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Giverso C, Loy N, Lucci G, Preziosi L. Cell orientation under stretch: A review of experimental findings and mathematical modelling. J Theor Biol 2023; 572:111564. [PMID: 37391125 DOI: 10.1016/j.jtbi.2023.111564] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 06/15/2023] [Indexed: 07/02/2023]
Abstract
The key role of electro-chemical signals in cellular processes had been known for many years, but more recently the interplay with mechanics has been put in evidence and attracted substantial research interests. Indeed, the sensitivity of cells to mechanical stimuli coming from the microenvironment turns out to be relevant in many biological and physiological circumstances. In particular, experimental evidence demonstrated that cells on elastic planar substrates undergoing periodic stretches, mimicking native cyclic strains in the tissue where they reside, actively reorient their cytoskeletal stress fibres. At the end of the realignment process, the cell axis forms a certain angle with the main stretching direction. Due to the importance of a deeper understanding of mechanotransduction, such a phenomenon was studied both from the experimental and the mathematical modelling point of view. The aim of this review is to collect and discuss both the experimental results on cell reorientation and the fundamental features of the mathematical models that have been proposed in the literature.
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Affiliation(s)
- Chiara Giverso
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
| | - Nadia Loy
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
| | - Giulio Lucci
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
| | - Luigi Preziosi
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
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2
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Li S, Liu C, Tang Y. Role of Fyn in hematological malignancies. J Cancer Res Clin Oncol 2023:10.1007/s00432-023-04608-2. [PMID: 36754870 DOI: 10.1007/s00432-023-04608-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/27/2023] [Indexed: 02/10/2023]
Abstract
BACKGROUND Tyrosine kinase Fyn is a member of the Src family of kinases. In addition to the wild type, three mRNA splice isoforms of Fyn have been identified; Fyn-B, Fyn-T, and Fyn-C. Fyn-T is highly expressed in T lymphocytes, and its expression level is significantly higher in mature T cells than in immature T cells. The abnormal expression of Fyn is closely related to the metabolism, proliferation, and migration of tumor cells. Recent studies have shown that Fyn is expressed in a variety of tumor tissues, and its expression and function vary among different tumors. In some tumors, Fyn acts as a pro-oncogene to promote tumor proliferation and metastasis. Moreover, Fyn mutations have been detected in many hematological tumors in recent years, suggesting a critical regulatory role of Fyn in the development of malignancies. METHODS This review analyzed the relevant literature in PubMed and other databases. PURPOSE The aim of this study was to systemically review recent research findings on various aspects of Fyn in the pathogenesis and treatment of different types of hematological malignancies and suggests possible future research directions for targeted tumor therapy. CONCLUSION Fyn could be a novel prognostic marker and therapeutic target. Treatment option targeting Fyn might be beneficial for future studies.
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Affiliation(s)
- Shan Li
- Hunan Province Key Laboratory of Tumor Cellular and Molecular Pathology, Cancer Research Institute, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Changqing Liu
- Hunan Province Key Laboratory of Tumor Cellular and Molecular Pathology, Cancer Research Institute, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China
| | - Yunlian Tang
- Hunan Province Key Laboratory of Tumor Cellular and Molecular Pathology, Cancer Research Institute, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
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3
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Friedland F, Babu S, Springer R, Konrad J, Herfs Y, Gerlach S, Gehlen J, Krause HJ, De Laporte L, Merkel R, Noetzel E. ECM-transmitted shear stress induces apoptotic cell extrusion in early breast gland development. Front Cell Dev Biol 2022; 10:947430. [PMID: 36105352 PMCID: PMC9465044 DOI: 10.3389/fcell.2022.947430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
Epithelial cells of human breast glands are exposed to various mechanical ECM stresses that regulate tissue development and homeostasis. Mechanoadaptation of breast gland tissue to ECM-transmitted shear stress remained poorly investigated due to the lack of valid experimental approaches. Therefore, we created a magnetic shear strain device that enabled, for the first time, to analyze the instant shear strain response of human breast gland cells. MCF10A-derived breast acini with basement membranes (BM) of defined maturation state and basoapical polarization were used to resemble breast gland morphogenesis in vitro. The novel biophysical tool was used to apply cyclic shear strain with defined amplitudes (≤15%, 0.2 Hz) over 22 h on living spheroids embedded in an ultrasoft matrix (<60 Pa). We demonstrated that breast spheroids gain resistance to shear strain, which increased with BM maturation and basoapical polarization. Most intriguingly, poorly developed spheroids were prone to cyclic strain-induced extrusion of apoptotic cells from the spheroid body. In contrast, matured spheroids were insensitive to this mechanoresponse—indicating changing mechanosensing or mechanotransduction mechanisms during breast tissue morphogenesis. Together, we introduced a versatile tool to study cyclic shear stress responses of 3D cell culture models. It can be used to strain, in principle, all kinds of cell clusters, even those that grow only in ultrasoft hydrogels. We believe that this approach opens new doors to gain new insights into dynamic shear strain-induced mechanobiological regulation circuits between cells and their ECM.
