Cellular Mechanotransduction

Author: Mohammad R. K. Mofrad
Publisher: Cambridge University Press
ISBN: 9781107682467
Size: 57.39 MB
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Cellular Mechanotransduction from the Author: Mohammad R. K. Mofrad. "Mechanotransduction" is the term for the ability, first described by 19th-century anatomist Julius Wolff, of living tissues to sense mechanical stress and respond by tissue remodeling. More recently, the scope of mechanotransduction has been expanded to include the sensation of stress, its translation into a biochemical signal, and the sequence of biological responses it produces. This book looks at mechanotransduction in a more restricted sense, focusing on the process of stress sensing and transducing a mechanical force into a cascade of biochemical signals. This stress has become increasingly recognized as one of the primary and essential factors controlling biological functions, ultimately affecting the function of the cells, tissues, and organs. A primary goal of this broad book is also to help define the new field of mechanomics, which attempts to describe the complete mechanical state of a biological system.

Study Of Cellular Mechanotransduction By Visualizing Actin And Nucleoskeleton Dynamics In Real Time

Author: Shu Kan
Size: 60.34 MB
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Study Of Cellular Mechanotransduction By Visualizing Actin And Nucleoskeleton Dynamics In Real Time from the Author: Shu Kan. Cellular mechanotransduction, the tight coupling between biochemical and mechanical properties of the cytoskeleton and nucleus, drives a large range of cellular processes including cell mobility, cytokinesis, vesicle transportation, or even cell fate determination affected by alterations in gene expression. In this study, we study cellular mechanotransduction by direct imaging of the actin cytoskeleton and component of nucleoskeleton during normal cellular processes and under different stresses. A novel class of cell permeable actin filament free barbed end dye was developed to achieve high spatial and temporal resolution of actin dynamic imaging. the generation of free barbed ends of actin filaments during lamellipodia protrusion, cytokinesis and endocytosis were monitored in this study, providing new insights on the regulation of free barbed end of actin filaments during these actin-driven processes. By distinguished visualization of the filaments and barbed end pool of actin in cells, the controversial views of whether new actin polymerization is involved during cleavage furrow closure and scission were resolved, we show that there is a surge of new actin polymerization during telophase, beginning with ingression of the contractile ring and ending with the separation of daughter cells, supporting the view that new actin polymerization is involved in cytokinesis. we further developed a triple labeling system with the genetically encoded florescent protein (FP) fused with nuclear component including emerin, Sun1, Sun2 and lamin A. The FP was carefully choosing so the excitation and emission spectrums of FP and (Si)TMR actin dyes are far apart enough to allow spontaneous imaging of the three components. Several chemicals were applied to disrupt cytoskeleton of the cells, the corresponding responses of the nucleus components were visualized real-time, providing insights on the interaction between nucleus and cytoskeleton. we also developed a label-free optical biosensor that employs a silicon-based high-contrast grating (HCG) resonator with a spectral linewidth of ~500pm sensitive to ligand-induced changes in surface properties in collaboration with Professor Constance Chang-Hasnain's group. The device is used to generate thermodynamic and kinetic data on surface-attached antibodies with their respective antigens. The device can detect serum cardiac troponin I, a biomarker of cardiac disease to 100pg/ml within 4-minutes, which is much faster than and as sensitive as current enzyme-linked immuno-assays for cTnI.

