Morphological features of hepatic cyst epithelium and biliary epithelium

MORPHOLOGICAL FEATURES OF HEPATIC CYST EPITHELIUM AND BILIARY EPITHELIUM 1PANNARALE L., 3ONORI P., 1FRANCHITTO A., 1MANCINELLI R., 3CONTINENZA M.A., 3RICCIARDI G., 2ALVARO D. 1 Department of Anatomy and 2Division of Gastroenterology, University of Rome “la Sapienza”, 3Department of Surgical Sciences, University of L'Aquila Background and aim: Hepatic cysts are formed by epithelial cells with high secretory and proliferative activities and characteristics of biliary epithelium. Cyst growth has been recently shown to be driven by growth factors (GF) and cytokines (1,2). Hepatic progenitor cells are known to proliferate in most liver diseases and are located in canaliculo-ductular junctions (3). Aim of this study is to investigate the morphological aspects of the canaliculo-ductular junction area and the hepatic cyst epithelium in autosomal dominant polycystic kidney disease (ADPKD), with particular focus on the presence of primary cilia and on the involvement of GF. Materials and methods: Six hepatic cysts were analyzed for: a) Immunohistochemistry for estrogen receptor (ER), insulin like growth factor-1 (IGF-1), and IGF-1R, GH-R, PCNA, and pAKT; b) scanning electron microscopy (SEM) of the luminal surface of the Hepatic cysts, and SEM corrosion casts of the canaliculo-ductular junction area. Results: Cystic epithelium showed immunolocalization of ER, IGF1, IGF-1R, GH-R, PCNA and pAKT. Estrogen and IGF1 support proliferation of LCDE. SEM revealed: i) the absence of primary cilia and microvilli in large cysts, and ii) rare shortened cilia in smaller cysts. Corrosion casts of intrahepatic biliary three showed the presence of numerous sockets on larger diameter duct surfaces; sockets were less frequently seen at the level of canals of Hering. These aspects are due to the impressions of numerous cilia that characterize and specialize the biliary epithelium surface. Conclusions: The hepatic cyst epithelium shows structural abnormalities of primary cilia and is sensitive to the proliferative effects of estrogen and IGF1. This study suggests that primary cilia play a role in the modulation of hepatic cyst epithelial cells proliferation. References. 1) James et al. Am.j. Physiol. 289: F1159- F1169 (2005); 2) Melissa et al. Lab Invest. 86, 940-950 (2006); 3) Gaudio et al., J.Submicrsc.Cytol., 13(4):581-598, 1981. Acknowledgements. This study was supported by MIUR grants (PRIN 2005 e.G. and P.O.) and faculty funds (Universita di Roma”La Sapienza”, I Facoltà di Medicina e Chirurgia) In: It.J. Anatomy and Embriology, vol.112, Suppl. 1, (2007), p. 203