Tumor necrosis factor alpha increases epithelial barrier permeability by disrupting tight junctions in Caco-2 cells
AUTOR(ES)
Cui, W., Li, L.X., Sun, C.M., Wen, Y., Zhou, Y., Dong, Y.L., Liu, P.
FONTE
Brazilian Journal of Medical and Biological Research
DATA DE PUBLICAÇÃO
2010-04
RESUMO
The objectives of this study were to determine the effect of tumor necrosis factor alpha (TNF-α) on intestinal epithelial cell permeability and the expression of tight junction proteins. Caco-2 cells were plated onto Transwell® microporous filters and treated with TNF-α (10 or 100 ng/mL) for 0, 4, 8, 16, or 24 h. The transepithelial electrical resistance and the mucosal-to-serosal flux rates of the established paracellular marker Lucifer yellow were measured in filter-grown monolayers of Caco-2 intestinal cells. The localization and expression of the tight junction protein occludin were detected by immunofluorescence and Western blot analysis, respectively. SYBR-Green-based real-time PCR was used to measure the expression of occludin mRNA. TNF-α treatment produced concentration- and time-dependent decreases in Caco-2 transepithelial resistance and increases in transepithelial permeability to the paracellular marker Lucifer yellow. Western blot results indicated that TNF-α decreased the expression of phosphorylated occludin in detergent-insoluble fractions but did not affect the expression of non-phosphorylated occludin protein. Real-time RT-PCR data showed that TNF-α did not affect the expression of occludin mRNA. Taken together, our data demonstrate that TNF-α increases Caco-2 monolayer permeability, decreases occludin protein expression and disturbs intercellular junctions.
Documentos Relacionados
- Activation of Rho GTPases by Escherichia coli Cytotoxic Necrotizing Factor 1 Increases Intestinal Permeability in Caco-2 Cells
- Rotavirus-Induced Structural and Functional Alterations in Tight Junctions of Polarized Intestinal Caco-2 Cell Monolayers
- Cryptosporidium parvum infection of Caco-2 cell monolayers induces an apical monolayer defect, selectively increases transmonolayer permeability, and causes epithelial cell death.
- Entamoeba histolytica interactions with polarized human intestinal Caco-2 epithelial cells.
- Acute bacterial pneumonia in rats increases alveolar epithelial fluid clearance by a tumor necrosis factor-alpha-dependent mechanism.