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Affiliation(s)
- F. Friedland
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
| | - S. Babu
- DWI-Leibniz Institute for Interactive Materials, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry (ITMC), Polymeric Biomaterials, RWTH University Aachen, Aachen, Germany
| | - R. Springer
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
| | - J. Konrad
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
| | - Y. Herfs
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
| | - S. Gerlach
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
| | - J. Gehlen
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
| | - H.-J. Krause
- Institute of Biological Information Processing 3 (IBI-3): Bioelectronics, Forschungszentrum Jülich, Jülich, Germany
| | - L. De Laporte
- DWI-Leibniz Institute for Interactive Materials, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry (ITMC), Polymeric Biomaterials, RWTH University Aachen, Aachen, Germany
- Advanced Materials for Biomedicine (AMB), Institute of Applied Medical Engineering (AME), University Hospital RWTH Aachen, Center for Biohybrid Medical Systems (CMBS), Aachen, Germany
| | - R. Merkel
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
| | - E. Noetzel
- Institute of Biological Information Processing 2 (IBI-2): Mechanobiology, Forschungszentrum Jülich, Jülich, Germany
- *Correspondence: E. Noetzel,
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4
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Nakano S, Nishikawa M, Kobayashi T, Harlin EW, Ito T, Sato K, Sugiyama T, Yamakawa H, Nagase T, Ueda H. The Rho guanine nucleotide exchange factor PLEKHG1 is activated by interaction with and phosphorylation by Src family kinase member FYN. J Biol Chem 2022; 298:101579. [PMID: 35031323 PMCID: PMC8819033 DOI: 10.1016/j.jbc.2022.101579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 01/01/2023] Open
Abstract
Rho family small GTPases (Rho) regulate various cell motility processes by spatiotemporally controlling the actin cytoskeleton. Some Rho-specific guanine nucleotide exchange factors (RhoGEFs) are regulated via tyrosine phosphorylation by Src family tyrosine kinase (SFK). We also previously reported that PLEKHG2, a RhoGEF for the GTPases Rac1 and Cdc42, is tyrosine-phosphorylated by SRC. However, the details of the mechanisms by which SFK regulates RhoGEFs are not well understood. In this study, we found for the first time that PLEKHG1, which has very high homology to the Dbl and pleckstrin homology domains of PLEKHG2, activates Cdc42 following activation by FYN, a member of the SFK family. We also show that this activation of PLEKHG1 by FYN requires interaction between these two proteins and FYN-induced tyrosine phosphorylation of PLEKHG1. We also found that the region containing the Src homology 3 and Src homology 2 domains of FYN is required for this interaction. Finally, we demonstrated that tyrosine phosphorylation of Tyr-720 and Tyr-801 in PLEKHG1 is important for the activation of PLEKHG1. These results suggest that FYN is a regulator of PLEKHG1 and may regulate cell morphology through Rho signaling via the interaction with and tyrosine phosphorylation of PLEKHG1.
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Affiliation(s)
- Shun Nakano
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan
| | - Masashi Nishikawa
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan
| | | | - Eka Wahyuni Harlin
- Graduate School of Natural Science and Technology, Gifu University, Gifu, Japan
| | - Takuya Ito
- Graduate School of Natural Science and Technology, Gifu University, Gifu, Japan
| | - Katsuya Sato
- Department of Molecular Pathobiochemistry, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Tsuyoshi Sugiyama
- Faculty of Pharmacy, Gifu University of Medical Science, Kani, Gifu, Japan
| | | | | | - Hiroshi Ueda
- United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu, Japan; Graduate School of Natural Science and Technology, Gifu University, Gifu, Japan.
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5
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Xu K, Liu X, Li X, Yin J, Wei P, Qian J, Sun J. Effect of Electrical and Electromechanical Stimulation on PC12 Cell Proliferation and Axon Outgrowth. Front Bioeng Biotechnol 2021; 9:757906. [PMID: 34746110 PMCID: PMC8566739 DOI: 10.3389/fbioe.2021.757906] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/15/2021] [Indexed: 11/13/2022] Open
Abstract
Peripheral nerve injuries have become a common clinical disease with poor prognosis and complicated treatments. The development of tissue engineering pointed a promising direction to produce nerve conduits for nerve regeneration. Electrical and mechanical stimulations have been incorporated with tissue engineering, since such external stimulations could promote nerve cell proliferation, migration and differentiation. However, the combination of electrical and mechanical stimulations (electromechanical stimulation) and its effects on neuron proliferation and axon outgrowth have been rarely investigated. Herein, silver nanowires (AgNWs) embedded polydimethylsiloxane (PDMS) electrodes were developed to study the effects of electromechanical stimulation on rat pheochromocytoma cells (PC12 cells) behaviors. AgNWs/PDMS electrodes demonstrated good biocompatibility and established a stable electric field during mechanical stretching. PC12 cells showed enhanced proliferation rate and axon outgrowth under electrical stimulation alone, and the cell number significantly increased with higher electrical stimulation intensity. The involvement of mechanical stretching in electrical stimulation reduced the cell proliferation rate and axon outgrowth, compared with the case of electrical stimulation alone. Interestingly, the cellular axons outgrowth was found to depend on the stretching direction, where the axons prefer to align perpendicularly to the stretch direction. These results suggested that AgNWs/PDMS electrodes provide an in vitro platform to investigate the effects of electromechanical stimulation on nerve cell behaviors and can be potentially used for nerve regeneration in the future.
