[Nutritional regulation of apolipoprotein genes. Effect of dietary carbohydrates and fatty acids].
The effect of nutritional factors on apolipoprotein gene expression by rat liver were studied. Dietary carbohydrates or fatty acids regulate the expression of apo E gene, by altering either gene transcription or mRNA stability. Conversely, apo A1 regulation occurs at a post transcriptional level. In vivo and in vitro experiments gave contradictory results concerning apo B gene expression. The more dramatic changes in plasma lipids and apolipoproteins are obtained under dietary fish oil. Hepatocytes from fish oil-fed rats retain for several days modification in fatty acid metabolism, i.e. a shift in oleic acid channeling towards oxidation at the expense of esterification and a reduced ability to synthesize and secrete triacylglycerol. These modifications are paralleled with a decrease in the synthesis and in the secretion of apo Bs. Hepatocytes from fish oil fed rats secrete degradative forms of apo B which might result from either a sluggish VLDL synthesis and secretion or a more specific effect of n-3 long chain polyunsaturated fatty acid peroxidative products. Hepatocytes from fish oil fed rats exhibit a reduced ability to synthesize cholesterol, associated with a decrease in apo A1 synthesis and secretion without any modification in apo A1 mRNA. In contrast, the hepatocytes exhibit a concomitent decrease in apo E synthesis and secretion and in cellular apo E mRNA levels.
Ribeiro
A
A
Equipe de Recherche sur la Biologie Cellulaire et Moléculaire des Médiateurs lipidiques et des lipoprotéines (CNRS URA 1283), CHU Saint-Antoine, Université Pierre et Marie Curie, France.
Mangeney
M
M
Cardot
P
P
Loriette
C
C
Chambaz
J
J
Rayssiguier
Y
Y
Bereziat
G
G
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001053:Apolipoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism*; D003314:Corn Oil / Q000494:pharmacology*; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005395:Fish Oils / Q000494:pharmacology*; D005786:Gene Expression Regulation; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014280:Triglycerides / Q000378:metabolism*
D001053:Apolipoproteins; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005395:Fish Oils; D010743:Phospholipids; D014280:Triglycerides; D003314:Corn Oil; D002784:Cholesterol
Régulation nutritionnelle des gènes d'apolipoprotéines. Effet des hydrates de carbone et des acides gras alimentaires.