title: Lycopene inhibits hepatic steatosis via microRNA-21-induced downregulation of fatty acid-binding protein 7 in mice fed a high-fat diet.
abstract: METHODS
  Nonalcoholic fatty liver disease (NAFLD) is a chronic disorder characterized by hepatic fat accumulation and abnormal lipid metabolism. Here, we investigated the protective effect of lycopene on high-fat diet-induced hepatic steatosis and fatty acid-induced intracellular lipid accumulation by miRNA regulation.
  
  
  RESULTS
  C57BL/6J mice were fed high-fat diet with or without 0.05% lycopene for 8 weeks. Hepa 1-6 cells were treated with stearic acid (SA) after 24 h pretreatment with lycopene. Treatment of lycopene improved hepatic steatosis in high-fat-fed mice and reduced intracellular lipid accumulation induced by SA in Hepa 1-6 cells. We demonstrated that miR-21 expression was decreased in livers from high-fat diet-fed mice and Hepa 1-6 cells treated with SA. Lycopene normalized the downregulation of miR-21, which led to the downregulation of fatty acid-binding protein 7 (FABP7), a direct target of miR-21, at both the transcriptional and translational levels. This specific negative regulation of miR-21 was achieved by targeting the FABP7 3'UTR. Upregulation of miR-21 markedly blocked SA-induced intracellular lipid accumulation by blocking FABP7 expression. Moreover, silencing of FABP7 reduced SA-evoked lipid accumulation in Hepa 1-6 cells.
  
  
  CONCLUSIONS
  The results suggest that lycopene may be a useful functional compound for treating NAFLD by regulating hepatic lipid metabolism.
authors.affiliation: Food Function Research Center, Korea Food Research Institute, Seoungnam, Korea.
authors.forename: Jiyun
authors.initials: J
authors.lastname: Ahn
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Lee
authors.forename: Chang Hwa
authors.initials: CH
authors.lastname: Jung
authors.forename: Taeyoul
authors.initials: T
authors.lastname: Ha
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000494:pharmacology*; D002478:Cells, Cultured; D059305:Diet, High-Fat / Q000009:adverse effects; D015536:Down-Regulation; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005234:Fatty Liver / Q000235:genetics* / Q000378:metabolism / Q000517:prevention & control*; D005786:Gene Expression Regulation / Q000187:drug effects; D050356:Lipid Metabolism / Q000187:drug effects; D000077276:Lycopene; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D065626:Non-alcoholic Fatty Liver Disease; D013229:Stearic Acids / Q000494:pharmacology
chemical_list: C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; C531950:MIRN21 microRNA, mouse; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; D013229:Stearic Acids; D002338:Carotenoids; C031183:stearic acid; D000077276:Lycopene