Tumor necrosis factor alpha increases epithelial barrier permeability by disrupting tight junctions in Caco-2 cells
Braz. j. med. biol. res
;
43(4): 330-337, Apr. 2010. ilus, graf
Artigo
em Inglês
| LILACS
| ID: lil-543582
ABSTRACT
The objectives of this study were to determine the effect of tumor necrosis factor alpha (TNF-á) 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-á (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-á 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-á 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-á did not affect the expression of occludin mRNA. Taken together, our data demonstrate that TNF-á increases Caco-2 monolayer permeability, decreases occludin protein expression and disturbs intercellular junctions.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Permeabilidade da Membrana Celular
/
Fator de Necrose Tumoral alfa
/
Junções Íntimas
/
Células Epiteliais
/
Mucosa Intestinal
/
Proteínas de Membrana
Limite:
Humanos
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2010
Tipo de documento:
Artigo
País de afiliação:
China
Instituição/País de afiliação:
China Medical University/CN
/
Fujian Medical University/CN
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