaches will be explained as well as leading fabrication methods used to create nano-architecture and their limitations. A review of the effects of nano-architecture surfaces on neural cells will be examined, depicting the various cellular responses to these modified surfaces in both in vitro and pre-clinical models. The proposed mechanism elucidating the ability of nano-architectures to influence cellular phenotype will be considered. Finally, the frontiers of next generation nano-architecture IMEs will be identified, with perspective given on the future impact of this interfacing approach.
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Affiliation(s)
- Youjoung Kim
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Seth M. Meade
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Keying Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - He Feng
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Jacob Rayyan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Allison Hess-Dunning
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
| | - Evon S. Ereifej
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
- Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, United States
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18
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Shao S, Xiang C, Qin K, ur Rehman Aziz A, Liao X, Liu B. Visualizing the spatiotemporal map of Rac activation in bovine aortic endothelial cells under laminar and disturbed flows. PLoS One 2017; 12:e0189088. [PMID: 29190756 PMCID: PMC5708838 DOI: 10.1371/journal.pone.0189088] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 11/17/2017] [Indexed: 01/07/2023] Open
Abstract
Disturbed flow can eliminate the alignment of endothelial cells in the direction of laminar flow, and significantly impacts on atherosclerosis in collateral arteries near the bifurcation and high curvature regions. While shear stress induced Rac polarity has been shown to play crucial roles in cell polarity and migration, little is known about the spatiotemporal map of Rac under disturbed flow, and the mechanism of flow-induced cell polarity still needs to be elucidated. In this paper, disturbed flow or laminar flow with 15 dyn/cm2 of average shear stress was applied on bovine aortic endothelial cells (BAECs) for 30 minutes. A genetically-encoded PAK-PBD-GFP reporter was transfected into BAECs to visualize the real-time activation of Rac in living cell under fluorescence microscope. The imaging of the fluorescence intensity was analyzed by Matlab and the normalized data was converted into 3D spatiotemporal map. Then the changes of data upon chemical interference were fitted with logistic curve to explore the rule and mechanism of Rac polarity under laminar or disturbed flow. A polarized Rac activation was observed at the downstream edge along the laminar flow, which was enhanced by benzol alcohol-enhanced membrane fluidity but inhibited by nocodazole-disrupted microtubules or cholesterol-inhibited membrane fluidity, while no obvious polarized Rac activation could be found upon disturbed flow application. It is concluded that disturbed flow inhibits the flow-induced Rac polarized activation, which is related to the interaction of cell membrane and cytoskeleton, especially the microtubules.
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Affiliation(s)
- Shuai Shao
- Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, China
- Mathematical Information Technology, Faculty of Information Technology, Department of Math, University of Jyvaskyla. Jyvaskyla, Finland
| | - Cheng Xiang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Kairong Qin
- Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, China
| | - Aziz ur Rehman Aziz
- Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, China
| | - Xiaoling Liao
- Biomaterials and Live Cell Imaging Institute, Chongqing University of Science and Technology, Chongqing, China
| | - Bo Liu
- Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, China
- * E-mail:
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19
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Matoba A, Matsuyama N, Shibata S, Masaki E, Emala CW, Mizuta K. The free fatty acid receptor 1 promotes airway smooth muscle cell proliferation through MEK/ERK and PI3K/Akt signaling pathways. Am J Physiol Lung Cell Mol Physiol 2017; 314:L333-L348. [PMID: 29097424 DOI: 10.1152/ajplung.00129.2017] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Obesity is a risk factor for asthma and influences airway hyperresponsiveness, which is in part modulated by airway smooth muscle proliferative remodeling. Plasma free fatty acids (FFAs) levels are elevated in obese individuals, and long-chain FFAs act as endogenous ligands for the free fatty acid receptor 1 (FFAR1), which couples to both Gq and Gi proteins. We examined whether stimulation of FFAR1 induces airway smooth muscle cell proliferation through classical MEK/ERK and/or phosphoinositide 3-kinase (PI3K)/Akt signaling pathways. The long-chain FFAs (oleic acid and linoleic acid) and a FFAR1 agonist (GW9508) induced human airway smooth muscle (HASM) cell proliferation, which was inhibited by the MEK inhibitor U0126 and the PI3K inhibitor LY294002 . The long-chain FFAs and GW9508 increased phosphorylation of ERK, Akt, and p70S6K in HASM cells and freshly isolated rat airway smooth muscle. Downregulation of FFAR1 in HASM cells by siRNA significantly attenuated oleic acid-induced phosphorylation of ERK and Akt. Oleic acid-induced ERK phosphorylation was blocked by either the Gαi-protein inhibitor pertussis toxin or U0126 and was partially inhibited by either the Gαq-specific inhibitor YM-254890 or the Gβγ signaling inhibitor gallein. Oleic acid significantly inhibited forskolin-stimulated cAMP activity, which was attenuated by pertussis toxin. Akt phosphorylation was inhibited by pertussis toxin, the ras inhibitor manumycin A, the Src inhibitor PP1, or LY294002 . Phosphorylation of p70S6K by oleic acid or GW9508 was significantly inhibited by LY294002 , U0126, and the mammalian target of rapamycin (mTOR) inhibitor rapamycin. In conclusion, the FFAR1 promoted airway smooth muscle cell proliferation and p70S6K phosphorylation through MEK/ERK and PI3K/Akt signaling pathways.
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Affiliation(s)
- Atsuko Matoba
- Department of Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry , Sendai , Japan
| | - Nao Matsuyama
- Department of Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry , Sendai , Japan
| | - Sumire Shibata
- Department of Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry , Sendai , Japan
| | - Eiji Masaki
- Department of Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry , Sendai , Japan
| | - Charles W Emala
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University , New York, New York
| | - Kentaro Mizuta
- Department of Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry , Sendai , Japan.,Department of Anesthesiology, College of Physicians and Surgeons of Columbia University , New York, New York
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20
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Baratchi S, Khoshmanesh K, Woodman OL, Potocnik S, Peter K, McIntyre P. Molecular Sensors of Blood Flow in Endothelial Cells. Trends Mol Med 2017; 23:850-868. [PMID: 28811171 DOI: 10.1016/j.molmed.2017.07.007] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/16/2017] [Accepted: 07/19/2017] [Indexed: 01/08/2023]
Abstract
Mechanical stress from blood flow has a significant effect on endothelial physiology, with a key role in initiating vasoregulatory signals. Disturbances in blood flow, such as in regions of disease-associated stenosis, arterial branch points, and sharp turns, can induce proatherogenic phenotypes in endothelial cells. The disruption of vascular homeostasis as a result of endothelial dysfunction may contribute to early and late stages of atherosclerosis, the underlying cause of coronary artery disease. In-depth knowledge of the mechanobiology of endothelial cells is essential to identifying mechanosensory complexes involved in the pathogenesis of atherosclerosis. In this review, we describe different blood flow patterns and summarize current knowledge on mechanosensory molecules regulating endothelial vasoregulatory functions, with clinical implications. Such information may help in the search for novel therapeutic approaches.
