title: Wnt impacts growth and differentiation in ex vivo liver development.
abstract: The Wnt-beta-catenin pathway plays a role in liver growth and development. Here, we investigate the direct effect of Wnt-3A on ex vivo liver development. Livers from mouse embryos at day 10 were cultured in serum-free Wnt-3A-conditioned media alone or with HGF and insulin for 72 h and analyzed for histology, proliferation, apoptosis and lineage. Control cultures grown in serum-free conditions or Wnt-3A and sFRP-1 combination display loss of architecture and proliferation and increased apoptosis. In the presence of Wnt-3A, embryonic liver cultures show CK-19-positive cells (biliary phenotype) displaying proliferation, minimal apoptosis and duct-like histological arrangement. HGF and Wnt combination exhibited normal histology as seen in the presence of 10% serum displaying stem cells, hepatocytes and primitive bile ducts. HGF, insulin and Wnt combination provided no additional benefits rather had an overall deleterious effect. Thus, Wnt supports biliary differentiation by enhancing stem cell specification, hepatocyte trans-differentiation and promoting biliary survival. HGF and Wnt combination supports stem cells, hepatocytes and bile ducts. The addition of insulin to the combination of HGF and Wnt provided no growth or differentiation advantage. Our results indicate usefulness of Wnt and HGF in hepatocyte cultures and suggest their balance during normal liver development.
authors.affiliation: Department of Pediatric Gastroenterology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Sunny Z
authors.initials: SZ
authors.lastname: Hussain
authors.forename: Tamara
authors.initials: T
authors.lastname: Sneddon
authors.forename: Xinping
authors.initials: X
authors.lastname: Tan
authors.forename: Amanda
authors.initials: A
authors.lastname: Micsenyi
authors.forename: George K
authors.initials: GK
authors.lastname: Michalopoulos
authors.forename: Satdarshan P S
authors.initials: SP
authors.lastname: Monga
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001652:Bile Ducts / Q000196:embryology; D002454:Cell Differentiation / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D019070:Cell Lineage; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D004357:Drug Synergism; D005260:Female; D006023:Glycoproteins / Q000494:pharmacology; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008099:Liver / Q000166:cytology / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D011518:Proto-Oncogene Proteins / Q000378:metabolism / Q000494:pharmacology*; D013997:Time Factors; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D000099274:Frizzled-Related Proteins
chemical_list: D016895:Culture Media, Serum-Free; D006023:Glycoproteins; D017228:Hepatocyte Growth Factor; D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D000099274:Frizzled-Related Proteins