Kumar Mechanotransduction

1. Auflage 2014
ISBN: 978-0-12-398327-5
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, Band Volume 126, 384 Seiten

Reihe: Progress in Molecular Biology and Translational Science

Progress in Molecular Biology and Translational Science provides a forum for discussion of new discoveries, approaches, and ideas in molecular biology. It contains contributions from leaders in their fields and abundant references. Volume 126 features in-depth reviews that focus on the tools required to investigate mechanotransduction. Additional chapters focus on how we can use these tools to answer fundamental questions about the interaction of physical forces with cell biology, morphogenesis, and function of mature structures. Chapters in the volume are authored by a unique combination of cell biologists and engineers, providing a range of perspectives on mechanotransduction. - Provides a unique combination of perspectives from biologists and engineers - Engaging to people of many training backgrounds

Autoren/Hrsg.

Kumar, Sanjay

Inhaltsverzeichnis

1;Front Cover;1
2;Mechanotransduction;4
3;Copyright;5
4;Contents;6
5;Contributors;12
6;Preface;14
7;Part One: Subcellular Tools for Activating and Measuring Mechanotransductive Signaling;16
7.1;Chapter One: The Detection and Role of Molecular Tension in Focal Adhesion Dynamics;18
7.1.1;1. Brief Introduction to Mechanobiology;19
7.1.2;2. Focal Adhesions in Mechanosensing;20
7.1.2.1;2.1. Focal adhesion structure;20
7.1.2.2;2.2. Molecular mechanisms of mechanotransduction;21
7.1.3;3. Design and Use of Optically Based Molecular Tension Sensors;24
7.1.3.1;3.1. Basics of Forster Resonance Energy Transfer (FRET);24
7.1.3.2;3.2. Designs of FRET-based force-sensitive biosensors;26
7.1.3.2.1;3.2.1. Extensible domain;26
7.1.3.2.2;3.2.2. Rotatable domain;28
7.1.3.2.3;3.2.3. Other designs;28
7.1.3.3;3.3. Use of FRET-based tension sensors: Relative versus absolute measurements;29
7.1.3.4;3.4. Critical control experiments and assumptions involved in the creation and use of FRET-based biosensors;30
7.1.3.5;3.5. Conformation sensors versus tension sensors;31
7.1.4;4. The Role of Molecular Tension in Focal Adhesion Dynamics;31
7.1.5;5. Future Outlook;34
7.1.6;Acknowledgments;34
7.1.7;References;34
7.2;Chapter Two: Single-Cell Imaging of Mechanotransduction in Endothelial Cells;40
7.2.1;1. Introduction;41
7.2.2;2. Atherosclerosis, EC Wound Healing, and Mechanotransduction;42
7.2.3;3. Signaling Molecules Involved in Mechanosensing and Mechanotransduction;44
7.2.4;4. The Effect of Subcellular Structure on Mechanotransduction;45
7.2.5;5. Focal Adhesion and FAK;50
7.2.6;6. Tools to Monitor Signal Transduction in Live Cells;51
7.2.6.1;6.1. FPs, FRET, and fluorescence lifetime imaging microscopy;51
7.2.6.2;6.2. Quantitative image-based analysis for live cells;52
7.2.6.3;6.3. The FRAP analysis and finite-element-based diffusion analysis;52
7.2.6.4;6.4. Automatic tracking of moving cells and subcellular features;53
7.2.7;7. Conclusion;55
7.2.8;References;56
8;Part Two: Focal Adhesions as Sensors;68
8.1;Chapter Three: Focal Adhesions Function as a Mechanosensor;70
8.1.1;1. Introduction: The Basic Organization of Focal Adhesions;70
8.1.2;2. Mechanosensitivity of Focal Adhesions;74
