3,832 results match your criteria vitro stretch

Recurrent Urinary Tract Infection: A Mystery in Search of Better Model Systems.

Front Cell Infect Microbiol 2021 26;11:691210. Epub 2021 May 26.

Centre for Urological Biology, Department of Renal Medicine, University College London, London, United Kingdom.

Urinary tract infections (UTIs) are among the most common infectious diseases worldwide but are significantly understudied. Uropathogenic (UPEC) accounts for a significant proportion of UTI, but a large number of other species can infect the urinary tract, each of which will have unique host-pathogen interactions with the bladder environment. Given the substantial economic burden of UTI and its increasing antibiotic resistance, there is an urgent need to better understand UTI pathophysiology - especially its tendency to relapse and recur. Read More

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Effects of substrate stiffness and actin velocity on in silico fibronectin fibril morphometry and mechanics.

PLoS One 2021 9;16(6):e0248256. Epub 2021 Jun 9.

Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA, United States of America.

Assembly of the extracellular matrix protein fibronectin (FN) into insoluble, viscoelastic fibrils is a critical step during embryonic development and wound healing; misregulation of FN fibril assembly has been implicated in many diseases, including fibrotic diseases and cancer. We have previously developed a computational model of FN fibril assembly that recapitulates the morphometry and mechanics of cell-derived FN fibrils. Here we use this model to probe two important questions: how is FN fibril formation affected by the contractile phenotype of the cell, and how is FN fibril formation affected by the stiffness of the surrounding tissue? We show that FN fibril formation depends strongly on the contractile phenotype of the cell, but only weakly on in vitro substrate stiffness, which is an analog for in vivo tissue stiffness. Read More

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Myofiber stretch induces tensile and shear deformation of muscle stem cells in their native niche.

Biophys J 2021 Jun 1. Epub 2021 Jun 1.

Laboratory for Myology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, 1081 HZ Amsterdam, The Netherlands. Electronic address:

Muscle stem cells (MuSCs) are requisite for skeletal muscle regeneration and homeostasis. Proper functioning of MuSCs, including activation, proliferation, and fate decision, is determined by an orchestrated series of events and communication between MuSCs and their niche. A multitude of biochemical stimuli are known to regulate MuSCs fate and function. Read More

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From stretch to deflection: the importance of context in the activation of mammalian, mechanically activated ion channels.

FEBS J 2021 Jun 1. Epub 2021 Jun 1.

EMBL Australia node in Single Molecule Science, School of Medical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, Australia.

The ability of cells to convert mechanical perturbations into biochemical information is an essential aspect of mammalian physiology. The molecules that mediate such mechanotransduction include mechanically activated ion channels, which directly convert mechanical inputs into electrochemical signals. The unifying feature of these channels is that their open probability increases with the application of a mechanical input. Read More

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The domain of unknown function 4005 (DUF4005) in an Arabidopsis IQD protein functions in microtubule binding.

J Biol Chem 2021 May 28:100849. Epub 2021 May 28.

State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China. Electronic address:

The dynamic responses of microtubules (MTs) to internal and external signals are modulated by a plethora of microtubule associated proteins (MAPs). In higher plants, many plant-specific MAPs have emerged during evolution as advantageous to their sessile lifestyle. Some members of the IQ67 domain (IQD) protein family have been shown to be plant-specific MAPs. Read More

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Trigger-Specific Remodeling of K2 Potassium Channels in Models of Atrial Fibrillation.

Pharmgenomics Pers Med 2021 20;14:579-590. Epub 2021 May 20.

Department of Cardiology, Medical University Hospital Heidelberg, Heidelberg, 69120, Germany.

Aim: Effective antiarrhythmic treatment of atrial fibrillation (AF) constitutes a major challenge, in particular, when concomitant heart failure (HF) is present. HF-associated atrial arrhythmogenesis is distinctly characterized by prolonged atrial refractoriness. Small-conductance, calcium-activated K (K, SK, ) channels contribute to cardiac action potential repolarization and are implicated in AF susceptibility and therapy. Read More

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Actuation enhances patterning in human neural tube organoids.

Nat Commun 2021 05 27;12(1):3192. Epub 2021 May 27.

