title: Morphological and functional characterization of non-alcoholic fatty liver disease induced by a methionine-choline-deficient diet in C57BL/6 mice.
abstract: BACKGROUND
  Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic steatohepatitis (NASH), appears to be increasingly common worldwide. Its histopathology and the effects of nutrition on liver function have not been fully determined.
  
  
  OBJECTIVE
  To elucidate the cellular mechanisms of NAFLD induced by a methionine-choline-deficient (MCD) diet in mice. Particular focus was placed on the role of phagocytic cells.
  
  
  METHODS
  Male C57BL/6 mice were fed an MCD diet for 30 weeks. A recovery model was also established wherein a normal control diet was provided for 2 weeks after a period of 8, 16, or 30 weeks.
  
  
  RESULTS
  Mice fed the MCD diet for ≥ 2 weeks exhibited severe steatohepatitis with elevated serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Steatohepatitis was accompanied by the infiltration of CD68-positive macrophages (Kupffer cells). The severity of steatohepatitis increased in the first 16 weeks but was seen to lessen by week 30. Fibrosis began to develop at 10 weeks and continued thereafter. Steatohepatitis and elevated serum hepatic enzyme concentrations returned to normal levels after switching the diet back to the control within the first 16 weeks, but fibrosis and CD68-positive macrophages remained.
  
  
  CONCLUSIONS
  The histopathological changes and irreversible fibrosis seen in this model were caused by prolonged feeding of an MCD diet. These results were accompanied by changes in the activity of CD68-positive cells with temporary elevation of CCL-2, MMP-13, and MMP-9 levels, all of which may trigger early steatohepatitis and late fibrosis through phagocytosis-associated MMP induction.
authors.affiliation: Department of Anatomy and Developmental Biology, Graduate School of Medicine, Tokyo Women's Medical University Tokyo, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Itagaki
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Shimizu
authors.forename: Shunichi
authors.initials: S
authors.lastname: Morikawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Ogawa
authors.forename: Taichi
authors.initials: T
authors.lastname: Ezaki
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001219:Aspartate Aminotransferases / Q000097:blood; D015415:Biomarkers / Q000097:blood; D049109:Cell Proliferation; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D002796:Choline Deficiency / Q000097:blood / Q000150:complications*; D004195:Disease Models, Animal; D005234:Fatty Liver / Q000097:blood / Q000209:etiology* / Q000473:pathology; D005786:Gene Expression Regulation; D007728:Kupffer Cells / Q000378:metabolism / Q000648:ultrastructure; D008099:Liver / Q000378:metabolism / Q000648:ultrastructure*; D008103:Liver Cirrhosis / Q000209:etiology / Q000473:pathology; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D008715:Methionine / Q000172:deficiency*; D051379:Mice; D008810:Mice, Inbred C57BL; D065626:Non-alcoholic Fatty Liver Disease; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D000097382:CD68 Molecule
chemical_list: D000410:Alanine Transaminase; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D001219:Aspartate Aminotransferases; D015415:Biomarkers; D018932:Chemokine CCL2; D053509:Matrix Metalloproteinase 13; D020780:Matrix Metalloproteinase 9; D008715:Methionine; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; C081026:CD68 protein, mouse; D000097382:CD68 Molecule; C491768:Ccl2 protein, mouse; C507081:Mmp13 protein, mouse; C501830:Mmp9 protein, mouse
keywords: CD68 antigen; Kupffer cells; liver fibrosis; matrix metalloproteinase (MMP); mouse; non-alcoholic fatty liver disease (NAFLD)