8.1.3;3. Focal Adhesions and the Effects of Environmental Parameters;80
8.1.4;4. Focal Adhesion Signals and Cell Migration;81
8.1.5;Acknowledgments;82
8.1.6;References;83
8.2;Chapter Four: Mechanosensation: A Basic Cellular Process;90
8.2.1;1. Introduction;91
8.2.1.1;1.1. Historical development;91
8.2.1.2;1.2. Mechanosensation/-transduction;91
8.2.1.3;1.3. Effects of extracellular matrix stiffness;92
8.2.1.4;1.4. Stress generated by external compression/contractility;93
8.2.1.5;1.5. Stress generated by cell contractility;94
8.2.1.6;1.6. Biological relevance of external and internal stress;94
8.2.2;2. Focal Adhesions;97
8.2.2.1;2.1. Mechanotransduction/-signaling;99
8.2.2.2;2.2. Focal adhesion proteins;99
8.2.2.2.1;2.2.1. Vinculin;99
8.2.2.2.2;2.2.2. Zyxin;100
8.2.2.2.3;2.2.3. Talin;100
8.2.2.2.4;2.2.4. Paxillin, Pyk2;101
8.2.2.2.5;2.2.5. p130Cas;101
8.2.2.2.6;2.2.6. Focal adhesion kinase;101
8.2.2.3;2.3. Force transduction at focal adhesions;102
8.2.2.4;2.4. Protein crosstalk;106
8.2.2.5;2.5. Cell signaling pathways;106
8.2.2.6;2.6. Translation of information gathered at focal adhesions;107
8.2.2.7;2.7. Focal adherence junctions;107
8.2.2.8;2.8. Measuring mechanotransduction/-sensation;108
8.2.2.8.1;2.8.1. Flow chambers and cone and plate rheometers;108
8.2.2.8.2;2.8.2. Magnetic and optical traps;108
8.2.2.8.3;2.8.3. Atomic force microscopy and biomembrane force probe;108
8.2.2.8.4;2.8.4. Cell stretcher;109
8.2.2.8.5;2.8.5. Hydrostatic pressure;109
8.2.2.8.6;2.8.6. Stretch-activated ion channels;109
8.2.3;3. Conclusions;110
8.2.4;Acknowledgments;111
8.2.5;References;111
8.3;Chapter Five: Mechanical Cues Direct Focal Adhesion Dynamics;118
8.3.1;1. Introduction;119
8.3.2;2. Form and Function of Focal Adhesions;121
8.3.2.1;2.1. Influence of the ECM;121
8.3.2.2;2.2. Integrins are integral;124
8.3.2.3;2.3. Formation of focal adhesions;124
8.3.2.4;2.4. Cytoskeletal interplay;127
8.3.3;3. AFM as a Tool to Stimulate a Cellular Response;130
8.3.3.1;3.1. Cytoskeletal strain directs focal adhesion formation;131
8.3.3.2;3.2. Forces and substrate elasticity influence traction;135
8.3.4;4. Future Directions;142
8.3.5;Acknowledgments;143
8.3.6;References;143
8.4;Chapter Six: Molecular Mechanisms Underlying the Force-Dependent Regulation of Actin-to-ECM Linkage at the Focal Adhesions;150
8.4.1;1. Introduction;151
8.4.2;2. Molecular Assembly in the Actin-Integrin-ECM Linkage;152
8.4.2.1;2.1. Formation of the initial linkage;152
8.4.2.2;2.2. Force-dependent maturation of the linkage;153
8.4.3;3. Force-Sensing/Transducing Molecules in the Regulation of the Actin-Integrin-ECM Linkage;155
8.4.3.1;3.1. Talin and vinculin;155
8.4.3.1.1;3.1.1. Force-dependent vinculin binding with talin;155
8.4.3.1.2;3.1.2. The talin-vinculin binding in strengthening of the actin-integrin linkage;157
8.4.3.2;3.2. Zyxin, filamin, and actin assembly;158
8.4.3.2.1;3.2.1. Zyxin-dependent actin polymerization;159
8.4.3.2.2;3.2.2. Filamin and bundling of actin filaments;159
8.4.3.3;3.3. Integrin-fibronectin binding;160
8.4.4;4. Dynamic Aspect of the Actin-Integrin-ECM Linkage: Molecular Clutch;161
8.4.5;5. Concluding Remarks;163
8.4.6;Acknowledgments;164
8.4.7;References;164
9;Part Three: Nuclear Mechanisms of Sensing;170
