CYP4A11 is repressed by retinoic acid in human liver cells

CYP4A11, the major fatty acid ω-hydroxylase in human liver is involved in the balance of lipids, but its role and regulation are both poorly understood. We studied the effects of retinoids on the regulation of CYP4A11 in the human hepatoma cell line HepaRG. Treatment of HepaRG cells with all-trans-retinoic acid resulted in a strong decrease in CYP4A11 gene expression and apoprotein content and, furthermore, was associated with a 50% decrease in the microsomal lauric acid hydroxylation activity. Such a strong suppression of CYP4A11 expression by retinoids could have a major impact on fatty acid metabolism in the liver.