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Affiliation(s)
- Sara Baratchi
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia; Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia.
| | | | - Owen L Woodman
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia
| | - Simon Potocnik
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia
| | - Karlheinz Peter
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia; Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Peter McIntyre
- School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC 3083, Australia
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21
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Interfacing 3D magnetic twisting cytometry with confocal fluorescence microscopy to image force responses in living cells. Nat Protoc 2017; 12:1437-1450. [PMID: 28686583 DOI: 10.1038/nprot.2017.042] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cells and tissues can undergo a variety of biological and structural changes in response to mechanical forces. Only a few existing techniques are available for quantification of structural changes at high resolution in response to forces applied along different directions. 3D-magnetic twisting cytometry (3D-MTC) is a technique for applying local mechanical stresses to living cells. Here we describe a protocol for interfacing 3D-MTC with confocal fluorescence microscopy. In 3D-MTC, ferromagnetic beads are bound to the cell surface via surface receptors, followed by their magnetization in any desired direction. A magnetic twisting field in a different direction is then applied to generate rotational shear stresses in any desired direction. This protocol describes how to combine magnetic-field-induced mechanical stimulation with confocal fluorescence microscopy and provides an optional extension for super-resolution imaging using stimulated emission depletion (STED) nanoscopy. This technology allows for rapid real-time acquisition of a living cell's mechanical responses to forces via specific receptors and for quantifying structural and biochemical changes in the same cell using confocal fluorescence microscopy or STED. The integrated 3D-MTC-microscopy platform takes ∼20 d to construct, and the experimental procedures require ∼4 d when carried out by a life sciences graduate student.
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22
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Abstract
Living cells and tissues experience physical forces and chemical stimuli in a human body. The process of converting mechanical forces into biochemical activities and gene expression is mechanochemical transduction or mechanotransduction. Significant advances have been made in understanding mechanotransduction at cellular and molecular levels over the last two decades. However, major challenges remain in elucidating how a living cell integrates signals from mechanotransduction with chemical signals to regulate gene expression and to generate coherent biological responses in living tissues in physiological conditions and diseases.
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Affiliation(s)
- Ning Wang
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; Department of Mechanical Science and Engineering, College of Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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23
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Tamiello C, Halder M, Kamps MAF, Baaijens FPT, Broers JLV, Bouten CVC. Cellular strain avoidance is mediated by a functional actin cap - observations in an Lmna-deficient cell model. J Cell Sci 2017; 130:779-790. [PMID: 28062850 DOI: 10.1242/jcs.184838] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 12/29/2016] [Indexed: 01/18/2023] Open
Abstract
In adherent cells, the relevance of a physical mechanotransduction pathway provided by the perinuclear actin cap stress fibers has recently emerged. Here, we investigate the impact of a functional actin cap on the cellular adaptive response to topographical cues and uniaxial cyclic strain. Lmna-deficient fibroblasts are used as a model system because they do not develop an intact actin cap, but predominantly form a basal layer of actin stress fibers underneath the nucleus. We observe that topographical cues induce alignment in both normal and Lmna-deficient fibroblasts, suggesting that the topographical signal transmission occurs independently of the integrity of the actin cap. By contrast, in response to cyclic uniaxial strain, Lmna-deficient cells show a compromised strain avoidance response, which is completely abolished when topographical cues and uniaxial strain are applied along the same direction. These findings point to the importance of an intact and functional actin cap in mediating cellular strain avoidance.
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Affiliation(s)
- Chiara Tamiello
- Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands
| | - Maurice Halder
- Department of Molecular Cell Biology, CARIM School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, Maastricht 6200 MD, The Netherlands
| | - Miriam A F Kamps
- Department of Molecular Cell Biology, GROW - School for Oncology & Developmental Biology, Maastricht University, P.O. Box 616, Maastricht 6200 MD, The Netherlands
| | - Frank P T Baaijens
- Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands
| | - Jos L V Broers
- Department of Molecular Cell Biology, CARIM School for Cardiovascular Diseases, Maastricht University, P.O. Box 616, Maastricht 6200 MD, The Netherlands
| | - Carlijn V C Bouten
- Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands
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24
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Tajik A, Zhang Y, Wei F, Sun J, Jia Q, Zhou W, Singh R, Khanna N, Belmont AS, Wang N. Transcription upregulation via force-induced direct stretching of chromatin. NATURE MATERIALS 2016; 15:1287-1296. [PMID: 27548707 PMCID: PMC5121013 DOI: 10.1038/nmat4729] [Citation(s) in RCA: 373] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 07/14/2016] [Indexed: 05/02/2023]
Abstract
Mechanical forces play critical roles in the function of living cells. However, the underlying mechanisms of how forces influence nuclear events remain elusive. Here, we show that chromatin deformation as well as force-induced transcription of a green fluorescent protein (GFP)-tagged bacterial-chromosome dihydrofolate reductase (DHFR) transgene can be visualized in a living cell by using three-dimensional magnetic twisting cytometry to apply local stresses on the cell surface via an Arg-Gly-Asp-coated magnetic bead. Chromatin stretching depended on loading direction. DHFR transcription upregulation was sensitive to load direction and proportional to the magnitude of chromatin stretching. Disrupting filamentous actin or inhibiting actomyosin contraction abrogated or attenuated force-induced DHFR transcription, whereas activating endogenous contraction upregulated force-induced DHFR transcription. Our findings suggest that local stresses applied to integrins propagate from the tensed actin cytoskeleton to the LINC complex and then through lamina-chromatin interactions to directly stretch chromatin and upregulate transcription.
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Affiliation(s)
- Arash Tajik
- Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 China
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Yuejin Zhang
- Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 China
| | - Fuxiang Wei
- Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 China
| | - Jian Sun
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Qiong Jia
- Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 China
| | - Wenwen Zhou
- Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 China
| | - Rishi Singh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Nimish Khanna
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Andrew S. Belmont
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Send correspondence to: Dr. Ning Wang at or Dr. Andrew Belmont at
| | - Ning Wang
- Department of Biomedical Engineering, School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 China
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
- Send correspondence to: Dr. Ning Wang at or Dr. Andrew Belmont at
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25
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Peñalver Bernabé B, Shin S, Rios PD, Broadbelt LJ, Shea LD, Seidlits SK. Dynamic transcription factor activity networks in response to independently altered mechanical and adhesive microenvironmental cues. Integr Biol (Camb) 2016; 8:844-60. [PMID: 27470442 DOI: 10.1039/c6ib00093b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Multiple aspects of the local extracellular environment profoundly affect cell phenotype and function. Physical and chemical cues in the environment trigger intracellular signaling cascades that ultimately activate transcription factors (TFs) - powerful regulators of the cell phenotype. TRACER (TRanscriptional Activity CEll aRrays) was employed for large-scale, dynamic quantification of TF activity in human fibroblasts cultured on hydrogels with a controlled elastic modulus and integrin ligand density. We identified three groups of TFs: responders to alterations in ligand density alone, substrate stiffness or both. Dynamic networks of regulatory TFs were constructed computationally and revealed distinct TF activity levels, directionality (i.e., activation or inhibition), and dynamics for adhesive and mechanical cues. Moreover, TRACER networks predicted conserved hubs of TF activity across multiple cell types, which are significantly altered in clinical fibrotic tissues. Our approach captures the distinct and overlapping effects of adhesive and mechanical stimuli, identifying conserved signaling mechanisms in normal and disease states.
