Appearance of surfactant-like particles in apical medium of Caco-2 cells may occur via tight junctions

1995 ◽  
Vol 268 (6) ◽  
pp. C1401-C1413 ◽  
Author(s):  
M. J. Engle ◽  
M. L. Grove ◽  
M. J. Becich ◽  
A. Mahmood ◽  
D. H. Alpers
Keyword(s):  
Tight Junctions ◽  
Secretory Pathway ◽  
Cell Monolayer ◽  
Cytochalasin D ◽  
Total Cell ◽  
Intestinal Lumen ◽  
Intestinal Alkaline Phosphatase ◽  
Particle Content ◽  
Quantitative Image ◽  
Monolayer Permeability

Intestinal alkaline phosphatase (AP) is secreted by Caco-2 cells bound to surfactant-like particles (SLP), which can be localized by electron microscopy to the basolateral space and the intestinal lumen, especially over tight junctions. To investigate the hypothesis that SLP are secreted basolaterally and enter the lumen through the tight junction, Caco-2 cells were incubated with agents known to increase permeability at tight junctions. Cytochalasin D and phorbol 12-myristate 13-acetate increased Caco-2 cell monolayer permeability and the appearance of particles in apical medium two- to threefold, as monitored by mannitol movement and AP activity, respectively. Blocking the apical secretory pathway by nocodazole or colchicine had no effect on either parameter. Estimation of SLP content demonstrated an increase in apical media particles similar to that determined by AP activity. Quantitative image analysis established that apical SLP content increased 4-10 times, whereas total cell particle content remained unchanged. These data indicate that SLP may be secreted initially into the basolateral space and then transported to the intestinal lumen through the tight junctions.

Abstract 546: L-NAME Attenuates the Cardiotonic Steroids-induced Monolayer Permeability in Lymphatic Endothelial Cells

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Juan Castor ◽  
Darijana Horvat ◽  
Walter E Cromer ◽  
Thomas J Kuehl ◽  
David C Zawieja ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Expression ◽  
Tight Junctions ◽  
Cell Monolayer ◽  
Hypertensive Disorder ◽  
Lymphatic Endothelial Cells ◽  
Vascular Leak Syndrome ◽  
Vascular Leak ◽  
Monolayer Permeability

Objective: Preeclampsia (preE) is a hypertensive disorder unique to pregnancy. Cardiotonic steroids (CTS) such as marinobufagenin (MBG), cinobufotalin (CINO), and ouabain (OUB) are Na + /K + ATPase inhibitors. MBG is elevated in a rat model and patients with preE. MBG causes a vascular leak syndrome in vivo and increases endothelial cell monolayer permeability. Edema is a common syndrome of preE. To assess whether CTS are involved in the leakage of lymphatic endothelial cells (LECs) lining during preE, we evaluated the effect of these CTS on monolayer permeability of LECs in culture. Methods: LECs were isolated from a rat mesenteric collecting lymphatic vessel. The cells were treated with DMSO (vehicle), MBG, CINO, or OUB (1, 10 or 100 nM). Some LECs were pretreated with L-NAME (N-Nitro-L-Arginine Methyl Ester) at a concentration of 1μM before treatment with 100 nM MBG or CINO. Monolayer permeability of CTS-induced LECs was measured by using a fluorescent dye that was quantified on a fluorescence plate reader. The expression of β-catenin and VE-cadherin in the CTS-treated LECs was measured by immunofluorescence. Western blot was performed to measure β-catenin, VE-cadherin, and LYVE-1 protein levels. Statistical comparisons were performed using analysis of variance with Dunnett's post hoc tests. Results: MBG (≥ 1 nM, p<0.05) and CINO (≥ 10 nM, p<0.05) significantly increased the monolayer permeability of LECs compared to DMSO while OUB had no effect. Pretreatment of LECs with 1μM L-NAME attenuated the monolayer permeability of LECs treated with either 100 nM of MBG (p<0.05) or 100 nM of CINO (p<0.05). The β-catenin protein expression in LECs was downregulated by both MBG (p<0.05) and CINO (p<0.05) treatment. However, CTS did not cause any disruption of the LECs tight junctions. CINO (p<0.05) downregulated the VE-cadherin and LYVE-1 protein expression, but MBG did not. Conclusions: We have demonstrated that bufadienolides, MBG and CINO, caused an increase in the monolayer permeability of LECs which was attenuated by L-NAME pretreatment. Moreover, the β-catenin protein expression was downregulated by MBG and CINO treatment with no significant effect on tight junctions. These data suggest that CTS may be involved in the vascular leak syndrome in the LEC lining in preE.