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Affiliation(s)
- Kailei Xu
- Central Laboratory, Ningbo First Hospital, Ningbo, China
- The State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
- Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| | - Xixia Liu
- The State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
- Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
- School of Mechanical Engineering, Guizhou University, Guiyang, China
| | - Xiaokeng Li
- The State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
- Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| | - Jun Yin
- The State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
- Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou, China
| | - Peng Wei
- Department of Hand and Foot Microsurgery, Ningbo First Hospital, Ningbo, China
| | - Jin Qian
- Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Department of Engineering Mechanics, Zhejiang University, Hangzhou, China
| | - Jie Sun
- Central Laboratory, Ningbo First Hospital, Ningbo, China
- Department of Neurosurgery, Ningbo First Hospital, Ningbo, China
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6
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González Wusener AE, González Á, Perez Collado ME, Maza MR, General IJ, Arregui CO. Protein tyrosine phosphatase 1B targets focal adhesion kinase and paxillin in cell-matrix adhesions. J Cell Sci 2021; 134:272564. [PMID: 34553765 DOI: 10.1242/jcs.258769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/14/2021] [Indexed: 11/20/2022] Open
Abstract
Protein tyrosine phosphatase 1B (PTP1B, also known as PTPN1) is an established regulator of cell-matrix adhesion and motility. However, the nature of substrate targets at adhesion sites remains to be validated. Here, we used bimolecular fluorescence complementation assays, in combination with a substrate trapping mutant of PTP1B, to directly examine whether relevant phosphotyrosines on paxillin and focal adhesion kinase (FAK, also known as PTK2) are substrates of the phosphatase in the context of cell-matrix adhesion sites. We found that the formation of catalytic complexes at cell-matrix adhesions requires intact tyrosine residues Y31 and Y118 on paxillin, and the localization of FAK at adhesion sites. Additionally, we found that PTP1B specifically targets Y925 on the focal adhesion targeting (FAT) domain of FAK at adhesion sites. Electrostatic analysis indicated that dephosphorylation of this residue promotes the closed conformation of the FAT 4-helix bundle and its interaction with paxillin at adhesion sites.
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Affiliation(s)
- Ana E González Wusener
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
| | - Ángela González
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
| | - María E Perez Collado
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
| | - Melina R Maza
- Escuela de Ciencia y Tecnología, Universidad Nacional de San Martin, Instituto de Ciencias Físicas and CONICET, San Martin, Buenos Aires 1650, Argentina
| | - Ignacio J General
- Escuela de Ciencia y Tecnología, Universidad Nacional de San Martin, Instituto de Ciencias Físicas and CONICET, San Martin, Buenos Aires 1650, Argentina
| | - Carlos O Arregui
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), San Martín, Buenos Aires 1650, Argentina
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7
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Höhfeld J, Benzing T, Bloch W, Fürst DO, Gehlert S, Hesse M, Hoffmann B, Hoppe T, Huesgen PF, Köhn M, Kolanus W, Merkel R, Niessen CM, Pokrzywa W, Rinschen MM, Wachten D, Warscheid B. Maintaining proteostasis under mechanical stress. EMBO Rep 2021; 22:e52507. [PMID: 34309183 PMCID: PMC8339670 DOI: 10.15252/embr.202152507] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
Cell survival, tissue integrity and organismal health depend on the ability to maintain functional protein networks even under conditions that threaten protein integrity. Protection against such stress conditions involves the adaptation of folding and degradation machineries, which help to preserve the protein network by facilitating the refolding or disposal of damaged proteins. In multicellular organisms, cells are permanently exposed to stress resulting from mechanical forces. Yet, for long time mechanical stress was not recognized as a primary stressor that perturbs protein structure and threatens proteome integrity. The identification and characterization of protein folding and degradation systems, which handle force-unfolded proteins, marks a turning point in this regard. It has become apparent that mechanical stress protection operates during cell differentiation, adhesion and migration and is essential for maintaining tissues such as skeletal muscle, heart and kidney as well as the immune system. Here, we provide an overview of recent advances in our understanding of mechanical stress protection.
