scholarly journals The Collagen-Based Medical Device MD-Tissue Acts as a Mechanical Scaffold Influencing Morpho-Functional Properties of Cultured Human Tenocytes

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2641
Author(s):  
Filippo Randelli ◽  
Patrizia Sartori ◽  
Cristiano Carlomagno ◽  
Marzia Bedoni ◽  
Alessandra Menon ◽  
...  
Keyword(s):  
Medical Device ◽  
Cell Fate ◽  
Cell Morphology ◽  
Tendon Healing ◽  
Mechanical Stimuli ◽  
Collagen Turnover ◽  
Mechanical Adaptation ◽  
Main Component ◽  
Biochemical Signals ◽  
Influence Gene Expression

Mechanotransduction is the ability of cells to translate mechanical stimuli into biochemical signals that can ultimately influence gene expression, cell morphology and cell fate. Tenocytes are responsible for tendon mechanical adaptation converting mechanical stimuli imposed during mechanical loading, thus affecting extracellular matrix homeostasis. Since we previously demonstrated that MD-Tissue, an injectable collagen-based medical compound containing swine-derived collagen as the main component, is able to affect tenocyte properties, the aim of this study was to analyze whether the effects triggered by MD-Tissue were based on mechanotransduction-related mechanisms. For this purpose, MD-Tissue was used to coat Petri dishes and cytochalasin B was used to deprive tenocytes of mechanical stimulation mediated by the actin cytoskeleton. Cell morphology, migration, collagen turnover pathways and the expression of key mechanosensors were analyzed by morphological and molecular methods. Our findings confirm that MD-Tissue affects collagen turnover pathways and favors cell migration and show that the MD-Tissue-induced effect represents a mechanical input involving the mechanotransduction machinery. Overall, MD-Tissue, acting as a mechanical scaffold, could represent an effective medical device for a novel therapeutic, regenerative and rehabilitative approach to favor tendon healing in tendinopathies.

Control of photoreceptor cell morphology, planar polarity and epithelial integrity during Drosophila eye development

Development ◽  
2002 ◽  
Vol 129 (9) ◽  
pp. 2247-2258 ◽  
Author(s):  
Amanda T. Pickup ◽  
Michele L. Lamka ◽  
Qi Sun ◽  
Man Lun R. Yip ◽  
Howard D. Lipshitz
Keyword(s):  
Cell Fate ◽  
Cell Morphology ◽  
Photoreceptor Cell ◽  
Zinc Finger Protein ◽  
Photoreceptor Cells ◽  
Planar Polarity ◽  
Tracheal System ◽  
General Role ◽  
Epithelial Integrity ◽  
Jnk Signaling

We report that the hindsight (hnt) gene, which encodes a nuclear zinc-finger protein, regulates cell morphology, cell fate specification, planar cell polarity and epithelial integrity during Drosophila retinal development. In the third instar larval eye imaginal disc, HNT protein expression begins in the morphogenetic furrow and is refined to cells in the developing photoreceptor cell clusters just before their determination as neurons. In hnt mutant larval eye tissue, furrow markers persist abnormally posterior to the furrow, there is a delay in specification of preclusters as cells exit the furrow, there are morphological defects in the preclusters and recruitment of cells into specific R cell fates often does not occur. Additionally, genetically mosaic ommatidia with one or more hnt mutant outer photoreceptor cells, have planar polarity defects that include achirality, reversed chirality and misrotation. Mutants in the JNK pathway act as dominant suppressors of the hnt planar polarity phenotype, suggesting that HNT functions to downregulate JUN kinase (JNK) signaling during the establishment of ommatidial planar polarity. HNT expression continues in the photoreceptor cells of the pupal retina. When an ommatidium contains four or more hnt mutant photoreceptor cells, both genetically mutant and genetically wild-type photoreceptor cells fall out of the retinal epithelium, indicating a role for HNT in maintenance of epithelial integrity. In the late pupal stages, HNT regulates the morphogenesis of rhabdomeres within individual photoreceptor cells and the separation of the rhabdomeres of adjacent photoreceptor cells. Apical F-actin is depleted in hnt mutant photoreceptor cells before the observed defects in cellular morphogenesis and epithelial integrity. The analyses presented here, together with our previous studies in the embryonic amnioserosa and tracheal system, show that HNT has a general role in regulation of the F-actin-based cytoskeleton, JNK signaling, cell morphology and epithelial integrity during development.

