title: Dietary soyasaponin supplementation to pea protein concentrate reveals nutrigenomic interactions underlying enteropathy in Atlantic salmon (Salmo salar).
abstract: BACKGROUND
  Use of plant ingredients in aquaculture feeds is impeded by high contents of antinutritional factors such as saponins, which may cause various pharmacological and biological effects. In this study, transcriptome changes were analyzed using a 21 k oligonucleotide microarray and qPCR in the distal intestine of Atlantic salmon fed diets based on five plant protein sources combined with soybean saponins.
  
  
  RESULTS
  Diets with corn gluten, sunflower, rapeseed or horsebean produced minor effects while the combination of saponins with pea protein concentrate caused enteritis and major transcriptome changes. Acute inflammation was characterised by up-regulation of cytokines, NFkB and TNFalpha related genes and regulators of T-cell function, while the IFN-axis was suppressed. Induction of lectins, complement, metalloproteinases and the respiratory burst complex parallelled a down-regulation of genes for free radical scavengers and iron binding proteins. Marked down-regulation of xenobiotic metabolism was also observed, possibly increasing vulnerability of the intestinal tissue. A hallmark of metabolic changes was dramatic down-regulation of lipid, bile and steroid metabolism. Impairment of digestion was further suggested by expression changes of nutrient transporters and regulators of water balance (e.g. aquaporin, guanylin). On the other hand, microarray profiling revealed activation of multiple mucosal defence processes. Annexin-1, with important anti-inflammatory and gastroprotective properties, was markedly up-regulated. Furthermore, augmented synthesis of polyamines needed for cellular proliferation (up-regulation of arginase and ornithine decarboxylase) and increased mucus production (down-regulation of glycan turnover and goblet cell hyperplasia) could participate in mucosal healing and restoration of normal tissue function.
  
  
  CONCLUSIONS
  The current study promoted understanding of salmon intestinal pathology and establishment of a model for feed induced enteritis. Multiple gene expression profiling further characterised the inflammation and described the intestinal pathology at the molecular level.
authors: Aquaculture Protein Centre (a CoE), Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, Oslo, Norway. Trond.Kortner@nvh.no
authors: Trond M
authors: TM
authors: Kortner
authors: Stanko
authors: S
authors: Skugor
authors: Michael H
authors: MH
authors: Penn
authors: Liv Torunn
authors: LT
authors: Mydland
authors: Brankica
authors: B
authors: Djordjevic
authors: Marie
authors: M
authors: Hillestad
authors: Aleksei
authors: A
authors: Krasnov
authors: Åshild
authors: Å
authors: Krogdahl
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D005393:Fish Diseases / Q000209:etiology* / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D007410:Intestinal Diseases / Q000209:etiology / Q000662:veterinary*; D007422:Intestines / Q000187:drug effects / Q000473:pathology; D054647:Nutrigenomics; D018532:Pisum sativum / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry / Q000494:pharmacology*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D020317:Salmo salar; D012503:Saponins / Q000009:adverse effects*; D059467:Transcriptome
chemical_list: D010940:Plant Proteins; D012503:Saponins