RT Journal Article
SR Electronic
T1 CYP4F3B Expression Is Associated with Differentiation of HepaRG Human Hepatocytes and Unaffected by Fatty Acid Overload
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 1987
OP 1996
DO 10.1124/dmd.110.036848
VO 39
IS 10
A1 Stéphanie Madec
A1 Virginie Cerec
A1 Emmanuelle Plée-Gautier
A1 Joseph Antoun
A1 Denise Glaise
A1 Jean-Pierre Salaun
A1 Christiane Guguen-Guillouzo
A1 Anne Corlu
YR 2011
UL http://dmd.aspetjournals.org/content/39/10/1987.abstract
AB Fatty acid microsomal ω-oxidation involves cytochrome P450 enzymes. Some of them belonging to the CYP4F3 family are mainly expressed in the liver, making this organ a major player in energy homeostasis and lipid metabolism. To study this important regulation pathway, we used HepaRG cells, which gradually undergo a complete differentiation process. Even at the early stage of the differentiation process, CYP4F3B generated by alternative splicing of the CYP4F3 gene represented the prevalent isoform in HepaRG cells as in the liver. Its increasing expression associated with hepatocyte differentiation status suggested a hepatic-specific control of this isoform. As in liver microsomes, the catalytic hydroxylation of the CYP4F3B substrate [1-14C]Z9(10)-epoxystearic acid led to major production of 18-hydroxy-9(10)-epoxystearic acid. When treated with saturated, monounsaturated, or polyunsaturated fatty acids, CYP4F3B and CYP4A11 expression remained unchanged whereas CYP4F2 and CYP4F12 expression was transiently up-regulated. A 24-h exposure of differentiated HepaRG cells to various polyunsaturated fatty acids and derivatives induced microvesicular steatosis; down-regulation of lipid metabolism gene regulators such as sterol regulatory element-binding protein-1c, fatty acid synthase, peroxisome proliferator-activated receptor γ (PPARγ), PPARα, and decreased expression of glucose-dependent metabolism genes, which could limit de novo lipogenesis. Docosahexaenoic acid seemed to be the most effective compound. These results suggest that a PPARα-independent pathway could participate to limit lipogenesis and emphasize the role of hepatocytes in the fatty acid ω-hydroxylation pathway. They also give insights on the use of HepaRG hepatocytes to open new avenues of investigations on factors mediating the lipid metabolic pathway and finding new hypolipidemic molecules.