scholarly journals Control of cellular responses to mechanical cues through YAP/TAZ regulation

2019 ◽  
Vol 294 (46) ◽  
pp. 17693-17706 ◽  
Author(s):  
Ishani Dasgupta ◽  
Dannel McCollum
Keyword(s):  
Cell Fate ◽  
Wound Repair ◽  
Hippo Pathway ◽  
Three Dimensional ◽  
Focal Adhesions ◽  
Mechanical Stimuli ◽  
Cell Contractility ◽  
Cell Fate Decisions ◽  
Disease States ◽  
The Hippo Pathway

To perceive their three-dimensional environment, cells and tissues must be able to sense and interpret various physical forces like shear, tensile, and compression stress. These forces can be generated both internally and externally in response to physical properties, like substrate stiffness, cell contractility, and forces generated by adjacent cells. Mechanical cues have important roles in cell fate decisions regarding proliferation, survival, and differentiation as well as the processes of tissue regeneration and wound repair. Aberrant remodeling of the extracellular space and/or defects in properly responding to mechanical cues likely contributes to various disease states, such as fibrosis, muscle diseases, and cancer. Mechanotransduction involves the sensing and translation of mechanical forces into biochemical signals, like activation of specific genes and signaling cascades that enable cells to adapt to their physical environment. The signaling pathways involved in mechanical signaling are highly complex, but numerous studies have highlighted a central role for the Hippo pathway and other signaling networks in regulating the YAP and TAZ (YAP/TAZ) proteins to mediate the effects of mechanical stimuli on cellular behavior. How mechanical cues control YAP/TAZ has been poorly understood. However, rapid progress in the last few years is beginning to reveal a surprisingly diverse set of pathways for controlling YAP/TAZ. In this review, we will focus on how mechanical perturbations are sensed through changes in the actin cytoskeleton and mechanosensors at focal adhesions, adherens junctions, and the nuclear envelope to regulate YAP/TAZ.

scholarly journals Design, Implementation, and Validation of a Piezoelectric Device to Study the Effects of Dynamic Mechanical Stimulation on Cell Proliferation, Migration and Morphology

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2155 ◽  
Author(s):  
Dahiana Mojena-Medina ◽  
Marina Martínez-Hernández ◽  
Miguel de la Fuente ◽  
Guadalupe García-Isla ◽  
Julio Posada ◽  
...  
Keyword(s):  
Mechanical Stimulation ◽  
Cell Monolayer ◽  
Mechanical Stimuli ◽  
Mechanical Parameters ◽  
Dynamic Stimuli ◽  
New Device ◽  
Dynamic Mechanical ◽  
Cell Functions ◽  
Biochemical Signals

Cell functions and behavior are regulated not only by soluble (biochemical) signals but also by biophysical and mechanical cues within the cells’ microenvironment. Thanks to the dynamical and complex cell machinery, cells are genuine and effective mechanotransducers translating mechanical stimuli into biochemical signals, which eventually alter multiple aspects of their own homeostasis. Given the dominant and classic biochemical-based views to explain biological processes, it could be challenging to elucidate the key role that mechanical parameters such as vibration, frequency, and force play in biology. Gaining a better understanding of how mechanical stimuli (and their mechanical parameters associated) affect biological outcomes relies partially on the availability of experimental tools that may allow researchers to alter mechanically the cell’s microenvironment and observe cell responses. Here, we introduce a new device to study in vitro responses of cells to dynamic mechanical stimulation using a piezoelectric membrane. Using this device, we can flexibly change the parameters of the dynamic mechanical stimulation (frequency, amplitude, and duration of the stimuli), which increases the possibility to study the cell behavior under different mechanical excitations. We report on the design and implementation of such device and the characterization of its dynamic mechanical properties. By using this device, we have performed a preliminary study on the effect of dynamic mechanical stimulation in a cell monolayer of an epidermal cell line (HaCaT) studying the effects of 1 Hz and 80 Hz excitation frequencies (in the dynamic stimuli) on HaCaT cell migration, proliferation, and morphology. Our preliminary results indicate that the response of HaCaT is dependent on the frequency of stimulation. The device is economic, easily replicated in other laboratories and can support research for a better understanding of mechanisms mediating cellular mechanotransduction.

