Tumor necrosis factor alpha disrupts tight junction assembly

J Surg Res. 2004 Jan;116(1):14-8. doi: 10.1016/s0022-4804(03)00311-1.


Background: We have previously shown an increase in intestinal permeability and a corresponding decrease in the expression of tight junction (TJ) proteins in the in testines of patients with Crohn's disease (CD). Tumor necrosis factor-alpha (TNFalpha) has been implicated in the inflammatory process of CD and its suppression has therapeutic benefit. ZO-1, occludin, and the claudins are key proteins in the TJ.

Hypothesis: TNFalpha disrupts the TJ.

Methods: MDCK cells were incubated with TNFalpha (0-100 ng/ml) for 5 days. Qualitative evaluation of the TJ was done with monoclonal antibody to ZO-1 detected by an immunofluorescence. Duplicate cells were lysed and ZO-1, occludin, and claudin-1 amount determined by western blot.

Results: Immunofluorescent staining of MDCK cells for ZO-1 showed TJ structural disruption with increasing amount of TNFalpha characterized by fragmented staining of ZO-1. There were no significant differences in quantitation of ZO-1 or occludin in the MDCK cells for all TNFalpha concentrations. There was a significant decrease in the amount of claudin-1 with increasing concentration of TNFalpha.

Conclusions: (1) MDCK TJs are qualitatively disrupted by TNFalpha. (2) This disruption is not because of a decrease in cell number, lack of cell layer confluency, or a decrease in the amount of ZO-1 or occludin. (3) The amount of claudin-1 present in the cell is decreased with increasing amounts of TNFalpha suggesting that the lack of claudin-1 may cause a relocation of ZO-1 away from the TJ. (4) This rearrangement may play a role in the increased intestinal permeability seen in CD and other diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Count
  • Cell Line
  • Claudin-1
  • Dogs
  • Fluorescent Antibody Technique
  • Humans
  • Immunoblotting
  • Kidney / cytology
  • Kidney / drug effects
  • Kidney / metabolism
  • Membrane Proteins / metabolism
  • Occludin
  • Phosphoproteins / metabolism
  • Recombinant Proteins / pharmacology
  • Staining and Labeling
  • Tight Junctions / drug effects*
  • Tumor Necrosis Factor-alpha / pharmacology*
  • Zonula Occludens-1 Protein


  • CLDN1 protein, human
  • Claudin-1
  • Membrane Proteins
  • OCLN protein, human
  • Occludin
  • Phosphoproteins
  • Recombinant Proteins
  • TJP1 protein, human
  • Tumor Necrosis Factor-alpha
  • Zonula Occludens-1 Protein