Like others [4, 15] we also BAY 11-7082 clinical trial detected a strong up-regulation of SMA positive cells in CDE livers. GW3965 datasheet Interestingly, periportal SMA positive cells co-expressed vimentin, a protein actually synthesized in fibroblasts , suggesting their origin
from periportal (myo-)fibroblasts rather than from HSCs, since co-expression of GFAP, a characteristic for the transdifferentiation into myofibroblasts demonstrated in vitro [35, 36] but not in vivo, was rarely detectable. Even though we might have missed such an event in an early phase after exposure to CDE, it is remarkably that the above mentioned activation of HSC persists even after two weeks. Thus, HSCs seem to have other functions than transdifferentiation to myofibroblasts as it was discussed in a recent study using a rat oval cell
model selleck compound . Up-regulation of CD31 (PECAM) in livers of CDE treated mice is another new finding of this study. The lack of any BrdU/CD31 co-expression points to an increase of CD31 in SECs. In untreated livers CD31 positive cells were hardly detected, whereas up-regulation seems to be associated with dedifferentiation of SECs into a defenestrated endothel during pseudocapillarization due to fibrotic processes  which also occur under CDE conditions . The impact of re-expression of LI-cadherin in adult mouse liver during CDE diet is still unclear and currently under investigation in double knock-out mice for LI and E-cadherin in our group. Possibly, re-expression of LI-cadherin, an embryonal marker of mouse liver , prevents the dissociation of cellular
connections on sites of insufficient expression of E-cadherin. Conclusions The present study clearly shows that in mouse liver M2-Pk is expressed in 2-hydroxyphytanoyl-CoA lyase nearly all cells of hepatic sinusoid. Undisputable CDE diet leads to an up-regulation of M-Pk, but this rise is the summation of M1- and M2-Pk. The elevation should no longer be misinterpreted as a specific oval cell response. Under CDE conditions GFAP expressing cells expand in a zonal specific pattern. Pericentral GFAP positive cells seem to present an activated cell type. Periportal oval cells express GFAP, a common HSC marker. Therefore, this marker does not seem suitable for tracing progenitors of hepatocytes under CDE conditions. Methods Animals GFAP-tTA mice (B6.Cg.Tg(GFAP-tTA)110Pop/J, Jacksons Laboratory, Bar Harbor, USA) were intercrossed with ptetCre mice (LC1, ) resulting in double transgenic mice expressing Cre-recombinase by GFAP promoter driven tTA expression (GFAP-Cre-mice). Mice of mixed genetic backround (DAB/C57Bl/6) and GFAP-Cre mice were given a CDE diet over 14 days. Cholin deficient animal chow without addition of methionine (Altromin, Lage, Germany) was provided ad libitum and drinking water was replaced by 0.165% ethionine solution (TCI, Europe, Zwijndrecht, Belgium) and was also given ad libitum.