title: Rat hepatocyte culture model of macrosteatosis: effect of macrosteatosis induction and reversal on viability and liver-specific function.
abstract: OBJECTIVE
  A common cause of liver donor ineligibility is macrosteatosis. Recovery of such livers could enhance donor availability. Living donor studies have shown diet-induced reduction of macrosteatosis enables transplantation. However, cadaveric liver macrosteatotic reduction must be performed ex vivo within hours. Towards this goal, we investigated the effect of accelerated macrosteatosis reduction on hepatocyte viability and function using a novel system of macrosteatotic hepatocytes.
  
  
  METHODS
  Hepatocytes isolated from lean Zucker rats were cultured in a collagen sandwich, incubated for 6 days in fatty acid-supplemented medium to induce steatosis, and then switched for 2 days to medium supplemented with lipid metabolism promoting agents. Intracellular lipid droplet size distribution and triglyceride, viability, albumin and urea secretion, and bile canalicular function were measured.
  
  
  RESULTS
  Fatty acid-supplemented medium induced microsteatosis in 3 days and macrosteatosis in 6 days, the latter evidenced by large lipid droplets dislocating the nucleus to the cell periphery. Macrosteatosis significantly impaired all functions tested. Macrosteatosis decreased upon returning hepatocytes to standard medium, and the rate of decrease was 4-fold faster with supplemented agents, yielding 80% reduction in 2 days. Viability of macrosteatosis reduced hepatocytes was similar to control lean cells. Accelerated macrosteatotic reduction led to faster recovery of urea secretion and bile canalicular function, but not of albumin secretion.
  
  
  CONCLUSIONS
  Macrosteatosis reversibly decreases hepatocyte function and supplementary agents accelerate macrosteatosis reduction and some functional restoration with no effect on viability. This in vitro model may be useful to screen agents for macrosteatotic reduction in livers before transplantation.
authors.affiliation: Department of Biomedical Engineering, Rutgers University, Piscataway, NJ, United States.
authors.forename: Nir I
authors.initials: NI
authors.lastname: Nativ
authors.forename: Gabriel
authors.initials: G
authors.lastname: Yarmush
authors.forename: Alvin
authors.initials: A
authors.lastname: Chen
authors.forename: David
authors.initials: D
authors.lastname: Dong
authors.forename: Scot D
authors.initials: SD
authors.lastname: Henry
authors.forename: James V
authors.initials: JV
authors.lastname: Guarrera
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Klein
authors.forename: Tim
authors.initials: T
authors.lastname: Maguire
authors.forename: Rene
authors.initials: R
authors.lastname: Schloss
authors.forename: Francois
authors.initials: F
authors.lastname: Berthiaume
authors.forename: Martin L
authors.initials: ML
authors.lastname: Yarmush
mesh_terms: D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D005234:Fatty Liver / Q000209:etiology*; D022781:Hepatocytes / Q000502:physiology*; D006801:Humans; D008297:Male; D051381:Rats; D011924:Rats, Zucker
keywords: 5-(and-6)-carboxy-2′,7′-dichlorofluorescein diacetate; Albumin; Bile; CMDD; EthD-1; FFA; H&E; I/R; Lipid metabolism; Liver transplantation; NSRS; PBS; SRS; Steatosis; TG; Triglyceride; Urea; calcein acetoxymethylester; calcein-AM; carboxy-DCFDA; choline and methionine-deficient diet; ethidium homodimer-1; free fatty acid; hematoxylin and eosin; ischemia/reperfusion; no steatosis reduction supplements; phosphate buffered saline; steatosis reduction supplements; triglycerides