title: Fibronectin and laminin induce expression of islet cell markers in hepatic oval cells in culture.
abstract: Hepatic oval cells (OC) are considered to be facultative liver stem cells and, because they may undergo differentiation into a variety of cell lineages, they might have the potential to be used in cellular therapy. Signals delivered by extracellular matrix (ECM) proteins take part in cellular differentiation in cooperation with signals from growth factors; indeed, some ECM proteins, such as laminin (LAM) and fibronectin (FN), have been shown to contribute to beta-cell differentiation and islet development, respectively. Since no previous studies have investigated the effect of ECM proteins on the expression of islet cell markers by cultured OC, the purpose of the present study was to evaluate whether FN and LAM modulate the expression of genes related to the endocrine pancreas in these liver cells. OC proliferation was induced in Wistar rats by prolonged treatment with 2-acetoaminofluorene/allyl alcohol and confirmed by reverse transcription/polymerase chain reaction and hepatic immunocytochemical and histopathological analyses. OC isolation was performed by Ficoll gradient and magnetic-activated cell sorting. OC were cultured for 1 and 2 months under several conditions with specific growth factors, over a FN or LAM substrate or in high glucose, nicotinamide and fetal calf serum. OC cultured on FN substrate expressed Pdx-1, Pax-6, insulin 2 and glucagon. LAM also induced the expression of Pdx-1, insulin 1 and insulin 2, glucagon, somatostatin and GLUT-2. Our results suggest that these ECM proteins can be used in protocols of OC transdifferentiation aimed at reducing the period necessary for complete transdifferentiation.
authors.affiliation: Laboratory for Cellular and Molecular Endocrinology LIM-25, University of São Paulo School of Medicine, Av. Dr. Arnaldo, 455 s/4307, 01246-903, São Paulo, Brazil.
authors.forename: Adriana Ribeiro
authors.initials: AR
authors.lastname: Leite
authors.forename: Maria Lúcia
authors.initials: ML
authors.lastname: Corrêa-Giannella
authors.forename: Maria Lúcia Zaidan
authors.initials: ML
authors.lastname: Dagli
authors.forename: Maria Angela Zanela
authors.initials: MA
authors.lastname: Fortes
authors.forename: Vanina Monique Tucci
authors.initials: VM
authors.lastname: Vegas
authors.forename: Daniel
authors.initials: D
authors.lastname: Giannella-Neto
mesh_terms: D015073:2-Acetylaminofluorene / Q000633:toxicity; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002469:Cell Separation; D002478:Cells, Cultured; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005353:Fibronectins / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D005934:Glucagon / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007328:Insulin / Q000235:genetics / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D007797:Laminin / Q000494:pharmacology*; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics / Q000378:metabolism; D010187:Pancreatic Hormones / Q000235:genetics / Q000378:metabolism*; D020005:Propanols / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013047:Specific Pathogen-Free Organisms; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism
chemical_list: D015415:Biomarkers; D005136:Eye Proteins; D005353:Fibronectins; D018398:Homeodomain Proteins; D007328:Insulin; D007797:Laminin; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D010187:Pancreatic Hormones; C000605733:Pax6 protein, rat; D020005:Propanols; D012097:Repressor Proteins; D015534:Trans-Activators; C084010:pancreatic and duodenal homeobox 1 protein; C006463:allyl alcohol; D005934:Glucagon; D015073:2-Acetylaminofluorene