Figure 4.

Dgat1-deficiency lessens fibrosis development in mice acutely treated with CCl₄. Trichrome staining of liver tissue sections from Dgat1^–/– and WT mice given IP injections of 1 µL of CCl₄ per gram of body weight [administered in corn oil, 1:4 (v/v)] 4 times at 48 h intervals (A). More collagen staining and more inflammatory cell infiltration was observed for WT compared to Dgat1^–/– liver. Although mRNA levels for markers for fibrogenesis, Col1a1 and Acta2, were not different between Dgat1^–/– (n=7) and WT mice (n=4) given four injections of corn oil vehicle, after CCl₄ treatment, expression levels of Col1a1 and Acta2 were significantly lower in Dgat1^–/– compared to WT livers (B,C). Hepatic retinyl ester levels were not different between the genotypes after corn oil treatment, but after CCl₄ injections, retinyl ester levels were significantly higher by more than 2-fold in Dgat1^–/– compared to WT livers (D). Compared with the corn oil treatment, CCl₄ treatment did not significantly reduce retinyl ester levels in the Dgat1^–/– livers, while retinyl ester levels in the livers of WT mice given CCl₄ were reduced to 24% of the levels in the livers of mice given only corn oil. All values are given as mean ± SD. Statistical significance between genotypes: *, P<0.05; **, P<0.01. Statistical significance between corn oil and CCl₄ treatments: ^#, P<0.05; ^##, P<0.01.