scholarly journals The Driving Force: Nuclear Mechanotransduction in Cellular Function, Fate, and Disease

2019 ◽  
Vol 21 (1) ◽  
pp. 443-468 ◽  
Author(s):  
Melanie Maurer ◽  
Jan Lammerding
Keyword(s):  
Cell Fate ◽  
Conformational Changes ◽  
Current Evidence ◽  
Mechanical Stimuli ◽  
Cellular Behavior ◽  
Biochemical Responses ◽  
Technological Developments ◽  
Transcriptional Changes ◽  
Partial Unfolding ◽  
New Treatment

Cellular behavior is continuously affected by microenvironmental forces through the process of mechanotransduction, in which mechanical stimuli are rapidly converted to biochemical responses. Mounting evidence suggests that the nucleus itself is a mechanoresponsive element, reacting to cytoskeletal forces and mediating downstream biochemical responses. The nucleus responds through a host of mechanisms, including partial unfolding, conformational changes, and phosphorylation of nuclear envelope proteins; modulation of nuclear import/export; and altered chromatin organization, resulting in transcriptional changes. It is unclear which of these events present direct mechanotransduction processes and which are downstream of other mechanotransduction pathways. We critically review and discuss the current evidence for nuclear mechanotransduction, particularly in the context of stem cell fate, a largely unexplored topic, and in disease, where an improved understanding of nuclear mechanotransduction is beginning to open new treatment avenues. Finally, we discuss innovative technological developments that will allow outstanding questions in the rapidly growing field of nuclear mechanotransduction to be answered.

A Study of Mechanosensing of an Osteoblast at Focal Adhesions Under Cyclic Strain Using Magnetic Micropillars

2019 ◽  
Author(s):  
Toshihiko Shiraishi ◽  
Kota Nagai
Keyword(s):  
Calcium Ion ◽  
Mechanical Vibration ◽  
Focal Adhesions ◽  
Cyclic Strain ◽  
Mechanical Stimuli ◽  
Osteoblast Cells ◽  
Intracellular Calcium Ion ◽  
A Cell ◽  
Sense And Respond ◽  
Biochemical Signals

Abstract It has been reported that cells sense and respond to mechanical stimuli. Mechanical vibration promotes the cell proliferation and the cell differentiation of osteoblast cells at 12.5 Hz and 50 Hz, respectively. It indicates that osteoblast cells have a mechansensing system for mechanical vibration. There may be some mechanosensors and we focus on cellular focal adhesions through which mechanical and biochemical signals may be transmitted from extracellular matrices into a cell. However, it is very difficult to directly apply mechanical stimuli to focal adhesions. We developed a magnetic micropillar substrate on which micron-sized pillars are deflected according to applied magnetic field strength and focal adhesions adhering to the top surface of the pillars are given mechanical stimuli. In this paper, we focus on intracellular calcium ion as a second messenger of cellular mechanosensing and investigate the mechanosensing mechanism of an osteoblast cell at focal adhesions under cyclic strain using a magnetic micropillar substrate. The experimental results indicate that the magnetic micropillars have enough performance to response to an electric current applied to a coil in an electromagnet and to apply the cyclic strain of less than 3% to a cell. In the cyclic strain of less than 3%, the calcium response of a cell was not observed.

A High Throughput System for Long Term Application of Intermittent Cyclic Hydrostatic Pressure on Cells in Culture

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Markus Rottmar ◽  
Sabine Ackerknecht ◽  
Peter Wick ◽  
Katharina Maniura-Weber
Keyword(s):  
Cell Proliferation ◽  
Hydrostatic Pressure ◽  
Cell Fate ◽  
High Throughput ◽  
Cell Response ◽  
Mechanical Stimulus ◽  
Bone Alkaline Phosphatase ◽  
Cell Counting ◽  
Present System ◽  
Mechanical Stimuli

The process of bone remodeling is governed by mechanical stresses and strains. Studies on the effects of mechanical stimulation on cell response are often difficult to compare as the nature of the stimuli and differences in parameters applied vary greatly. Experimental systems for the investigation of mechanical stimuli are mostly limited in throughput or flexibility and often the sum of several stimuli is applied. In this work, a flexible system that allows the investigation of cell response to isolated intermittent cyclic hydrostatic pressure (icHP) on a high throughput level is shown. Human bone derived cells were cultivated with or without mechanical stimulus in the presence or absence of chemical cues triggering osteogenesis for 7–10 days. Cell proliferation and osteogenic differentiation were evaluated by cell counting and immunohistochemical staining for bone alkaline phosphatase as well as collagen 1, respectively. In either medium, both cell proliferation and level of differentiation were increased when the cultures were mechanically stimulated. These initial results therefore qualify the present system for studies on the effects of isolated icHP on cell fate and encourage further investigations on the details behind the observed effects.

