Absence of muricholic acid due to Cyp2c-deficiency protects against high fat diet-induced obesity in male mice but promotes liver damage

Abstract

ObjectiveMurine-specific muricholic acids (MCAs) are reported to protect against obesity and associated metabolic disorders. However, the response of mice with genetic depletion of MCA to an obesogenic diet has not been evaluated. We used Cyp2c-deficient (Cyp2c-/-) mice, which lack MCAs and thus have a human-like bile acid (BA) profile, to directly investigate the potential role of MCAs in diet-induced obesity. MethodsMale and female Cyp2c-/- mice and wild-type controls were fed a standard chow diet or a high fat diet (HFD) for 18 weeks. We measured BA composition from a pool of liver, gallbladder, and intestine, as well as weekly body weight, food intake, lean and fat mass, systemic glucose homeostasis, energy expenditure, intestinal lipid absorption, fecal lipid, and energy content. ResultsCyp2c deficiency depleted MCAs and caused other changes in BA composition, namely a decrease in the ratio of 12-hydroxylated (12-OH) BAs to non-12-OH BAs, without altering the total BA levels. While wild-type male mice became obese after HFD-feeding, Cyp2c-/- male mice were protected from obesity and associated metabolic dysfunctions. Cyp2c-/- male mice also showed reduced intestinal lipid absorption and increased lipid excretion, which was reversed by oral gavage with the 12-OH BA, taurocholic acid. Cyp2c-/- mice also showed increased liver damage, which appeared stronger in females. ConclusionMCA does not protect against diet-induced obesity but may protect against liver injury. Reduced lipid absorption in Cyp2c-deficient male mice is potentially due to a reduced ratio of 12-OH/non-12-OH BAs.