Human zonulin, a potential modulator of intestinal tight junctions

2000 ◽  
Vol 113 (24) ◽  
pp. 4435-4440 ◽  
Author(s):  
W. Wang ◽  
S. Uzzau ◽  
S.E. Goldblum ◽  
A. Fasano
Keyword(s):  
Tight Junction ◽  
Tight Junctions ◽  
Ussing Chamber ◽  
Intestinal Lumen ◽  
Epithelial Surface ◽  
Ussing Chambers ◽  
Zonula Occludens ◽  
Surface Receptor ◽  
Dynamic Structures ◽  
Zonula Occludens Toxin

Intercellular tight junctions are dynamic structures involved in vectorial transport of water and electrolytes across the intestinal epithelium. Zonula occludens toxin derived from Vibrio cholerae interacts with a specific intestinal epithelial surface receptor, with subsequent activation of a complex intracellular cascade of events that regulate tight junction permeability. We postulated that this toxin may mimic the effect of a functionally and immunologically related endogenous modulator of intestinal tight junctions. Affinity-purified anti-zonula occludens toxin antibodies and the Ussing chamber assay were used to screen for one or more mammalian zonula occludens toxin analogues in both fetal and adult human intestine. A novel protein, zonulin, was identified that induces tight junction disassembly in non-human primate intestinal epithelia mounted in Ussing chambers. Comparison of amino acids in the active zonula occludens toxin fragment and zonulin permitted the identification of the putative receptor binding domain within the N-terminal region of the two proteins. Zonulin likely plays a pivotal role in tight junction regulation during developmental, physiological, and pathological processes, including tissue morphogenesis, movement of fluid, macromolecules and leukocytes between the intestinal lumen and the interstitium, and inflammatory/autoimmune disorders.

Image Analysis of Fly Ash in the Characterization of the Shape of the Grains

1994 ◽  
Vol 370 ◽  
Author(s):  
M. Barrioulet ◽  
H. Cros ◽  
B. Husson ◽  
E. Ringot
Keyword(s):  
Image Analysis ◽  
Fly Ash ◽  
Mineralogical Composition ◽  
Fly Ashes ◽  
Particle Content ◽  
Power Stations ◽  
Fresh Material ◽  
Quantitative Image ◽  
Strength And Durability

AbstractFly ash from power stations is used as concrete additive to improve strength and durability. Surprisingly, studies of ashes of identical mineralogical composition from two different places have reported different results in terms of the rheological properties of the fresh material. The viscosity of the pastes made from these different fly ashes seems to be linked to the proportion of spherical and smooth-shaped grains found in them. A quantitative image analysis was carried out to characterize the shape of the grains of these two ashes from different geographical origins. The main result proves that the higher the glassy particle content of the fly ash, the more the hydraulic matrix is fluid.

scholarly journals Attenuation of Glomerular Endothelial Cells from High Glucose-Induced Injury by Blockade of MAD2B

2015 ◽  
Vol 35 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Yu-Mei Wang ◽  
Yu Hao ◽  
Xian-Fang Meng ◽  
Fang-Fang He ◽  
Shan Chen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
High Glucose ◽  
Cell Monolayer ◽  
No Production ◽  
Protein Levels ◽  
Glomerular Endothelial Cells ◽  
Monolayer Permeability ◽  
Glucose Treatment ◽  
In Cells

