title: Deletion of Nrf2 leads to rapid progression of steatohepatitis in mice fed atherogenic plus high-fat diet.
abstract: BACKGROUND
  The transcription factor nuclear factor-E2-related factor-2 (Nrf2) inhibits lipid accumulation and oxidative stress in the liver by interfering with lipogenic pathways and inducing antioxidative stress genes.
  
  
  METHODS
  The involvement of Nrf2 in defense against the development of steatohepatitis was studied in an experimental model induced by an atherogenic plus high-fat (Ath + HF) diet. Wild-type (WT) and Nrf2-null mice were fed the diet. Their specimens were analyzed for pathology as well as for the expression levels of genes involved in fatty acid metabolism and those involved via the Nrf2 transcriptional pathway.
  
  
  RESULTS
  In Nrf2-null mice fed the diet, steatohepatitis developed rapidly, leading to precirrhosis. The Ath + HF diet increased hepatic triglyceride levels and changed fatty acid composition in both mouse groups. However, oleic acid (C18:1 n-9) predominated in the livers of Nrf2-null mice. Correlating well with the pathology, the mRNA levels of the factors involved in fatty acid metabolism (Lxr, Srebp-1a, 1c, Acc-1, Fas, Scd-1, and Fatty acid transporting peptides 1, 3, 4), the inflammatory cytokine genes (Tnf-α and IL-1β), and the fibrogenesis-related genes (Tgf-β1 and α-Sma) were significantly increased in the livers of Nrf2-null mice fed the diet, compared with the levels of these factors in matched WT mice. Oxidative stress was significantly increased in the livers of Nrf2-null mice fed the diet. This change was closely associated with the decreased levels of antioxidative stress genes.
  
  
  CONCLUSIONS
  Nrf2 deletion leads to the rapid onset and progression of steatohepatitis induced by an Ath + HF diet, through both up-regulation of co-regulators of fatty acid metabolism and down-regulation of oxidative metabolism regulators in the liver.
authors.affiliation: Division of Medical Science, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8574, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Okada
authors.forename: Eiji
authors.initials: E
authors.lastname: Warabi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Masaki
authors.initials: M
authors.lastname: Horie
authors.forename: Naohiro
authors.initials: N
authors.lastname: Gotoh
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Tokushige
authors.forename: Etsuko
authors.initials: E
authors.lastname: Hashimoto
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Utsunomiya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ishii
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Junichi
authors.initials: J
authors.lastname: Shoda
mesh_terms: D000818:Animals; D004036:Diet, Atherogenic; D059305:Diet, High-Fat; D018450:Disease Progression; D005234:Fatty Liver / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D051267:NF-E2-Related Factor 2 / Q000235:genetics*; D013997:Time Factors
chemical_list: D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse