Figure 2.

FGF7 signal emanates from Thy1⁺ cells and acts on LPCs. (A, left panel) Liver sections prepared from mice fed DDC diet for 3 wk were subjected to in situ hybridization analysis for Fgfr2 expression. (Right panel) The same section was subsequently overlaid with immunohistochemical staining using anti-CK19 antibody to confirm its expression in LPCs. Bars, 200 μm. (B,C) EpCAM⁺ and EpCAM⁻ cells were sorted from NPCs in the livers of the mice fed the DDC-containing diet for 5 wk. Cytospin preparations of these cells were stained for FGFR2b (green) and EpCAM (red). Representative images are shown in B, and the result of quantitation are shown in C (EpCAM⁻, n = 980; EpCAM⁺, n = 1454). Mean ± SD. Bars, 40 μm. (***) P < 0.001. (D) Hepatocyte, NPC, EpCAM⁺ cell (LPC), Thy1⁺ CD45⁻ mesenchymal cell (Thy1⁺MC), Thy1⁺ CD45⁺ T-cell (T-cell), and Thy1⁻ CD45⁺ cell (blood cell, excluding T-cell) fractions were isolated from the livers of DDC-treated mice. Expression of the indicated genes was examined by quantitative RT–PCR. Mean ± SD (n = 3). (*) Significantly different from each of the other five fractions (ANOVA, with Tukey post hoc tests, P < 0.05).