Figure 2.

Recombinant Delta-like ligand 4 (rDll4) attenuates carbon tetrachloride (CCl₄)-induced liver fibrosis and hepatocyte apoptosis. A: mRNA levels of Hes1 and Hes5 in mouse liver tissues from different groups was quantified by real-time quantitative PCR (qPCR). B: Sirius red and α-smooth muscle actin (α-Sma) staining were used to assess fibrosis and myofibroblasts. Red arrows depict cleaved-caspase3 positive cells. Boxed area is highly magnified on the left to highlight α-Sma positive cells in CCl₄-challenged mice. Immunohistochemistry for cleaved-caspase3 was performed to examine apoptosis of liver cells in different groups. C: Semiquantification for Masson, α-Sma, and cleaved-caspase3 staining was performed using Leica microscope imaging software. D: mRNA expression of collagen1α1 and α-Sma in mouse liver was quantified by qPCR. Hydroxyproline content assay was performed to evaluate collagen content in CCl₄-challenged mice. E: Serum alanine aminotransferase (ALT) levels were measured in mice. F: mRNA expression of death receptors (Tnfr1, Fas, Trail-R/Dr5) was quantified using qPCR. Except staining and serum ALT measurement, other experiments were repeated at least three times. Data are presented as means ± SEM (A and C–E). n = 6 per group (A). ^∗P < 0.05, ^∗∗P < 0.01, and ^∗∗∗∗P < 0.0001. Scale bars: 200 μm (B, top panels); 100 μm (B, middle panels); 50 μm (B, bottom panels); 20 μm (B, magnification).