EMP-1 is a junctional protein in a liver stem cell line and in the liver
Journal
Biochemical and Biophysical Research Communications
Journal Volume
334
Journal Issue
4
Pages
996-1003
Date Issued
2005
Author(s)
Sherley J.L.
Chen J.J.W.
Chiu C.-C.
Chiou L.-L.
Abstract
In an attempt to discover cell markers for liver stem cells, a cDNA microarray analysis was carried out to compare the gene expression profiles between an adult liver stem cell line, Lig-8, and mature hepatocytes. Several genes in the categories of extracellular matrix, cell membrane, cell adhesion, transcription factor, signal molecule, transporter, and metabolic enzyme were shown to be differentially expressed in Lig-8 cells. Among them, epithelial membrane protein (EMP)-1 has been previously implicated with stem cell phenotypes. Antiserum to EMP-1 was produced to localize its expression. On monolayers of Lig-8 cells, EMP-1 was expressed along the intercellular border. In the liver harboring proliferating oval cells, the liver progenitors, EMP-1 was localized as ribbon bands, a staining pattern for epithelial junctions, all the way through bile duct epithelia, oval cell ductules, and into peri-hepatocytic regions. These peri-hepatocytic regions were proved to be bile canaliculi by co-localization of EMP-1 and dipeptidyl peptidase IV, an enzyme located on bile canaliculi. This report is the first to indicate EMP-1 to be a junctional protein in the liver. © 2005 Elsevier Inc. All rights reserved.
Subjects
Adult liver stem cells
Bile canaliculi
Bile ductules
cDNA microarray
Cell junction
Cytokeratin-19
Epithelial membrane protein-1
Extracellular matrix
Oval cells
Tetraspan protein
Type
journal article