scholarly journals Alpha-Gal on the Protein Surface Hampers Transcytosis through the Caco-2 Monolayer

2020 ◽  
Vol 21 (16) ◽  
pp. 5742
Author(s):  
Maja Krstić Ristivojević ◽  
Jeanette Grundström ◽  
Danijela Apostolović ◽  
Mirjana Radomirović ◽  
Vesna Jovanović ◽  
...  
Keyword(s):  
Cell Monolayer ◽  
Protein Glycosylation ◽  
Transepithelial Transport ◽  
Intact Protein ◽  
Gastric Digestion ◽  
Delayed Reaction ◽  
Meat Allergy ◽  
Galectin 3 ◽  
Ige Response ◽  
Mammalian Meat

Transepithelial transport of proteins is an important step in the immune response to food allergens. Mammalian meat allergy is characterized by an IgE response against the carbohydrate moiety galactosyl-α-1,3-galactose (α-Gal) present on mammalian glycoproteins and glycolipids, which causes severe allergic reactions several hours after red meat consumption. The delayed reaction may be related to the processing of α-Gal carrying proteins in the gastrointestinal tract. The aim of this study was to investigate how protein glycosylation by α-Gal affects the susceptibility to gastric digestion and transport through the Caco-2 cell monolayer. We found that α-Gal glycosylation altered protein susceptibility to gastric digestion, where large protein fragments bearing the α-Gal epitope remained for up to 2 h of digestion. Furthermore, α-Gal glycosylation of the protein hampered transcytosis of the protein through the Caco-2 monolayer. α-Gal epitope on the intact protein could be detected in the endosomal fraction obtained by differential centrifugation of Caco-2 cell lysates. Furthermore, the level of galectin-3 in Caco-2 cells was not affected by the presence of α-Gal glycosylated BSA (bovine serum albumin) (BSA-α-Gal). Taken together, our data add new knowledge and shed light on the digestion and transport of α-Gal glycosylated proteins.

Copper repletion enhances apical iron uptake and transepithelial iron transport by Caco-2 cells

2002 ◽  
Vol 282 (3) ◽  
pp. G527-G533 ◽  
Author(s):  
Okhee Han ◽  
Marianne Wessling-Resnick
Keyword(s):  
Iron Uptake ◽  
Iron Transport ◽  
Cell Monolayer ◽  
Transepithelial Transport ◽  
Apical Surface ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter ◽  
Metal Transporter ◽  
Copper Status ◽  
Copper Supplementation

The influence of copper status on Caco-2 cell apical iron uptake and transepithelial transport was examined. Cells grown for 7–8 days in media supplemented with 1 μM CuCl2had 10-fold higher cellular levels of copper compared with control. Copper supplementation did not affect the integrity of differentiated Caco-2 cell monolayers grown on microporous membranes. Copper-repleted cells displayed increased uptake of iron as well as increased transport of iron across the cell monolayer. Northern blot analysis revealed that expression of the apical iron transporter divalent metal transporter-1 (DMT1), the basolateral transporter ferroportin-1 (Fpn1), and the putative ferroxidase hephaestin (Heph) was upregulated by copper supplementation, whereas the recently identified ferrireductase duodenal cytochrome b (Dcytb) was not. These results suggest that DMT1, Fpn1, and Heph are involved in the iron uptake process modulated by copper status. Although a clear role for Dcytb was not identified, an apical surface ferrireductase was modulated by copper status, suggesting that its function also contributes to the enhanced iron uptake by copper-repleted cells. A model is proposed wherein copper promotes iron depletion of intestinal Caco-2 cells, creating a deficiency state that induces upregulation of iron transport factors.

scholarly journals Could chiggers be contributing to the prevalence of galactose-alpha-1,3-galactose sensitization and mammalian meat allergy?

