The reversibility of cellular mechano-activation

The cellular microenvironment is highly heterogeneous and dynamic. Therefore, cells must be equipped with molecular tools to adapt and respond to constantly fluctuating inputs. One such input is mechanical force, which activates signalling and regulates cell behaviour in the process of mechanotransduction. Whereas the mechanisms activating mechanotransduction are well studied, the reversibility of this process, whereby cells disassemble and reverse force-activated signalling pathways upon cessation of mechanical stimulation is far less understood. In this review we will outline some of the key experimental techniques to investigate the reversibility of mechanical signalling, and key discoveries arising from them.Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved

Special issue on "mechanotransduction in cell fate determination" - From molecular switches to organ-level regulation

Non peer reviewe

Mechanosensing at integrin-mediated cell–matrix adhesions: from molecular to integrated mechanisms

Integrin-mediated adhesions between cells and the extracellular matrix are fundamental for cell function, and one of their main roles is to sense and respond to mechanical force. Here we discuss the different mechanisms that can confer mechanosensitivity to adhesions. We first address molecular mechanisms mediated by force-induced changes in molecular properties, such as binding dynamics or protein conformation. Then, we discuss recent evidence on how these mechanisms are integrated with cellular and extracellular parameters such as myosin and actin activity, membrane tension, and ECM properties, endowing cells with an exquisite ability to both detect and respond to physical and mechanical cues from their environment

Búsqueda y análisis de nuevos métodos de seguimiento del funcionamiento de centrales nucleares PWR

El siguiente proyecto ha sido realizado en el departamento STEP (Simulation and information technologies for power generation systems) de la división R&D (investigación y desarrollo) en la empresa EDF (Electricité de France). Este proyecto estudia nuevas metodologías de seguimiento del funcionamiento de una central nuclear mediante el programa CEF (Contrôle Economique du Fonctionnement), utilizado por las centrales para controlar el funcionamiento termodinámico del circuito secundario. El objetivo principal es incrementar el rendimiento del circuito. Esta memoria comienza con una presentación detallada del funcionamiento del circuito secundario y terciario, de la actividad concreta de STEP y del programa CEF para facilitar la comprensión del estudio. Después de un amplio estudio bibliográfico y de reuniones con expertos en centrales nucleares del departamento STEP, se ha creado un documento con la descripción de los principales problemas de cada uno de los componentes pertenecientes al circuito secundario y terciario y los métodos de EDF de control de funcionamiento y detección de problemas. Gracias a dicho documento puede encontrarse degradaciones actualmente no detectables y analizar si podría automatizarse la detección utilizando el CEF. El análisis de este documento ha permitido el estudio de dos casos susceptibles de ser mejorados mediante un método de detección termodinámico. El primero es la erosión de las turbinas de alta presión debido a la humedad del vapor. En el segundo se trata de un incidente creado por la ruptura de la tubería de acceso al condensador del circuito de refrigeración. Ambos estudios contienen un planteamiento teórico donde varios parámetros son propuestos con la intención de poder anticipar la aparición de ambos sucesos. Después se realiza una aplicación práctica con datos reales de las centrales francesas para comprobar la validez y la utilidad de los parámetros propuestos. Este estudio ha permitido identificar algunos indicadores bastante esperanzadores y, por tanto, será necesario que la investigación prosiga para confirmar su validez y estudiar las modalidades prácticas de utilización en las centrales nucleares del parque de producción de EDF

Casa Sagnier, història i arquitectura

L'objectiu d'aquest PFG és estudiar i analitzar la Casa Sagnier, situada al carrer Brusi 51-61, mitjançant l'aixecament arquitectònic i la recerca de la seva història. Actualment és un centre cívic que pertany a l'ajuntament de Barcelona. Hem escollit aquest edifici, més que per la seva arquitectura, pel seu creador, Enric Sagnier, arquitecte desvalorat desde la seva mort. Els autors d'aquest projecte hem aprofitat el treball realitzat per incrementar el nostre coneixement en eines d'expressió gràfica, com són Sutocad, Sketchup o photoshop. D'aquesta manera, hem pogut adquirir més experiència i valors cap a formes constructives i èpoques de segles anteriors

Integrins as biomechanical sensors of the microenvironment

Integrins, and integrin-mediated adhesions, have long been recognized to provide the main molecular link attaching cells to the extracellular matrix (ECM) and to serve as bidirectional hubs transmitting signals between cells and their environment. Recent evidence has shown that their combined biochemical and mechanical properties also allow integrins to sense, respond to and interact with ECM of differing properties with exquisite specificity. Here, we review this work first by providing an overview of how integrin function is regulated from both a biochemical and a mechanical perspective, affecting integrin cell-surface availability, binding properties, activation or clustering. Then, we address how this biomechanical regulation allows integrins to respond to different ECM physicochemical properties and signals, such as rigidity, composition and spatial distribution. Finally, we discuss the importance of this sensing for major cell functions by taking cell migration and cancer as examples

Quantifying forces in cell biology

Cells exert, sense, and respond to physical forces through an astounding diversity of mechanisms. Here we review recently developed tools to quantify the forces generated by cells. We first review technologies based on sensors of known or assumed mechanical properties, and discuss their applicability and limitations. We then proceed to draw an analogy between these human-made sensors and force sensing in the cell. As mechanics is increasingly revealed to play a fundamental role in cell function we envisage that tools to quantify physical forces may soon become widely applied in life-sciences laboratories

New genus and species of ant-like true bug (Hemiptera: Miridae) from the Canary Islands

Roca-Cusachs, Marcos, Goula, Marta (2016): New genus and species of ant-like true bug (Hemiptera: Miridae) from the Canary Islands. Zootaxa 4173 (1), DOI: http://doi.org/10.11646/zootaxa.4173.1.

Control of Mechanotransduction by Molecular Clutch Dynamics

By considering the molecular and mechanical properties of actin filaments, myosin motors, adaptor proteins, and integrins/cadherins, the molecular clutch model can quantitatively predict cell response to internal and external mechanical factors. These factors include cell contractility, matrix rigidity, and the density, nature, and distribution of matrix ligands, and affect cell response largely by controlling the rate of force loading in specific molecules. Due to its dynamic nature, clutch-mediated mechanosensing requires force application to at least two molecular mechanosensors in series, with differential response to force. The type of cell responses involved so far in clutch-mediated mechanosensing include cytoskeletal dynamics, the growth of cell adhesions, the nuclear localization of transcriptional regulators, and cell migration. The linkage of cells to their microenvironment is mediated by a series of bonds that dynamically engage and disengage, in what has been conceptualized as the molecular clutch model. Whereas this model has long been employed to describe actin cytoskeleton and cell migration dynamics, it has recently been proposed to also explain mechanotransduction (i.e., the process by which cells convert mechanical signals from their environment into biochemical signals). Here we review the current understanding on how cell dynamics and mechanotransduction are driven by molecular clutch dynamics and its master regulator, the force loading rate. Throughout this Review, we place a specific emphasis on the quantitative prediction of cell response enabled by combined experimental and theoretical approaches.This work was supported by the Spanish Ministry of Economy and Competitiveness (BFU2015-65074-P to X.T. and BFU2016-79916-P to P.R.-C.), the European Commission (H2020-FETPROACT-01-2016-731957 to X.T. and P.R.-C.), the Generalitat de Catalunya (2014-SGR-927), the European Research Council (CoG-616480 to X.T.), and Obra Social “La Caixa”. A.E.-A was supported by a Juan de la Cierva Fellowship (Spanish Ministry of Economy and Competitiveness, IJCI2014-19156)

Casa Sagnier: Història i Arquitectura

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