Ventilation-Like Mechanical Strain Modulates the Inflammatory Response of BEAS2B Epithelial Cells

Protective mechanical ventilation is aimed at preventing ventilator-induced lung injury while ensuring sufficient gas exchange. A new approach focuses on the temporal profile of the mechanical ventilation. We hypothesized that the temporal mechanical strain profile modulates inflammatory signalling. We applied cyclic strain with various temporal profiles to human bronchial epithelial cells (BEAS2B) and assessed proinflammatory response. The cells were subjected to sinusoidal, rectangular, or triangular strain profile and rectangular strain profile with prestrain set to 0, 25, 50, or 75% of the maximum stain, static strain, and strain resembling a mechanical ventilation-like profile with or without flow-controlled expiration. The BEAS2B response to mechanical load included altered mitochondrial activity, increased superoxide radical levels, NF-kappaB translocation, and release of interleukin-8. The response to strain was substantially modulated by the dynamics of the stimulation pattern. The rate of dynamic changes of the strain profile correlates with the degree of mechanical stress-induced cell response.

Download Full-text

Src and focal adhesion kinase mediate mechanical strain-induced proliferation and ERK1/2 phosphorylation in human H441 pulmonary epithelial cells

AJP Cell Physiology ◽

10.1152/ajpcell.00529.2006 ◽

2007 ◽

Vol 292 (5) ◽

pp. C1701-C1713 ◽

Cited By ~ 59

Author(s):

Lakshmi S. Chaturvedi ◽

Harold M. Marsh ◽

Marc D. Basson

Keyword(s):

Epithelial Cells ◽

Focal Adhesion Kinase ◽

Focal Adhesion ◽

Mechanical Strain ◽

A549 Cells ◽

Cyclic Strain ◽

Short Interfering Rna ◽

Erk Activation ◽

Pulmonary Epithelial Cells ◽

Interfering Rna

Pulmonary epithelial cells are exposed to repetitive deformation during physiological breathing and mechanical ventilation. Such deformation may influence pulmonary growth, development, and barotrauma. Although deformation stimulates proliferation and activates extracellular signal-regulated kinases (ERK1/2) in human pulmonary epithelial H441 cells, the upstream mechanosensors that induce ERK activation are poorly understood. We investigated whether c-Src or focal adhesion kinase (FAK) mediates cyclic mechanical strain-induced ERK1/2 activation and proliferation in human pulmonary epithelial (NCI-H441) cells. The H441 and A549 cells were grown on collagen I-precoated membranes and were subjected to an average 10% cyclic mechanical strain at 20 cycles/min. Cyclic strain activated Src within 2 min by increasing phosphorylation at Tyr418, followed by rapid phosphorylation of FAK at Tyr397 and Tyr576 and ERK1/2 at Thr202/Tyr204 ( n = 5, P < 0.05). Twenty-four (A549 cells) and 24–72 h (H441 cells) of cyclic mechanical strain increased cell numbers compared with static culture. Twenty-four hours of cyclic strain also increased H441 FAK, Src, and ERK phosphorylation without affecting total FAK, Src, or ERK protein. The mitogenic effect was blocked by Src (10 μmol/l PP2 or short interfering RNA targeted to Src) or MEK (50 μmol/l PD-98059) inhibition. PP2 also blocked strain-induced phosphorylation of FAK-Tyr576 and ERK-Thr202/Tyr204 but not FAK-Tyr397. Reducing FAK by FAK-targeted short interfering RNA blocked mechanical strain-induced mitogenicity and significantly attenuated strain-induced ERK activation but not strain-induced Src phosphorylation. Together, these results suggest that repetitive mechanical deformation induced by ventilation supports pulmonary epithelial proliferation by a pathway involving Src, FAK, and then ERK signaling.

