TY - JOUR
T1 - Identification of adult hepatic progenitor cells capable of repopulating injured rat liver
AU - Yovchev, Mladen I.
AU - Grozdanov, Petar N.
AU - Zhou, Hongchao
AU - Racherla, Harini
AU - Guha, Chandan
AU - Dabeva, Mariana D.
PY - 2008/2
Y1 - 2008/2
N2 - Oval cells appear and expand in the liver when hepatocyte proliferation is compromised. Many different markers have been attributed to these cells, but their nature still remains obscure. This study is a detailed gene expression analysis aimed at revealing their identity and repopulating in vivo capacity. Oval cells were activated in 2-acetylaminofluorene-treated rats subjected to partial hepatectomy or in D-galactosamine-treated rats. Two surface markers [epithelial cell adhesion molecule (EpCAM) and thymus cell antigen 1 (Thy-1)] were used for purification of freshly isolated cells. Their gene expression analysis was studied with Affymetrix Rat Expression Array 230 2.0, reverse-transcriptase polymerase chain reaction, and immunofluorescent microscopy. We found that EpCAM+ and Thy-1+ cells represent two different populations of cells in the oval cell niche. EpCAM + cells express the classical oval cell markers (alpha-fetoprotein, cytokeratin-19, OV-1 antigen, a6 integrin, and connexin 43), cell surface markers recently identified by us (CD44, CD24, EpCAM, aquaporin 5, claudin-4, secretin receptor, claudin-7, V-ros sarcoma virus oncogene homolog 1, cadherin 22, mucin-1, and CD133), and liver-enriched transcription factors (forkhead box q, forkhead box a2, onecut 1, and transcription factor 2). Oval cells do not express previously reported hematopoietic stem cell markers Thy-1, c-kit, and CD34 or the neuroepithelial marker neural cell adhesion molecule 1. However, oval cells express a number of mesenchymal markers including vimentin, mesothelin, bone morphogenetic protein 7, and Tweak receptor (tumor necrosis factor receptor superfamily, member 12A). A group of novel differentially expressed oval cell genes is also presented. It is shown that Thy-1+ cells are mesenchymal cells with characteristics of myofibroblasts/activated stellate cells. Transplantation experiments reveal that EpCAM+ cells are true progenitors capable of repopulating injured rat liver. Conclusion: We have shown that EpCAM+ oval cells are bipotential adult hepatic epithelial progenitors. These cells display a mixed epithelial/mesenchymal phenotype that has not been recognized previously. They are valuable candidates for liver cell therapy.
AB - Oval cells appear and expand in the liver when hepatocyte proliferation is compromised. Many different markers have been attributed to these cells, but their nature still remains obscure. This study is a detailed gene expression analysis aimed at revealing their identity and repopulating in vivo capacity. Oval cells were activated in 2-acetylaminofluorene-treated rats subjected to partial hepatectomy or in D-galactosamine-treated rats. Two surface markers [epithelial cell adhesion molecule (EpCAM) and thymus cell antigen 1 (Thy-1)] were used for purification of freshly isolated cells. Their gene expression analysis was studied with Affymetrix Rat Expression Array 230 2.0, reverse-transcriptase polymerase chain reaction, and immunofluorescent microscopy. We found that EpCAM+ and Thy-1+ cells represent two different populations of cells in the oval cell niche. EpCAM + cells express the classical oval cell markers (alpha-fetoprotein, cytokeratin-19, OV-1 antigen, a6 integrin, and connexin 43), cell surface markers recently identified by us (CD44, CD24, EpCAM, aquaporin 5, claudin-4, secretin receptor, claudin-7, V-ros sarcoma virus oncogene homolog 1, cadherin 22, mucin-1, and CD133), and liver-enriched transcription factors (forkhead box q, forkhead box a2, onecut 1, and transcription factor 2). Oval cells do not express previously reported hematopoietic stem cell markers Thy-1, c-kit, and CD34 or the neuroepithelial marker neural cell adhesion molecule 1. However, oval cells express a number of mesenchymal markers including vimentin, mesothelin, bone morphogenetic protein 7, and Tweak receptor (tumor necrosis factor receptor superfamily, member 12A). A group of novel differentially expressed oval cell genes is also presented. It is shown that Thy-1+ cells are mesenchymal cells with characteristics of myofibroblasts/activated stellate cells. Transplantation experiments reveal that EpCAM+ cells are true progenitors capable of repopulating injured rat liver. Conclusion: We have shown that EpCAM+ oval cells are bipotential adult hepatic epithelial progenitors. These cells display a mixed epithelial/mesenchymal phenotype that has not been recognized previously. They are valuable candidates for liver cell therapy.
UR - http://www.scopus.com/inward/record.url?scp=39549111466&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=39549111466&partnerID=8YFLogxK
U2 - 10.1002/hep.22047
DO - 10.1002/hep.22047
M3 - Article
C2 - 18023068
AN - SCOPUS:39549111466
SN - 0270-9139
VL - 47
SP - 636
EP - 647
JO - Hepatology
JF - Hepatology
IS - 2
ER -