Clinical Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 28, 2005; 11(24): 3710-3713
Published online Jun 28, 2005. doi: 10.3748/wjg.v11.i24.3710
High expressions of caveolins on the proliferating bile ductules in primary biliary cirrhosis
Hiroaki Yokomori, Masaya Oda, Go Wakabayashi, Masaki Kitajima, Kazunori Yoshimura, Masahiko Nomura, Toshifumi Hibi
Hiroaki Yokomori, Department of Internal Medicine, Kitasato Medical Center Hospital, Saitama 364-850, Japan
Masaya Oda, Organized Center of Clinical Medicine, International University of Health and Welfare, Tokyo 107-0052, Japan
Go Wakabayashi, Masaki Kitajima, Department of Surgery, School of Medicine, Keio University, Tokyo 160-0016, Japan
Kazunori Yoshimura, Masahiko Nomura, Department of Physiology, Saitama Medical School, Saitama 350-0495, Japan
Toshifumi Hibi, Department of Internal Medicine, School of Medicine, Keio University, Tokyo 160-0016, Japan
Author contributions: All authors contributed equally to the work.
Correspondence to: Hiroaki Yokomori, MD, Kitasato Institute Medical Center Hospital, 121-1 Arai, Kitamotoshi, Saitama 364-8501, Japan. yokomori-hr@kitasato.or.jp
Telephone: +81-485-93-1212 Fax: +81-485-93-1239
Received: October 29, 2004
Revised: October 30, 2004
Accepted: December 20, 2004
Published online: June 28, 2005
Abstract

AIM: An increase in bile ductular structures is observed in diverse human liver diseases, especially in primary biliary cirrhosis (PBC). These structures harbor the progenitor cell component of the liver. Caveolins are cholesterol-binding proteins involved in the regulation of several intracellular processes including cholesterol transport. This study aims to examine the role of caveolin in PBC.

METHODS: Immunohistochemical and Western blotting studies were performed on human liver specimens obtained from patients with PBC and normal liver samples. The expression of caveolin (CAV)-1 and -2 was determined using specific antibodies.

RESULTS: In normal liver, scanty immunostaining for CAV-1 and -2 was observed in bile ductules. In PBC liver samples, the expression levels of CAV-1 and -2 were increased on proliferating bile ductules especially in stage 3 cases, but was sparse on interlobular bile duct in stage 1 specimens. Especially, the regenerating bile ductules at the interface of portal tracts and necrotic areas were immunostained intensely for CAV-1 and -2. These phenomena were confirmed by Western blot.

CONCLUSION: The present results demonstrate increased expression of caveolins in proliferating bile ductules in PBC, which may be related to the homeostasis of cholesterol transport in regenerating bile ductules in PBC liver.

Keywords: Proliferating bile ductule, Caveolin, Immunohis-tochemistry, Primary biliary cirrhosis