Differentially expressed genes in a porcine adult hepatic stem-like cell line and their expression in developing and regenerating liver.
To identify differentially expressed genes in adult hepatic stem cells, we performed suppression-subtractive hybridization (SSH) between adult porcine hepatic stem-like cells (HSLCs) and hepatocytes, and the expression of selected genes was assessed in porcine fetal livers and regenerating liver in an 80% hepatectomy model. SSH and subsequent differential screening selected 39 clones that were expressed differentially in HSLCs, including six known genes, 10 unknown genes, one unidentified gene and some chimeric fragments. Four of these genes showed significantly higher expression in HSLCs than in mature hepatocytes: anti-leukoproteinase, matrix Gla protein, amyloid-beta precursor protein (APP) and dickkopf-3 (DKK-3). Among them, the mRNA expression of APP and DKK-3 was significantly higher in fifth GW fetal liver than in seventh and thirteenth GW fetal and adult livers, unlike the expression patterns of alpha-fetoprotein (AFP) or albumin. These mRNAs were detected in the parenchyma of fifth GW fetal liver, whereas in normal adult liver possible expression was limited to the periportal area. On the other hand, immunohistochemistry, Masson's trichrome staining and silver impregnation demonstrated APP and DKK-3 proteins in fifth GW fetal liver in which intralobular bile ducts and hepatic plates had not completely developed. DKK-3 and AFP mRNAs were upregulated on the seventh day (7D) after 80% hepatectomy. In the liver tissue, DKK-3 and AFP proteins were detected in mesenchymal cells in the periportal area and parenchyma, respectively. These data for DKK-3 expression in adult livers suggest the possible presence of adult HSLCs in the periportal area. The pattern of histological staining suggested that 7D liver was in the process of regeneration, showing a character similar to the fifth GW fetal liver. It is speculated that DKK-3 is upregulated in immature and developing livers, and has possible involvement in hepatic differentiation and liver regeneration.
Department of Pathology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan. junkano@md.tsukuba.ac.jp
Junko
J
Kano
Tadashi
T
Ishiyama
Tatsuo
T
Iijima
Yukio
Y
Morishita
Soichiro
S
Murata
Katsuji
K
Hisakura
Nobuhiro
N
Ohkohchi
Masayuki
M
Noguchi
D053687:Adult Stem Cells / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005333:Fetus / Q000378:metabolism; D015870:Gene Expression; D020869:Gene Expression Profiling; D022781:Hepatocytes / Q000378:metabolism; D017403:In Situ Hybridization; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D008115:Liver Regeneration / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000378:metabolism; D013552:Swine; D000097568:Matrix Gla Protein
D016564:Amyloid beta-Protein Precursor; D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; D036341:Intercellular Signaling Peptides and Proteins; D053481:Secretory Leukocyte Peptidase Inhibitor; D000097568:Matrix Gla Protein