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26
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Siedlik MJ, Varner VD, Nelson CM. Pushing, pulling, and squeezing our way to understanding mechanotransduction. Methods 2016; 94:4-12. [PMID: 26318086 PMCID: PMC4761538 DOI: 10.1016/j.ymeth.2015.08.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/23/2015] [Accepted: 08/25/2015] [Indexed: 01/28/2023] Open
Abstract
Mechanotransduction is often described in the context of force-induced changes in molecular conformation, but molecular-scale mechanical stimuli arise in vivo in the context of complex, multicellular tissue structures. For this reason, we highlight and review experimental methods for investigating mechanotransduction across multiple length scales. We begin by discussing techniques that probe the response of individual molecules to applied force. We then move up in length scale to highlight techniques aimed at uncovering how cells transduce mechanical stimuli into biochemical activity. Finally, we discuss approaches for determining how these stimuli arise in multicellular structures. We expect that future work will combine techniques across these length scales to provide a more comprehensive understanding of mechanotransduction.
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Affiliation(s)
- Michael J Siedlik
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, United States
| | - Victor D Varner
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, United States
| | - Celeste M Nelson
- Department of Chemical & Biological Engineering, Princeton University, Princeton, NJ 08544, United States; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, United States.
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27
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Marjoram RJ, Guilluy C, Burridge K. Using magnets and magnetic beads to dissect signaling pathways activated by mechanical tension applied to cells. Methods 2016; 94:19-26. [PMID: 26427549 PMCID: PMC4761479 DOI: 10.1016/j.ymeth.2015.09.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 08/21/2015] [Accepted: 09/27/2015] [Indexed: 12/29/2022] Open
Abstract
Cellular tension has implications in normal biology and pathology. Membrane adhesion receptors serve as conduits for mechanotransduction that lead to cellular responses. Ligand-conjugated magnetic beads are a useful tool in the study of how cells sense and respond to tension. Here we detail methods for their use in applying tension to cells and strategies for analyzing the results. We demonstrate the methods by analyzing mechanotransduction through VE-cadherin on endothelial cells using both permanent magnets and magnetic tweezers.
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Affiliation(s)
- R J Marjoram
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599-7295, United States.
| | - C Guilluy
- Inserm UMR_S1087, CNRS UMR_C6291, L'institut du Thorax, Nantes, France; Université de Nantes, Nantes, France
| | - K Burridge
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599-7295, United States; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599-7295, United States; McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599-7295, United States
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28
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Abstract
Cells that undergo epithelial-to-mesenchymal transitions (EMTs) commonly switch from expressing E-cadherin to N-cadherin. But why this occurs is not well understood. In the current issue of Developmental Cell, Scarpa et al. (2015) identify a reason: cadherin switching controls Rac signaling to determine how cell locomotion is regulated by contact.
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Affiliation(s)
- Rashmi Priya
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Alpha S Yap
- Division of Cell Biology and Molecular Medicine, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
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29
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Xu W, Wan Q, Na S, Yokota H, Yan JL, Hamamura K. Suppressed invasive and migratory behaviors of SW1353 chondrosarcoma cells through the regulation of Src, Rac1 GTPase, and MMP13. Cell Signal 2015; 27:2332-42. [PMID: 26303573 DOI: 10.1016/j.cellsig.2015.08.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 10/23/2022]
Abstract
Chondrosarcoma is the second frequent type of primary bone cancer. In response to stress to the endoplasmic reticulum, activation of eIF2α-mediated signaling is reported to induce apoptosis. However, its effects on invasive and migratory behaviors of chondrosarcoma have not been understood. Focusing on potential roles of Src kinase, Rac1 GTPase, and MMP13, we investigated eIF2α-driven regulation of SW1353 chondrosarcoma cells. In particular, we employed two chemical agents (salubrinal, Sal; and guanabenz, Gu) that elevate the level of eIF2α phosphorylation. The result revealed that both Sal and Gu reduced invasion and motility of SW1353 chondrosarcoma cells in a dose dependent manner. Live imaging using a fluorescent resonance energy transfer (FRET) technique showed that Sal and Gu downregulated activities of Src kinase as well as Rac1 GTPase in an eIF2α dependent manner. RNA interference experiments supported an eIF2α-mediated regulatory network in the inhibitory role of Sal and Gu. Partial silencing of MMP13 also suppressed malignant phenotypes of SW1353 chondrosarcoma cells. However, MMP13 was not regulated via eIF2α since administration of Sal but not Gu reduced expression of MMP13. In summary, we demonstrate that eIF2α dependent and independent pathways regulate invasion and motility of SW1353 chondrosarcoma cells, and inactivation of Src, Rac1, and MMP13 by Sal could provide a potential adjuvant therapy for combating metastatic chondrosarcoma cells.
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Affiliation(s)
- Wenxiao Xu
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA; Department of Orthopedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China
| | - Qiaoqiao Wan
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Sungsoo Na
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Hiroki Yokota
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA; Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202 USA
| | - Jing-Long Yan
- Department of Orthopedics, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150086, China.
| | - Kazunori Hamamura
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN 46202, USA; Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, Nagoya 464-8650, Japan.
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30
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Model of cellular mechanotransduction via actin stress fibers. Biomech Model Mechanobiol 2015; 15:331-44. [PMID: 26081725 DOI: 10.1007/s10237-015-0691-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/04/2015] [Indexed: 10/24/2022]
Abstract
Mechanical stresses due to blood flow regulate vascular endothelial cell structure and function and play a key role in arterial physiology and pathology. In particular, the development of atherosclerosis has been shown to correlate with regions of disturbed blood flow where endothelial cells are round and have a randomly organized cytoskeleton. Thus, deciphering the relation between the mechanical environment, cell structure, and cell function is a key step toward understanding the early development of atherosclerosis. Recent experiments have demonstrated very rapid (∼100 ms) and long-distance (∼10 μm) cellular mechanotransduction in which prestressed actin stress fibers play a critical role. Here, we develop a model of mechanical signal transmission within a cell by describing strains in a network of prestressed viscoelastic stress fibers following the application of a force to the cell surface. We find force transmission dynamics that are consistent with experimental results. We also show that the extent of stress fiber alignment and the direction of the applied force relative to this alignment are key determinants of the efficiency of mechanical signal transmission. These results are consistent with the link observed experimentally between cytoskeletal organization, mechanical stress, and cellular responsiveness to stress. Based on these results, we suggest that mechanical strain of actin stress fibers under force constitutes a key link in the mechanotransduction chain.
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31
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Taylor-Weiner H, Ravi N, Engler AJ. Traction forces mediated by integrin signaling are necessary for definitive endoderm specification. J Cell Sci 2015; 128:1961-8. [PMID: 25908864 DOI: 10.1242/jcs.166157] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/24/2015] [Indexed: 12/28/2022] Open
Abstract
Pluripotent embryonic stem cells (ESCs) exert low-traction forces on their niche in vitro whereas specification to definitive endoderm in vivo coincides with force-mediated motility, suggesting a differentiation-mediated switch. However, the onset of contractility and extent to which force-mediated integrin signaling regulates fate choices is not understood. To address the requirement of tractions forces for differentiation, we examined mouse embryonic stem cell (ESC) specification towards definitive endoderm on fibrillar fibronectin containing a deformation-sensitive FRET probe. Inhibiting contractility resulted in an increase in the observed fibronectin FRET intensity ratio but also decreased the amount of phosphorylated nuclear SMAD2, leading to reduced expression of the definitive endoderm marker SOX17. By contrast ESCs maintained in pluripotency medium did not exert significant tractions against the fibronectin matrix. When laminin-111 was added to fibrillar matrices to improve the efficiency of definitive endoderm induction, ESCs decreased their fibronectin traction forces in a laminin-dependent manner; blocking the laminin-binding α3-integrin restored fibronectin matrix deformation and reduced SOX17 expression and SMAD2 phosphorylation, probably because of compensation of inhibitory signaling from SMAD7 after 5 days in culture. These data imply that traction forces and integrin signaling are important regulators of early fate decisions in ESCs.
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Affiliation(s)
- Hermes Taylor-Weiner
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Neeraja Ravi
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Adam J Engler
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA Biomedical Sciences Program, University of California, San Diego, La Jolla, CA 92093, USA
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32
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Sylow L, Møller LLV, Kleinert M, Richter EA, Jensen TE. Stretch-stimulated glucose transport in skeletal muscle is regulated by Rac1. J Physiol 2015; 593:645-56. [PMID: 25416624 DOI: 10.1113/jphysiol.2014.284281] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 11/13/2014] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Rac1 regulates stretch-stimulated (i.e. mechanical stress) glucose transport in muscle. Actin depolymerization decreases stretch-induced glucose transport in skeletal muscle. Rac1 is a required part of the mechanical stress-component of the contraction-stimulus to glucose transport in skeletal muscle. ABSTRACT An alternative to the canonical insulin signalling pathway for glucose transport is muscle contraction/exercise. Mechanical stress is an integrated part of the muscle contraction/relaxation cycle, and passive stretch stimulates muscle glucose transport. However, the signalling mechanism regulating stretch-stimulated glucose transport is not well understood. We recently reported that the actin cytoskeleton regulating GTPase, Rac1, was activated in mouse muscle in response to stretching. Rac1 is a regulator of contraction- and insulin-stimulated glucose transport, however, its role in stretch-stimulated glucose transport and signalling is unknown. We therefore investigated whether stretch-induced glucose transport in skeletal muscle required Rac1 and the actin cytoskeleton. We used muscle-specific inducible Rac1 knockout mice as well as pharmacological inhibitors of Rac1 and the actin cytoskeleton in isolated soleus and extensor digitorum longus muscles. In addition, the role of Rac1 in contraction-stimulated glucose transport during conditions without mechanical load on the muscles was evaluated in loosely hanging muscles and muscles in which cross-bridge formation was blocked by the myosin ATPase inhibitors BTS and Blebbistatin. Knockout as well as pharmacological inhibition of Rac1 reduced stretch-stimulated glucose transport by 30-50% in soleus and extensor digitorum longus muscle. The actin depolymerizing agent latrunculin B similarly decreased glucose transport in response to stretching by 40-50%. Rac1 inhibition reduced contraction-stimulated glucose transport by 30-40% in tension developing muscle but did not affect contraction-stimulated glucose transport in muscles in which force development was prevented. Our findings suggest that Rac1 and the actin cytoskeleton regulate stretch-stimulated glucose transport and that Rac1 is a required part of the mechanical stress-component of the contraction-stimulus to glucose transport in skeletal muscle.
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Affiliation(s)
- Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
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33
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Tian X, Tian Y, Gawlak G, Meng F, Kawasaki Y, Akiyama T, Birukova AA. Asef controls vascular endothelial permeability and barrier recovery in the lung. Mol Biol Cell 2014; 26:636-50. [PMID: 25518936 PMCID: PMC4325835 DOI: 10.1091/mbc.e14-02-0725] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
This is the first report of Asef involvement in the regulation of endothelial vascular permeability in vitro and in vivo. Asef activation in endothelial cells by hepatocyte growth factor suppressed the Rho-dependent pathway of agonist-induced endothelial permeability and promoted Rac1-dependent endothelial barrier recovery. Increased levels of hepatocyte growth factor (HGF) in injured lungs may reflect a compensatory response to diminish acute lung injury (ALI). HGF-induced activation of Rac1 GTPase stimulates endothelial barrier protective mechanisms. This study tested the involvement of Rac-specific guanine nucleotide exchange factor Asef in HGF-induced endothelial cell (EC) cytoskeletal dynamics and barrier protection in vitro and in a two-hit model of ALI. HGF induced membrane translocation of Asef and stimulated Asef Rac1-specific nucleotide exchange activity. Expression of constitutively activated Asef mutant mimicked HGF-induced peripheral actin cytoskeleton enhancement. In contrast, siRNA-induced Asef knockdown or expression of dominant-negative Asef attenuated HGF-induced Rac1 activation evaluated by Rac-GTP pull down and FRET assay with Rac1 biosensor. Molecular inhibition of Asef attenuated HGF-induced peripheral accumulation of cortactin, formation of lamellipodia-like structures, and enhancement of VE-cadherin adherens junctions and compromised HGF-protective effect against thrombin-induced RhoA GTPase activation, Rho-dependent cytoskeleton remodeling, and EC permeability. Intravenous HGF injection attenuated lung inflammation and vascular leak in the two-hit model of ALI induced by excessive mechanical ventilation and thrombin signaling peptide TRAP6. This effect was lost in Asef−/− mice. This study shows for the first time the role of Asef in HGF-mediated protection against endothelial hyperpermeability and lung injury.
