title: Soya protein stimulates bile acid excretion by the liver and intestine through direct and indirect pathways influenced by the presence of dietary cholesterol.
abstract: Several studies using different animal models have demonstrated that the consumption of soya protein (SP) reduces serum cholesterol concentrations by increasing the excretion of bile acids (BA). However, the mechanism by which SP enhances BA excretion is not fully understood. Therefore, the aim of the present study was to determine whether the consumption of SP regulates the expression of key enzymes involved in hepatic BA synthesis and the transporters involved in reverse cholesterol transport (RCT) via fibroblast growth factor 15 (FGF15) and/or small heterodimer protein (SHP) in rats. To achieve this aim, four groups of rats were fed experimental diets containing 20 % casein (C) or SP with or without the addition of 0·2 % cholesterol and the expression of hepatic genes involved in BA synthesis and the ileal and hepatic RCT was measured. Rats fed the SP diet had higher concentrations of ileal FGF15 and hepatic FGF15 receptor (FGFR4) and increased expression of SHP and liver receptor homolog 1 (LRH1) than those fed the C diet; as a result, the excretion of faecal BA was greater. The addition of cholesterol to the diet repressed the protein abundance of FGF15 and FGFR4; however, SP increased the expression of SHP and LRH1 to a lesser extent. Nonetheless, the expression of ABCG5/8 was increased in the intestine of rats fed the SP diet, and the effect was enhanced by the addition of cholesterol to the diet. In conclusion, SP in the presence of cholesterol increases BA synthesis via the repressions of FGF15 and SHP and accelerates BA excretion to prevent cholesterol overload in the enterocytes by increasing RCT.
authors.affiliation: Departamento de Fisiología de la Nutrición,Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, DF 14000, Mexico.
authors.forename: Gloria Leticia
authors.initials: GL
authors.lastname: Arellano-Martínez
authors.affiliation: Departamento de Fisiología de la Nutrición,Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, DF 14000, Mexico.
authors.forename: Omar
authors.initials: O
authors.lastname: Granados
authors.affiliation: Departamento de Fisiología de la Nutrición,Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, DF 14000, Mexico.
authors.forename: Berenice
authors.initials: B
authors.lastname: Palacios-González
authors.affiliation: Departamento de Fisiología de la Nutrición,Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, DF 14000, Mexico.
authors.forename: Nimbe
authors.initials: N
authors.lastname: Torres
authors.affiliation: Departamento de Fisiología de la Nutrición,Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, DF 14000, Mexico.
authors.forename: Isabel
authors.initials: I
authors.lastname: Medina-Vera
authors.affiliation: Departamento de Fisiología de la Nutrición,Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, DF 14000, Mexico.
authors.forename: Armando R
authors.initials: AR
authors.lastname: Tovar
mesh_terms: D000071018:ATP Binding Cassette Transporter, Subfamily G, Member 5; D000071019:ATP Binding Cassette Transporter, Subfamily G, Member 8; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000924:Anticholesteremic Agents / Q000378:metabolism; D001647:Bile Acids and Salts / Q000235:genetics / Q000378:metabolism*; D002756:Cholagogues and Choleretics / Q000378:metabolism*; D002791:Cholesterol, Dietary / Q000378:metabolism*; D005346:Fibroblast Growth Factors / Q000378:metabolism; D007082:Ileum / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D014674:Plant Proteins, Dietary / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D051499:Receptor, Fibroblast Growth Factor, Type 4 / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D030262:Soybean Proteins / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D000071018:ATP Binding Cassette Transporter, Subfamily G, Member 5; D000071019:ATP Binding Cassette Transporter, Subfamily G, Member 8; D018528:ATP-Binding Cassette Transporters; C480692:Abcg5 protein, rat; C480693:Abcg8 protein, rat; D000924:Anticholesteremic Agents; D001647:Bile Acids and Salts; D002756:Cholagogues and Choleretics; D002791:Cholesterol, Dietary; D008074:Lipoproteins; C417002:NR5A2 protein, rat; D014674:Plant Proteins, Dietary; D018160:Receptors, Cytoplasmic and Nuclear; D030262:Soybean Proteins; C099713:nuclear receptor subfamily 0, group B, member 2; D005346:Fibroblast Growth Factors; C496373:Fgfr4 protein, rat; D051499:Receptor, Fibroblast Growth Factor, Type 4