Download Full-text

Gastrin induces IL-8 expression in gastric epithelial cells through the activation of NF-kappaB and AP-1

Gastroenterology ◽

10.1016/s0016-5085(01)83620-9 ◽

2001 ◽

Vol 120 (5) ◽

pp. A727-A727

Author(s):

Y MIYAZAKI ◽

S HIRAOKA ◽

S KITAMURA ◽

M TOYOTA ◽

T KIYOHARA ◽

...

Keyword(s):

Epithelial Cells ◽

Gastric Epithelial Cells ◽

Nf Kappab

Download Full-text

Cadmium induces cytotoxicity in human bronchial epithelial cells through upregulation of eIF5A1 and NF-kappaB

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2014.01.146 ◽

2014 ◽

Vol 445 (1) ◽

pp. 95-99 ◽

Cited By ~ 22

Author(s):

De-Ju Chen ◽

Yan-Ming Xu ◽

Ji-Ying Du ◽

Dong-Yang Huang ◽

Andy T.Y. Lau

Keyword(s):

Epithelial Cells ◽

Bronchial Epithelial Cells ◽

Human Bronchial Epithelial Cells ◽

Bronchial Epithelial ◽

Nf Kappab

Download Full-text

A rig for controlled cyclic strain and temperature testing

The Journal of Strain Analysis for Engineering Design ◽

10.1243/03093247v171045 ◽

1982 ◽

Vol 17 (1) ◽

pp. 45-52 ◽

Cited By ~ 7

Author(s):

D J Beauchamp ◽

E G Ellison

Keyword(s):

Mechanical Strain ◽

Thermal Strain ◽

Cyclic Strain ◽

Heating System ◽

Temperature Cycle ◽

Transient Temperature ◽

Microprocessor System ◽

Hydraulic Test ◽

Heating And Cooling ◽

Phase Temperature

A servo-hydraulic test rig capable of applying combined temperature and strain or load cycles has been developed and commissioned. The nature of the test has dictated the specimen form as a hollow, hour-glass type. The critical problem of a suitable extensometer for temperature and strain cycling has been solved. The device designed and produced shows negligible transient temperature effects, has a high resolution of better than 0.1 μm, and is mechanically very stable. The heating and cooling is controlled by an induction heating system with grip cooling; additional cooling is available using compressed air passing through the hollow specimen. The system is capable of following a temperature ramp to within 1°C linearity. The thermal strain associated with a temperature cycle is compensated for using a microprocessor system specially developed for the purpose, which also enables a mechanical strain-stress loop to be plotted during a test. Both ‘in-phase’ and ‘out-of-phase’ temperature/strain cycles have been carried out and development continues to include dwell periods.

Download Full-text

Attenuation of nuclear factor kappa B (NF-kappaB) promotes apoptosis of kidney epithelial cells: a potential mechanism of mercury-induced nephrotoxicity.

Environmental Health Perspectives ◽

10.1289/ehp.02110s5819 ◽

2002 ◽

Vol 110 (suppl 5) ◽

pp. 819-822 ◽

Cited By ~ 28

Author(s):

James S Woods ◽

Francisco J Dieguez-Acuña ◽

Maureen E Ellis ◽

John Kushleika ◽

P Lynne Simmonds

Keyword(s):

Epithelial Cells ◽

Nuclear Factor Kappa B ◽

Nuclear Factor ◽

Potential Mechanism ◽

Nuclear Factor Kappa ◽

Kidney Epithelial Cells ◽

Nf Kappab

Download Full-text

985 - Human Long Non-Coding RNA (LNCRNA) CCAT1 and UCA1 Regulate Proinflammatory Response and Cell Migration in Human and Mouse Intestinal Epithelial Cells

Gastroenterology ◽

10.1016/s0016-5085(18)31023-0 ◽

2018 ◽

Vol 154 (6) ◽

pp. S-183-S-184 ◽

Cited By ~ 2

Author(s):

Ivy Ka Man Law ◽

David M. Padua ◽

Dimitrios Iliopoulos ◽

Charalabos Pothoulakis

Keyword(s):

