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.

Use of Flexible Materials with a Novel Pressure Driven Equibiaxial Cell Stretching Device for Mechanical Stimulation of Single Mammalian Cells

2003 ◽  
Vol 773 ◽  
Author(s):  
James D. Kubicek ◽  
Stephanie Brelsford ◽  
Philip R. LeDuc
Keyword(s):  
Cell Fate ◽  
Mechanical Stimulation ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Single Cells ◽  
Complex Nature ◽  
Cellular Behavior ◽  
Cell Stretching ◽  
Stimulation Of ◽  
Pressure Driven

AbstractMechanical stimulation of single cells has been shown to affect cellular behavior from the molecular scale to ultimate cell fate including apoptosis and proliferation. In this, the ability to control the spatiotemporal application of force on cells through their extracellular matrix connections is critical to understand the cellular response of mechanotransduction. Here, we develop and utilize a novel pressure-driven equibiaxial cell stretching device (PECS) combined with an elastomeric material to control specifically the mechanical stimulation on single cells. Cells were cultured on silicone membranes coated with molecular matrices and then a uniform pressure was introduced to the opposite surface of the membrane to stretch single cells equibiaxially. This allowed us to apply mechanical deformation to investigate the complex nature of cell shape and structure. These results will enhance our knowledge of cellular and molecular function as well as provide insights into fields including biomechanics, tissue engineering, and drug discovery.

scholarly journals E3 Ubiquitin Ligase SPL2 Is a Lanthanide-Binding Protein

2021 ◽  
Vol 22 (11) ◽  
pp. 5712
Author(s):  
Michał Tracz ◽  
Ireneusz Górniak ◽  
Andrzej Szczepaniak ◽  
Wojciech Białek
Keyword(s):  
Ubiquitin Ligase ◽  
Conformational Changes ◽  
Protein Interactions ◽  
E3 Ubiquitin Ligase ◽  
Lanthanide Ions ◽  
E3 Ligases ◽  
Fluorescence Measurements ◽  
Partial Unfolding

The SPL2 protein is an E3 ubiquitin ligase of unknown function. It is one of only three types of E3 ligases found in the outer membrane of plant chloroplasts. In this study, we show that the cytosolic fragment of SPL2 binds lanthanide ions, as evidenced by fluorescence measurements and circular dichroism spectroscopy. We also report that SPL2 undergoes conformational changes upon binding of both Ca2+ and La3+, as evidenced by its partial unfolding. However, these structural rearrangements do not interfere with SPL2 enzymatic activity, as the protein retains its ability to auto-ubiquitinate in vitro. The possible applications of lanthanide-based probes to identify protein interactions in vivo are also discussed. Taken together, the results of this study reveal that the SPL2 protein contains a lanthanide-binding site, showing for the first time that at least some E3 ubiquitin ligases are also capable of binding lanthanide ions.

APPLICATION OF BIOMECHANICS TO TISSUE ENGINEERING: A PERSONAL VIEW

2008 ◽  
Vol 08 (02) ◽  
pp. 153-160 ◽  
Author(s):  
BRUCE K. MILTHORPE
Keyword(s):  
Tissue Engineering ◽  
Mechanical Stimuli ◽  
Personal View ◽  
Tissue Engineering Scaffolds ◽  
Cellular Behavior ◽  
Cellular Biomechanics ◽  
Biological Studies ◽  
Biomechanical Stimuli ◽  
Relationship Of

Cellular biomechanics is an area of study that is receiving more attention as time progresses. The response of cells to their mechanical environment, including biomechanical stimuli, has far-reaching ramifications for the area of tissue engineering, especially for tissues designed to withstand mechanical loading (e.g. bone, cartilage, tendons and ligaments, and arteries). The effects of mechanical stimuli on cells are only recently being examined, and the potential role of mechanical stimuli in tissue engineering is still one that is largely ignored in the design of tissue engineering scaffolds. The relationship of mechanical properties of scaffolds or of mechanical stimuli to cell behavior is complex, but vital to the development of the field. Also, understanding the complex interplay of form and environment on cells involves an increase in our knowledge of how cells react to their total environment including mechanical stimuli and material properties. In order to improve tissue engineering outcomes, a nexus must be developed between the mechanical, biochemical, and biological studies of cellular behavior, in the context of extremely complex systems.

scholarly journals In Silico Electrophysiology of Inner-Ear Mechanotransduction Channel TMC1 Models

2021 ◽  
Author(s):  
Sanket Walujkar ◽  
Jeffrey M Lotthammer ◽  
Collin R Nisler ◽  
Joseph C Sudar ◽  
Angela Ballesteros ◽  
...  
Keyword(s):  
Inner Ear ◽  
Conformational Changes ◽  
Hair Cells ◽  
Head Movements ◽  
Mechanical Stimuli ◽  
Ion Conduction ◽  
Sensory Hair Cells ◽  
Activation Mechanisms ◽  
Dynamics Simulations ◽  
Molecular Components

Inner-ear sensory hair cells convert mechanical stimuli from sound and head movements into electrical signals during mechanotransduction. Identification of all molecular components of the inner-ear mechanotransduction apparatus is ongoing; however, there is strong evidence that TMC1 and TMC2 are pore-forming subunits of the complex. We present molecular dynamics simulations that probe ion conduction of TMC1 models built based on two different structures of related TMEM16 proteins. Unlike most channels, the TMC1 models do not show a central pore. Instead, simulations of these models in a membrane environment at various voltages reveal a peripheral permeation pathway that is exposed to lipids and that shows cation permeation at rates comparable to those measured in hair cells. Furthermore, our analyses suggest that TMC1 gating mechanisms involve protein conformational changes and tension-induced lipid-mediated pore widening. These results provide insights into ion conduction and activation mechanisms of hair-cell mechanotransduction channels essential for hearing and balance.