scholarly journals Cell fate decisions: emerging roles for metabolic signals and cell morphology

EMBO Reports ◽  
2017 ◽  
Vol 18 (12) ◽  
pp. 2105-2118 ◽  
Author(s):  
Sumitra Tatapudy ◽  
Francesca Aloisio ◽  
Diane Barber ◽  
Todd Nystul
Keyword(s):  
Cell Fate ◽  
Cell Morphology ◽  
Cell Fate Decisions

Constructing stem cell microenvironments using bioengineering approaches

2013 ◽  
Vol 45 (23) ◽  
pp. 1123-1135 ◽  
Author(s):  
David A. Brafman
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Disease Modeling ◽  
Mechanical Stimuli ◽  
Culture Methods ◽  
Stem Cell Fate ◽  
And Function

Within the adult organism, stem cells reside in defined anatomical microenvironments called niches. These architecturally diverse microenvironments serve to balance stem cell self-renewal and differentiation. Proper regulation of this balance is instrumental to tissue repair and homeostasis, and any imbalance can potentially lead to diseases such as cancer. Within each of these microenvironments, a myriad of chemical and physical stimuli interact in a complex (synergistic or antagonistic) manner to tightly regulate stem cell fate. The in vitro replication of these in vivo microenvironments will be necessary for the application of stem cells for disease modeling, drug discovery, and regenerative medicine purposes. However, traditional reductionist approaches have only led to the generation of cell culture methods that poorly recapitulate the in vivo microenvironment. To that end, novel engineering and systems biology approaches have allowed for the investigation of the biological and mechanical stimuli that govern stem cell fate. In this review, the application of these technologies for the dissection of stem cell microenvironments will be analyzed. Moreover, the use of these engineering approaches to construct in vitro stem cell microenvironments that precisely control stem cell fate and function will be reviewed. Finally, the emerging trend of using high-throughput, combinatorial methods for the stepwise engineering of stem cell microenvironments will be explored.

scholarly journals A mechanical memory of pancreatic cancer cells

2019 ◽  
Author(s):  
Ilaria Carnevale ◽  
Mjriam Capula ◽  
Elisa Giovannetti ◽  
Thomas Schmidt ◽  
Stefano Coppola
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Nuclear Translocation ◽  
Traction Force ◽  
Long Term Memory ◽  
Mechanical Stimuli ◽  
Mechanical Adaptation ◽  
Pancreatic Cancer Cells ◽  
Mechanical Memory

Cells sense and respond to mechanical stimuli in healthy and pathological conditions. Although the major mechanisms un-derlying cellular mechanotransduction have been described, it remains largely unclear how cells store information on past mechanical cues over time. Such mechanical memory is extremely relevant in the onset of metastasis in which cancer cells migrate through tissues of different stiffness, e.g. from a stiffer tumor microenvironment to softer metastatic sites as commonly occurs for pancreatic cancer. Here, we used micropillar-based traction force microscopy to show that Suit-2.28 pancreatic cancer cells mechanically primed on a stiff matrix exerted higher traction forces even when transferred to a soft secondary matrix, as compared to soft-primed cells. This mechanical memory effect was mediated by the Yes-associated protein (YAP) and the microRNA-21 (miR-21) that are two mechanosensors initially identified as long-term memory keepers in mesenchymal stem cells. Soft-primed cells showed (i) a lower YAP nuclear translocation when transferred to a stiff secondary matrix and (ii) a loss of rigidity sensing through YAP, as compared to stiff-primed cells. The mechanical adaptation resulted in a differential expression of miR-21, inversely proportional to the priming rigidity. The long-term mechanical memory retained by miR-21 unveiled a previously unidentified mechanical modulation of drug resistance by past matrix stiffness. The higher expression of miR-21 in soft-primed cells correlated with the increased resistance to gemcitabine, as compared to stiff-primed and non-primed pancreatic cancer cells.

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