Toll-like receptor 4 is involved in the mechanism of early alcohol-induced liver injury in mice

Hepatology. 2001 Jul;34(1):101-8. doi: 10.1053/jhep.2001.25350.


Chronic alcohol administration increases gut-derived endotoxin in the portal blood, which activates Kupffer cells and causes liver injury. Mice (C3H/HeJ) with mutations in toll-like receptor 4 (TLR4) are hyporesponsive to endotoxin. To test the hypothesis that TLR4 is involved in early alcohol-induced liver injury, the long-term intragastric ethanol feeding protocol developed by Tsukamoto and French for rats was adapted to mice. Animals with nonfunctional TLR4 and wild-type mice (C3H/HeOuJ) were compared. Two-month-old female mice were fed a high-fat liquid diet with either ethanol or isocaloric maltose-dextrin as control continuously for 4 weeks. There was no difference in mean urine alcohol concentrations between the groups. Dietary alcohol significantly increased liver-to-body weight ratios and serum alanine transaminase (ALT) levels in wild-type mice (109 +/- 18 U/L) over high-fat controls (40 +/- 3 U/L), effects that were blunted significantly in mice with a mutation of TLR4 (55 +/- 9 U/L). While no significant pathologic changes were observed in high-fat controls, dietary ethanol caused steatosis, mild inflammation, and focal necrosis in wild-type animals (pathology score = 5.2 +/- 1.2). These pathologic changes were significantly lower in TLR4-deficient mice fed ethanol (score = 2.0 +/- 1.3). Endotoxin levels in the portal vein were increased significantly after 4 weeks in both groups fed ethanol. Moreover, ethanol increased tumor necrosis factor alpha (TNF-alpha) mRNA expression in wild-type, but not in TLR4-deficient, mice. These data are consistent with the hypothesis that Kupffer cell activation by endotoxin via TLR4 is involved in early alcohol-induced liver injury.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alanine Transaminase / blood
  • Animals
  • Body Weight
  • Dietary Fats / administration & dosage
  • Drosophila Proteins*
  • Endotoxins / blood
  • Ethanol / administration & dosage*
  • Ethanol / urine
  • Fatty Liver / chemically induced
  • Female
  • Hepatitis, Alcoholic / etiology
  • Liver / chemistry
  • Liver / pathology
  • Liver Diseases, Alcoholic / etiology*
  • Liver Diseases, Alcoholic / genetics
  • Liver Diseases, Alcoholic / pathology
  • Membrane Glycoproteins / deficiency
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / physiology*
  • Mice
  • Mice, Inbred C3H
  • Mutation
  • Necrosis
  • Organ Size
  • Portal Vein
  • RNA, Messenger / analysis
  • Receptors, Cell Surface / deficiency
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / physiology*
  • Toll-Like Receptor 4
  • Toll-Like Receptors
  • Tumor Necrosis Factor-alpha / genetics


  • Dietary Fats
  • Drosophila Proteins
  • Endotoxins
  • Membrane Glycoproteins
  • RNA, Messenger
  • Receptors, Cell Surface
  • Toll-Like Receptor 4
  • Toll-Like Receptors
  • Tumor Necrosis Factor-alpha
  • Ethanol
  • Alanine Transaminase