Differentiated properties of hepatocytes induced from pancreatic cells.
Transdifferentiation of pancreas to liver is a well-recognized phenomenon and has been described in animal experiments and human pathology. We recently produced an in vitro model for the transdifferentiation (or conversion) of the pancreatic cell line AR42J-B13 to hepatocytes based on culture with dexamethasone (Dex). To determine whether the hepatocytes express markers of hepatic intermediary metabolism and detoxification, we investigated the patterns of expression of glucokinase, cytochrome P450s CYP3A1 and CYP2B1/2, testosterone/4-nitrophenol uridine diphosphate glucuronosyltransferase (UDPGT), and aryl sulfotransferase. All were expressed. We also determined the expression of 2 enzymes involved in ammonia detoxification: carbamoylphosphate synthetase I (CPS I) and glutamine synthetase (GS). These enzymes are normally strictly compartmentalized in liver in a wide periportal pattern and the last downstream perivenous hepatocytes, respectively. Following culture with Dex, CPS I and GS are expressed in 2 different cell populations, suggesting that both periportal and perivenous hepatocytes are induced. We also produced a reporter assay based on the activation of green fluorescent protein (GFP) by the transthyretin (TTR) promoter or glucose-6-phosphatase (G6Pase) promoter. After culture with Dex, transfected cells begin to express GFP, showing that hepatic promoters are activated in concert with the induction of the hepatocyte phenotype. Lastly, we examined the stability of the hepatic phenotype and found that some cells still express liver markers (transferrin or albumin) up to 14 days after removal of Dex. In conclusion, these results suggest that pancreatic hepatocytes produced by this method may offer an alternative model to primary cultures of hepatocytes for the study of liver function.
Tosh
David
D
Developmental Biology Programme, Department of Biology and Biochemistry, University of Bath, Bath, England. D.Tosh@bath.ac.uk
Shen
Chia-Ning
CN
Slack
Jonathan M W
JM
D000681:Amylases / Q000032:analysis; D000818:Animals; D015239:Arylsulfotransferase / Q000032:analysis; D015815:Cell Adhesion Molecules; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D011508:Chondroitin Sulfate Proteoglycans / Q000032:analysis; D002995:Clofibric Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D003907:Dexamethasone / Q000494:pharmacology; D058607:Fibric Acids; D015870:Gene Expression; D017930:Genes, Reporter; D005938:Glucocorticoids / Q000494:pharmacology; D014453:Glucuronosyltransferase / Q000032:analysis; D049452:Green Fluorescent Proteins; D022781:Hepatocytes / Q000737:chemistry / Q000166:cytology* / Q000201:enzymology; D006821:Hyaluronoglucosaminidase; D000960:Hypolipidemic Agents / Q000494:pharmacology; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000032:analysis; D010179:Pancreas / Q000166:cytology*; D010641:Phenotype; D011169:Portal Vein / Q000166:cytology; D011401:Promoter Regions, Genetic
D015815:Cell Adhesion Molecules; D011508:Chondroitin Sulfate Proteoglycans; D058607:Fibric Acids; D005938:Glucocorticoids; D000960:Hypolipidemic Agents; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D002995:Clofibric Acid; D003907:Dexamethasone; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C104464:CYP3A protein, human; D051544:Cytochrome P-450 CYP3A; D014453:Glucuronosyltransferase; D015239:Arylsulfotransferase; D000681:Amylases; D006821:Hyaluronoglucosaminidase; C066852:hyaluronidase PH-20; C019304:ciprofibrate