title: Inflammation-associated interleukin-6/signal transducer and activator of transcription 3 activation ameliorates alcoholic and nonalcoholic fatty liver diseases in interleukin-10-deficient mice.
abstract: Alcoholic and nonalcoholic steatohepatitis are characterized by fatty liver plus inflammation. It is generally believed that steatosis promotes inflammation, whereas inflammation in turn aggregates steatosis. Thus, we hypothesized the deletion of interleukin (IL)-10, a key anti-inflammatory cytokine, exacerbates liver inflammation, steatosis, and hepatocellular damage in alcoholic and nonalcoholic fatty liver disease models that were achieved via feeding mice with a liquid diet containing 5% ethanol for 4 weeks or a high-fat diet (HFD) for 12 weeks, respectively. IL-10 knockout (IL-10(-/-)) mice and several other strains of genetically modified mice were generated and used. Compared with wild-type mice, IL-10(-/-) mice had greater liver inflammatory response with higher levels of IL-6 and hepatic signal transducer and activator of transcription 3 (STAT3) activation, but less steatosis and hepatocellular damage after alcohol or HFD feeding. An additional deletion of IL-6 or hepatic STAT3 restored steatosis and hepatocellular damage but further enhanced liver inflammatory response in IL-10(-/-) mice. In addition, the hepatic expression of sterol regulatory element-binding protein 1 and key downstream lipogenic proteins and enzymes in fatty acid synthesis were down-regulated in IL-10(-/-) mice. Conversely, IL-10(-/-) mice displayed enhanced levels of phosphorylated adenosine monophosphate-activated protein kinase and its downstream targets including phosphorylated acetyl-coenzyme A carboxylase and carnitine palmitoyltransferase 1 in the liver. Such dysregulations were corrected in IL-10(-/-) IL-6(-/-) or IL-10(-/-) STAT3(Hep-/-) double knockout mice.
  
  
  CONCLUSIONS
  IL-10(-/-) mice are prone to liver inflammatory response but are resistant to steatosis and hepatocellular damage induced by ethanol or HFD feeding. Resistance to steatosis in these mice is attributable to elevation of inflammation-associated hepatic IL-6/STAT3 activation that subsequently down-regulates lipogenic genes but up-regulates fatty acid oxidation-associated genes in the liver.
authors: Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA.
authors: Andrew M
authors: AM
authors: Miller
authors: Hua
authors: H
authors: Wang
authors: Adeline
authors: A
authors: Bertola
authors: Ogyi
authors: O
authors: Park
authors: Norio
authors: N
authors: Horiguchi
authors: Sung Hwan
authors: SH
authors: Ki
authors: Shi
authors: S
authors: Yin
authors: Fouad
authors: F
authors: Lafdil
authors: Bin
authors: B
authors: Gao
mesh_terms: D000818:Animals; D060467:Disease Resistance; D005234:Fatty Liver / Q000517:prevention & control*; D005235:Fatty Liver, Alcoholic / Q000517:prevention & control*; D007249:Inflammation / Q000276:immunology*; D016753:Interleukin-10 / Q000502:physiology*; D015850:Interleukin-6 / Q000502:physiology*; D008297:Male; D051379:Mice; D065626:Non-alcoholic Fatty Liver Disease; D050796:STAT3 Transcription Factor / Q000502:physiology*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000502:physiology
chemical_list: D015850:Interleukin-6; D050796:STAT3 Transcription Factor; C497388:Srebf1 protein, mouse; C494087:Stat3 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1; D016753:Interleukin-10