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Affiliation(s)
- Xinyong Tian
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Yufeng Tian
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Grzegorz Gawlak
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Fanyong Meng
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Yoshihiro Kawasaki
- Laboratory of Molecular and Genetic Information, Institute for Molecular and Cellular Biosciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Tetsu Akiyama
- Laboratory of Molecular and Genetic Information, Institute for Molecular and Cellular Biosciences, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Anna A Birukova
- Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637
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34
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Liu B, Lu S, Hu YL, Liao X, Ouyang M, Wang Y. RhoA and membrane fluidity mediates the spatially polarized Src/FAK activation in response to shear stress. Sci Rep 2014; 4:7008. [PMID: 25387906 PMCID: PMC4228346 DOI: 10.1038/srep07008] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 10/07/2014] [Indexed: 01/05/2023] Open
Abstract
While Src plays crucial roles in shear stress-induced cellular processes, little is known on the spatiotemporal pattern of high shear stress (HSS)-induced Src activation. HSS (65 dyn/cm2) was applied on bovine aortic endothelial cells to visualize the dynamic Src activation at subcellular levels utilizing a membrane-targeted Src biosensor (Kras-Src) based on fluorescence resonance energy transfer (FRET). A polarized Src activation was observed with higher activity at the side facing the flow, which was enhanced by a cytochalasin D-mediated disruption of actin filaments but inhibited by a benzyl alcohol-mediated enhancement of membrane fluidity. Further experiments revealed that HSS decreased RhoA activity, with a constitutively active RhoA mutant inhibiting while a negative RhoA mutant enhancing the HSS-induced Src polarity. Cytochalasin D can restore the polarity in cells expressing the active RhoA mutant. Further results indicate that HSS stimulates FAK activation with a spatial polarity similar to Src. The inhibition of Src by PP1, as well as the perturbation of RhoA activity and membrane fluidity, can block this HSS-induced FAK polarity. These results indicate that the HSS-induced Src and subsequently FAK polarity depends on the coordination between intracellular tension distribution regulated by RhoA, its related actin structures and the plasma membrane fluidity.
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Affiliation(s)
- Bo Liu
- 1] Department of Biomedical Engineering, Dalian University of Technology, Dalian, Liaoning Province, 116024, P. R. China [2] Department of Bioengineering and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shaoying Lu
- Department of Bioengineering, University of California at San Diego, CA 92093, USA
| | - Ying-li Hu
- Department of Bioengineering, University of California at San Diego, CA 92093, USA
| | - Xiaoling Liao
- 1] Department of Bioengineering and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA [2] Biomaterials and Live Cell Imaging Institute, Chongqing University of Science and Technology, Chongqing, 401331, P. R. China
| | - Mingxing Ouyang
- Department of Bioengineering, University of California at San Diego, CA 92093, USA
| | - Yingxiao Wang
- 1] Department of Bioengineering and the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA [2] Department of Integrative and Molecular Physiology, Center for Biophysics and Computational Biology, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA [3] Department of Bioengineering, University of California at San Diego, CA 92093, USA
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35
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Liu YS, Lee OK. In search of the pivot point of mechanotransduction: mechanosensing of stem cells. Cell Transplant 2014; 23:1-11. [PMID: 24439034 DOI: 10.3727/096368912x659925] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Stem cells are undifferentiated cells with the ability to self-renew and to differentiate into diverse specialized cell types; hence, they have great potential in tissue engineering and cell therapies. In addition to biochemical regulation, the physical properties of the microenvironments, such as scaffold topography, substrate stiffness, and mechanical forces, including fluid shear stress, compression, and tensile strain, can also regulate the proliferation and differentiation of stem cells. Upon physical stimuli, cytoskeleton rearrangements are expected to counterbalance the extracellular mechanical forces, trigger signaling cascades, and eventually cause epigenetic modifications. This article mainly focuses on the mechanosensing, which is the upstream event of stem cell mechanotransduction and the downstream one of physical stimuli. Putative mechanosensors such as ion channels, integrins, and cell membrane as well as primary cilia are discussed. Because mechanical environment is an important stem cell niche, identification of mechanosensors not only can elucidate the mechanisms of mechanotransduction and fate commitments but also bring new prospects of the mechanical control as well as drug development for clinical application.
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Affiliation(s)
- Yi-Shiuan Liu
- Stem Cell Research Center, National Yang-Ming University, Taipei, Taiwan
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36
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Sylow L, Møller LLV, Kleinert M, Richter EA, Jensen TE. Rac1--a novel regulator of contraction-stimulated glucose uptake in skeletal muscle. Exp Physiol 2014; 99:1574-80. [PMID: 25239922 DOI: 10.1113/expphysiol.2014.079194] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Muscle contraction stimulates muscle glucose uptake by facilitating translocation of glucose transporter 4 from intracellular locations to the cell surface, which allows for diffusion of glucose into the myofibres. The intracellular mechanisms regulating this process are not well understood. The GTPase Rac1 has, until recently, been investigated only with regard to its involvement in insulin-stimulated glucose uptake. However, we recently found that Rac1 is activated during muscle contraction and exercise in mice and humans. Remarkably, Rac1 seems to be necessary for exercise and contraction-stimulated glucose uptake in skeletal muscle, because muscle-specific Rac1 knockout mice display reduced ex vivo contraction- and in vivo exercise-stimulated glucose uptake. The molecular mechanism by which Rac1 regulates glucose uptake is presently unknown. However, recent studies link Rac1 to the actin cytoskeleton, the small GTPase RalA and/or free radical production, which have previously been shown to be regulators of glucose uptake in muscle. We propose a model in which Rac1 is activated by contraction- and exercise-induced mechanical stress signals and that Rac1 in conjunction with other signalling regulates glucose uptake during muscle contraction and exercise.
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Affiliation(s)
- Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Lisbeth L V Møller
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Maximilian Kleinert
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
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37
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Wan Q, Xu W, Yan JL, Yokota H, Na S. Distinctive subcellular inhibition of cytokine-induced SRC by salubrinal and fluid flow. PLoS One 2014; 9:e105699. [PMID: 25157407 PMCID: PMC4144888 DOI: 10.1371/journal.pone.0105699] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/23/2014] [Indexed: 12/17/2022] Open
Abstract
A non-receptor protein kinase Src plays a crucial role in fundamental cell functions such as proliferation, migration, and differentiation. While inhibition of Src is reported to contribute to chondrocyte homeostasis, its regulation at a subcellular level by chemical inhibitors and mechanical stimulation has not been fully understood. In response to inflammatory cytokines and stress to the endoplasmic reticulum (ER) that increase proteolytic activities in chondrocytes, we addressed two questions: Do cytokines such as interleukin 1 beta (IL1β) and tumor necrosis factor alpha (TNFα) induce location-dependent Src activation? Can cytokine-induced Src activation be suppressed by chemically alleviating ER stress or by applying fluid flow? Using live cell imaging with two Src biosensors (i.e., cytosolic, and plasma membrane-bound biosensors) for a fluorescence resonance energy transfer (FRET) technique, we determined cytosolic Src activity as well as membrane-bound Src activity in C28/I2 human chondrocytes. In response to TNFα and IL1β, both cytosolic and plasma membrane-bound Src proteins were activated, but activation in the cytosol occurred earlier than that in the plasma membrane. Treatment with salubrinal or guanabenz, two chemical agents that attenuate ER stress, significantly decreased cytokine-induced Src activities in the cytosol, but not in the plasma membrane. In contrast, fluid flow reduced Src activities in the plasma membrane, but not in the cytosol. Collectively, the results demonstrate that Src activity is differentially regulated by salubrinal/guanabenz and fluid flow in the cytosol and plasma membrane.