Laboratory of Bioengineering and Morphogenesis, Biomechanics Section, Department of Mechanical Engineering, KU Leuven, Leuven, Belgium.

Tissues achieve their complex spatial organization through an interplay between gene regulatory networks, cell-cell communication, and physical interactions mediated by mechanical forces. Current strategies to generate in-vitro tissues have largely failed to implement such active, dynamically coordinated mechanical manipulations, relying instead on extracellular matrices which respond to, rather than impose mechanical forces. Here, we develop devices that enable the actuation of organoids. Read More

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Development of Delivery Systems Enhances the Potency of Cell-Based HIV-1 Therapeutic Vaccine Candidates.

J Immunol Res 2021 20;2021:5538348. Epub 2021 Apr 20.

Department of Hepatitis and AIDs, Pasteur Institute of Iran, Tehran, Iran.

An effective therapeutic vaccine to eradicate HIV-1 infection does not exist yet. Among different vaccination strategies, cell-based vaccines could achieve in clinical trials. Cell viability and low nucleic acid expression are the problems related to dendritic cells (DCs) and mesenchymal stem cells (MSCs), which are transfected with plasmid DNA. Read More

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Evidence for synergy between sarcomeres and fibroblasts in an in vitro model of myocardial reverse remodeling.

J Mol Cell Cardiol 2021 May 14;158:11-25. Epub 2021 May 14.

Department of Biomedical Engineering, Yale University, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA. Electronic address:

We have created a novel in-vitro platform to study reverse remodeling of engineered heart tissue (EHT) after mechanical unloading. EHTs were created by seeding decellularized porcine myocardial sections with a mixture of primary neonatal rat ventricular myocytes and cardiac fibroblasts. Each end of the ribbon-like constructs was fixed to a plastic clip, allowing the tissues to be statically stretched or slackened. Read More

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Evaluation of the Straightening Phenomenon of Various Types of Coils.

Neurol Med Chir (Tokyo) 2021 Jun 8;61(6):356-360. Epub 2021 May 8.

Department of Neurosurgery, Nagoya University Graduate School of Medicine.

The straightening phenomenon is known as a cause of catheter kickback in the late phase of coil embolization. The mechanism is supposed to be the relative shortage of the stretch resistance (SR) line, and it occurs when a coil is folded too small. Among many SR coils available, there should be a coil-specific tendency to cause this phenomenon. Read More

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An Investigation Into the Role of Strain and Structure on Vascular Smooth Muscle Cell Growth.

Front Bioeng Biotechnol 2021 20;9:641794. Epub 2021 Apr 20.

Trinity Centre for Biomedical Engineering, Trinity College Dublin, Trinity Biomedical Sciences Institute, Dublin, Ireland.

The orientation of vascular cells can greatly influence the mechanical properties and functionality of soft vascular tissues. How cell orientation mediates the growth response of cells is of critical importance in understanding the response of soft tissues to mechanical stimuli or injury. To date, considerable evidence has shown that cells align with structural cues such as collagen fibers. Read More

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Quantifying supraspinatus tendon responses to exposures emulative of human physiological levels in an animal model.

J Biomech 2021 Jun 25;122:110476. Epub 2021 Apr 25.

Department of Kinesiology, University of Waterloo, Waterloo Canada. Electronic address:

Rotator cuff pathology typically originates in the supraspinatus tendon, but uncertainty exists on how combinations of glenohumeral elevation angle and load intensity influence responses of the intact, functional supraspinatus unit. This study exposed the supraspinatus tendon to mechanical loading scenarios emulative of derived muscle force and postural conditions measured in vivo to document its responses. Right shoulders from 48 Sprague-Dawley rats were placed into one of eight testing groups combining glenohumeral elevation angles (0/30/60/75°) and a high or low load intensity for 1500 cycles at 0. Read More

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Substrate Stiffness and Stretch Regulate Profibrotic Mechanosignaling in Pulmonary Arterial Adventitial Fibroblasts.

Cells 2021 Apr 23;10(5). Epub 2021 Apr 23.

Department of Bioengineering, University of California San Diego, La Jolla, CA 92093-0412, USA.

