Expression of CCAAT/enhancer binding protein family genes in monolayer and sandwich culture of hepatocytes: induction of stress-inducible GADD153.
Removal of hepatocytes from their physiological environment for experimentation in vitro activates loss of liver-specific phenotype. Hepatocytes cultured in a sandwich configuration reportedly maintain greater expression of certain liver-specific genes than hepatocytes in monolayer cultures. We show that sandwich culture of rat hepatocytes improves retention of expression of a liver-enriched transcription factor, C/EBPalpha (CCAAT/enhancer binding protein alpha), which regulates many liver-specific genes. However, we also demonstrate increased expression of a stress-responsive C/EBP homologue, GADD153 (growth arrest and DNA damage gene 153), during monolayer culture, which may promote dedifferentiation. Induction of GADD153 was not prevented in sandwich cultured hepatocytes. Activation of a homologue of the mouse GADD153 target gene, doc1, was observed in monolayer and sandwich culture, suggesting that GADD153 was transcriptionally active. We suggest that the capability of sandwich cultures to maintain hepatocyte phenotype may be limited by the altered profile of transcription factor activity.
Wilkinson
R C
RC
School of Biological Sciences, University of Manchester, 2.205 Stopford Building, Manchester, M13 9PT, United Kingdom.
Dickson
A J
AJ
D000818:Animals; D064197:Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000235:genetics; D022762:CCAAT-Enhancer-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics*; D018929:Cell Culture Techniques / Q000379:methods; D018797:Cell Cycle Proteins / Q000235:genetics; D002454:Cell Differentiation; D002478:Cells, Cultured; D015870:Gene Expression; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D005810:Multigene Family; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D029701:Saccharomyces cerevisiae Proteins; D051742:Transcription Factor CHOP; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*
D064197:Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome; D022763:CCAAT-Enhancer-Binding Protein-alpha; D022762:CCAAT-Enhancer-Binding Proteins; D018797:Cell Cycle Proteins; C577456:DOC1 protein, S cerevisiae; C497251:Ddit3 protein, rat; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D051742:Transcription Factor CHOP