The expression of mesenchymal, neural and haematopoietic stem cell markers in adult hepatocytes proliferating in vitro.
OBJECTIVE
Cultured adult hepatocytes may be stimulated into clonal expansion. We raise the question whether adult hepatocytes proliferating in vitro recapitulate the early process of hepatic development.


METHODS
A non-enzymatic method was used to isolate hepatocytes free of contamination with non-parenchymal cells. Hepatocytes were stimulated into proliferation in the presence of mitogens and conditioned media from non-parenchymal cell and hepatocyte culture supernatants. Immunofluorescence methods and PCR analysis were used to demonstrate immunophenotypical characteristics and gene expression profiles similar to those of progenitor cells.


RESULTS
Rapid growth occurred during the first 7 days of culture. Cells continued to express hepatic markers (phosphoenolpyruvate carboxykinase, cytokeratin 18, transferrin and dipeptidylpeptidase IV), but the gap junction protein connexin 32 was down-regulated. In the early stage of proliferation, cells started to express biliary and extrahepatic progenitor markers (cytokeratin 19, CD49b, CD49f, nestin, vimentin, Thy1 and c-kit), followed by cytokeratin 7, connexin 43, and neural cell adhesion molecule. Co-expression of the epithelial liver progenitor marker alpha-foetoprotein with either nestin (neural marker) or Thy1 (mesenchymal marker) was also demonstrated.


CONCLUSIONS
Mature hepatocytes reveal their potential to regain a spectrum of progenitor markers from different germ layers, suggesting enormous plasticity and differentiation potential of adult liver cells.
Koenig
Sarah
S
Department of General Surgery, Georg-August University Goettingen, Germany.
Krause
Petra
P
Drabent
Birgit
B
Schaeffner
Ines
I
Christ
Bruno
B
Schwartz
Peter
P
Unthan-Fechner
Kirsten
K
Probst
Irmelin
I
D000818:Animals; D015415:Biomarkers / Q000032:analysis* / Q000378:metabolism; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D022781:Hepatocytes / Q000737:chemistry* / Q000166:cytology* / Q000378:metabolism; D008297:Male; D008648:Mesoderm / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000737:chemistry* / Q000378:metabolism
D015415:Biomarkers; D012333:RNA, Messenger