Figure 4

Sterol analyses of liver tissues from wild-type, knockout and knockout- transgenic pups. Panel A shows that the significant cholesterol deficiency in Dhcr7^-/-Tg- neonates (1.0 ± 0.53 mg/g tissue, P < 0.001 cf to WT) was restored to normal by the transgene expression (2.03 ± 0.64 mg/g tissue) and was not statistically different from WT livers (2.48 ± 0.38 mg/g tissue). Cholesterol level in livers from Dhcr7^+/+Tg+ littermates was 2.45 ± 0.42 mg/g tissue (data not shown). Massive accumulation of 7/8DHC in livers of Dhcr7^-/-Tg- neonates (1.46 ± 0.45 mg/g tissue, Panel B), was significantly decreased to 0.48 ± 0.33 mg/g tissue in Dhcr7^-/-Tg+ livers and only trace levels in livers of WT mice were detected (0.01 ± 0.02 mg/g tissue). The percent of sterol precursors in total sterols was also significantly improved in Dhcr7^-/-Tg+ livers (19 ± 13 %), compared to Dhcr7^-/-Tg- mice (59 ± 12 %, p < 0.001, Panel C). No significant difference (p > 0.05) was found in total sterol levels (mg/g tissue) among the three groups (2.49 ± 0.49 in WT, 2.43 ± 0.53in Dhcr7^-/-Tg- and 2.51 ± 0.51in Dhcr7^-/-Tg+). Results are expressed as mean ± SD.