RRC ID 63337
Author Kimura K, Teranishi S, Fukuda K, Kawamoto K, Nishida T.
Title Delayed disruption of barrier function in cultured human corneal epithelial cells induced by tumor necrosis factor-alpha in a manner dependent on NF-kappaB.
Journal Invest Ophthalmol Vis Sci
Abstract PURPOSE:The corneal epithelium provides a barrier that is both important for corneal homeostasis and dependent on tight junctions (TJs) between adjacent epithelial cells. The authors examined the effects of tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine, on barrier function and the expression of TJ proteins in simian virus 40-transformed human corneal epithelial (HCE) cells.
METHODS:The barrier function of cultured HCE cells was evaluated by measurement of transepithelial electrical resistance (TER). The subcellular distribution of the TJ proteins zonula occludens-1 (ZO-1) and occludin and that of the p65 subunit of nuclear factor-kappaB (NF-kappaB) were determined by immunofluorescence staining. The expression of ZO-1 and occludin and the phosphorylation and degradation of the NF-kappaB inhibitory protein IkappaB-alpha were examined by immunoblot analysis.
RESULTS:TNF-alpha induced a decrease in the TER of HCE cells in a concentration- and time-dependent manner. It also induced the disappearance of ZO-1 from the interfaces of neighboring HCE cells without affecting the localization of occludin. The abundance of neither ZO-1 nor occludin was affected by TNF-alpha. TNF-alpha induced the phosphorylation and downregulation of IkappaB-alpha and the translocation of the p65 subunit of NF-kappaB to the nucleus. The NF-kappaB inhibitor curcumin blocked the effects of TNF-alpha on TER and the subcellular localization of ZO-1 at late phase.
CONCLUSIONS:TNF-alpha disrupted the barrier function of HCE cells, apparently by affecting the localization of ZO-1 at TJs in a manner dependent on NF-kappaB at late phase. This action of TNF-alpha may contribute to the loss of corneal epithelial barrier function associated with ocular inflammation.
Volume 49(2)
Pages 565-71
Published 2008-2-1
DOI 10.1167/iovs.07-0419
PII 49/2/565
PMID 18235000
MeSH Cell Membrane Permeability / drug effects Cells, Cultured Curcumin / pharmacology Dose-Response Relationship, Drug Down-Regulation Electric Impedance Epithelium, Corneal / cytology Epithelium, Corneal / drug effects* Epithelium, Corneal / metabolism Fluorescent Antibody Technique, Indirect Humans I-kappa B Proteins / metabolism Immunoblotting Membrane Proteins / metabolism NF-KappaB Inhibitor alpha Occludin Phosphoproteins / metabolism Phosphorylation Tight Junctions / drug effects* Tight Junctions / metabolism Time Factors Transcription Factor RelA / antagonists & inhibitors Transcription Factor RelA / metabolism* Tumor Necrosis Factor-alpha / pharmacology* Zonula Occludens-1 Protein
IF 3.47
Human and Animal Cells HCE-T(RCB2280)