Volume 130, Issue 2, Pages 532-541 (February 2006) The Transcription Factor Hepatocyte Nuclear Factor-6 Controls the Development of Pancreatic Ducts in the Mouse  Christophe E. Pierreux, Aurélie V. Poll, Caroline R. Kemp, Frédéric Clotman, Miguel A. Maestro, Sabine Cordi, Jorge Ferrer, Luc Leyns, Guy G. Rousseau, Frédéric P. Lemaigre  Gastroenterology  Volume 130, Issue 2, Pages 532-541 (February 2006) DOI: 10.1053/j.gastro.2005.12.005 Copyright © 2006 American Gastroenterological Association Terms and Conditions

Figure 1 HNF-6 is expressed in the epithelium of all segments of the pancreatic ducts. Wild-type pancreata at different stages of embryonic development were examined by immunofluorescence using antibodies directed against HNF-6, Muc-1, and acetylated tubulin. HNF-6 was first expressed throughout the pancreatic epithelium and then became restricted to the ductal compartment. (A) Muc-1 was found in the developing ductal structures. Acetylated tubulin was only found in HNF-6-positive ductal cells. (B) da, differentiating acini; dd, differentiating duct; ial, intralobular duct; ic, intercalated duct; iel, interlobular duct. Gastroenterology 2006 130, 532-541DOI: (10.1053/j.gastro.2005.12.005) Copyright © 2006 American Gastroenterological Association Terms and Conditions

Figure 2 Pancreatic duct morphogenesis is affected in Hnf6−/− embryos. Wild-type and Hnf6−/− pancreata at various stages of development were processed for whole-mount immunochemistry using an anti-Muc-1 antibody. At e11.5, the pancreatic lumen (l) was enlarged in the Hnf6−/− dorsal pancreatic bud (delineated by a dotted line), and fewer Muc-1-positive cells were found around the main duct, as compared with controls. At e12.5, Muc-1-positive staining in Hnf6−/− pancreas displayed an irregular ductal network instead of an arborescence of developing ducts around a central duct, as seen in controls. At e15.5, differentiating acini and ducts were identified in control pancreas, whereas, in the Hnf6−/− pancreas, the acini were connected to cystic (asterisk) ducts. At e17.5 in Hnf6−/− pancreas, the acini were connected to cystic ducts (asterisk) via morphologically normal intercalated ducts. The differentiation boundary between the acini and intercalated ducts was preserved in Hnf6−/− pancreas, as evidenced by the normal expression of CPA (red) in acini and lack of CPA in the ducts. The intercalated ducts that connect the acini to the ductal compartment (Muc-1 staining, green) are not affected. d, duodenum; da, differentiating acini; dd, differentiating duct; ial, intralobular duct; ic, intercalated duct; iel, interlobular duct; st, stomach. Gastroenterology 2006 130, 532-541DOI: (10.1053/j.gastro.2005.12.005) Copyright © 2006 American Gastroenterological Association Terms and Conditions

Figure 3 The epithelium lining the cysts in Hnf6−/− pancreas is dysmorphic. Sections from wild-type and Hnf6−/− pancreata were examined by immunofluorescence using antibodies specific for β-catenin (red) and for Muc-1 (green in insets). As compared with the ductal epithelium in control pancreas, the cells lining the cysts (asterisk) in Hnf6−/− pancreas showed discontinuous Muc-1 staining (arrowheads) and mislocalized β-catenin expression, and they formed a disorganized epithelium, which was sometimes multilayered. Gastroenterology 2006 130, 532-541DOI: (10.1053/j.gastro.2005.12.005) Copyright © 2006 American Gastroenterological Association Terms and Conditions

Figure 4 Cells lining the cysts in Hnf6−/− pancreas do not assemble primary cilia. (A) Sections from wild-type and Hnf6−/− pancreata were examined by immunofluorescence using antibodies specific for acetylated tubulin (red) and for Muc-1 (green). As compared with the ciliated ductal epithelium in control pancreata, ductal cells (e14.5 and e15.5) and cells lining the cysts in Hnf6−/− pancreata did not assemble primary cilia. At e17.5, cilia were observed in morphologically normal ducts (arrowheads) but not in cystic ducts (asterisk). (B) Sections from wild-type and Hnf6−/− pancreata were examined by immunofluorescence using an HNF-1β-specific antibody. In wild-type pancreas, HNF-1β (red) was expressed in the ductal epithelium. In Hnf6−/− pancreas, HNF-1β was absent from most cells lining the cysts (asterisk) but was expressed at normal levels in normal-size ducts (arrowheads) and in some cells that line the cysts and that are located close to nonaffected ducts (open arrowheads). Gastroenterology 2006 130, 532-541DOI: (10.1053/j.gastro.2005.12.005) Copyright © 2006 American Gastroenterological Association Terms and Conditions

Figure 5 Expression of Hnf1β and of cystic disease genes is affected in Hnf6−/− pancreas. Real-time PCR experiments were performed on wild-type and Hnf6−/− pancreata before the occurrence of cysts (e12.5–e14.5), at the onset of cyst formation (e15.5), or at later stages (e16.5–e17.5). Expression levels were normalized to that of β-actin × 1000 for Hnf1β and × 10,000 for Pkhd1, Cys1, and Pkd1. Expression of Hnf1β and of Pkhd1 was reduced in Hnf6−/− pancreas from e12.5 to e16.5 but was normalized at e17.5, whereas that of Cys1 was persistently reduced throughout development. Expression of Pkd1 was unaffected in Hnf6−/− pancreas, like that of Pkd2, Polaris, Sec63, and Prkcsh (see Figure 9). Gastroenterology 2006 130, 532-541DOI: (10.1053/j.gastro.2005.12.005) Copyright © 2006 American Gastroenterological Association Terms and Conditions