Effects of dietary plant meal and soya-saponin supplementation on intestinal and hepatic lipid droplet accumulation and lipoprotein and sterol metabolism in Atlantic salmon (Salmo salarL.)

Altered lipid metabolism has been shown in fish fed plant protein sources. The present study aimed to gain further insights into how intestinal and hepatic lipid absorption and metabolism are modulated by plant meal (PM) and soya-saponin (SA) inclusion in salmon feed. Post-smolt Atlantic salmon were fed for 10 weeks one of four diets based on fishmeal or PM, with or without 10 g/kg SA. PM inclusion resulted in decreased growth performance, excessive lipid droplet accumulation in the pyloric caeca and liver, and reduced plasma cholesterol levels. Intestinal and hepatic gene expression profiling revealed an up-regulation of the expression of genes involved in lipid absorption and lipoprotein (LP) synthesis (apo, fatty acid transporters, microsomal TAG transfer protein, acyl-CoA cholesterol acyltransferase, choline kinase and choline-phosphate cytidylyltransferase A), cholesterol synthesis (3-hydroxy-3-methylglutaryl-CoA reductase) and associated transcription factors (sterol regulatory element-binding protein 2 and PPARγ). SA inclusion resulted in reduced body pools of cholesterol and bile salts. The hepatic gene expression of the rate-limiting enzyme in bile acid biosynthesis (cytochrome P450 7A1 (cyp7a1)) as well as the transcription factor liver X receptor and the bile acid transporterabcb11(ATP-binding cassette B11) was down-regulated by SA inclusion. A significant interaction was observed between PM inclusion and SA inclusion for plasma cholesterol levels. In conclusion, gene expression profiling suggested that the capacity for LP assembly and cholesterol synthesis was up-regulated by PM exposure, probably as a compensatory mechanism for excessive lipid droplet accumulation and reduced plasma cholesterol levels. SA inclusion had hypocholesterolaemic effects on Atlantic salmon, accompanied by decreased bile salt metabolism.

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Hepatic gene expression profiling reveals protective responses in Atlantic salmon vaccinated against furunculosis

BMC Genomics ◽

10.1186/1471-2164-10-503 ◽

2009 ◽

Vol 10 (1) ◽

pp. 503 ◽

Cited By ~ 35

Author(s):

Stanko Škugor ◽

Sven Jørgensen ◽

Bjarne Gjerde ◽

Aleksei Krasnov

Keyword(s):

Gene Expression ◽

Atlantic Salmon ◽

Gene Expression Profiling ◽

Expression Profiling ◽

Hepatic Gene Expression

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Transcriptional regulation of cholesterol and bile acid metabolism after dietary soyabean meal treatment in Atlantic salmon (Salmo salar L.)

British Journal Of Nutrition ◽

10.1017/s0007114512002024 ◽

2012 ◽

Vol 109 (4) ◽

pp. 593-604 ◽

Cited By ~ 63

Author(s):

Trond M. Kortner ◽

Jinni Gu ◽

Åshild Krogdahl ◽

Anne Marie Bakke

Keyword(s):

