title: Alcohol directly stimulates epigenetic modifications in hepatic stellate cells.
abstract: OBJECTIVE
  Alcohol is a primary cause of liver disease and an important co-morbidity factor in other causes of liver disease. A common feature of progressive liver disease is fibrosis, which results from the net deposition of fibril-forming extracellular matrix (ECM). The hepatic stellate cell (HSC) is widely considered to be the major cellular source of fibrotic ECM. We determined if HSCs are responsive to direct stimulation by alcohol.
  
  
  METHODS
  HSCs undergoing transdifferentiation were incubated with ethanol and expression of fibrogenic genes and epigenetic regulators was measured. Mechanisms responsible for recorded changes were investigated using ChIP-Seq and bioinformatics analysis. Ethanol induced changes were confirmed using HSCs isolated from a mouse alcohol model and from ALD patient's liver and through precision cut liver slices.
  
  
  RESULTS
  HSCs responded to ethanol exposure by increasing profibrogenic and ECM gene expression including elastin. Ethanol induced an altered expression of multiple epigenetic regulators, indicative of a potential to modulate chromatin structure during HSC transdifferentiation. MLL1, a histone 3 lysine 4 (H3K4) methyltransferase, was induced by ethanol and recruited to the elastin gene promoter where it was associated with enriched H3K4me3, a mark of active chromatin. Chromatin immunoprecipitation sequencing (ChIPseq) revealed that ethanol has broad effects on the HSC epigenome and identified 41 gene loci at which both MML1 and its H3K4me3 mark were enriched in response to ethanol.
  
  
  CONCLUSIONS
  Ethanol directly influences HSC transdifferentiation by stimulating global changes in chromatin structure, resulting in the increased expression of ECM proteins. The ability of alcohol to remodel the epigenome during HSC transdifferentiation provides mechanisms for it to act as a co-morbidity factor in liver disease.
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Agata
authors.initials: A
authors.lastname: Page
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Pier P
authors.initials: PP
authors.lastname: Paoli
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Hill
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Howarth
authors.affiliation: Southern California Research Center for ALPD and Cirrhosis and Department of Pathology, University of Southern California Keck School of Medicine, USA; Department of Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
authors.forename: Raymond
authors.initials: R
authors.lastname: Wu
authors.affiliation: Southern California Research Center for ALPD and Cirrhosis and Department of Pathology, University of Southern California Keck School of Medicine, USA; Department of Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
authors.forename: Soo-Mi
authors.initials: SM
authors.lastname: Kweon
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Jeremy
authors.initials: J
authors.lastname: French
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: White
authors.affiliation: Southern California Research Center for ALPD and Cirrhosis and Department of Pathology, University of Southern California Keck School of Medicine, USA; Department of Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Tsukamoto
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
authors.forename: Derek A
authors.initials: DA
authors.lastname: Mann
authors.affiliation: Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, William Leech Building, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK. Electronic address: Jelena.Mann@ncl.ac.uk.
authors.forename: Jelena
authors.initials: J
authors.lastname: Mann
mesh_terms: D000818:Animals; D054338:Cell Transdifferentiation; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics*; D004195:Disease Models, Animal; D018450:Disease Progression; D044127:Epigenesis, Genetic; D000431:Ethanol / Q000009:adverse effects*; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008104:Liver Cirrhosis, Alcoholic / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D016133:Polymerase Chain Reaction; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016326:Extracellular Matrix Proteins; D000431:Ethanol; D004247:DNA
keywords: ALD; Elastin; Epigenetics; H3K4me3; HSC; MLL1