Background/Aims: To assess the role of mitotic arrest-deficient 2-like protein 2 (MAD2B) in high glucose-induced injury in mouse glomerular endothelial cells (GEnCs). Methods: GEnCs were cultured in vitro, and MAD2B protein levels were measured by Western blot in cells stimulated with high glucose (30 mM) for various periods of time. MAD2B and scrambled shRNA were introduced into GEnCs by liposomal transfection. Cell proliferation, apoptosis, nitric oxide (NO) production, and monolayer permeability were then measured in cells grown in the following conditions: control, high glucose treatment, MAD2B shRNA transfection with high glucose treatment, and scrambled shRNA transfection with high glucose treatment. Results: High glucose increased the protein levels of MAD2B in GEnCs. Compared with control cells, apoptosis was increased by high glucose treatment, which was attenuated by transfection with MAD2B shRNA transfection. Cells treated with high glucose produced less NO than control cells, whereas MAD2B shRNA transfection increased NO production. Cell monolayer permeability was enhanced in high glucose treated cells, but MAD2B shRNA transfection reduced permeability. Conclusion: High glucose levels induced the expression of MAD2B in GEnCs, whereas suppressing its expression reduced high glucose-induced endothelial cell apoptosis and high permeability, and promoted cell proliferation and NO production.

Tu1746 Activation of Snail via Reactive Oxygen Species Mediates Acetaldehyde-Induced Disruption of Tight Junctions in CACO-2 Cell Monolayer

2013 ◽  
Vol 144 (5) ◽  
pp. S-836
Author(s):  
Elhaseen Elamin ◽  
Ad Masclee ◽  
Freddy Troost ◽  
Jan Dekker ◽  
Daisy Jonkers
Keyword(s):  
Reactive Oxygen Species ◽  
Tight Junctions ◽  
Cell Monolayer ◽  
Reactive Oxygen ◽  
Oxygen Species

scholarly journals The enterocyte microvillus is a vesicle-generating organelle

2009 ◽  
Vol 185 (7) ◽  
pp. 1285-1298 ◽  
Author(s):  
Russell E. McConnell ◽  
James N. Higginbotham ◽  
David A. Shifrin ◽  
David L. Tabb ◽  
Robert J. Coffey ◽  
...  
Keyword(s):  
Brush Border ◽  
Membrane Surface ◽  
Intestinal Lumen ◽  
Intestinal Alkaline Phosphatase ◽  
Brush Border Enzymes ◽  
Membrane Surface Area ◽  
Catalytically Active ◽  
The Right

For decades, enterocyte brush border microvilli have been viewed as passive cytoskeletal scaffolds that serve to increase apical membrane surface area. However, recent studies revealed that in the in vitro context of isolated brush borders, myosin-1a (myo1a) powers the sliding of microvillar membrane along core actin bundles. This activity also leads to the shedding of small vesicles from microvillar tips, suggesting that microvilli may function as vesicle-generating organelles in vivo. In this study, we present data in support of this hypothesis, showing that enterocyte microvilli release unilamellar vesicles into the intestinal lumen; these vesicles retain the right side out orientation of microvillar membrane, contain catalytically active brush border enzymes, and are specifically enriched in intestinal alkaline phosphatase. Moreover, myo1a knockout mice demonstrate striking perturbations in vesicle production, clearly implicating this motor in the in vivo regulation of this novel activity. In combination, these data show that microvilli function as vesicle-generating organelles, which enable enterocytes to deploy catalytic activities into the intestinal lumen.

Encapsulation of pterostilbene in nanoemulsions: influence of lipid composition on physical stability, in vitro digestion, bioaccessibility, and Caco-2 cell monolayer permeability

2019 ◽  
Vol 10 (10) ◽  
pp. 6604-6614 ◽  
Author(s):  
Qianyuan Liu ◽  
Jingjing Chen ◽  
Yang Qin ◽  
Bo Jiang ◽  
Tao Zhang
Keyword(s):  
Lipid Composition ◽  
Cell Monolayer ◽  
Physical Stability ◽  
In Vitro Digestion ◽  
Medium Chain Triglycerides ◽  
Medium Chain ◽  
Monolayer Permeability ◽  
Long Chain Triglycerides ◽  
Long Chain

Nanoemulsions fabricated using medium chain triglycerides as carrier lipid are more effective for delivering pterostilbene than long chain triglycerides.

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