Cell Migration ◽

Epithelial Cells ◽

Intestinal Epithelial Cells ◽

Intestinal Epithelial ◽

Proinflammatory Response ◽

Non Coding Rna ◽

Long Non Coding Rna ◽

Human And Mouse

Download Full-text

E11/gp38 Selective Expression in Osteocytes: Regulation by Mechanical Strain and Role in Dendrite Elongation

Molecular and Cellular Biology ◽

10.1128/mcb.02120-05 ◽

2006 ◽

Vol 26 (12) ◽

pp. 4539-4552 ◽

Cited By ~ 170

Author(s):

Keqin Zhang ◽

Cielo Barragan-Adjemian ◽

Ling Ye ◽

Shiva Kotha ◽

Mark Dallas ◽

...

Keyword(s):

Shear Stress ◽

Cell Lines ◽

Mechanical Load ◽

Mechanical Strain ◽

Three Dimensional ◽

Cell Communication ◽

Bone Surface ◽

Cellular Processes ◽

Primary Osteoblasts

ABSTRACT Within mineralized bone, osteocytes form dendritic processes that travel through canaliculi to make contact with other osteocytes and cells on the bone surface. This three-dimensional syncytium is thought to be necessary to maintain viability, cell-to-cell communication, and mechanosensation. E11/gp38 is the earliest osteocyte-selective protein to be expressed as the osteoblast differentiates into an osteoid cell or osteocyte, first appearing on the forming dendritic processes of these cells. Bone extracts contain large amounts of E11, but immunostaining only shows its presence in early osteocytes compared to more deeply embedded cells, suggesting epitope masking by mineral. Freshly isolated primary osteoblasts are negative for E11 expression but begin to express this protein in culture, and expression increases with time, suggesting differentiation into the osteocyte phenotype. Osteoblast-like cell lines 2T3 and Oct-1 also show increased expression of E11 with differentiation and mineralization. E11 is highly expressed in MLO-Y4 osteocyte-like cells compared to osteoblast cell lines and primary osteoblasts. Differentiated, mineralized 2T3 cells and MLO-Y4 cells subjected to fluid flow shear stress show an increase in mRNA for E11. MLO-Y4 cells show an increase in dendricity and elongation of dendrites in response to shear stress that is blocked by small interfering RNA specific to E11. In vivo, E11 expression is also increased by a mechanical load, not only in osteocytes near the bone surface but also in osteocytes more deeply embedded in bone. Maximal expression is observed not in regions of maximal strain but in a region of potential bone remodeling, suggesting that dendrite elongation may be occurring during this process. These data suggest that osteocytes may be able to extend their cellular processes after embedment in mineralized matrix and have implications for osteocytic modification of their microenvironment.

Download Full-text

Mitochondrial-Targeted Antioxidant MitoQ Prevents E. coli Lipopolysaccharide-Induced Accumulation of Triacylglycerol and Lipid Droplets Biogenesis in Epithelial Cells

Journal of Lipids ◽

10.1155/2018/5745790 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Ekaterina Fock ◽

Vera Bachteeva ◽

Elena Lavrova ◽

Rimma Parnova

Keyword(s):