9.1;Chapter Seven: The Cellular Mastermind(?)-Mechanotransduction and the Nucleus;172
9.1.1;1. Introduction;174
9.1.2;2. Overview of Nuclear Structure and Organization;176
9.1.2.1;2.1. Chromatin and chromosome territories;177
9.1.2.2;2.2. Subnuclear structures and nuclear bodies;180
9.1.2.3;2.3. The nucleoskeleton;181
9.1.2.4;2.4. Lamins, the nuclear lamina, and nuclear mechanics;182
9.1.2.5;2.5. Lamin-binding proteins;185
9.1.2.6;2.6. Nuclear membranes and nuclear pore complexes;186
9.1.2.7;2.7. LINC complexes;187
9.1.3;3. Mechanically Induced Changes in Nuclear Structure;189
9.1.3.1;3.1. Nuclear deformation during cell migration;189
9.1.3.2;3.2. Nuclear deformation under shear stress;191
9.1.3.3;3.3. Nuclear deformation under compression;191
9.1.3.4;3.4. Nuclear deformation under strain application;192
9.1.3.5;3.5. Substrate stiffness and patterning;192
9.1.3.6;3.6. Micromanipulation;192
9.1.4;4. Potential Mechanisms for Direct Nuclear Mechanosensing;193
9.1.5;5. Mechanotransduction Signaling in the Nucleus;195
9.1.5.1;5.1. MAPK/ERK/Fos;197
9.1.5.2;5.2. Wnt signaling;198
9.1.5.3;5.3. TGF-ß and Smad signaling;198
9.1.5.4;5.4. MKL1/SRF signaling;199
9.1.5.5;5.5. YAP/TAZ signaling;200
9.1.5.6;5.6. Interaction of retinoblastoma protein, lamins A/C, and LAP2a;201
9.1.5.7;5.7. Phosphorylation of nuclear envelope proteins;201
9.1.6;6. Functional Consequences of Impaired Mechanotransduction and Disease;202
9.1.6.1;6.1. Muscular dystrophy;203
9.1.6.2;6.2. Dilated cardiomyopathy;204
9.1.6.3;6.3. Hutchinson-Gilford progeria syndrome;204
9.1.7;7. Open Questions and Future Research Directions;205
9.1.8;8. Conclusions;206
9.1.9;Acknowledgments;208
9.1.10;References;208
9.2;Chapter Eight: Nuclear Forces and Cell Mechanosensing;220
9.2.1;1. Introduction;220
9.2.2;2. Cytoskeletal Forces are Exerted on the Nucleus;221
9.2.3;3. The LINC Complex Transmits Cytoskeletal Forces to the Nuclear Surface;223
9.2.4;4. The Role of the Nucleus in Cell Mechanosensing;225
9.2.5;5. Conclusions;226
9.2.6;Acknowledgments;226
9.2.7;References;227
10;Part Four: Mechano-Sensing in Stem Cells;232
10.1;Chapter Nine: From Stem Cells to Cardiomyocytes: The Role of Forces in Cardiac Maturation, Aging, and Disease;234
10.1.1;1. Introduction;235
10.1.2;2. Cardiac Morphogenesis During the Lifespan of the Heart;236
10.1.2.1;2.1. Specification, differentiation, and heart morphogenesis;236
10.1.2.2;2.2. Cell maturation and maintenance;236
10.1.3;3. Mechanosensitive Compartments in Cardiomyocytes;237
10.1.4;4. The Sarcomere;238
10.1.4.1;4.1. Cardiac structure and mechanosignaling;238
10.1.4.2;4.2. Sarcomere mutations, microenvironmental changes, and their impact;240
10.1.5;5. Other Intracellular Mechanosensitive Structures;241
10.1.5.1;5.1. Actin-associated intercalated disc and costameric proteins;241
10.1.5.2;5.2. Intermediate filament and microtubule networks;243
10.1.5.3;5.3. The cardiomyocyte membrane;244
10.1.6;6. ECM and Mechanosensing;244
10.1.7;7. The Influence of Mechanotransduction on Applications of Cardiac Regeneration;245
10.1.8;8. Conclusion;246
10.1.9;References;247
10.2;Chapter Ten: Matrix Regulation of Tumor-Initiating Cells;258
10.2.1;1. Introduction;259
10.2.1.1;1.1. What are tumor-initiating cells?;259
10.2.1.2;1.2. Significance of TICs;260