High Throughput Microcavitation Bubble Induced Cellular Mechanotransduction

Author: Jonathan Lee Compton
ISBN: 9781303810183
Size: 43.87 MB
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High Throughput Microcavitation Bubble Induced Cellular Mechanotransduction from the Author: Jonathan Lee Compton. Focused pulsed laser irradiation allows for the deposition of energy with high spatial and temporal resolution. These attributes provide an optimal tool for non-contact manipulation in cellular biology such as laser microsurgery, cell membrane permeabilization, as well as targeted cell death. In this thesis we investigate the direct physical effects produced by laser- generated microcavitation bubbles in adherent cell cultures. We examine how variation in pulse durations (180 ps - 6ns) and pulse energy (0.5 - 40 ╬╝;J) affect microcavitation bubble (╬╝;CB) generated cell lysis, necrosis, and molecular delivery. To compare the effects of pulse duration we employ classical fluid dynamics modeling to quantify the perturbation caused on cell populations from ╬╝;CB generated microTsunamis (a transient microscale burst of hydrodynamic shear stress). Through time-resolved imaging we capture the ╬╝;CB dynamics at various energies and pulse durations. Moreover, the mathematical modeling provides information regarding the cellular exposure to time varying shear stress and impulse as a function of radial location from the ╬╝;CB center. We demonstrate that the resultant cellular effect can be predicted based on the total impulse across a two order of magnitude span of pulse duration and pulse energy. We also examine the region of cells beyond the zone of molecular delivery to investigate possible cellular reactions to ╬╝ ;Tsunami exposure. Our studies have shown that cellular mechanotransduction occurs within cell populations spanning an area of up to 1 mm2 surrounding the ╬╝ ;CB. Visualization of mechanotransduction is achieved through the visualization of intracellular calcium signaling via fluorescence microscopy that occurs due to the ability of the ╬╝ Tsunami generated shear stresses to stimulate G-protein coupled receptors at the apical cell surface. Moreover, we have shown that the observed signaling can be attenuated in a dose-dependent manner using 2-APB which is a known inhibitor to IP3 induced Ca2+ release. This capability opens the development of a high-throughput screening platform for molecules that modulate cellular mechanotransduction. We have applied this approach to screen the effects of a small set of small molecules, in a 96-well plate in less than an hour. These detailed studies offer a basis for the design, development, and implementation of a novel high-throughput mechanotransduction assay to rapidly screen the the effect of small molecules on cellular mechanotransduction at high throughput.

Cellular Mechanotransduction Via Microfabricated Post Arrays

Author: Adrienne Higa
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Cellular Mechanotransduction Via Microfabricated Post Arrays from the Author: Adrienne Higa. Substrate-based biophysical cues, which interact with cells through mechanotransductive pathways, influence many biological processes and cellular behaviors. By leveraging microfabrication techniques, this work aims to build biophysical stimuli into cellular substrates through discrete microtopographic features to study cellular responses. Here, uniform and gradient arrays of circular microposts have been geometrically tuned to change the apparent rigidity of a substrate and the placement of available cellular attachment sites. Three areas of cellular interaction with these micropost array substrates have been investigated: (i) single cell motility, (ii) maintenance and inhibition of collective cell behavior, and (iii) reprogramming and differentiation processes of induced pluripotent stem cells (iPSCs). Single cell migration was induced through gradients in substrate stiffness and spacing of available attachment sites - phenomena known as durotaxis and herein referred to as spatiotaxis, respectively. Unidirectional micropost arrays gradients were designed with increasing stiffnesses at low and high gradient strengths of 0.5 nN/[mu]m and 7.5 nN/[mu]m, respectively. On these surfaces, bovine aortic endothelial cells (BAECs) were found to preferentially migrate toward the direction of increasing micropost stiffness. In 18-hour studies, with more than 12 single cells in each case, BAECs had average displacements of 26.5 ┬▒ 8.7 [mu]m and 41.9 ┬▒ 14.7 [mu]m for the low and high gradient strengths, respectively. Furthermore, BAECs were found to migrate in favor of the direction of decreasing interpost spacing over the direction of increasing stiffness in the prototype micropost arrays, demonstrating that spatial cues can dominate stiffness cues in the migratory response of cells. The maintenance and inhibition of collective cell behavior was studied through changes in substrate stiffness and spacing via uniform and gradient micropost arrays with stiffnesses in the range of 24-106 nN/[mu]m. BAEC collectives directly cultured on these surfaces exhibited area contraction or expansion, which corresponded to maintenance and inhibition of group behavior on soft and stiff substrates, respectively. The micropost mechanical stiffness required for collective-to-single cell transitions was characterized as 30 ┬▒ 6 nN/[mu]m. Effects of spacing on collective cell behavior were also explored, and results showed that BAEC collectives were unable to maintain group behavior with favorable stiffness cues, demonstrating again the significance of micropost spacing. The effects of microtopography on the reprogramming and differentiation of iPSCs was investigated through uniform micropost arrays of varying radii and heights with mouse ear fibroblasts (mERFs) on micropost arrays with stiffnesses in the range of 24-2900 nN/[mu]m. Preliminary results have shown that microtopography had influence over the formation of iPSC colonies and the number of colonies that exhibited beating. Specifically, beating colonies were observed as early as 10 days after the infection of mERFs on micropost surfaces, suggesting that microtopography might direct the differentiation of iPSCs. Characterizations of changes in mERF morphology, expression of nuclear structural proteins, and intracellular localization of proteins that regulate gene expression provide evidence for possible mechanisms responsible for the effects of microtopography on the reprogramming and differentiation processes of iPSCs.

