Jude Liver Resource. Extracted DNA was genotyped for c.388A>G (rs2306283) and c.521C>T (rs2306283) in SLCO1B1 and c.334G>T (rs4149117) and c.699G>A, (rs7311758) in SLCO1B3. Genotyping was performed by way of direct sequencing (Supporting Table 1). An unpaired t test was used to determine statistical significance, but for experiments relating to the impact of Slco1b2 deletion to the time course of oral glucose tolerance test, cell-based Luciferase assay, and transport http://www.selleckchem.com/products/ITF2357(Givinostat).html experiments, the statistical significance was validated using analysis of variance (ANOVA). Associations between gene expression in human livers were evaluated

using linear regression modeling determining the linear regression coefficient r2 and by performing an F-test. The degree of linear relationship of two www.selleckchem.com/products/LBH-589.html variables is reflected by the Pearson product-moment correlation coefficient. The impact of genotypes was evaluated using Kruskal-Wallis

one-way ANOVA. Finally, P values were adjusted according to the Benjamini-Hochberg false discovery rate; adjusted P < 0.05 was considered statistically significant.10 Statistical analysis was performed using the GraphPad Prism software (GraphPad Software, Inc., San Diego, CA). Data are presented as mean ± SD throughout the manuscript. Because bile acids (BAs) are known substrates of the OATP1B transporters,11 we first examined whether loss of Oatp1b2 has an effect on BA homeostasis. Associated with the deletion of Slco1b2 was a modest but not statistically significant reduction of total BAs in livers of 10-week-old mice, whereas plasma levels were three-fold lower compared with wild-type mice (Fig. 1A). Recent data by Csanaky et al.12 using a similar mouse model showed significantly increased levels of serum total BAs

comparing wild-type and Slco1b2−/− mice aged between 36 and 48 weeks.12 When we examined hepatic expression of Cyp7a1, selleckchem the key enzyme involved in BA formation from cholesterol, consistent with our first hypothesis, Slco1b2−/− mice exhibited significantly lower mRNA expression of Cyp7a1 (Cyp7a1 relative to wild-type mice (wild-type, 1.04 ± 0.28 [n = 10]; Slco1b2−/−, 0.45 ± 0.29 [n = 10]; adjusted P = 0.009). This finding is similar to that shown by Csanaky et al. Similar results were obtained when the protein level of Cyp7a1 was determined (Fig. 1B). Consistent with reduced Cyp7a1 expression, there was a 1.7-fold higher increase in plasma cholesterol levels in knockout mice after exposure to a high-fat diet (Fig. 1C). However, when we determined the level of the BA precursor 7-α-hydroxy-4-cholesten-3-one, which is thought to be a surrogate marker of CYP7A1 activity in humans,13 we did not observe statistically significant differences between wild-type and knockout animals (Supporting Fig. 1).