10.2.2;2. Identification and Isolation of TICs;262
10.2.3;3. Role of Extracellular Matrix and Mechanical Signals in Regulating TIC Function;262
10.2.3.1;3.1. Extracellular matrix;262
10.2.3.2;3.2. Propagation of TICs in ECM-adherent cultures;264
10.2.3.3;3.3. Mechanisms of mechanotransduction;265
10.2.4;4. Conclusion;266
10.2.5;References;267
10.3;Chapter Eleven: Biomaterials Approaches in Stem Cell Mechanobiology;272
10.3.1;1. Introduction;273
10.3.2;2. Mechanical Regulation of Stem Cell Fate;274
10.3.2.1;2.1. Tensional homeostasis and the origins of cellular force;274
10.3.2.2;2.2. Matrix stiffness, cell shape, and tension as regulators of stem cell fate;276
10.3.3;3. Mechanosensing and Mechanotransduction;280
10.3.3.1;3.1. Focal adhesions as mechanical sensors;280
10.3.3.2;3.2. Integrin-mediated mechanical signaling;281
10.3.3.3;3.3. Mechanically responsive ion channels, chromatin remodeling, and transcription factors;281
10.3.4;4. Pushing Ahead: Biomaterials Approaches to Probe Stem Cell Mechanobiology;284
10.3.4.1;4.1. Resolving interactions between mechanical and molecular signals;284
10.3.4.2;4.2. Controlling mechanics in space and time;286
10.3.5;5. Summary and Outlook;287
10.3.6;References;288
11;Part Five: Multi-Cellular Sensing;294
11.1;Chapter Twelve: Mechanotransduction in C. elegans Morphogenesis and Tissue Function;296
11.1.1;1. Intracellular Sensation and Response to Mechanical Input;297
11.1.1.1;1.1. Introduction;297
11.1.1.2;1.2. Mechanical influences in the C. elegans zygote;298
11.1.1.3;1.3. Cell shape changes;300
11.1.1.4;1.4. Nuclear response;300
11.1.2;2. Mechanical Influences in Embryonic Development;301
11.1.2.1;2.1. C. elegans integrins and mechanotransduction;302
11.1.2.2;2.2. Mechanical stability and attachment to apical ECM;302
11.1.2.3;2.3. Introduction to cell-cell junctions in C. elegans;304
11.1.2.4;2.4. Role of adherens junctions in C. elegans embryonic elongation;305
11.1.2.5;2.5. Mechanical coordination between tissues;308
11.1.3;3. Mechanical Influences in Larval Development and Tissue Function;310
11.1.3.1;3.1. Excretory canal development;310
11.1.3.2;3.2. Mechanical inputs into spermathecal function;312
11.1.4;4. Tools for Manipulation and Imaging;316
11.1.4.1;4.1. FRET-based sensors;316
11.1.4.2;4.2. Optogenetics;317
11.1.5;5. Future Prospects;319
11.1.6;Acknowledgments;320
11.1.7;References;320
11.2;Chapter Thirteen: Mechanical Force Sensing in Tissues;332
11.2.1;1. Introduction: Molecular Mechanisms of Multicellular Force Sensing;333
11.2.1.1;1.1. Force sensing by adhesion complexes;334
11.2.1.2;1.2. Force sensing by actomyosin networks;335
11.2.1.3;1.3. Force sensing by the cell plasma membrane;338
11.2.1.4;1.4. Force sensing by change in cell geometry;339
11.2.2;2. Multicellular Sensing During Tissue Growth;340
11.2.2.1;2.1. Mechanical regulation of tissue growth;341
11.2.2.2;2.2. Mechanical regulation of cell growth orientation;345
11.2.3;3. Multicellular Sensing During Tissue Morphogenesis;349
11.2.3.1;3.1. Mechanical coordination of actomyosin contractility;349
11.2.3.2;3.2. Mechanical reinforcement of junctions;354
11.2.3.3;3.3. Extrinsic mechanical constraints influencing tissue shape;356
11.2.4;Acknowledgments;359
11.2.5;References;359
12;Index;368
13;Color Plate;381

