FIGURE 5.
Adenovirus-mediated expression of RORα induces CYP8B1 mRNA and protein levels in mouse liver. A, effect of adenovirus-mediated transduction of RORα on CYP8B1 mRNA expression in mouse liver. Mice (C57Bl/6J, n = 6) were injected (intravenously) with adenovirus expressing RORα (Ad-RORα) (2 × 109 pfu/mouse) or same amount of empty adenovirus (Ad-null). Relative mRNA expression was calculated with respect to Ad-null injected mice. Inset, Western immunoblot analysis of RORα and CYP8B1 protein in microsomes isolated from livers pooled from Ad-RORα infected mice (n = 6) and control (Ad-null n = 6) mice. B, analysis of total bile acid pool size including liver, gallbladder, and intestine of Ad-RORα and Ad-null infected mice. Results were expressed as the mean ± S.E.; n = 6; asterisks indicate statistical significance, p < 0.05, Ad- RORα versus Ad-null infused mice. C, gallbladder bile acid analysis. Wild type C57BL6 mice were injected with Ad-null (n = 3) or Ad-RORα (n = 6). Seven days post injection, gallbladder bile was extracted for analysis of bile acid composition using LC/MS/MS as described under “Experimental Procedures.” Each bile acid was calculated as % of total bile acids measured (22284.65 pm). The ratio of 12α-hydroxylated bile acid to non-12α-hydroxylated bile acids was calculated. 12α-Hydroxylated bile acid species are CA, deoxycholic acid, tauro-cholic acid (TCA), and tauro-deoxycholic acids (TDCA). Non-12α-hydroxylated bile acid species are tauro-chenodeoxycholic acid (TCDCA), TαMCA, TβMCA, tauro-urodeoxycholic acids (TUDCA), tauro-hyocholic acid (THCA), tauro-murideoxycholic acid (TMDCA), tauro-lithocholic acid (TLCA). The asterisk indicates statistical significance, p < 0.05, Ad-RORα versus Ad-null infused mice.