Fatty Acids ◽

Epithelial Cells ◽

Lipid Droplets ◽

Cellular Respiration ◽

Mitochondrial Activity ◽

Energy Regulation ◽

Metabolic Shift ◽

Functional Connections ◽

The Impact

The effect of bacterial lipopolysaccharide (LPS) on eukaryotic cell could be accompanied by a significant metabolic shift that includes accumulation of triacylglycerol (TAG) in lipid droplets (LD), ubiquitous organelles associated with fatty acid storage, energy regulation and demonstrated tight spatial and functional connections with mitochondria. The impairment of mitochondrial activity under pathological stimuli has been shown to provoke TAG storage and LD biogenesis. However the potential mechanisms that link mitochondrial disturbances and TAG accumulation are not completely understood. We hypothesize that mitochondrial ROS (mROS) may play a role of a trigger leading to subsequent accumulation of intracellular TAG and LD in response to a bacterial stimulus. Using isolated epithelial cells from the frog urinary bladder, we showed that LPS decreased fatty acids oxidation, enhanced TAG deposition, and promoted LD formation. LPS treatment did not affect the mitochondrial membrane potential but increased cellular ROS production and led to impairment of mitochondrial function as revealed by decreased ATP production and a reduced maximal oxygen consumption rate (OCR) and OCR directed at ATP turnover. The mitochondrial-targeted antioxidant MitoQ at a dose of 25 nM did not prevent LPS-induced alterations in cellular respiration, but, in contrast to nonmitochondrial antioxidant α-tocopherol, reduced the effect of LPS on the generation of ROS, restored the LPS-induced decline of fatty acids oxidation, and prevented accumulation of TAG and LD biogenesis. The data obtained indicate the key signaling role of mROS in the lipid metabolic shift that occurs under the impact of a bacterial pathogen in epithelial cells.

Download Full-text

Abstract 139: Using Cyclic Strain to Improve Cardiac Progenitor Cell Cooperation

Circulation Research ◽

10.1161/res.113.suppl_1.a139 ◽

2013 ◽

Vol 113 (suppl_1) ◽

Author(s):

Kristin M French ◽

Marcos J Fierro ◽

Todd D Johnson ◽

Karen L Christman ◽

Michael E Davis

Keyword(s):

Connexin 43 ◽

Matrix Protein ◽

Mechanical Strain ◽

Cyclic Strain ◽

Culture Conditions ◽

Cardiac Cells ◽

Rhodamine Phalloidin ◽

Cell Therapies ◽

Static Conditions

Introduction: Cell therapies have grown in popularity for myocardial regeneration post-infarction, but still suffer from poor retention, maturation and integration of delivered cells. Mechanical strain has been shown to alter cell size, shape, adherence and gene expression in cardiac cells. As a more recently identified cell type, the effect of mechanical strain on cardiac progenitor cells (CPCs) is unknown. This work aims to elucidate the role mechanical strain plays in CPC phenotype and if this response is matrix protein specific. We hypothesize that mechanical strain will improve CPC alignment and potential for connectivity. Methods: To examine the role of mechanical strain on CPCs, CPCs were seeded on FlexCell plates in the presence of a naturally-derived cardiac extracellularmatrix (cECM), collagen I (COL) or no protein (TCP) and strained 0% (static) or 10% at 1 Hz for 24 hours in a BioFlex system. CPC elongation, alignment, and size were evaluated by rhodamine-phalloidin staining. Connexin-43 expression was measured by Western and normalized to GAPDH. Data were analyzed by two-way ANOVA and Bonferroni post-test. Results: CPC area, independent of culture conditions, was 1020 ± 40 um2, corresponding to neonatal cardiomyocyte area. The aspect ratio (major/minor axis) of CPCs showed a trend for increased elongation with strain at (e.x. 2.0±0.2 for unstrained cECM compared to 2.7±0.1 for strained cECM; n=4, p>0.05). Static culture conditions, independent of matrix coating, showed 20±3% alignment of CPCs. Under strain, alignment increased to 30±2% on COL (n=4; p>0.05 for strained COL verus static COL) and 48±8% on cECM (n=4; p< 0.01 for strained cECM versus strained COL and p<0.001 for strained cECM verus static cECM). A fold change >2 for connexin-43 protein in strained versus static conditions, independent of matrix, was observed (n=2, p>0.05) and confirmed by immunocytochemistry. Conclusion: This work suggests that mechanical strain alters CPC phenotype. Increased strain-induced alignment appears to be matrix dependent. In conclusion, these studies provide insight into the role of both mechanical forces and biochemical responses in the function of CPCs; which could lead to improved outcomes following cellular transplantation.

Download Full-text