A system to impose prescribed homogenous strains on cultured cells

There is presently significant interest in cellular responses to physical forces, and numerous devices have been developed to apply stretch to cultured cells. Many of the early devices were limited by the heterogeneity of deformation of cells in different locations and by the high degree of anisotropy at a particular location. We have therefore developed a system to impose cyclic, large-strain, homogeneous stretch on a multiwell surface-treated silicone elastomer substrate plated with pulmonary epithelial cells. The pneumatically driven mechanism consists of four plates each with a clamp to fix one edge of the cruciform elastomer substrate. Four linear bearings set at predetermined angles between the plates ensure a constant ratio of principal strains throughout the stretch cycle. We present the design of the device and membrane shape, the surface modifications of the membrane to promote cell adhesion, predicted and experimental measurements of the strain field, and new data using cultured airway epithelial cells. We present for the first time the relationship between the magnitude of cyclic mechanical strain and the extent of wound closure and cell spreading.

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Mechanical stretch decreases FAK phosphorylation and reduces cell migration through loss of JIP3-induced JNK phosphorylation in airway epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00076.2009 ◽

2009 ◽

Vol 297 (3) ◽

pp. L520-L529 ◽

Cited By ~ 26

Author(s):

Leena P. Desai ◽

Steven R. White ◽

Christopher M. Waters

Keyword(s):

Cell Migration ◽

Epithelial Cells ◽

Mechanical Strain ◽

Mechanical Stretch ◽

Inhibitory Effect ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Interacting Protein ◽

Kinase Activation ◽

Mapk Cascades

JNK is a nonreceptor kinase involved in the early events that signal cell migration after injury. However, the linkage to early signals required to initiate the migration response to JNK has not been defined in airway epithelial cells, which exist in an environment subjected to cyclic mechanical strain (MS). The present studies demonstrate that the JNK/stress-activated protein kinase-associated protein 1 (JSAP1; also termed JNK-interacting protein 3, JIP3), a scaffold factor for MAPK cascades that links JNK activation to focal adhesion kinase (FAK), are both associated and activated following mechanical injury in 16HBE14o− human airway epithelial cells and that both FAK and JIP3 phosphorylation seen after injury are decreased in cells subjected to cyclic MS. Overexpression of either wild-type (WT)-FAK or WT-JIP3 enhanced phosphorylation and kinase activation of JNK and reduced the inhibitory effect of cyclic MS. These results suggest that cyclic MS impairs signaling of cell migration after injury via a pathway that involves FAK-JIP3-JNK.

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The cell biology of asthma

The Journal of Cell Biology ◽

10.1083/jcb.201401050 ◽

2014 ◽

Vol 205 (5) ◽

pp. 621-631 ◽

Cited By ~ 162

Author(s):

David J. Erle ◽

Dean Sheppard

Keyword(s):

Smooth Muscle ◽

Epithelial Cells ◽

Airway Obstruction ◽

Cell Biology ◽

Complex Disease ◽

Cultured Cells ◽

Clinical Manifestations ◽

Cell Types ◽

Airway Epithelial Cells ◽

Airway Epithelial

The clinical manifestations of asthma are caused by obstruction of the conducting airways of the lung. Two airway cell types are critical for asthma pathogenesis: epithelial cells and smooth muscle cells. Airway epithelial cells, which are the first line of defense against inhaled pathogens and particles, initiate airway inflammation and produce mucus, an important contributor to airway obstruction. The other main cause of airway obstruction is contraction of airway smooth muscle. Complementary experimental approaches involving cultured cells, animal models, and human clinical studies have provided many insights into diverse mechanisms that contribute to airway epithelial and smooth muscle cell pathology in this complex disease.

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Cyclic stretch induces PlGF expression in bronchial airway epithelial cells via nitric oxide release

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00075.2006 ◽

2007 ◽

Vol 292 (2) ◽

pp. L559-L566 ◽

Cited By ~ 26

Author(s):

Kamal A. Mohammed ◽

Najmunnisa Nasreen ◽

Robert S. Tepper ◽

Veena B. Antony

Keyword(s):