Pulmonary arterial adventitial fibroblasts (PAAFs) are important regulators of fibrotic vascular remodeling during the progression of pulmonary arterial hypertension (PAH), a disease that currently has no effective anti-fibrotic treatments. We conducted in-vitro experiments in PAAFs cultured on hydrogels attached to custom-made equibiaxial stretchers at 10% stretch and substrate stiffnesses representing the mechanical conditions of mild and severe stages of PAH. The expression of collagens α(1)I and α(1)III and elastin messenger RNAs (, , ) were upregulated by increased stretch and substrate stiffness, while lysyl oxidase-like 1 and α-smooth muscle actin messenger RNAs (, ) were only significantly upregulated when the cells were grown on matrices with an elevated stiffness representative of mild PAH but not on a stiffness representative of severe PAH. Read More

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Power Amplification Increases With Contraction Velocity During Stretch-Shortening Cycles of Skinned Muscle Fibers.

Front Physiol 2021 31;12:644981. Epub 2021 Mar 31.

Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany.

Muscle force, work, and power output during concentric contractions (active muscle shortening) are increased immediately following an eccentric contraction (active muscle lengthening). This increase in performance is known as the stretch-shortening cycle (SSC)-effect. Recent findings demonstrate that the SSC-effect is present in the sarcomere itself. Read More

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Dickkopf-1 promotes Vascular Smooth Muscle Cell proliferation and migration through upregulating UHRF1 during Cyclic Stretch application.

Int J Biol Sci 2021 21;17(5):1234-1249. Epub 2021 Mar 21.

The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Qilu Hospital of Shandong University,107 Wenhuaxi Road, 250012 Jinan, China.

Dickkopf-1 (DKK1) was recently shown to play an important role in cardiovascular disease. The aim of this work was to assess the role of DKK1 in the regulation of smooth muscle cell function by mechanical stretch and the mechanisms underlying this process. Wild-type C57BL/6J mice were subjected to sham or abdominal aortic constriction (AAC) surgery. Read More

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Nrf2 activation is involved in osteogenic differentiation of periodontal ligament stem cells under cyclic mechanical stretch.

Exp Cell Res 2021 Jun 15;403(2):112598. Epub 2021 Apr 15.

School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University, China; Shandong Key Laboratory of Oral Tissue Regeneration, Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, China. Electronic address:

During orthodontic treatment, mechanical stretch serves a crucial function in osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Up-regulated reactive oxygen species (ROS) level is a result of cyclic mechanical stretch in many cell types. Nuclear factor erythroid-2-related factor-2 (Nrf2) is a master regulator in various antioxidants expression. Read More

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Secreted Extracellular Cyclophilin A is a Novel Mediator of Ventilator Induced Lung Injury.

Am J Respir Crit Care Med 2021 Apr 13. Epub 2021 Apr 13.

Imperial College London, Anaesthetics & Intensive Care, London, United Kingdom of Great Britain and Northern Ireland;

Rationale: Mechanical ventilation is a mainstay of intensive care but contributes to the mortality of patients through ventilator induced lung injury. Extracellular Cyclophilin A is an emerging inflammatory mediator and metalloproteinase inducer, and the gene responsible for its expression has recently been linked to COVID-19 infection.

Objectives: Here we explore the involvement of extracellular Cyclophilin A in the pathophysiology of ventilator-induced lung injury. Read More

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FleXert: A Soft, Actuatable Multiwell Plate Insert for Cell Culture under Stretch.

ACS Biomater Sci Eng 2021 Jun 12;7(6):2225-2245. Epub 2021 Apr 12.

Bristol Robotics Laboratory, University of Bristol, T Block, Frenchay Campus, Coldharbour Lane, Bristol BS16 1QY, United Kingdom.

Porous multiwell plate inserts are widely used in biomedical research to study transport processes or to culture cells/tissues at the air-liquid interface. These inserts are made of rigid materials and used under static culture conditions, which are unrepresentative of biological microenvironments. Here, we present FleXert, a soft, actuatable cell culture insert that interfaces with six-well plates. Read More

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Cyclically stretched ACL fibroblasts emigrating from spheroids adapt their cytoskeleton and ligament-related expression profile.