Leseproben

Chapter One

The Detection and Role of Molecular Tension in Focal Adhesion Dynamics

Brenton D. Hoffman    Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA

Abstract

Cells are exquisitely sensitive to the mechanical nature of their environment, including applied force and the stiffness of the extracellular matrix (ECM). Recent evidence has shown that these variables are critical regulators of diverse processes mediating embryonic development, adult tissue physiology, and many disease states, including cancer, atherosclerosis, and myopathies. Often, detection of mechanical stimuli is mediated by the structures that link cells that surround ECM, the focal adhesions (FAs). FAs are intrinsically force sensitive and display altered dynamics, structure, and composition in response to applied load. While much progress has been made in determining the proteins that localize to and regulate the formation of these structures, less is known about the role of tension across specific proteins in this process. A recently developed class of force-sensitive biosensors is enabling a greater understanding of the molecular bases of cellular mechanosensitivity and cell migration.

Keywords

Mechanotransduction

Mechanobiology

Cell migration, Focal adhesions

Forster Resonance Energy Transfer

Tension sensor

Vinculin

1 Brief Introduction to Mechanobiology

The mechanical nature of the cellular microenvironment is increasingly recognized as a key determinant of many developmental, physiological, and pathophysiological processes1–6 as well as an important variable in tissue engineering and regenerative medicine.7–9 In vivo cells adhere to a deformable extracellular matrix (ECM) that is both a source of applied forces and a means of mechanical support.10–12 Cells detect, interpret, and respond to these mechanical signals through a poorly understood process called mechanotransduction.13,14 Mechanosensitive signaling affects several fundamental cellular processes, including cell contraction,15 migration,16 differentiation,17 and growth.18 For instance, during gastrulation in Drosophila melanogaster, germband extension causes compression of the stomodeal cells required for subsequent tissue invagination.19 Similarly, mechanical effects also mediate many physiological principles. These include Wolfe's law, which describes how mechanical loading leads to enhanced bone formation to enable adaptation of the skeleton,20 as well as the Bayliss effect, which describes the reduction in the diameter of arterioles after a pressure increase to maintain constant flow in downstream capillaries.21

Pathological mechanotransduction, often due to alterations in the mechanical nature of the microenvironment, is critically important in many prevalent and poorly understood human diseases.4,6,22 Inside the vasculature, cyclic blood flow leads to dynamic shear stresses on endothelial cells and alterations in blood pressure, stretching the vessel wall. Atherosclerotic lesions preferentially form in areas with perturbed hemodynamics and reduced forces applied to cells. Tumors are characterized by enhanced cell growth and perturbed ECM structure, leading to changes in the local tissue stiffness.15 These alterations in mechanical properties enable palpation exams for “lumps” as a common method of tumor detection. Recently, these rigidity changes have been shown to have a causative role in tumor progression.23

Traditionally, biological regulation has been understood through the principles of solution chemistry; reaction rates, diffusion, and binding affinities have been considered the dominant molecular scale variables. A central premise of biochemistry is that protein structure dictates function, suggesting that the diverse properties exhibited by proteins are due to their intricate three-dimensional shapes. A significant challenge in the field of mechanobiology is determining how macroscale mechanical variables alter molecular scale biochemical processes.24 A major advance was the demonstration that proteins are deformable at forces that can be generated by cells.25–27 Thus, a simple mechanism for mechanotransduction is that applied load alters protein structure, leading to novel functions. While many ground-breaking studies have enumerated the changes in cell signaling or protein expression after mechanical stimulation,28,29 relatively few have focused on determining the relationship between protein deformation and alterations in biochemical properties, such as differential enzymatic activity or binding lifetimes, in living cells. Recently, a new class of biosensor has been developed that reports the deformation within or the tension across specific proteins in living cells.30–32 These have started to reveal some of the molecular mechanisms mediating mechanotransduction, particularly in the context of adhesion biology.