Nitric Oxide ◽

Growth Factors ◽

Epithelial Cells ◽

Mechanical Strain ◽

Airway Epithelial Cells ◽

Cyclic Stretch ◽

Mitogen Activated Protein Kinase ◽

No Production ◽

Dependent Manner ◽

Airway Epithelial

Mechanical strain of lung tissue is an important stimulus for the production of growth factors that are critical for lung growth and development. However, excessive mechanical strain, as may occur during mechanical ventilation, may produce an increase in growth factors that may contribute to lung injury. We hypothesized that mechanical strain of primary bronchial airway epithelial cells (BAEpCs) induced the production of placental growth factor (PlGF), a member of the VEGF family. BAEpCs were cultured on a deformable silicoelastic membrane and exposed to different magnitudes of stretch. Stretch induced PlGF and nitric oxide (NO) production that increased with increasing magnitude of stretch. Stretch also induced PlGF and inducible NO synthase ( iNOS) gene expression. The stretch-induced PlGF production and NO synthesis were attenuated by PD98059, a specific mitogen-activated protein kinase kinase-1 and -2 inhibitor. Inhibition of NO generation by l-NAME or l-NMMA or scavenging NO by carboxy-PTIO prevented stretch-mediated erk1/2 activation. In addition, in unstretched BAEpCs, exogenous NO enhanced erk1/erk2 activation. Our data suggest that mechanical stretch of BAEpCs induces iNOS expression and induces PlGF release in an erk1/2 activation-dependent manner.

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Aerosolized drug-loaded nanoparticles targeting migration inhibitory factors inhibit Pseudomonas aeruginosa-induced inflammation and biofilm formation

Nanomedicine ◽

10.2217/nnm-2020-0344 ◽

2020 ◽

Vol 15 (30) ◽

pp. 2933-2953

Author(s):

Mohammad Doroudian ◽

Andrew O'Neill ◽

Ciaran O'Reilly ◽

Aisling Tynan ◽

Leona Mawhinney ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Enzymatic Activity ◽

Biofilm Formation ◽

Droplet Size Distribution ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Nano Formulation ◽

High Degree ◽

First Time

Aim: Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine, which has been shown to promote disease severity in cystic fibrosis. Methods: In this study, aerosolized drug-loaded nanoparticles containing SCD-19, an inhibitor of MIF's tautomerase enzymatic activity, were developed and characterized. Results: The aerosolized nanoparticles had an optimal droplet size distribution for deep lung deposition, with a high degree of biocompatibility and significant cellular uptake. Conclusion: For the first time, we have developed an aerosolized nano-formulation against MIF's enzymatic activity that achieved a significant reduction in the inflammatory response of macrophages, and inhibited Pseudomonas aeruginosa biofilm formation on airway epithelial cells. This represents a potential novel adjunctive therapy for the treatment of P. aeruginosa infection in cystic fibrosis.

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Thrombin stimulates the expression of PDGF in lung epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.2000.279.3.l503 ◽

2000 ◽

Vol 279 (3) ◽

pp. L503-L510 ◽

Cited By ~ 55

Author(s):

Shino Shimizu ◽

Esteban C. Gabazza ◽

Tatsuya Hayashi ◽

Masaru Ido ◽

Yukihiko Adachi ◽

...

Keyword(s):

Epithelial Cells ◽

Airway Remodeling ◽

Airway Epithelial Cells ◽

Alveolar Epithelial Cells ◽

Lung Epithelial Cells ◽

Lung Fibroblasts ◽

Airway Epithelial ◽

Rt Pcr ◽

Alveolar Epithelial ◽

First Time

Several growth factors, including platelet-derived growth factor (PDGF), have been implicated in the mechanism of lung and airway remodeling. In the present study, we evaluated whether thrombin may promote lung and airway remodeling by increasing PDGF production from lung and airway epithelial cells. Conditioned medium (CM) was prepared by treating epithelial cells with increasing concentrations of thrombin; before use in the assays, CM was treated with hirudin until complete inhibition of thrombin activity. CM from epithelial cells stimulated the proliferation of lung fibroblasts and bronchial smooth muscle cells. Anti-PDGF antibody significantly inhibited this CM proliferative activity, implicating PDGF in this effect. Enzyme immunoassay and RT-PCR demonstrated that thrombin induced the secretion and expression of PDGF from bronchial and alveolar epithelial cells. RT-PCR showed that epithelial cells express the thrombin receptors protease-activated receptor (PAR)-1, PAR-3, and PAR-4. The PAR-1 agonist peptide was also found to induce PDGF secretion from epithelial cells, suggesting that the cellular effect of thrombin occurs via a PAR-1-mediated mechanism. Overall, this study showed for the first time that thrombin may play an important role in the process of lung and airway remodeling by stimulating the expression of PDGF via its cellular receptor, PAR-1.

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