Absence of CD36 alters systemic vitamin A homeostasis

Abstract

AbstractFatty acid translocase (CD36) is a scavenger receptor with multiple ligands and diverse physiological actions. We recently reported that alcohol-induced hepatic retinoid mobilization is impaired inCd36−/−mice, leading us to hypothesize that CD36 has a novel role in hepatic vitamin A mobilization. Given the central role of the liver in systemic vitamin A homeostasis we also postulated that absence of CD36 would affect whole-body vitamin A homeostasis. We tested this hypothesis in aging wild type andCd36−/−mice, as well as mice fed a vitamin A-deficient diet. In agreement with our hypothesis,Cd36−/−mice accumulated hepatic retinyl ester stores with age to a greater extent than wild type mice. However, contrary to expectations,Cd36−/−mice consuming a vitamin A-deficient diet mobilized hepatic retinoid similar to wild type mice. Interestingly, we observed thatCd36−/−mice had significantly reduced white adipose tissue retinoid levels compared to wild type mice. In conclusion, we demonstrate that the absence of CD36 alters whole-body vitamin A homeostasis and suggest that this phenotype is secondary to the impaired chylomicron metabolism previously reported in these mice.