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Feeding diets containing rice protein isolate (RPI) results in activation of hepatic PPAR and LXR‐regulated genes in weanling rats.
Author(s) -
Ronis Martin J,
Chen Ying,
Badeaux Jamie,
Badger Thomas M
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1015-a
Subject(s) - cd36 , glucokinase , medicine , endocrinology , peroxisome proliferator activated receptor , biology , cholesterol 7 alpha hydroxylase , sterol regulatory element binding protein , lipid metabolism , carnitine , biochemistry , cholesterol , gene , sterol , insulin
Feeding rice protein isolate (RPI) has been reported to prevent the development of atherosclerotic plaques in apoE knockout mice and to improve body composition indices in rats. The mechanisms remain unknown. The current study examined the effects of feeding (RPI) on expression of genes and transcription factors involved in fatty acid (FA) and cholesterol metabolism and transport. Sprague‐Dawley rats were weaned onto AIN‐93G diets containing RPI or casein (CAS) as the sole protein source from dams fed casein diets throughout gestation and lactation. At sacrifice on PND34, expression of PPAR alpha‐regulated genes (acyl CoA oxidase (ACO), hydroxyacyl‐Coenzyme A dehydrogenase, carnitine palmitoyltransferase); PPAR gamma‐regulated genes (glucokinase,, CD36) and LXR‐regulated genes (CYP7A1, ABCA1, ABCG5, ABCG8) were induced (p < 0.05) by feeding RPI relative to expression in liver of those rats fed CAS as determined by real time RT‐PCR. This was accompanied by increased binding of the PPAR alphaƒnand PPAR gamma to their response elements on the ACO and glucokinase promoters as measured in EMSA and ChIP assays. Increased expression of PPAR mRNAs and apoprotein were also observed (p < 0.05). LXR binding to the CYP7A1 promoter was not significantly affected by feeding RPI. These data suggest that RPI increases hepatic FA and transport via induction of PPARs and increases cholesterol metabolism and transport more indirectly. Supported in part by ARS CRIS #6251‐51000‐003‐065 and Riceland Foods Inc.