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Affiliation(s)
- Qiaoqiao Wan
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
| | - Wenxiao Xu
- Department of Orthopedics, Second Clinical Hospital of Harbin Medical University, Harbin, China
| | - Jing-long Yan
- Department of Orthopedics, Second Clinical Hospital of Harbin Medical University, Harbin, China
| | - Hiroki Yokota
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Sungsoo Na
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
- * E-mail:
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38
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Pereira AM, Tudor C, Pouille PA, Shekhar S, Kanger JS, Subramaniam V, Martín-Blanco E. Plasticity of the MAPK signaling network in response to mechanical stress. PLoS One 2014; 9:e101963. [PMID: 25025279 PMCID: PMC4099004 DOI: 10.1371/journal.pone.0101963] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Accepted: 06/12/2014] [Indexed: 11/18/2022] Open
Abstract
Cells display versatile responses to mechanical inputs and recent studies have identified the mitogen-activated protein kinase (MAPK) cascades mediating the biological effects observed upon mechanical stimulation. Although, MAPK pathways can act insulated from each other, several mechanisms facilitate the crosstalk between the components of these cascades. Yet, the combinatorial complexity of potential molecular interactions between these elements have prevented the understanding of their concerted functions. To analyze the plasticity of the MAPK signaling network in response to mechanical stress we performed a non-saturating epistatic screen in resting and stretched conditions employing as readout a JNK responsive dJun-FRET biosensor. By knocking down MAPKs, and JNK pathway regulators, singly or in pairs in Drosophila S2R+ cells, we have uncovered unexpected regulatory links between JNK cascade kinases, Rho GTPases, MAPKs and the JNK phosphatase Puc. These relationships have been integrated in a system network model at equilibrium accounting for all experimentally validated interactions. This model allows predicting the global reaction of the network to its modulation in response to mechanical stress. It also highlights its context-dependent sensitivity.
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Affiliation(s)
- Andrea M. Pereira
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Cientific de Barcelona, Baldiri Reixac 10–12, Barcelona, Spain
| | - Cicerone Tudor
- Nanobiophysics, MESA+ Institute for Nanotechnology & MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Philippe-Alexandre Pouille
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Cientific de Barcelona, Baldiri Reixac 10–12, Barcelona, Spain
| | - Shashank Shekhar
- Nanobiophysics, MESA+ Institute for Nanotechnology & MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Johannes S. Kanger
- Nanobiophysics, MESA+ Institute for Nanotechnology & MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Vinod Subramaniam
- Nanobiophysics, MESA+ Institute for Nanotechnology & MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
- * E-mail: (VS); (EMB)
| | - Enrique Martín-Blanco
- Instituto de Biología Molecular de Barcelona (CSIC), Parc Cientific de Barcelona, Baldiri Reixac 10–12, Barcelona, Spain
- * E-mail: (VS); (EMB)
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Ingber DE, Wang N, Stamenović D. Tensegrity, cellular biophysics, and the mechanics of living systems. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:046603. [PMID: 24695087 PMCID: PMC4112545 DOI: 10.1088/0034-4885/77/4/046603] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The recent convergence between physics and biology has led many physicists to enter the fields of cell and developmental biology. One of the most exciting areas of interest has been the emerging field of mechanobiology that centers on how cells control their mechanical properties, and how physical forces regulate cellular biochemical responses, a process that is known as mechanotransduction. In this article, we review the central role that tensegrity (tensional integrity) architecture, which depends on tensile prestress for its mechanical stability, plays in biology. We describe how tensional prestress is a critical governor of cell mechanics and function, and how use of tensegrity by cells contributes to mechanotransduction. Theoretical tensegrity models are also described that predict both quantitative and qualitative behaviors of living cells, and these theoretical descriptions are placed in context of other physical models of the cell. In addition, we describe how tensegrity is used at multiple size scales in the hierarchy of life—from individual molecules to whole living organisms—to both stabilize three-dimensional form and to channel forces from the macroscale to the nanoscale, thereby facilitating mechanochemical conversion at the molecular level.
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Affiliation(s)
- Donald E. Ingber
- Wyss Institute for Biologically Inspired Engineering at Harvard University, Harvard Medical School, Harvard School of Engineering and Applied Sciences, and Boston Children’s Hospital, 3 Blackfan Circle, CLSB5, Boston, MA 02115
| | - Ning Wang
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W. Green St, Urbana, IL 61801
| | - Dimitrije Stamenović
- Department of Biomedical Engineering, and Division of Material Science and Engineering, College of Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215
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Abstract
Mechanical forces influence many biological processes via activation of signaling molecules, including the family of Rho GTPases. Within the endothelium, the mechanical force of fluid shear stress regulates the spatiotemporal activation of Rho GTPases, including Rac1. Shear stress-induced Rac1 activation is required for numerous essential biological processes, including changes in permeability, alignment of the actin cytoskeleton, redox signaling, and changes in gene expression. Thus, identifying mechanisms of Rac1 activation and the spatial cues that direct proper localization of the GTPase is essential in order to gain a comprehensive understanding the role of Rac1 in shear stress responses. This commentary will highlight our current understanding of how Rac1 activity is regulated in response to shear stress, as well as the downstream consequences of Rac1 activation.
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Affiliation(s)
- Caitlin Collins
- Department of Cell Biology and Physiology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Ellie Tzima
- Department of Cell Biology and Physiology; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
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Wormer DB, Davis KA, Henderson JH, Turner CE. The focal adhesion-localized CdGAP regulates matrix rigidity sensing and durotaxis. PLoS One 2014; 9:e91815. [PMID: 24632816 PMCID: PMC3954768 DOI: 10.1371/journal.pone.0091815] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 02/14/2014] [Indexed: 02/07/2023] Open
Abstract
Motile cells are capable of sensing the stiffness of the surrounding extracellular matrix through integrin-mediated focal adhesions and migrate towards regions of higher rigidity in a process known as durotaxis. Durotaxis plays an important role in normal development and disease progression, including tumor invasion and metastasis. However, the signaling mechanisms underlying focal adhesion-mediated rigidity sensing and durotaxis are poorly understood. Utilizing matrix-coated polydimethylsiloxane gels to manipulate substrate compliance, we show that cdGAP, an adhesion-localized Rac1 and Cdc42 specific GTPase activating protein, is necessary for U2OS osteosarcoma cells to coordinate cell shape changes and migration as a function of extracellular matrix stiffness. CdGAP regulated rigidity-dependent motility by controlling membrane protrusion and adhesion dynamics, as well as by modulating Rac1 activity. CdGAP was also found to be necessary for U2OS cell durotaxis. Taken together, these data identify cdGAP as an important component of an integrin-mediated signaling pathway that senses and responds to mechanical cues in the extracellular matrix in order to coordinate directed cell motility.
