Anticoagulant effect of dietary fish oil in hyperlipidemia: a study of hepatic gene expression in APOE2 knock-in mice.
OBJECTIVE
In hyperlipidemia, dietary fish oil containing n-3 polyunsaturated fatty acids (PUFA) provokes plasma triacylglycerol lowering and hypocoagulant activity. Using APOE2 knock-in mice, the relation of these fish-oil effects with altered gene expression was investigated.


RESULTS
Male APOE2 knock-in mice, fed regular low-fat diet, had elevated plasma levels of triacylglycerol and coagulation factors. Plasma lipids and (anti)coagulant factors reduced on feeding the mice with fish oil (n-3 PUFA) or, to a lesser degree, with sunflower seed oil (n-6 PUFA). The fish-oil diet provoked a 40% reduction in thrombin generation. Microarray (Affymetrix) and single-gene expression analysis of mouse livers showed that fish oil induced: (1) upregulation of genes contributing to lipid degradation and oxidation; (2) downregulation of genes of gamma-glutamyl carboxylase and of transcription factors implicated in lipid synthesis; (3) unchanged expression of coagulation factor genes. After fish-oil diet, vitamin K-dependent coagulation factors accumulated in periportal areas of the liver; prothrombin was partly retained in uncarboxylated form. Only part of the changes in gene expression were different from the effects of sunflower seed oil diet.


CONCLUSIONS
The hypocoagulant effect of n-3 PUFA is not caused by reduced hepatic synthesis of coagulation factors, but rather results from retention of uncarboxylated coagulation factors. In contrast, the lipid-lowering effect of n-3 PUFA links to altered expression of genes that regulate transcription and fatty acid metabolism.
Vanschoonbeek
Kristof
K
Department of Biochemistry, CARIM and NUTRIM, Maastricht University, Maastricht, The Netherlands.
Wouters
Kristiaan
K
van der Meijden
Paola E J
PE
van Gorp
Patrick J
PJ
Feijge
Marion A H
MA
Herfs
Marjolein
M
Schurgers
Leon J
LJ
Hofker
Marten H
MH
de Maat
Moniek P M
MP
Heemskerk
Johan W M
JW