Author: Séverine OudinPublisher:
ISBN:
Category :
Languages : en
Pages : 250
Book Description
Effects of Mechanical Stretch on Human Bronchial Epithelial Cells
Author: Séverine OudinEffect of Mechanical Stretch on Human Bronchial Epithelial Cells
Author: Séverine OudinPublisher:
ISBN:
Category :
Languages : en
Pages : 250
Book Description
L'objectif de cette thèse était d'identifier les mécanismes moléculaires et cellulaires qui transforment un stress mécanique en séquelle biochimique, dans le cadre d'une approche biologique de l'inflammation pulmonaire induite par la ventilation mécanique (VILI) observée chez les patients des soins intensifs de médecine. Il a été démontré que les cellules bronchiques humaines répondent au stress d'étirement en sécrétant l'interleukine (IL)-8, chimiokine importante dans le VILI. Cette sécrétion est due au moins en partie à une activation transcriptionnelle du gène de l'IL-8, laquelle est due à l'activation des voies de signalisations aboutissant à l'activation du facteur de transcription NF-kappaB. D'autre part, les voies de signalisation des MAP kinases, en particulier p38, participent aussi à l'activation des cellules bronchiques par l'étirement. Finalement, il a été établit que deux autres ARN messagers sont actives en sus de l'IL-8 au cours de l'étirement mécanique parmi les 588 ARNm testés : MCP-1 et GADD45.
Effects of Mechanical Stimuli of Vibration and Stretch on Airway Epithelial Cells
Author: Ferranda Puig i CotadoPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Effects of Cyclic Stretch on Surfactant Secretion and Cell Viability in Alveolar Epithelial Cells Grown in Culture
Author: Stephen Paul AroldPublisher:
ISBN:
Category :
Languages : en
Pages : 258
Book Description
Abstract: Mechanical ventilation is vital among patients suffering from acute lung injury; however, studies have shown that it likely damages the lung through ventilator induced lung injury (VILI). VILI is thought to arise partly from the deleterious effects of non-physiologic forces imparted to the pulmonary epithelium. We have demonstrated that a novel ventilation strategy, "variable ventilation," whereby tidal volume is varied on a cycle-by-cycle basis, increases pulmonary surfactant content in rodents. We hypothesized that the variable stretch patterns enhanced surfactant secretion in the alveolar epithelial type II (AEII) cells. The broad goal of this study was to directly test this hypothesis. Here we describe the design and validation of a stretching device capable of delivering cyclic, biaxial strains to cells grown in culture including the novel stretch patterns required for this study. We utilized this device to characterize the effects of strain and underlying substratum on surfactant secretion and cell viability on the mouse lung epithelial-12 (MLE-12) cell line. Next, we cultured rat AEII cells and examined the combined effects of time duration and stretch magnitude on surfactant secretion and uptake, cell viability, and secretion of surfactant proteins. Finally, we stretched cultured AEII cells utilizing a "variable stretch" pattern mimicking those conditions thought to occur in-vivo during variable ventilation. We found that the MLE-12 cells did not exhibit surfactant secretion in response to stretch, however surfactant secretion was enhanced when grown on a fibronectin-like substratum in comparison with those grown on collagen I. While isolated AEII cells increased surfactant secretion in response to short periods of strain, 1 hour of cyclic stretch diminished surfactant secretion regardless of strain magnitude. Finally, variable stretch patterns applied to AEII increased surfactant secretion at high and moderate degrees of strain. This suggests ventilator strategies utilizing monotonous ventilation patterns may inhibit surfactant secretion in a clinical setting, whereas application of variable stretch may result in enhanced surfactant secretion into the alveolar space, possibly reducing VILI. These results may have a broader application to physiologic systems in general where purely periodic signals imposed by human intervention could have a detrimental effect on a system's natural function.
TNF-©{u008E}℗ł and Mechanical Stretch: Synergistic Damage to Alveolar Epithelial Cells
Author: Corey Garrett HoltPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Acute respiratory distress syndrome (ARDS) is difficult to treat and has a mortalitly rate of 40-60%. During ARDS, cytokine levels in the lungs are elevated and patients are treated with hyperoxia and mechanical ventilaion. Alone, these three factors can cause lung injury but the combination is thought to worsen lung damage. Using an over-distension model of lung injury, I investigated the effect of excessive mechanical stretch on a monolayer of murine alveolar epithelial cells (MLE-12) treated with the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α). Results show that monolayer damage, i.e., formation of cell-free areas, may begin as early as 30 minutes from the beginning of excessive stretch. Moreover, the cell-free area formation due to TNF-α and stretch together was 16% greater than the cell-free area formed due to either stimulus alone. Future studies are needed to elucidate the cause of this form of damage.
