Hepatic villin expression in biliary atresia

Abstract

Background: Villin is a protein that severs, binds, and bundles actin filaments, necessary for maintenance of the structural integrity of the microvilli in the absorptive epithelia, which include enterocytes, kidney proximal tubule cells, and bile canaliculi. Biliary atresia (BA) is a progressive, sclerosing, inflammatory process that results in complete obliteration of the extrahepatic bile ducts. Liver histopathology in BA might be similar to idiopathic neonatal hepatitis (INH). Objective: We compared the hepatic expression of villin in children with BA and INH. Methods: This study was conducted on stored liver specimens of 28 children with BA (age 2.78±1.33 months) and 10 children with INH (age 2.40±1.26 months). Villin was investigated on liver tissue by immunohistochemistry. Villin mRNA analyzes were undertaken on liver homogenates using real-time PCR technique, with primers from coding regions of the human villin gene. Amounts of villin PCR product (villin mRNA relative to the concentrations of GAPDH product) were expressed as median (minimum, maximum). Results: Villin mRNA expression in patients with BA and INH were 15.98 (0.02, 11880.47) and 0.09 (0, 111.95), respectively. Villin mRNA expression in BA patients was significantly higher than in patients with INH (p = 0.01). Villin staining and mRNA expression were undetectable in two INH. Conclusions: The higher villin expression in BA might have been due to pronounced bile duct proliferation in comparison with INH. Hepatic villin expression might be helpful in discrimination BA from INH and hence BA patients can be timely diagnosed. Keywords: Actin, biliary atresia, cholestatic liver disease, idiopathic neonatal hepatitis, villin