scholarly journals Precision medicine applications for severe asthma

2019 ◽  
Vol 6 (4) ◽  
pp. 117-135
Author(s):  
Orit Gourgy Hacohen ◽  
Shai Cohen
Keyword(s):  
Precision Medicine ◽  
Severe Asthma ◽  
Oral Corticosteroid ◽  
Treatment Options ◽  
Current Evidence ◽  
Blood Eosinophil ◽  
Eosinophilic Asthma ◽  
Severe Eosinophilic Asthma ◽  
Beneficial Effects ◽  
New Treatment

Asthma is a heterogeneous condition in which multiple pathological pathways manifest with similar symptoms. Severe asthma (SA) is challenging to manage and comprises a significant health and economic burden. Many studies have been conducted in an attempt to define different clinical phenotypes that translate into biological endotypes, with the goal of tailoring treatment based on precision medicine. This review summarizes the current evidence for the treatments of SA, and in particular, the biologic treatments that are currently available: omalizumab, mepolizumab, reslizumab, benralizumab and dupilumab. We found only limited high-quality direct evidence regarding treatment with anti-IgE (omalizumab) in SA patients. Data regarding anti-interleukin (IL)-5 (mepolizumab, reslizumab and benralizumab) showed beneficial effects in severe eosinophilic asthma (SEA) with different levels of blood eosinophils used in clinical trials. Dupilumab, anti-IL-4/IL-13, was shown to be effective in SEA and is the only agent currently FDA-approved for the indication of oral corticosteroid dependent asthma, regardless of the blood eosinophil level. This review also summarizes the existing knowledge regarding the characteristics of the patient who may respond to the different therapies. As of today, more studies are needed to better understand the diverse mechanisms that underlie SA phenotypes. We have not yet adequately reached the goal of precision medicine. Additional studies are necessary in order to find novel surrogate markers that can predict the response to a specific biologic therapy, especially in patients who are oral corticosteroid dependent. In addition, efforts must be invested into research looking for new treatment options for patients with non-type-2 inflammation SA. Statement of novelty: we review the current evidence regarding tailored treatment therapies in SA, with a particular focus on the knowledge regarding patient selection for specific biologic treatments.

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.

Conformational changes and inactivation of rabbit muscle creatine kinase in dimethyl sulfoxide solutions

2002 ◽  
Vol 80 (4) ◽  
pp. 427-434 ◽  
Author(s):  
Wen-bin Ou ◽  
Ri-Sheng Wang ◽  
Hai-Meng Zhou
Keyword(s):  
Creatine Kinase ◽  
Dimethyl Sulfoxide ◽  
Conformational Changes ◽  
Sodium Dodecyl ◽  
Rabbit Muscle ◽  
Hydrophobic Surfaces ◽  
Muscle Creatine Kinase ◽  
Organic Mixture ◽  
Dmso Concentration ◽  
Partial Unfolding

The effects of dimethyl sulfoxide (DMSO) on creatine kinase (CK) conformation and enzymatic activity were studied by measuring activity changes, aggregation, and fluorescence spectra. The results showed that at low concentrations (<65% v/v), DMSO had little effect on CK activity and structure. However, higher concentrations of DMSO led to CK inactivation, partial unfolding, and exposure of hydrophobic surfaces and thiol groups. DMSO caused aggregation during CK denaturation. A 75% DMSO concentration induced the most significant aggregation of CK. The CK inactivation and unfolding kinetics were single phase. The unfolding of CK was an irreversible process in the DMSO solutions. The results suggest that to a certain extent, an enzyme can maintain catalytic activity and conformation in water–organic mixture environments. Higher concentrations of DMSO affected the enzyme structure but not its active site. Inactivation occurred along with noticeable conformational change during CK denaturation. The inactivation and unfolding of CK in DMSO solutions differed from other denaturants such as guanidine, urea, and sodium dodecyl sulfate. The exposure of hydrophobic surfaces was a primary reason for the protein aggregation.Key words: creatine kinase, dimethyl sulfoxide, denaturation, activity, conformation.

scholarly journals The plasma membrane as a mechanochemical transducer

2019 ◽  
Vol 374 (1779) ◽  
pp. 20180221 ◽  
Author(s):  
Anabel-Lise Le Roux ◽  
Xarxa Quiroga ◽  
Nikhil Walani ◽  
Marino Arroyo ◽  
Pere Roca-Cusachs
Keyword(s):  
Plasma Membrane ◽  
Cellular Response ◽  
Mechanical Response ◽  
Membrane Curvature ◽  
Mechanical Stresses ◽  
Mechanical Stimuli ◽  
Biochemical Responses ◽  
Interdisciplinary Approaches ◽  
Mechanochemical Transduction

Cells are constantly submitted to external mechanical stresses, which they must withstand and respond to. By forming a physical boundary between cells and their environment that is also a biochemical platform, the plasma membrane (PM) is a key interface mediating both cellular response to mechanical stimuli, and subsequent biochemical responses. Here, we review the role of the PM as a mechanosensing structure. We first analyse how the PM responds to mechanical stresses, and then discuss how this mechanical response triggers downstream biochemical responses. The molecular players involved in PM mechanochemical transduction include sensors of membrane unfolding, membrane tension, membrane curvature or membrane domain rearrangement. These sensors trigger signalling cascades fundamental both in healthy scenarios and in diseases such as cancer, which cells harness to maintain integrity, keep or restore homeostasis and adapt to their external environment. This article is part of a discussion meeting issue ‘Forces in cancer: interdisciplinary approaches in tumour mechanobiology’.

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.

Sign in / Sign up

Export Citation Format

Share Document