In this article, I first review mechanosensitive behavior in the subcellular structure most associated with mechanosensitive phenomena, the focal adhesion (FA).33 We divide this process into mechanotransmission, mechanosensing, and mechanoresponse and briefly highlight critical molecular determinants of each step. Then, I discuss issues associated with the development and use of force-sensitive biosensors. I also describe recent advances in the understanding of the force-sensitive regulation of FA dynamics made possible by the development of these new sensors. I end by highlighting several future experiments that would further our understanding of the biophysical and biochemical processes mediating mechanotransduction.

2 Focal Adhesions in Mechanosensing

2.1 Focal adhesion structure

While the signaling pathways mediating mechanotransduction are still being elucidated, important subcellular structures have been identified.34 These include the structures that cells utilize to interact with the ECM, FAs.35 FAs are dynamic mechanosensitive scaffolds containing > 150 proteins that mechanically link the ECM and actin cytoskeleton.36,37 Connections to the ECM are mediated by integrins, heterodimeric transmembrane proteins which mediate cell adhesion through conformational regulation.38 Integrins primarily mediate changes in FA structure through the direct and indirect recruitment of proteins. Recent work using super-resolution microscopy with enhanced resolution in the vertical direction has shown that the proteins within FAs are arranged in a weakly stratified structure, comprising an integrin signaling layer, a force transduction layer, an actin regulatory layer, and finally actin-based stress fibers. The stress fibers simultaneously load the FA with forces generated by the cytoskeleton and resist deformation due to the application of external loads39 (Fig. 1.1). The cytoplasmic domains of integrins mediate interactions with numerous adaptor proteins (e.g., talin, paxillin, kindlin) and recruit, directly or indirectly, a host of signaling proteins (e.g., FA kinase, Src family kinases) to comprise the integrin signaling layer. The force transmission layer comprises many additional adaptor proteins (e.g., vinculin, talin, zyxin) that enable the dynamic and biochemically regulated transmission of force between the other layers. These proteins bind to a host of actin regulatory proteins (e.g., VASP) and actin cross-linking proteins (e.g, actinin) that mediate formation and reinforcement of the actin stress fibers. Note that some proteins exist in multiple layers. Talin, for instance, is thought to be oriented at an angle to link multiple layers.39

Figure 1.1 The stratified structure of a focal adhesion (FA). Integrins are transmembrane proteins that bind to the ECM and several intracellular proteins, including paxillin and FAK. Many of the proteins found near the plasma membrane are signaling proteins, which determine the activation state and binding partners of integrins. Slightly higher in the FA reside many adaptor proteins whose main functions are to transmit force between the layers and transduce these forces into biochemically detectable signals. Key elements include talin and vinculin. Higher still is a layer of proteins associated with actin regulation. This class is typified by VASP. At the highest point, the FA links to actin stress fibers. These layers work in concert to regulating the mechanosensitive behavior of the FA.

2.2 Molecular mechanisms of mechanotransduction

Descriptions of mechanotransduction typically involve three distinct steps: transmission of the applied load to specialized structures, transduction of the force into a biochemically detectable signal, and the subsequent response of the cell13,40 (Fig. 1.2). These are commonly referred to as mechanotransmission, mechanosensing, and mechanoresponse, respectively. Here, I focus on the first two steps. Mechanoresponses, including the long-term adaptation of cellular adhesion structures and the actin cytoskeleton, activation of transcription factors leading differential protein expression, as well as many physiological processes mediating tissue homeostasis in response to mechanical perturbations, are not necessarily force-dependent and have been extensively reviewed...