title: Notch inhibition promotes fetal liver stem/progenitor cells differentiation into hepatocytes via the inhibition of HNF-1β.
abstract: In a previous study, the Notch pathway inhibited with N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (also called DAPT) was shown to promote the differentiation of fetal liver stem/progenitor cells (FLSPCs) into hepatocytes and to impair cholangiocyte differentiation. The precise mechanism for this, however, was not elucidated. Two mechanisms are possible: Notch inhibition might directly up-regulate hepatocyte differentiation via HGF (hepatocyte growth factor) and HNF (hepatocyte nuclear factor)-4α or might impair cholangiocyte differentiation thereby indirectly rendering hepatocyte differentiation as the dominant state. In this study, HGF and HNF expression was detected after the Notch pathway was inhibited. Although our initial investigation indicated that the inhibition of Notch induced hepatocyte differentiation with an efficiency similar to the induction via HGF, the results of this study demonstrate that Notch inhibition does not induce significant up-regulation of HGF or HNF-4α in FLSPCs. This suggests that Notch inhibition induces hepatocyte differentiation without the influence of HGF or HNF-4α. Moreover, significant down-regulation of HNF-1β was observed, presumably dependent on an impairment of cholangiocyte differentiation. To confirm this presumption, HNF-1β was blocked in FLSPCs and was followed by hepatocyte differentiation. The expression of markers of mature cholangiocyte was impaired and hepatocyte markers were elevated significantly. The data thus demonstrate that the inhibition of cholangiocyte differentiation spontaneously induces hepatocyte differentiation and further suggest that hepatocyte differentiation from FLSPCs occurs at the expense of the impairment of cholangiocyte differentiation, probably being enhanced partially via HNF-1β down-regulation or Notch inhibition.
authors.affiliation: General Surgery Center, Chengdu Military General Hospital, Chengdu, Sichuan Province, 610083, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Hong-Yin
authors.initials: HY
authors.lastname: Liang
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Yan
authors.forename: Ning
authors.initials: N
authors.lastname: Lin
authors.forename: Li-Ye
authors.initials: LY
authors.lastname: Liu
authors.forename: Hao
authors.initials: H
authors.lastname: Luo
authors.forename: Zhu
authors.initials: Z
authors.lastname: Huang
authors.forename: Nan-Lin
authors.initials: NL
authors.lastname: Li
authors.forename: Wei-Hui
authors.initials: WH
authors.lastname: Liu
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Tang
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology; D004151:Dipeptides / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology*; D051539:Hepatocyte Nuclear Factor 1-beta / Q000037:antagonists & inhibitors*; D022781:Hepatocytes / Q000166:cytology*; D008099:Liver / Q000166:cytology* / Q000196:embryology*; D051381:Rats; D011916:Rats, Inbred F344; D051880:Receptors, Notch / Q000037:antagonists & inhibitors*; D015398:Signal Transduction; D014162:Transfection
chemical_list: D004151:Dipeptides; C419410:N-(N-(3,5-difluorophenacetyl)alanyl)phenylglycine tert-butyl ester; D051880:Receptors, Notch; D051539:Hepatocyte Nuclear Factor 1-beta