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Affiliation(s)
- Jörg Höhfeld
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC)University of CologneCologneGermany
| | - Wilhelm Bloch
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
| | - Dieter O Fürst
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Sebastian Gehlert
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
- Department for the Biosciences of SportsInstitute of Sports ScienceUniversity of HildesheimHildesheimGermany
| | - Michael Hesse
- Institute of Physiology I, Life & Brain CenterMedical FacultyRheinische Friedrich‐Wilhelms UniversityBonnGermany
| | - Bernd Hoffmann
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Thorsten Hoppe
- Institute for GeneticsCologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD) and CMMCUniversity of CologneCologneGermany
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA3Forschungszentrum JülichJülichGermany
- CECADUniversity of CologneCologneGermany
| | - Maja Köhn
- Institute of Biology IIIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
| | - Waldemar Kolanus
- LIMES‐InstituteRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Rudolf Merkel
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Carien M Niessen
- Department of Dermatology and CECADUniversity of CologneCologneGermany
| | | | - Markus M Rinschen
- Department of Biomedicine and Aarhus Institute of Advanced StudiesAarhus UniversityAarhusDenmark
- Department of MedicineUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Dagmar Wachten
- Institute of Innate ImmunityUniversity Hospital BonnBonnGermany
| | - Bettina Warscheid
- Institute of Biology IIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
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8
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Gögele C, Hoffmann C, Konrad J, Merkel R, Schwarz S, Tohidnezhad M, Hoffmann B, Schulze-Tanzil GG. Cyclically stretched ACL fibroblasts emigrating from spheroids adapt their cytoskeleton and ligament-related expression profile. Cell Tissue Res 2021; 384:675-690. [PMID: 33835257 PMCID: PMC8211585 DOI: 10.1007/s00441-021-03416-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 01/13/2021] [Indexed: 01/09/2023]
Abstract
Mechanical stress of ligaments varies; hence, ligament fibroblasts must adapt their expression profile to novel mechanomilieus to ensure tissue resilience. Activation of the mechanoreceptors leads to a specific signal transduction, the so-called mechanotransduction. However, with regard to their natural three-dimensional (3D) microenvironment cell reaction to mechanical stimuli during emigrating from a 3D spheroid culture is still unclear. This study aims to provide a deeper understanding of the reaction profile of anterior cruciate ligament (ACL)-derived fibroblasts exposed to cyclic uniaxial strain in two-dimensional (2D) monolayer culture and during emigration from 3D spheroids with respect to cell survival, cell and cytoskeletal orientation, distribution, and expression profile. Monolayers and spheroids were cultured in crosslinked polydimethyl siloxane (PDMS) elastomeric chambers and uniaxially stretched (14% at 0.3 Hz) for 48 h. Cell vitality, their distribution, nuclear shape, stress fiber orientation, focal adhesions, proliferation, expression of ECM components such as sulfated glycosaminoglycans, collagen type I, decorin, tenascin C and cell-cell communication-related gap junctional connexin (CXN) 43, tendon-related markers Mohawk and tenomodulin (myodulin) were analyzed. In contrast to unstretched cells, stretched fibroblasts showed elongation of stress fibers, cell and cytoskeletal alignment perpendicular to strain direction, less rounded cell nuclei, increased numbers of focal adhesions, proliferation, amplified CXN43, and main ECM component expression in both cultures. The applied cyclic stretch protocol evoked an anabolic response and enhanced tendon-related marker expression in ACL-derived fibroblasts emigrating from 3D spheroids and seems also promising to support in future tissue formation in ACL scaffolds seeded in vitro with spheroids.
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Affiliation(s)
- Clemens Gögele
- Institute of Anatomy and Cell Biology, Paracelsus Medical University, Prof.-Ernst-Nathan Str. 1, 90419 Nuremberg and Salzburg, Nuremberg, Germany
- Department of Biosciences, Paris Lodron University Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria
| | - Christina Hoffmann
- Institute of Biological Information Processing: IBI-2, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Jens Konrad
- Institute of Biological Information Processing: IBI-2, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Rudolf Merkel
- Institute of Biological Information Processing: IBI-2, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Silke Schwarz
- Institute of Anatomy and Cell Biology, Paracelsus Medical University, Prof.-Ernst-Nathan Str. 1, 90419 Nuremberg and Salzburg, Nuremberg, Germany
| | - Mersedeh Tohidnezhad
- Department of Anatomy and Cell Biology, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Bernd Hoffmann
- Institute of Biological Information Processing: IBI-2, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Gundula Gesine Schulze-Tanzil
- Institute of Anatomy and Cell Biology, Paracelsus Medical University, Prof.-Ernst-Nathan Str. 1, 90419 Nuremberg and Salzburg, Nuremberg, Germany
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9
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Koudelková L, Brábek J, Rosel D. Src kinase: Key effector in mechanosignalling. Int J Biochem Cell Biol 2020; 131:105908. [PMID: 33359015 DOI: 10.1016/j.biocel.2020.105908] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 02/07/2023]
Abstract
Cells have developed a unique set of molecular mechanisms that allows them to probe mechanical properties of the surrounding environment. These systems are based on deformable primary mechanosensors coupled to tension transmitting proteins and enzymes generating biochemical signals. This modular setup enables to transform a mechanical load into more versatile biochemical information. Src kinase appears to be one of the central components of the mechanotransduction network mediating force-induced signalling across multiple cellular contexts. In tight cooperation with primary sensors and the cytoskeleton, Src functions as an effector molecule necessary for transformation of mechanical stimuli into biochemical outputs executing cellular response and adaptation to mechanical cues.
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Affiliation(s)
- Lenka Koudelková
- Department of Cell Biology, Charles University, 12800, Prague, Czech Republic; Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), 25250, Vestec, Czech Republic
| | - Jan Brábek
- Department of Cell Biology, Charles University, 12800, Prague, Czech Republic; Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), 25250, Vestec, Czech Republic
| | - Daniel Rosel
- Department of Cell Biology, Charles University, 12800, Prague, Czech Republic; Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), 25250, Vestec, Czech Republic.