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Affiliation(s)
- Duncan B. Wormer
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, United States of America
| | - Kevin A. Davis
- Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York, United States of America
| | - James H. Henderson
- Syracuse Biomaterials Institute, Syracuse University, Syracuse, New York, United States of America
| | - Christopher E. Turner
- Department of Cell and Developmental Biology, State University of New York Upstate Medical University, Syracuse, New York, United States of America
- * E-mail:
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Jafri MS. Mechanisms of Myofascial Pain. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:523924. [PMID: 25574501 PMCID: PMC4285362 DOI: 10.1155/2014/523924] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 06/08/2014] [Accepted: 06/10/2014] [Indexed: 01/17/2023]
Abstract
Myofascial pain syndrome is an important health problem. It affects a majority of the general population, impairs mobility, causes pain, and reduces the overall sense of well-being. Underlying this syndrome is the existence of painful taut bands of muscle that contain discrete, hypersensitive foci called myofascial trigger points. In spite of the significant impact on public health, a clear mechanistic understanding of the disorder does not exist. This is likely due to the complex nature of the disorder which involves the integration of cellular signaling, excitation-contraction coupling, neuromuscular inputs, local circulation, and energy metabolism. The difficulties are further exacerbated by the lack of an animal model for myofascial pain to test mechanistic hypothesis. In this review, current theories for myofascial pain are presented and their relative strengths and weaknesses are discussed. Based on new findings linking mechanoactivation of reactive oxygen species signaling to destabilized calcium signaling, we put forth a novel mechanistic hypothesis for the initiation and maintenance of myofascial trigger points. It is hoped that this lays a new foundation for understanding myofascial pain syndrome and how current therapies work, and gives key insights that will lead to the improvement of therapies for its treatment.
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Affiliation(s)
- M. Saleet Jafri
- Krasnow Institute for Advanced Study, George Mason University, 4400 University Drive, MNS 2A1, Fairfax, VA 22030, USA
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Abstract
Morphogenesis is the remarkable process by which cells self-assemble into complex tissues and organs that exhibit specialized form and function during embryological development. Many of the genes and chemical cues that mediate tissue and organ formation have been identified; however, these signals alone are not sufficient to explain how tissues and organs are constructed that exhibit their unique material properties and three-dimensional forms. Here, we review work that has revealed the central role that physical forces and extracellular matrix mechanics play in the control of cell fate switching, pattern formation, and tissue development in the embryo and how these same mechanical signals contribute to tissue homeostasis and developmental control throughout adult life.
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Affiliation(s)
- Tadanori Mammoto
- Vascular Biology Program, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115;
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Hadjiantoniou S, Guolla L, Pelling AE. Mechanically induced deformation and strain dynamics in actin stress fibers. Commun Integr Biol 2013; 5:627-30. [PMID: 23740335 PMCID: PMC3541333 DOI: 10.4161/cib.21677] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
It is becoming evident that physical forces in the microenvironment play a key role in regulating many important aspects of cell biology. However, although mechanical cues are known to have clear effects over the long-term (days), the short-term (seconds to minutes) cellular responses to mechanical stimuli are less well characterized. In our recent study, we exposed committed fibroblast cells to well controlled nanoscale forces while simultaneously imaging force transduction through the actin cytoskeleton. One of the earliest responses of a cell to physical force is rapid deformation of the cytoskeleton, taking place over the course of seconds. We were able to directly visualize deformation, force-propagation and strain dynamics in actin stress fibers in response to a relatively simple mechanical stimulus. Moreover, these dynamics were also dependent on myosin-driven contractility and the presence of an intact microtubule cytoskeleton. Interestingly, although stem cells are sensitive to mechanical cues, they do not display the same degree of stress fiber organization as observed in committed cells indicating the possibility of alternative sensing and mechanotransduction mechanisms.
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Dipaolo BC, Davidovich N, Kazanietz MG, Margulies SS. Rac1 pathway mediates stretch response in pulmonary alveolar epithelial cells. Am J Physiol Lung Cell Mol Physiol 2013; 305:L141-53. [PMID: 23686855 DOI: 10.1152/ajplung.00298.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Alveolar epithelial cells (AECs) maintain the pulmonary blood-gas barrier integrity with gasketlike intercellular tight junctions (TJ) that are anchored internally to the actin cytoskeleton. We have previously shown that AEC monolayers stretched cyclically and equibiaxially undergo rapid magnitude- and frequency-dependent actin cytoskeletal remodeling to form perijunctional actin rings (PJARs). In this work, we show that even 10 min of stretch induced increases in the phosphorylation of Akt and LIM kinase (LIMK) and decreases in cofilin phosphorylation, suggesting that the Rac1/Akt pathway is involved in these stretch-mediated changes. We confirmed that Rac1 inhibitors wortmannin or EHT-1864 decrease stretch-stimulated Akt and LIMK phosphorylation and that Rac1 agonists PIP3 or PDGF increase phosphorylation of these proteins in unstretched cells. We also confirmed that Rac1 pathway inhibition during stretch modulated stretch-induced changes in occludin content and monolayer permeability, actin remodeling and PJAR formation, and cell death. As further validation, overexpression of Rac GTPase-activating protein β2-chimerin also preserved monolayer barrier properties in stretched monolayers. In summary, our data suggest that constitutive activity of Rac1, which is necessary for stretch-induced activation of the Rac1 downstream proteins, mediates stretch-induced increases in permeability and PJAR formation.