Gene Expression ◽

Bile Acid ◽

Atlantic Salmon ◽

Acid Metabolism ◽

Expression Profiles ◽

Gene Expression Profiles ◽

Bile Acid Metabolism ◽

Atp Binding ◽

Hepatic Gene Expression ◽

Soyabean Meal

Inclusion of plant protein sources such as soyabean meal (SBM) in aquafeeds is associated with decreased lipid digestibility, reduced bile acid levels and hypocholesterolaemia. The mechanism for these metabolic abnormalities is unknown. The present study aimed at gaining further insight into how cholesterol and bile acid metabolism is modulated by SBM feeding by quantifying a number of mRNA species corresponding to key proteins involved in cholesterol and bile acid metabolism using quantitative real-time PCR. A 21 d feeding trial with sequential sampling at ten time points following initiation of 20 % SBM exposure was conducted on Atlantic salmon. A histological evaluation confirmed distal intestinal enteritis after 5 d of dietary exposure to the SBM, whereas diminished glycogen/lipid deposition was the only relevant finding observed in the liver. SBM inclusion resulted in reduced body pools of cholesterol and bile acids. Hepatic gene expression profiles revealed up-regulation of genes encoding rate-limiting enzymes in cholesterol (3-hydroxy-3-methyl-glutaryl-CoA reductase; HMGCR) and bile acid (cytochrome P4507A1 (CYP7A1)) biosynthesis, as well as up-regulation of their associated transcription factors (sterol regulatory element binding proteins 1 and 2, liver X receptor, farnesoid X receptor and PPAR isoforms). Hepatic gene expressions of cholesterol (ATP binding cassette G5 (ABCG5)) and bile acid (ATP binding cassette B11 (ABCB11)) transporters were, by and large, not influenced by the SBM, but distal intestinal expression patterns of ABCG5 and apical Na-dependent bile acid transporter indicated impaired cholesterol and bile acid reabsorption. In conclusion, hepatic gene expression profiles indicated that the capacity for cholesterol and bile acid synthesis was up-regulated, whereas the indicated impaired cholesterol and bile acid reabsorption probably occurred as a direct result of distal intestinal inflammation.

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Faculty Opinions recommendation of Conjugated bile acid-activated S1P receptor 2 is a key regulator of sphingosine kinase 2 and hepatic gene expression.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725223790.793538885 ◽

2017 ◽

Author(s):

John YL Chiang

Keyword(s):

Gene Expression ◽

Bile Acid ◽

Sphingosine Kinase ◽

Hepatic Gene Expression ◽

Sphingosine Kinase 2 ◽

S1p Receptor

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Enzyme characterisation and gene expression profiling of Atlantic salmon chicken- and goose-type lysozymes

Developmental & Comparative Immunology ◽

10.1016/j.dci.2013.01.010 ◽

2013 ◽

Vol 40 (1) ◽

pp. 11-19 ◽

Cited By ~ 23

Author(s):

Bjørnar Myrnes ◽

Marit Seppola ◽

Audny Johansen ◽

Kersti Øverbø ◽

Lien Callewaert ◽

...

Keyword(s):

Gene Expression ◽

Atlantic Salmon ◽

Gene Expression Profiling ◽

Expression Profiling ◽

Enzyme Characterisation

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Multiple microarray platforms utilized for hepatic gene expression profiling of GH transgenic coho salmon with and without ration restriction

Journal of Molecular Endocrinology ◽

10.1677/jme.1.02031 ◽

2006 ◽

Vol 37 (2) ◽

pp. 259-282 ◽

Cited By ~ 56

Author(s):

M. L Rise ◽

S. E Douglas ◽

D. Sakhrani ◽

J. Williams ◽

K V. Ewart ◽

...

Keyword(s):

Gene Expression ◽

Gene Expression Profiling ◽

Expression Profiling ◽

Coho Salmon ◽

Hepatic Gene Expression

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Bile Acids: The Good, the Bad, and the Ugly

Physiology ◽

10.1152/physiologyonline.1999.14.1.24 ◽

1999 ◽

Vol 14 (1) ◽

pp. 24-29 ◽

Cited By ~ 48

Author(s):

Alan F. Hofmann

Keyword(s):

Bile Acids ◽

Enterohepatic Circulation ◽

Cholesterol Metabolism ◽

Plasma Cholesterol ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Lipid Absorption ◽

Bile Acid Metabolism ◽

Cholesterol Levels ◽

Density Lipoprotein Receptor

Bile acids, amphipathic end products of cholesterol metabolism, are “good” in the infant because they enhance lipid absorption and thereby promote growth. Bile acids also induce bile flow and biliary lipid secretion. The enterohepatic circulation of bile acids is “bad” in the adult because it downregulates hepatocyte low-density lipoprotein receptor activity and thereby elevates plasma cholesterol levels. Defects in bile acid metabolism such as impaired biosynthesis or transport are “ugly” because they cause morbidity and death. New approaches for treating these defects are being developed.

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