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10
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Ebrahimi M, Botelho M, Lu W, Monmaturapoj N. Integrated approach in designing biphasic nanocomposite collagen/nBCP scaffolds with controlled porosity and permeability for bone tissue engineering. J Biomed Mater Res B Appl Biomater 2019; 108:1738-1753. [PMID: 31750983 DOI: 10.1002/jbm.b.34518] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/27/2019] [Accepted: 11/04/2019] [Indexed: 02/06/2023]
Abstract
The bone scaffold for tissue engineering should be biomimetic, particularly in simulating the porosity features of natural bony tissue including pore size, pore shape, pore distribution pattern, and porosity percentage. Control of these can impact the scaffold hydrophilicity and permeability, which in turn influence the protein adsorption, cellular functions, and vascularization process. Various methods have been investigated for control of porosity parameters; however, the field still suffers from major challenges, that is, inadequate control of porosity and hydrophilicity at different levels. In this study, we developed an integrated approach for generation and control of porosity within nanocomposite collagen/nanobiphasic calcium phosphate (collagen/nBCP) scaffold. A modified freeze-drying procedure was applied alongside a chemical foaming method exploring the ability of "Tween 20" as a potent biocompatible porogen. Several processing variables were also examined including; quenching rate (-18 and -80°C), collagen/nBCP ratio (92/8% and 85/15%), and Tween ratio (10%, 20%, and 30%). Detailed physicochemical and porosimetry analysis confirmed the ability of Tween to actively modify the scaffold permeability and pore size by increasing the range of pore size while quenching rate mostly influenced the pore shape, and collagen/nBCP ratio affected total porosity and roughness. The collagen/nBCP ratio of 92/8% treated with low Tween ratios (10% and 20%) and exposed to -80°C quenching rate displayed more favorable physicochemical behavior, significantly higher permeability, a gradient porosity, and better in vitro performances. The proposed technique in this study provides an insight into the production of customized scaffolds for various tissue engineering applications.
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Affiliation(s)
- Mehdi Ebrahimi
- Restorative Dental Sciences, Prince Philip Dental Hospital, The University of Hong Kong, Sai Ying Pun, Hong Kong
| | - Michael Botelho
- Restorative Dental Sciences, Prince Philip Dental Hospital, The University of Hong Kong, Sai Ying Pun, Hong Kong
| | - William Lu
- Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Naruporn Monmaturapoj
- National Metal and Materials Technology Center (MTEC), NSTDA, Khlong Nueng, Thailand
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Abraham JA, Linnartz C, Dreissen G, Springer R, Blaschke S, Rueger MA, Fink GR, Hoffmann B, Merkel R. Directing Neuronal Outgrowth and Network Formation of Rat Cortical Neurons by Cyclic Substrate Stretch. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7423-7431. [PMID: 30110535 DOI: 10.1021/acs.langmuir.8b02003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Neuronal mechanobiology plays a vital function in brain development and homeostasis with an essential role in neuronal maturation, pathfinding, and differentiation but is also crucial for understanding brain pathology. In this study, we constructed an in vitro system to assess neuronal responses to cyclic strain as a mechanical signal. The selected strain amplitudes mimicked physiological as well as pathological conditions. By subjecting embryonic neuronal cells to cyclic uniaxial strain we could steer the direction of neuronal outgrowth perpendicular to strain direction for all applied amplitudes. A long-term analysis proved maintained growth direction. Moreover, stretched neurons showed an enhanced length, growth, and formation of nascent side branches with most elevated growth rates subsequent to physiological straining. Application of cyclic strain to already formed neurites identified retraction bulbs with destabilized microtubule structures as spontaneous responses. Importantly, neurons were able to adapt to the mechanical signals without induction of cell death and showed a triggered growth behavior when compared to unstretched neurons. The data suggest that cyclic strain plays a critical role in neuronal development.
