Figure 5.

Overexpression of FGF7 can induce the LPC response in the adult mouse liver. (A) The level of proliferation of HSCE1 cells was examined by WST-1 assay. Stimulation with epidermal growth factor (EGF) and hepatocyte growth factor (HGF) was used as a control. Mean ± SD (n = 3). (***) P < 0.001 compared with no cytokine treatment (0). (B) Quantitative RT–PCR analysis was performed to assess human FGF7 mRNA levels in the liver after 3 wk of Dox administration. Mean ± SE (control, n = 3; Tg, n = 5). (**) P < 0.01. (C) Serum levels of human FGF7 protein after 3 wk of Dox administration were determined by ELISA. Mean ± SE (control, n = 4; Tg, n = 6). (**) P < 0.01. (D) Immunostaining of CK19 (red) and Thy1 (green) in the livers of FGF7 Tg mice and control mice treated with Dox for 4 wk. Bars, 100 μm. (PV) Portal vein. (E) Quantitative analysis of CK19-positive areas showed an increased number of LPC-like cells in FGF7 Tg mice treated with Dox for 4 wk. Mean ± SD (n = 3). (**) P < 0.01. (F) Immunostaining of CK19 (red) and A6 (green) showed expansion of CK19⁺ A6⁺ LPCs in the livers of FGF7 Tg mice treated with Dox for 4 wk. CK19⁻ A6⁺ newly formed hepatocytes were also observed (arrowheads). Bars, 50 μm. (PV) Portal vein. (G) Immunostaining of CK19 (red) and collagen (green) in the livers of FGF7 Tg and control mice, wild-type mice fed a normal diet, and DDC-treated wild-type mice. Bars, 100 μm. (PV) Portal vein. (H) Quantitative RT–PCR analysis of Col1a1 and Col3a1 mRNA. Mean ± SE (control, n = 3; Tg, n = 5; DDC, n = 3). (**) P < 0.01; (***) P < 0.001; (NS) not significant. (I) EpCAM⁺ cells were isolated from the livers of FGF7 Tg mice and control mice 3 wk after Dox treatment and subjected to the in vitro colony formation assay. Mean ± SD (n = 3). (**) P < 0.01; (***) P < 0.001. (J) Immunofluorescence images of representative large colonies stained with anti-CK19 (green) and albumin (red). Bars, 200 μm.