TJ protein expression in epithelial cells during ALF (original magnification, ×400). A: NS-treated group, B: 2 h after GalN/LPS administration, C: 6 h after GalN/LPS administration, D: 9 h after GalN/LPS administration, E: LPS-treated group, F: GalN-treated group, G: anti-TNF-α-treated group, H: anti-TNF-α R1-treated group, I: TNF-α-treated group, J: 9 h after GalN/TNF-α administration. The mucosal tissue sections were double labeled for ZO-1 (brown color). Labeled sections were analyzed immunohistochemically. Decreased ZO-1 staining in the epithelial cells was observed at 9 h (D) after GalN/LPS and GalN/TNF-α (J) administration. In contrast to ZO-1 expression in colon tissue 2 h (B) and 6 h (C) after GalN/LPS administration, ZO-1 expression in the NS group (A), LPS group (E), D-GalN group (F), anti-TNF-α IgG group (G), anti-TNF-α receptor1 group (H), and TNF-α group (I) were not down-regulated (arrows indicate ZO-1).