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Junction Permeability (junction + permeability)

Distribution by Scientific Domains
Medical Sciences75%

Kinds of Junction Permeability

  • tight junction permeability
    		•

    Selected Abstracts

    A comparative molecular force spectroscopy study of homophilic JAM-A interactions and JAM-A interactions with reovirus attachment protein ,1

    JOURNAL OF MOLECULAR RECOGNITION, Issue 4 2008
    Sri Ram Krishna Vedula
    Abstract JAM-A belongs to a family of immunoglobulin-like proteins called junctional adhesion molecules (JAMs) that localize at epithelial and endothelial intercellular tight junctions. JAM-A is also expressed on dendritic cells, neutrophils, and platelets. Homophilic JAM-A interactions play an important role in regulating paracellular permeability and leukocyte transmigration across epithelial monolayers and endothelial cell junctions, respectively. In addition, JAM-A is a receptor for the reovirus attachment protein, ,1. In this study, we used single molecular force spectroscopy to compare the kinetics of JAM-A interactions with itself and ,1. A chimeric murine JAM-A/Fc fusion protein and the purified ,1 head domain were used to probe murine L929 cells, which express JAM-A and are susceptible to reovirus infection. The bond half-life (t1/2) of homophilic JAM-A interactions was found to be shorter () than that of ,1/JAM-A interactions (). These results are in accordance with the physiological functions of JAM-A and ,1. A short bond lifetime imparts a highly dynamic nature to homophilic JAM-A interactions for regulating tight junction permeability while stable interactions between ,1 and JAM-A likely anchor the virus to the cell surface and facilitate viral entry. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Assessment of a bioactive compound for its potential antiinflammatory property by tight junction permeability

    PHYTOTHERAPY RESEARCH, Issue 12 2005
    Young Hoon Bai
    Abstract Lactobacillus probiotic strains are proving to be abundant sources of bioactive components, including antiinflammatory components. Lifree was made of fruits fermented by Lactobacillus paracasei, Lactobacillus reuterrii and Saccharomyces cerevisiae. This study was designed to test these compounds in cell assays measuring epithelial barrier function and proliferation in the first instance. Cell proliferation was measured in mouse fibroblasts cells (3T3NIH) and rat intestinal epithelial cells (IEC-6), and tight junction activity in the kidney epithelial cell line (MDCK). Tight junction permeability was assessed by measuring transepithelial electrical resistance (TER) across confluent monolayers, following the addition of Lifree with or without a challenge with EGTA. Lifree promoted tight junction formation and recovery following loss of TER from challenge with EGTA. On the other hand, Lifree did not stimulate cell growth in either 3T3NIH and IEC-6 cells. Lifree stimulates tight junction maintenance and formation, suggesting it may have potential antiinflammatory properties. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Comparison of ceftibuten transport across Caco-2 cells and rat jejunum mounted on modified ussing chambers

    BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 7 2003
    R.M. Menon
    Abstract Ceftibuten uptake into Caco-2 cells and intestinal brush border membrane vesicles is mediated by the dipeptide transport system (PEPT1). The apical to basolateral transport characteristics of ceftibuten across Caco-2 cells and rat jejunum mounted on a modified Ussing chamber was examined. Mannitol was used as a paracellular marker along with trans-epithelial electrical resistance (TEER) for monitoring tight junction permeability. Transport across Caco-2 cells and rat jejunum mounted on a modified Ussing chamber was linear across the concentration range 0.25,10 mm. The net flux of mannitol and ceftibuten was higher across rat jejunum compared with Caco-2 cells. At a donor concentration of 0.25 mm, ceftibuten transport across Caco-2 cells was found to be pH dependent. Glycyl proline, a dipeptide, and 2,4- dinitrophenol, an energy poison, caused a reduction in the permeability of 0.25 mm ceftibuten across Caco-2 cells. Benzoic acid and adipic acid also inhibited transcellular transport of ceftibuten. At a donor concentration of 0.25 mm, passive paracellular transport accounts for about 60% and the active carrier mediated mechanism accounts for about 40% of ceftibuten transport across Caco-2 cells. None of the inhibitors however, had a significant effect on ceftibuten transport across rat jejunum mounted on a modified Ussing chamber at a donor concentration of 0.25 mm. In the concentration range 0.25,10 mm, ceftibuten is predominantly transported by paracellular mechanisms across rat jejunum and a mixture of active and passive transport across Caco-2 cells. Copyright © 2003 John Wiley & Sons, Ltd. [source]