Tissue Engineering

Author: John P. Fisher
Publisher: CRC Press
ISBN: 1439874034
Size: 39.45 MB
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Tissue Engineering from the Author: John P. Fisher. Tissue engineering research continues to captivate the interest of researchers and the general public alike. Popular media outlets like The New York Times, Time, and Wired continue to engage a wide audience and foster excitement for the field as regenerative medicine inches toward becoming a clinical reality. Putting the numerous advances in the field into a broad context, Tissue Engineering: Principles and Practices explores current thoughts on the development of engineered tissues. With contributions from experts and pioneers, this book begins with coverage of the fundamentals, details the supporting technology, and then elucidates their applications in tissue engineering. It explores strategic directions, nanobiomaterials, biomimetics, gene therapy, cell engineering, and more. The chapters then explore the applications of these technologies in areas such as bone engineering, cartilage tissue, dental tissue, vascular engineering, and neural engineering. A comprehensive overview of major research topics in tissue engineering, the book: Examines the properties of stem cells, primary cells, growth factors, and extracellular matrix as well as their impact on the development of tissue-engineered devices Focuses upon those strategies typically incorporated into tissue-engineered devices or utilized in their development, including scaffolds, nanocomposites, bioreactors, drug delivery systems, and gene therapy techniques Presents synthetic tissues and organs that are currently under development for regenerative medicine applications The contributing authors are a diverse group with backgrounds in academia, clinical medicine, and industry. Furthermore, this book includes contributions from Europe, Asia, and North America, helping to broaden the views on the development and application of tissue-engineered devices. The book provides a useful reference for courses devoted to tissue engineering fundamentals and those laboratories developing tissue-engineered devices for regenerative medicine therapy.

Mesenchymal Cell Activation By Biomechanical Stimulation And Its Clinical Prospects

Author: Nahum Rosenberg
Publisher: Bentham Science Publishers
ISBN: 1681081997
Size: 12.53 MB
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Mesenchymal Cell Activation By Biomechanical Stimulation And Its Clinical Prospects from the Author: Nahum Rosenberg. The electrical response of cells to mechanical stimulus is known as mechanotransduction. This monograph is a summary of the mechanotransduction in musculoskeletal cells responsible for body tissue maintenance, support, cover and movement. While mechanotransduction is similar among these cells, there are also several important differences in mechanical parameters and cellular pathways characteristic to each cell type. Therefore, readers will have the opportunity to update their knowledge about the increasing volume of information on mechanotransduction in these cells gained from current research. The book features a primer on general aspects of cellular biomechanics and the experimental methods and equipment commonly used for investigating cellular mechanotransduction in vitro in two dimensional cultures in which cells are adherent to plastic surfaces. Characteristic mechanotransduction pathways in mesenchymal stem cells (MSCs), chondrocytes, osteoblasts and fibroblasts are described in the accompanying chapters. Finally, a description of clinical implementation of mechanical stimulation is presented with emphasis on distraction osteogenesis, involving osteoblast stimulation, and skin stretching techniques based on fibroblast stimulation. This monograph is a useful reference for readers involved in graduate courses or basic research in cell biology and musculoskeletal physiology.

Trends In Stem Cell Biology And Technology

Author: Hossein Baharvand
Publisher: Springer Science & Business Media
ISBN: 1603279040
Size: 36.93 MB
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Trends In Stem Cell Biology And Technology from the Author: Hossein Baharvand. The study of stem cell research has recently gained the attention from a growing, multidisciplinary community of scientist; this exponential growth of interest is driven by the hope of discovering cures for several diseases through transplantation medicine. Trends in Stem Cells Biology and Technology aptly serves this developing community as it reveals new aspects of stem cell research by specifically covering studies focused on spermatogonial stem cells, uniparental embryonic stem cell lines, the generation of gametes from stem cells, reprogramming germ cells to stem cells, nuclear and somatic cell genetic reprogramming, tissue engineering and mechanotransduction of stem cells and finally the development of stem cell technologies for the treatment of deafness, heart disease, corneal injury and diabetes. With contributions by leading scientists and renowned scholars, Trends in Stem Cells Biology and Technology offers a wide audience cutting edge information at a crucial time in this ever expanding field.