Cell Tissue Res 2021 Apr 9. Epub 2021 Apr 9.

Institute of Anatomy and Cell Biology, Paracelsus Medical University, Prof.-Ernst-Nathan Str. 1, 90419, Nuremberg and Salzburg, Nuremberg, Germany.

Mechanical stress of ligaments varies; hence, ligament fibroblasts must adapt their expression profile to novel mechanomilieus to ensure tissue resilience. Activation of the mechanoreceptors leads to a specific signal transduction, the so-called mechanotransduction. However, with regard to their natural three-dimensional (3D) microenvironment cell reaction to mechanical stimuli during emigrating from a 3D spheroid culture is still unclear. Read More

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Remodeling of an microvessel exposed to cyclic mechanical stretch.

APL Bioeng 2021 Jun 2;5(2):026102. Epub 2021 Apr 2.

Integrative Vascular Biology Laboratory, Max-Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC),13092 Berlin, Germany.

In the lungs, vascular endothelial cells experience cyclic mechanical strain resulting from rhythmic breathing motions and intraluminal blood pressure. Mechanical stress creates evident physiological, morphological, biochemical, and gene expression changes in vascular endothelial cells. However, the exact mechanisms of the mechanical signal transduction into biological responses remain to be clarified. Read More

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Aquaporins in platelet function.

Platelets 2021 Apr 4:1-7. Epub 2021 Apr 4.

School of Physiology, Pharmacology and Neuroscience, University of Bristol, England, UK.

Structurally, aquaporins (AQPs) are small channel proteins with monomers of ~ 30 kDa that are assembled as tetramers to form pores on cell membranes. Aquaporins mediate the conduction of water but at times also small solutes including glycerol across cell membranes and along osmotic gradients. Thirteen isoforms of AQPs have been reported in mammalian cells, and several of these are likely expressed in platelets. Read More

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Engineering a Human Pluripotent Stem Cell-Based Microphysiological System for Studying the Metformin Response in Aortic Smooth Muscle Cells.

Front Bioeng Biotechnol 2021 18;9:627877. Epub 2021 Mar 18.

Department of Cardiac Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.

Aortic aneurysm is a common cardiovascular disease characterised by continuous dilation of the aorta, and this disease places a heavy burden on healthcare worldwide. Few drugs have been suggested to be effective in controlling the progression of aortic aneurysms. Preclinical drug responses from traditional cell culture and animals are usually controversial. Read More

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Development of an In Vitro Airway Epithelial-Endothelial Cell Culture Model on a Flexible Porous Poly(Trimethylene Carbonate) Membrane Based on Calu-3 Airway Epithelial Cells and Lung Microvascular Endothelial Cells.

Membranes (Basel) 2021 Mar 11;11(3). Epub 2021 Mar 11.

Technical Medical (TechMed) Centre, Department of Biomaterials Science and Technology, Faculty of Science and Technology, University of Twente, 7522 NB Enschede, The Netherlands.

Due to the continuing high impact of lung diseases on society and the emergence of new respiratory viruses, such as SARS-CoV-2, there is a great need for in vitro lung models that more accurately recapitulate the in vivo situation than current models based on lung epithelial cell cultures on stiff membranes. Therefore, we developed an in vitro airway epithelial-endothelial cell culture model based on Calu-3 human lung epithelial cells and human lung microvascular endothelial cells (LMVECs), cultured on opposite sides of flexible porous poly(trimethylene carbonate) (PTMC) membranes. Calu-3 cells, cultured for two weeks at an air-liquid interface (ALI), showed good expression of the tight junction (TJ) protein Zonula Occludens 1 (ZO-1). Read More

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Preparation and characterization of gelatin-polysaccharide composite hydrogels for tissue engineering.

PeerJ 2021 15;9:e11022. Epub 2021 Mar 15.

College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan, China.

Background: Tissue engineering, which involves the selection of scaffold materials, presents a new therapeutic strategy for damaged tissues or organs. Scaffold design based on blends of proteins and polysaccharides, as mimicry of the native extracellular matrix, has recently become a valuable strategy for tissue engineering.