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Affiliation(s)
- Brian C Dipaolo
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
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Rac1 and Cdc42 GTPases regulate shear stress-driven β-catenin signaling in osteoblasts. Biochem Biophys Res Commun 2013; 433:502-7. [PMID: 23524265 DOI: 10.1016/j.bbrc.2013.03.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 03/06/2013] [Indexed: 01/29/2023]
Abstract
Beta-catenin-dependent TCF/LEF (T-cell factor/lymphocyte enhancing factor) is known to be mechanosensitive and an important regulator for promoting bone formation. However, the functional connection between TCF/LEF activity and Rho family GTPases is not well understood in osteoblasts. Herein we investigated the molecular mechanisms underlying oscillatory shear stress-induced TCF/LEF activity in MC3T3-E1 osteoblast cells using live cell imaging. We employed fluorescence resonance energy transfer (FRET)-based and green fluorescent protein (GFP)-based biosensors, which allowed us to monitor signal transduction in living cells in real time. Oscillatory (1Hz) shear stress (10 dynes/cm2) increased TCF/LEF activity and stimulated translocation of β-catenin to the nucleus with the distinct activity patterns of Rac1 and Cdc42. The shear stress-induced TCF/LEF activity was blocked by the inhibition of Rac1 and Cdc42 with their dominant negative mutants or selective drugs, but not by a dominant negative mutant of RhoA. In contrast, constitutively active Rac1 and Cdc42 mutants caused a significant enhancement of TCF/LEF activity. Moreover, activation of Rac1 and Cdc42 increased the basal level of TCF/LEF activity, while their inhibition decreased the basal level. Interestingly, disruption of cytoskeletal structures or inhibition of myosin activity did not significantly affect shear stress-induced TCF/LEF activity. Although Rac1 is reported to be involved in β-catenin in cancer cells, the involvement of Cdc42 in β-catenin signaling in osteoblasts has not been identified. Our findings in this study demonstrate that both Rac1 and Cdc42 GTPases are critical regulators in shear stress-driven β-catenin signaling in osteoblasts.
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Abstract
Mechanical forces influence nearly all aspects of biology. Cells are equipped with numerous mechanosensitive proteins that activate various signaling cascades in response to mechanical cues from their environment. Much interest lies in understanding how cells respond to external stresses. A number of studies have highlighted the coordination of mechanical and chemical signaling cascades downstream of integrins. In recent years, the study of mechanotransduction has expanded to other mechanosensitive adhesion receptors, such as platelet endothelial cell adhesion molecule-1 (PECAM-1). This commentary will highlight our current understanding of integrin and PECAM-1-mediated mechanotransduction and expand on the observation that a localized mechanical stress can elicit a global mechanosignaling response.
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Affiliation(s)
- Caitlin Collins
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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48
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Wan Q, Kim SJ, Yokota H, Na S. Differential activation and inhibition of RhoA by fluid flow induced shear stress in chondrocytes. Cell Biol Int 2013; 37:568-76. [PMID: 23408748 DOI: 10.1002/cbin.10072] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 02/06/2013] [Indexed: 12/25/2022]
Abstract
Physical force environment is a major factor that influences cellular homeostasis and remodelling. It is not well understood, however, as a potential role of force intensities in the induction of cellular mechanotransduction. Using a fluorescence resonance energy transfer-based approach, we asked whether activities of GTPase RhoA in chondrocytes are dependent on intensities of flow-induced shear stress. We hypothesized that RhoA activities can be either elevated or reduced by selecting different levels of shear-stress intensities. The result indicates that C28/I2 chondrocytes have increased RhoA activities in response to high shear stress (10 or 20 dyn/cm(2) ), whereas a decrease in activity was seen with an intermediate shear stress of 5 dyn/cm(2) . No changes were seen under low shear stress (2 dyn/cm(2) ). The observed two-level switch of RhoA activities is closely linked to the shear-stress-induced alterations in actin cytoskeleton and traction forces. In the presence of constitutively active RhoA (RhoA-V14), intermediate shear stress suppressed RhoA activities, while high shear stress failed to activate them. In chondrocytes, expression of various metalloproteinases is, in part, regulated by shear and normal stresses through a network of GTPases. Collectively, the data suggest that intensities of shear stress are critical in differential activation and inhibition of RhoA activities in chondrocytes.
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Affiliation(s)
- Qiaoqiao Wan
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, 723 West Michigan Street, Indianapolis, IN 46202, USA
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Shen MY, Michaelson J, Huang H. Rheological responses of cardiac fibroblasts to mechanical stretch. Biochem Biophys Res Commun 2012; 430:1028-33. [PMID: 23261449 DOI: 10.1016/j.bbrc.2012.12.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
Abstract
Rheological characterization of cells using passive particle tracking techniques can yield substantial information regarding local cellular material properties. However, limited work has been done to establish the changes in material properties of mechanically-responsive cells that experience external stimuli. In this study, cardiac fibroblasts plated on either fibronectin or collagen were treated with cytochalasin, mechanically stretched, or both, and their trajectories and complex moduli were extracted. Results demonstrate that both solid and fluid components were altered by such treatments in a receptor-dependent manner, and that, interestingly, cells treated with cytochalasin were still capable of stiffening in response to mechanical stimuli despite gross stress fiber disruption. These results suggest that the material properties of cells are dependent on a variety of environmental cues and can provide insight into physiological and disease processes.
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Affiliation(s)
- Min Ye Shen
- Columbia University, New York, NY 10027, USA
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50
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Birukova AA, Tian Y, Dubrovskyi O, Zebda N, Sarich N, Tian X, Wang Y, Birukov KG. VE-cadherin trans-interactions modulate Rac activation and enhancement of lung endothelial barrier by iloprost. J Cell Physiol 2012; 227:3405-16. [PMID: 22213015 DOI: 10.1002/jcp.24041] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Small GTPase Rac is important regulator of endothelial cell (EC) barrier enhancement by prostacyclin characterized by increased peripheral actin cytoskeleton and increased interactions between VE-cadherin and other adherens junction (AJ) proteins. This study utilized complementary approaches including siRNA knockdown, culturing in Ca(2+) -free medium, and VE-cadherin blocking antibody to alter VE-cadherin extracellular interactions to investigate the role of VE-cadherin outside-in signaling in modulation of Rac activation and EC barrier regulation by prostacyclin analog iloprost. Spatial analysis of Rac activation in pulmonary EC by FRET revealed additional spike in iloprost-induced Rac activity at the sites of newly formed cell-cell junctions. In contrast, disruption of VE-cadherin extracellular trans-interactions suppressed iloprost-activated Rac signaling and attenuated EC barrier enhancement and cytoskeletal remodeling. These inhibitory effects were associated with decreased membrane accumulation and activation of Rac-specific guanine nucleotide exchange factors (GEFs) Tiam1 and Vav2. Conversely, plating of pulmonary EC on surfaces coated with extracellular VE-cadherin domain further promoted iloprost-induced Rac signaling. In the model of thrombin-induced EC barrier recovery, blocking of VE-cadherin trans-interactions attenuated activation of Rac pathway during recovery phase and delayed suppression of Rho signaling and restoration of EC barrier properties. These results suggest that VE-cadherin outside-in signaling controls locally Rac activity stimulated by barrier protective agonists. This control is essential for maximal EC barrier enhancement and accelerated barrier recovery.
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Affiliation(s)
- Anna A Birukova
- Lung Injury Center, Section of Pulmonary and Critical Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA.
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