OBJECTIVES: Maf is a family of transcription factor proteins characterized by a typical bZip structure, and mafA, a member of the large-maf family, is a strong transactivator of insulin in cell lines. The present study investigated the expression profiles of the large-maf family proteins in porcine pancreatic tissue and in primary culture cells. METHODS: Immunohistochemical staining was performed to localize each maf protein. Messenger RNA expression was quantitated by real-time polymerase chain reaction, and protein expression was assessed by Western blotting. RESULTS: Islet formation was not as clear in newborn pancreatic tissue as in adult pancreatic tissue. MafA- and c-maf-positive cells were more diffusely localized in pancreatic tissue with fewer mafB-positive cell clusters scattered throughout. By contrast, islet formation was clearer, and positive staining for mafA and c-maf tended to be more prominent in the islets of adult pancreatic tissue. Messenger RNA and protein expressions were consistent with the immunohistochemical findings. MafA, mafB, and c-maf coexpressed with insulin-positive cells, and c-maf coexpressed with glucagon-positive cells in adult porcine pancreas based on the results of a double-staining study. CONCLUSIONS: Large mafs were identified in normal porcine and human pancreas, and the expression levels and localizations of the large mafs in newborn and adult pancreatic tissues differed. Mafs may play important roles in establishing endocrine function during pancreatic cell differentiation.
OBJECTIVES:Maf is a family of transcription factor proteins characterized by a typical bZip structure, and mafA, a member of the large-maf family, is a strong transactivator of insulin in cell lines. The present study investigated the expression profiles of the large-maf family proteins in porcine pancreatic tissue and in primary culture cells. METHODS: Immunohistochemical staining was performed to localize each maf protein. Messenger RNA expression was quantitated by real-time polymerase chain reaction, and protein expression was assessed by Western blotting. RESULTS: Islet formation was not as clear in newborn pancreatic tissue as in adult pancreatic tissue. MafA- and c-maf-positive cells were more diffusely localized in pancreatic tissue with fewer mafB-positive cell clusters scattered throughout. By contrast, islet formation was clearer, and positive staining for mafA and c-maf tended to be more prominent in the islets of adult pancreatic tissue. Messenger RNA and protein expressions were consistent with the immunohistochemical findings. MafA, mafB, and c-maf coexpressed with insulin-positive cells, and c-maf coexpressed with glucagon-positive cells in adult porcine pancreas based on the results of a double-staining study. CONCLUSIONS: Large mafs were identified in normal porcine and human pancreas, and the expression levels and localizations of the large mafs in newborn and adult pancreatic tissues differed. Mafs may play important roles in establishing endocrine function during pancreatic cell differentiation.
Authors: Yasodha Natkunam; Sara Tedoldi; Jennifer C Paterson; Shuchun Zhao; Manuel Rodriguez-Justo; Andrew H Beck; Reiner Siebert; David Y Mason; Teresa Marafioti Journal: Am J Clin Pathol Date: 2009-09 Impact factor: 2.493
Authors: David Meyre; Jérôme Delplanque; Jean-Claude Chèvre; Cécile Lecoeur; Stéphane Lobbens; Sophie Gallina; Emmanuelle Durand; Vincent Vatin; Franck Degraeve; Christine Proença; Stefan Gaget; Antje Körner; Peter Kovacs; Wieland Kiess; Jean Tichet; Michel Marre; Anna-Liisa Hartikainen; Fritz Horber; Natascha Potoczna; Serge Hercberg; Claire Levy-Marchal; François Pattou; Barbara Heude; Maithé Tauber; Mark I McCarthy; Alexandra I F Blakemore; Alexandre Montpetit; Constantin Polychronakos; Jacques Weill; Lachlan J M Coin; Julian Asher; Paul Elliott; Marjo-Riitta Järvelin; Sophie Visvikis-Siest; Beverley Balkau; Rob Sladek; David Balding; Andrew Walley; Christian Dina; Philippe Froguel Journal: Nat Genet Date: 2009-01-18 Impact factor: 38.330