Objective: This study aimed to construct composite hydrogels based on natural polymers for tissue engineering. Read More

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Piezo 1 activation facilitates cholangiocarcinoma metastasis via Hippo/YAP signaling axis.

Mol Ther Nucleic Acids 2021 Jun 26;24:241-252. Epub 2021 Feb 26.

Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.

Tumor metastasis is one of the major factors for the high mortality in cholangiocarcinoma (CCA), but its underlying mechanisms are not fully understood. Here, we report that Piezo-type mechanosensitive ion channel component 1 (Piezo 1) is detected to be significantly upregulated in CCA tissues, which is linked to a poor prognosis in patients, suggesting that Piezo 1 may act in a pro-metastatic role in CCA development. Piezo 1 is activated through 20% simulated physiological stretch, and deleting Piezo 1 impedes epithelial-to-mesenchymal transition (EMT) of CCA cells, as well as impairing their metastatic capacity and . Read More

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Assessment of the Effects of Stretch-Injury on Primary Rat Microglia.

Mol Neurobiol 2021 Mar 24. Epub 2021 Mar 24.

Neuroscience Program, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD, 20814, USA.

Mechanical stretch-injury is a prominent force involved in the etiology of traumatic brain injury (TBI). It is known to directly cause damage and dysfunction in neurons, astrocytes, and endothelial cells. However, the deleterious effects of stretch-injury on microglia, the brain's primary immunocompetent cell, are currently unknown. Read More

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Neurodegenerative phosphoprotein signaling landscape in models of SCA3.

Mol Brain 2021 03 19;14(1):57. Epub 2021 Mar 19.

Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Calwerstrasse 7, 72076, Tuebingen, Germany.

Spinocerebellar ataxia type 3 (SCA3) is a rare neurodegenerative disorder resulting from an aberrant expansion of a polyglutamine stretch in the ataxin-3 protein and subsequent neuronal death. The underlying intracellular signaling pathways are currently unknown. We applied the Reverse-phase Protein MicroArray (RPMA) technology to assess the levels of 50 signaling proteins (in phosphorylated and total forms) using three in vitro and in vivo models expressing expanded ataxin-3: (i) human embryonic kidney (HEK293T) cells stably transfected with human ataxin-3 constructs, (ii) mouse embryonic fibroblasts (MEF) from SCA3 transgenic mice, and (iii) whole brains from SCA3 transgenic mice. Read More

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Quantitative high-throughput assay to measure MC4R-induced intracellular calcium.

J Mol Endocrinol 2021 04 26;66(4):285-297. Epub 2021 Apr 26.

Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.

The melanocortin-4 receptor (MC4R), a critical G-protein-coupled receptor (GPCR) regulating energy homeostasis, activates multiple signalling pathways, including mobilisation of intracellular calcium ([Ca2+]i). However, very little is known about the physiological significance of MC4R-induced [Ca2+]i since few studies measure MC4R-induced [Ca2+]i. High-throughput, read-out assays for [Ca2+]i have proven unreliable for overexpressed GPCRs like MC4R, which exhibit low sensitivity mobilising [Ca2+]i. Read More

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Remodelling of adult cardiac tissue subjected to physiological and pathological mechanical load in vitro.

Cardiovasc Res 2021 Mar 16. Epub 2021 Mar 16.

National Heart and Lung Institute, Imperial College London, UK.

Aims: Cardiac remodelling is the process by which the heart adapts to its environment. Mechanical load is a major driver of remodelling. Cardiac tissue culture has been frequently employed for in vitro studies of load-induced remodelling; however, current in vitro protocols (e. Read More

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EphA2 super-enhancer promotes tumor progression by recruiting FOSL2 and TCF7L2 to activate the target gene EphA2.

Cell Death Dis 2021 03 12;12(3):264. Epub 2021 Mar 12.

School of Life Science and Technology, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, China.

Super-enhancers or stretch enhancers (SEs) consist of large clusters of active transcription enhancers which promote the expression of critical genes that define cell identity during development and disease. However, the role of many super-enhancers in tumor cells remains unclear. This study aims to explore the function and mechanism of a new super-enhancer in various tumor cells. Read More

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