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Affiliation(s)
- Jella-Andrea Abraham
- Institute of Complex Systems (ICS-7): Biomechanics , Research Centre Jülich , Jülich 52425 , Germany
| | - Christina Linnartz
- Institute of Complex Systems (ICS-7): Biomechanics , Research Centre Jülich , Jülich 52425 , Germany
| | - Georg Dreissen
- Institute of Complex Systems (ICS-7): Biomechanics , Research Centre Jülich , Jülich 52425 , Germany
| | - Ronald Springer
- Institute of Complex Systems (ICS-7): Biomechanics , Research Centre Jülich , Jülich 52425 , Germany
| | - Stefan Blaschke
- Department of Neurology , University Hospital of Cologne , Cologne 50937 , Germany
- Institute of Neuroscience and Medicine (INM-3): Cognitive Neuroscience , Research Centre Jülich , Jülich 52425 , Germany
| | - Maria A Rueger
- Department of Neurology , University Hospital of Cologne , Cologne 50937 , Germany
- Institute of Neuroscience and Medicine (INM-3): Cognitive Neuroscience , Research Centre Jülich , Jülich 52425 , Germany
| | - Gereon R Fink
- Department of Neurology , University Hospital of Cologne , Cologne 50937 , Germany
- Institute of Neuroscience and Medicine (INM-3): Cognitive Neuroscience , Research Centre Jülich , Jülich 52425 , Germany
| | - Bernd Hoffmann
- Institute of Complex Systems (ICS-7): Biomechanics , Research Centre Jülich , Jülich 52425 , Germany
| | - Rudolf Merkel
- Institute of Complex Systems (ICS-7): Biomechanics , Research Centre Jülich , Jülich 52425 , Germany
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12
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Rao MV, Zaidel-Bar R. Formin-mediated actin polymerization at cell-cell junctions stabilizes E-cadherin and maintains monolayer integrity during wound repair. Mol Biol Cell 2016; 27:2844-56. [PMID: 27440924 PMCID: PMC5025271 DOI: 10.1091/mbc.e16-06-0429] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 07/12/2016] [Indexed: 02/05/2023] Open
Abstract
Cadherin-mediated cell–cell adhesion is required for epithelial tissue integrity in homeostasis, during development, and in tissue repair. Fmnl3 and mDia1 cooperate in stabilizing E-cadherin at cell–cell junctions and facilitate strong cell adhesion and monolayer cohesion during collective cell migration. Cadherin-mediated cell–cell adhesion is required for epithelial tissue integrity in homeostasis, during development, and in tissue repair. E-cadherin stability depends on F-actin, but the mechanisms regulating actin polymerization at cell–cell junctions remain poorly understood. Here we investigated a role for formin-mediated actin polymerization at cell–cell junctions. We identify mDia1 and Fmnl3 as major factors enhancing actin polymerization and stabilizing E-cadherin at epithelial junctions. Fmnl3 localizes to adherens junctions downstream of Src and Cdc42 and its depletion leads to a reduction in F-actin and E-cadherin at junctions and a weakening of cell–cell adhesion. Of importance, Fmnl3 expression is up-regulated and junctional localization increases during collective cell migration. Depletion of Fmnl3 or mDia1 in migrating monolayers results in dissociation of leader cells and impaired wound repair. In summary, our results show that formin activity at epithelial cell–cell junctions is important for adhesion and the maintenance of epithelial cohesion during dynamic processes, such as wound repair.
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Affiliation(s)
- Megha Vaman Rao
- Mechanobiology Institute, National University of Singapore, Singapore 117411
| | - Ronen Zaidel-Bar
- Mechanobiology Institute, National University of Singapore, Singapore 117411 Department of Biomedical Engineering, National University of Singapore, Singapore 117575
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13
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Kuang R, Wang Z, Xu Q, Cai X, Liu T. Exposure to Varying Strain Magnitudes Influences the Conversion of Normal Skin Fibroblasts Into Hypertrophic Scar Cells. Ann Plast Surg 2016; 76:388-93. [DOI: 10.1097/sap.0000000000000654] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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14
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Scott DW, Tolbert CE, Burridge K. Tension on JAM-A activates RhoA via GEF-H1 and p115 RhoGEF. Mol Biol Cell 2016; 27:1420-30. [PMID: 26985018 PMCID: PMC4850030 DOI: 10.1091/mbc.e15-12-0833] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/10/2016] [Indexed: 12/20/2022] Open
Abstract
Forces on JAM-A activate RhoA to increase cell stiffness. Activation of RhoA requires GEF-H1 and p115 RhoGEF activation downstream of FAK/ERK and Src family kinases, respectively. Junctional adhesion molecule A (JAM-A) is a broadly expressed adhesion molecule that regulates cell–cell contacts and facilitates leukocyte transendothelial migration. The latter occurs through interactions with the integrin LFA-1. Although we understand much about JAM-A, little is known regarding the protein’s role in mechanotransduction or as a modulator of RhoA signaling. We found that tension imposed on JAM-A activates RhoA, which leads to increased cell stiffness. Activation of RhoA in this system depends on PI3K-mediated activation of GEF-H1 and p115 RhoGEF. These two GEFs are further regulated by FAK/ERK and Src family kinases, respectively. Finally, we show that phosphorylation of JAM-A at Ser-284 is required for RhoA activation in response to tension. These data demonstrate a direct role of JAM-A in mechanosignaling and control of RhoA and implicate Src family kinases in the regulation of p115 RhoGEF.
