Expression of MRP2 and MDR1
Transporters and Other Hepatic Markers in Rat and Human Liver
and in WRL 68 Cell Line
D. ČÍŽKOVÁ1, J. MOKRÝ1, S.
MIČUDA2, J. ÖSTERREICHER3,
J. MARTÍNKOVÁ2
1Department of Histology and Embryology, 2Department
of Pharmacology, Faculty of Medicine in Hradec Králové, Charles
University, and 3Department of Radiobiology, Purkyně
Military Medical Academy, Hradec Králové, Czech Republic
Received July 28, 2004
Accepted October 11, 2004
On-line available December 9, 2004
Summary
Here we describe a comparative study of phenotypic properties of
hepatic cells in situ and in vitro. We analyzed the expression
levels and distribution patterns of ABC transporters MRP2 and
MDR1, pan-cytokeratin, cytokeratin 18, albumin,
alpha-fetoprotein and the specific hepatocyte marker OCH1E5 in
the fetal and adult rat as well as human liver tissue and in
human fetal hepatocytes of WRL 68 cell line using peroxidase
immunohistochemistry or immunofluorescence. Transporters MRP2
and MDR1 were expressed in all examined liver tissues, except
rat ED13 embryo. The immunopositivity of these proteins was
localized to the canalicular membrane of differentiating and
mature hepatocytes but in the later developmental stages and in
the adult liver tissues it was also found in the apical membrane
of cholangiocytes. In WRL 68 cells, MRP2 and MDR1
immunoreactivity appeared after 5-6 days of cultivation and both
transporters were fully expressed in the plasmalemma and in the
cytoplasm 9 days after the passage. In conclusion, we observed
only moderate variances reflecting diverse ontogenetic phases
between the fetal and adult liver tissue. To study functions of
hepatocytes in vitro, WRL 68 cells have to differentiate prior
to the examination. Our findings indicate that WRL 68 cells can
undergo differentiation in vitro and their antigenic profile
closely resembles hepatocytes in the human liver.
Key words
MRP2 protein • MDR1 protein • WRL 68 cell line • Liver •
Immunohistochemistry
|