2019 ◽  
Vol 7 (2) ◽  
pp. 664-666 ◽  
Author(s):  
Lindsey P. Stoltz ◽  
Leslie M. Cristiano ◽  
Ashley P.G. Dowling ◽  
Jeffrey M. Wilson ◽  
Thomas A.E. Platts-Mills ◽  
...  
Keyword(s):  
Meat Allergy ◽  
Mammalian Meat

scholarly journals Electrical currents flow out of domes formed by cultured epithelial cells.

1984 ◽  
Vol 99 (4) ◽  
pp. 1541-1544 ◽  
Author(s):  
K Sugahara ◽  
J H Caldwell ◽  
R J Mason
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Active Transport ◽  
Cell Monolayer ◽  
Extracellular Fluid ◽  
Outward Current ◽  
Alveolar Epithelial Cells ◽  
Transepithelial Transport ◽  
Alveolar Type

Domes are localized areas of fluid accumulation between a cultured epithelial cell monolayer and the impermeable substratum on which the cells are cultured in vitro. Dome formation has been documented in a variety of epithelial cell lines that retain their transepithelial transport properties in vitro. However, it is not known whether domes are predominantly areas of specific active transport, or, alternatively, are predominantly areas of relative weak attachment to the culture surface. In the present study we adapted a vibrating microelectrode, which can detect small currents flowing in extracellular fluid, to determine if current was flowing into or out of domes and thereby to determine if domes were specialized areas of active transport. We used alveolar type II cells as the main epithelial cell type because they readily form domes in vitro and because they transport sodium from the apical to the basal surface. We found that electrical current flowed out of domes. The direction of the current was independent of the size of a dome, of the age of an individual dome, and of the number of days in primary culture for alveolar epithelial cells. This current was inhibited by amiloride and ouabain and was dependent on sodium in the medium. We made similar observations (outward current from domes which is blocked by amiloride and by sodium substitution) with domes formed by the Madin-Darby canine kidney cell line. The data support the hypothesis that sodium is transported across the entire monolayer and leaks back mainly through the domes. We conclude that domes in epithelial monolayers are not predominantly special sites of active transport but are more likely simply areas of weak attachment to the substratum.

Potential bioactive ingredient from elderberry fruit: Process optimization for a maximum phenolic recovery, physicochemical characterization, and bioaccesibility

2020 ◽  
pp. 1-18
Author(s):  
Milagros Lucía Gomez Mattson ◽  
Rocío Corfield ◽  
Leonardo Bajda ◽  
Oscar Edgardo Pérez ◽  
Carolina Schebor ◽  
...  
Keyword(s):  
Physical Properties ◽  
Cell Monolayer ◽  
Physicochemical Characterization ◽  
In Vitro Digestion ◽  
Transepithelial Transport ◽  
Antioxidant Compounds ◽  
Assisted Extraction ◽  
Freeze Dried ◽  
Bioactive Content

BACKGROUND: Dark-skin berries constitute a polyphenol-rich source of interest for the development of functional ingredients. OBJECTIVE: To develop an elderberry powder, addressing technological aspects for maximum bioactive recovery, including physical quality and bioaccesibility of the antioxidant compounds. METHODS: An optimization of the combined process of enzyme-assisted extraction and freeze-drying was undertaken. Polyphenols and anthocyanins were quantified by spectrophotometric and HPLC-DAD analysis along processing stages and an in vitro digestion model was used to study the antioxidant compound activity through gastrointestinal tract and after transepithelial transport across a Caco-2 cell monolayer. Powder physical properties were also evaluated. RESULTS: The best extraction conditions were 45°C and 160 ppm enzyme. 10% maltodextrin was the minimum carrier concentration needed to get a freeze-dried powder with good physical properties and maximum bioactive content. The phenolic compounds identified in fruits (mainly cyanidin-based anthocyanins, quercetin-3-rutinoside, catechin and, in smaller amounts, gallic and chlorogenic acids) were also present in the optimum extract and the powder. High bioaccesibility of bioactive compounds and antioxidant activity were obtained after in vitro digestion and transepithelial transport. CONCLUSION: The designed elderberry powder showed great potential as functional ingredient to be used in berry juice-based beverages or other products formulated with fruit powders.

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