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Affiliation(s)
- David W Scott
- Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Caitlin E Tolbert
- Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Keith Burridge
- Department of Cell Biology and Physiology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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15
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Hamzeh MT, Sridhara R, Alexander LD. Cyclic stretch-induced TGF-β1 and fibronectin expression is mediated by β1-integrin through c-Src- and STAT3-dependent pathways in renal epithelial cells. Am J Physiol Renal Physiol 2014; 308:F425-36. [PMID: 25477471 DOI: 10.1152/ajprenal.00589.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Extracellular matrix (ECM) proteins, including fibronectin, may contribute to the early development and progression of renal interstitial fibrosis associated with chronic renal disease. Recent studies showed that β1-integrin is associated with the development of renal fibrosis in a murine model of unilateral ureteral obstruction (UUO). However, the molecular events responsible for β1-integrin-mediated signaling, following UUO, have yet to be determined. In this study, we investigated the mechanism by which mechanical stretch, an in vitro model for chronic obstructive nephropathy, regulates fibronectin and transforming growth factor-β1 (TGF-β1) expression in cultured human proximal tubular epithelium (HK-2) cells. Mechanical stretch upregulated fibronectin and TGF-β1 expression and activated signal transducer and transcription factor 3 (STAT3) in a time-dependent manner. Stretch-induced fibronectin and TGF-β1 were suppressed by a STAT3 inhibitor, S3I-201, and by small interfering RNA (siRNA) targeting human STAT3 (STAT3 siRNA). Similarly, fibronectin and TGF-β1 expression and STAT3 activation induced by mechanical stretch were suppressed by the Src family kinase inhibitor PP2 and by transfection of HK-2 cells with a dominant-negative mutant of c-Src (DN-Src), whereas PP3, an inactive analog of PP2, had no significant effect. Furthermore, mechanical stretch resulted in increased β1-integrin mRNA and protein levels in HK-2 cells. Furthermore, neutralizing antibody against β1-integrin and silencing of β1-integrin expression with siRNAs resulted in decreased c-Src and STAT3 activation and TGF-β1 and fibronectin expression evoked by mechanical stretch. This work demonstrates, for the first time, a role for β1-integrin in stretch-induced renal fibrosis through the activation of c-Src and STAT3 signaling pathways.
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Affiliation(s)
- Mona T Hamzeh
- Department of Biology, Division of Natural Sciences, University of Michigan-Dearborn, Dearborn, Michigan
| | - Rashmi Sridhara
- Midwestern University, Arizona College of Osteopathic Medicine, Department of Physiology, Glendale, Arizona; and
| | - Larry D Alexander
- Midwestern University, Arizona College of Osteopathic Medicine, Department of Physiology, Glendale, Arizona; and
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16
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Janoštiak R, Pataki AC, Brábek J, Rösel D. Mechanosensors in integrin signaling: The emerging role of p130Cas. Eur J Cell Biol 2014; 93:445-54. [DOI: 10.1016/j.ejcb.2014.07.002] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/11/2014] [Accepted: 07/01/2014] [Indexed: 12/17/2022] Open
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Gong J, Zhang D, Tseng Y, Li B, Wirtz D, Schafer BW. Form-finding model shows how cytoskeleton network stiffness is realized. PLoS One 2013; 8:e77417. [PMID: 24146992 PMCID: PMC3798660 DOI: 10.1371/journal.pone.0077417] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 09/10/2013] [Indexed: 11/18/2022] Open
Abstract
In eukaryotic cells the actin-cytoskeletal network provides stiffness and the driving force that contributes to changes in cell shape and cell motility, but the elastic behavior of this network is not well understood. In this paper a two dimensional form-finding model is proposed to investigate the elasticity of the actin filament network. Utilizing an initially random array of actin filaments and actin-cross-linking proteins the form-finding model iterates until the random array is brought into a stable equilibrium configuration. With some care given to actin filament density and length, distance between host sites for cross-linkers, and overall domain size the resulting configurations from the form-finding model are found to be topologically similar to cytoskeletal networks in real cells. The resulting network may then be mechanically exercised to explore how the actin filaments deform and align under load and the sensitivity of the network’s stiffness to actin filament density, length, etc. Results of the model are consistent with the experimental literature, e.g. actin filaments tend to re-orient in the direction of stretching; and the filament relative density, filament length, and actin-cross-linking protein’s relative density, control the actin-network stiffness. The model provides a ready means of extension to more complicated domains and a three-dimensional form-finding model is under development as well as models studying the formation of actin bundles.
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Affiliation(s)
- Jinghai Gong
- Department of Civil Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
- Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Daxu Zhang
- Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yiider Tseng
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, United States of America
| | - Baolong Li
- Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Denis Wirtz
- Department of Chemical and Biomolecular Engineering, Department of Oncology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Benjamin William Schafer
- Department of Civil Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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18
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A Uniaxial Cell Stretcher In Vitro Model Simulating Tissue Expansion of Plastic Surgery. J Craniofac Surg 2013; 24:1431-5. [DOI: 10.1097/scs.0b013e31828dcc1f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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19
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Orientation-specific responses to sustained uniaxial stretching in focal adhesion growth and turnover. Proc Natl Acad Sci U S A 2013; 110:E2352-61. [PMID: 23754369 DOI: 10.1073/pnas.1221637110] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cells are mechanosensitive to extracellular matrix (ECM) deformation, which can be caused by muscle contraction or changes in hydrostatic pressure. Focal adhesions (FAs) mediate the linkage between the cell and the ECM and initiate mechanically stimulated signaling events. We developed a stretching apparatus in which cells grown on fibronectin-coated elastic substrates can be stretched and imaged live to study how FAs dynamically respond to ECM deformation. Human bone osteosarcoma epithelial cell line U2OS was transfected with GFP-paxillin as an FA marker and subjected to sustained uniaxial stretching. Two responses at different timescales were observed: rapid FA growth within seconds after stretching, and delayed FA disassembly and loss of cell polarity that occurred over tens of minutes. Rapid FA growth occurred in all cells; however, delayed responses to stretch occurred in an orientation-specific manner, specifically in cells with their long axes perpendicular to the stretching direction, but not in cells with their long axes parallel to stretch. Pharmacological treatments demonstrated that FA kinase (FAK) promotes but Src inhibits rapid FA growth, whereas FAK, Src, and calpain 2 all contribute to delayed FA disassembly and loss of polarity in cells perpendicular to stretching. Immunostaining for phospho-FAK after stretching revealed that FAK activation was maximal at 5 s after stretching, specifically in FAs oriented perpendicular to stretch. We hypothesize that orientation-specific activation of strain/stress-sensitive proteins in FAs upstream to FAK and Src promote orientation-specific responses in FA growth and disassembly that mediate polarity rearrangement in response to sustained stretch.
