title: The interplay between hepatic stellate cells and hepatocytes in an in vitro model of NASH.
abstract: OBJECTIVE
  A complex interplay exists between hepatocytes and hepatic stellate cells (HSC) in hepatic fibrogenesis. The activation of HSCs after liver injury leads to production of extracellular matrix (ECM). Co-culture models could be useful to mimic the liver microenvironment. This study evaluates the effect of free fatty acids (FFA) on HSC cells and the interplay with hepatocytes via both soluble-mediator and cell-cell contact.
  
  
  METHODS
  The human hepatocyte cell line (HuH7) and HSC cells (LX2) were exposed to FFA for 24 h in 3 different experimental set-ups: (A) monoculture of HSC; (B) Transwell® system (effect of soluble mediators); and (C) Simultaneous Co-Culture (SCC) (cell-to-cell connections). Intracellular FFA accumulation was assessed qualitatively (microscopy) and quantitatively (flow cytometry); the activation of HSC (alpha smooth muscle actin, α-SMA) expression of ECM components were quantified by RT-PCR.
  
  
  RESULTS
  FFA exposure induces intracellular fat accumulation in all the experimental set-up but the expression of α-SMA was significantly increased only in SCC. On the contrary, the expression of ECM was substantially decreased in the transwell® system.
  
  
  CONCLUSIONS
  The HSC activation is independent of FFA accumulation but requires cell-to-cell interaction with hepatocyte. On the contrary, the gene regulation of ECM components seems to occur through paracrine mediators.
authors.affiliation: Liver Research Unit, Medica Sur Clinic & Foundation, Mexico City, Puente de Piedra 150, Col. Toriello Guerra, Tlalpan, C.P. 14050 Mexico City, Mexico; Centro Studi Fegato (CSF) - Liver Research Center, Fondazione Italiana Fegato, Bldg Q AREA Science Park, Basovizza Campus SS 14 km 163.5, 34149 Trieste, Italy. Electronic address: varenka_bb@hotmail.com.
authors.forename: Varenka J
authors.initials: VJ
authors.lastname: Barbero-Becerra
authors.affiliation: Centro Studi Fegato (CSF) - Liver Research Center, Fondazione Italiana Fegato, Bldg Q AREA Science Park, Basovizza Campus SS 14 km 163.5, 34149 Trieste, Italy. Electronic address: pablo.giraudi@csf.units.it.
authors.forename: Pablo J
authors.initials: PJ
authors.lastname: Giraudi
authors.affiliation: Liver Research Unit, Medica Sur Clinic & Foundation, Mexico City, Puente de Piedra 150, Col. Toriello Guerra, Tlalpan, C.P. 14050 Mexico City, Mexico. Electronic address: khavez@gmail.com.
authors.forename: Norberto C
authors.initials: NC
authors.lastname: Chávez-Tapia
authors.affiliation: Liver Research Unit, Medica Sur Clinic & Foundation, Mexico City, Puente de Piedra 150, Col. Toriello Guerra, Tlalpan, C.P. 14050 Mexico City, Mexico. Electronic address: muribe@medicasur.org.mx.
authors.forename: Misael
authors.initials: M
authors.lastname: Uribe
authors.affiliation: Centro Studi Fegato (CSF) - Liver Research Center, Fondazione Italiana Fegato, Bldg Q AREA Science Park, Basovizza Campus SS 14 km 163.5, 34149 Trieste, Italy; Department of Medical Sciences, University of Trieste, 34100 Trieste, Italy. Electronic address: ctliver@csf.units.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: Tiribelli
authors.affiliation: Centro Studi Fegato (CSF) - Liver Research Center, Fondazione Italiana Fegato, Bldg Q AREA Science Park, Basovizza Campus SS 14 km 163.5, 34149 Trieste, Italy. Electronic address: natalia.rosso@csf.units.it.
authors.forename: Natalia
authors.initials: N
authors.lastname: Rosso
mesh_terms: D000199:Actins / Q000235:genetics; D002450:Cell Communication; D002460:Cell Line; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D024042:Collagen Type I / Q000235:genetics; D000090602:Collagen Type I, alpha 1 Chain; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology; D050958:HSP47 Heat-Shock Proteins / Q000235:genetics; D055166:Hepatic Stellate Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000235:genetics; D065626:Non-alcoholic Fatty Liver Disease / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D005230:Fatty Acids, Nonesterified; D050958:HSP47 Heat-Shock Proteins; D012333:RNA, Messenger; C494660:SERPINH1 protein, human; C560822:TIMP1 protein, human; C560823:TIMP2 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2; C522362:Mmp2 protein, mouse
keywords: Extracellular matrix; Fatty acids; Hepatic stellate cells; NAFLD