Mechanical Stretch and Cytokines
Author: Andre KamkinPublisher: Springer Science & Business Media
ISBN: 9400720041
Category : Science
Languages : en
Pages : 247
Book Description
This book presents the latest findings in the field of investigation of molecular mechanisms of mechanical stretch and the role of cytokines in response of different tissues to it. On the one hand this Volume demonstrates how mechanical stretch enhances cytokines production. It describes how cytokines influence tissues and cells on a background of a mechanical stretching. It provides a description of how cells in different tissues are activated by stretch and cytokines via various signaling pathways, and how they change their gene expression. The book is a unique collection of reviews outlining current knowledge and future developments in this rapidly growing field. Knowledge of biomechanics, and mechanisms which underlie it on molecular, cellular and tissue, is necessary for understanding of the normal functioning of living organisms and allows to predict changes, which arise due to alterations of their environment.
The Effect of Mechanical Ventilation on Lung Epithelial Cell Fate
Author: Joyce LeeOptimizing New in Vitro Methodologies for Assessing the Effects of Mechanical Stimuli on Lung Cells
Author: Alicia E. TannebergerPublisher:
ISBN:
Category : Extracellular matrix
Languages : en
Pages : 206
Book Description
Chronic lung diseases affect millions of people in the United States and are a leading cause of both morbidity and mortality. Studying how environmental factors affect lung cell biology and function is being increasingly recognized as a critical step in understanding lung disease pathogenesis and the development of new therapeutic approaches that combat lung diseases. These factors include lung extracellular matrix (ECM) composition and the mechanobiological factors of stiffness and cyclic mechanical strain, which during breathing, act on cells during the normal expansion and contraction of the lung. However, current methodologies for studying these factors have significant limitations and new approaches are necessary, particularly for investigating how these factors are altered in diseased lungs. As such, the goal of this thesis was to develop and optimize new in vitro methodologies that can be used to assess the effects of these three factors (ECM composition, stiffness, and cyclic mechanical strain (stretch)) on lung cells under both normal and diseased conditions, where idiopathic pulmonary fibrosis served as the disease model. I present work from two independent sets of studies that were designed to investigate the effects of these factors individually and in combinatorial fashion. The first study focused on how stiffness and ECM composition, alone and in combination, can cause changes in a representative relevant human lung cell type, human lung fibroblasts (HLF). A novel approach utilized ECM protein (hydrogel) solutions derived from decellularized normal or diseased human lungs (composition factor) coated onto the surface of CytoSoft® stiffness specific plates (2 kPa, 8 kPa, or 16 kPa) (stiffness factor). Endpoint assessments included cell morphology, growth, metabolism, and relevant gene expression. These results demonstrate that ECM composition and substrate stiffness, both alone and in combination affect HLF behavior. In the second series of studies, the goal was to assess how cyclic mechanical stretch impact function of an important lung cell type: alveolar epithelial type II (AT2) cells, critical for surfactant production. Utilizing AT2s derived from induced pluripotent stem cells (iAT2s) as a model system, the cells underwent biaxial stretch using a FlexCell® FX-5000[trademark symbol] Tension System for either 2 or 24 hours. Endpoint assessments included imaging and gene expression compared to un-stretched cells. The results show unique morphological changes in the stretched samples, while the gene expression data prove to be more variable. Collectively, this work shows how environmental and mechanical factors, including matrix composition, stiffness, and stretch, impact lung cell function and provides optimized methods to study such interactions. The unique methodology utilized should enable further investigations into both normal physiology and lung pathologies.
Endothelial Cell Culture
Author: Roy BicknellPublisher: Cambridge University Press
ISBN: 9780521559904
Category : Science
Languages : en
Pages : 156
Book Description
The aim of the Handbooks in Practical Animal Cell Biology is to provide practical workbooks for those involved in primary cell culture. Each volume addresses a different cell lineage, and contains an introductory section followed by individual chapters on the culture of specific differentiated cell types. The authors of each chapter are leading researchers in their fields and use their first-hand experience to present reliable techniques in a clear and thorough manner. Endothelial Cell Culture contains chapters on endothelial cells derived from 1) lung, 2) bone marrow, 3) brain, 4) mammary glands, 5) skin, 6) adipose tissue, 7) female reproductive system, and 8) synovium.
Ventilator-Induced Lung Injury
Author: Didier DreyfussPublisher: CRC Press
ISBN: 1420019260
Category : Medical
Languages : en
Pages : 776
Book Description
This reference surveys current best practices in the prevention and management of ventilator-induced lung injury (VILI) and spans the many pathways and mechanisms of VILI including cell injury and repair, the modulation of alveolar-capillary barrier properties, and lung and systemic inflammatory consequences of injurous mechanical ventilation. Cons