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20
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Rustad KC, Wong VW, Gurtner GC. The role of focal adhesion complexes in fibroblast mechanotransduction during scar formation. Differentiation 2013; 86:87-91. [PMID: 23623400 DOI: 10.1016/j.diff.2013.02.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 02/14/2013] [Indexed: 11/17/2022]
Abstract
Historically, great efforts have been made to elucidate the biochemical pathways that direct the complex process of wound healing; however only recently has there been recognition of the importance that mechanical signals play in the process of tissue repair and scar formation. The body's physiologic response to injury involves a dynamic interplay between mechanical forces and biochemical cues which directs a cascade of signals leading ultimately to the formation of fibrotic scar. Fibroblasts are a highly mechanosensitive cell type and are also largely responsible for the generation of the fibrotic matrix during scar formation and are thus a critical player in the process of mechanotransduction during tissue repair. Mechanotransduction is initiated at the interface between the cell membrane and the extracellular matrix where mechanical signals are first translated into a biochemical response. Focal adhesions are dynamic multi-protein complexes through which the extracellular matrix links to the intracellular cytoskeleton. These focal adhesion complexes play an integral role in the propagation of this initial mechanical cue into an extensive network of biochemical signals leading to widespread downstream effects including the influx of inflammatory cells, stimulation of angiogenesis, keratinocyte migration, fibroblast proliferation and collagen synthesis. Increasing evidence has demonstrated the importance of the biomechanical milieu in healing wounds and suggests that an integrated approach to the discovery of targets to decrease scar formation may prove more clinically efficacious than previous purely biochemical strategies.
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Affiliation(s)
- Kristine C Rustad
- Department of Surgery, Stanford University, Stanford, California, USA
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Burridge K, Wittchen ES. The tension mounts: stress fibers as force-generating mechanotransducers. ACTA ACUST UNITED AC 2013; 200:9-19. [PMID: 23295347 PMCID: PMC3542796 DOI: 10.1083/jcb.201210090] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Stress fibers (SFs) are often the most prominent cytoskeletal structures in cells growing in tissue culture. Composed of actin filaments, myosin II, and many other proteins, SFs are force-generating and tension-bearing structures that respond to the surrounding physical environment. New work is shedding light on the mechanosensitive properties of SFs, including that these structures can respond to mechanical tension by rapid reinforcement and that there are mechanisms to repair strain-induced damage. Although SFs are superficially similar in organization to the sarcomeres of striated muscle, there are intriguing differences in their organization and behavior, indicating that much still needs to be learned about these structures.
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Affiliation(s)
- Keith Burridge
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA.
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Lewitzky M, Simister PC, Feller SM. Beyond 'furballs' and 'dumpling soups' - towards a molecular architecture of signaling complexes and networks. FEBS Lett 2012; 586:2740-50. [PMID: 22710161 DOI: 10.1016/j.febslet.2012.04.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Accepted: 04/16/2012] [Indexed: 12/14/2022]
Abstract
The molecular architectures of intracellular signaling networks are largely unknown. Understanding their design principles and mechanisms of processing information is essential to grasp the molecular basis of virtually all biological processes. This is particularly challenging for human pathologies like cancers, as essentially each tumor is a unique disease with vastly deranged signaling networks. However, even in normal cells we know almost nothing. A few 'signalosomes', like the COP9 and the TCR signaling complexes have been described, but detailed structural information on their architectures is largely lacking. Similarly, many growth factor receptors, for example EGF receptor, insulin receptor and c-Met, signal via huge protein complexes built on large platform proteins (Gab, Irs/Dok, p130Cas[BCAR1], Frs families etc.), which are structurally not well understood. Subsequent higher order processing events remain even more enigmatic. We discuss here methods that can be employed to study signaling architectures, and the importance of too often neglected features like macromolecular crowding, intrinsic disorder in proteins and the sophisticated cellular infrastructures, which need to be carefully considered in order to develop a more mature understanding of cellular signal processing.
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Affiliation(s)
- Marc Lewitzky
- Biological Systems Architecture Group, Weatherall Institute of Molecular Medicine, Department of Oncology, University of Oxford, Oxford OX3 9DS, United Kingdom.
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