title: Rat hepatocyte spheroids formed by rocked technique maintain differentiated hepatocyte gene expression and function.
abstract: The culture of primary hepatocytes as spheroids creates an efficient three-dimensional tissue construct for hepatic studies in vitro. Spheroids possess structural polarity and functional bile canaliculi with normal differentiated function. Thus, hepatocyte spheroids have been proposed as the cell source in a variety of diagnostic, discovery, and therapeutic applications, such as a bioartificial liver. Using a novel rocking technique to induce spheroid formation, kinetics of spheroid formation, cell-cell adhesion, gene expression, and biochemical activities of rat hepatocyte spheroids were tested over 14 days of culture. Evidence was provided that the formation of spheroids occurred faster and with fewer nonadherent hepatocytes in rocked suspension culture compared to a traditional rotational system. Hepatocyte spheroids in rocked culture showed stable expression of more than 80% of 242 liver-related genes including those of albumin synthesis, urea cycle, phase I and II metabolic enzymes, and clotting factors. Biochemical activity of rocked spheroid hepatocytes was superior to monolayer culture of hepatocytes on tissue culture plastic and collagen.
  
  
  CONCLUSIONS
  Spheroid formation by rocker technique was more rapid and more efficient than by rotational technique. Rocker-formed spheroids appear suitable for application in a bioartificial liver or as an in vitro liver tissue construct.
authors.affiliation: Department of Surgery, Division of Transplant Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Brophy
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Luebke-Wheeler
authors.forename: Bruce P
authors.initials: BP
authors.lastname: Amiot
authors.forename: Harris
authors.initials: H
authors.lastname: Khan
authors.forename: Rory P
authors.initials: RP
authors.lastname: Remmel
authors.forename: Piero
authors.initials: P
authors.lastname: Rinaldo
authors.forename: Scott L
authors.initials: SL
authors.lastname: Nyberg
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D002469:Cell Separation / Q000379:methods; D048430:Cell Shape; D002470:Cell Survival; D003470:Culture Media; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression / Q000502:physiology*; D022781:Hepatocytes / Q000166:cytology* / Q000502:physiology*; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D051381:Rats
chemical_list: D003470:Culture Media; D012313:RNA; D004247:DNA