title: The trans-10,cis-12 conjugated linoleic acid increases triacylglycerol hydrolysis in yeast Saccharomyces cerevisiae.
abstract: OBJECTIVE
  The trans-10,cis-12 conjugated linoleic acid (CLA) is known for its antilipogenic effect but the mechanism is not fully clear. In this study, the potential of yeast (Saccharomyces cerevisiae) metabolism to offer evidence for the mechanism was investigated.
  
  
  RESULTS
  The inhibitory effect of CLA on lipid accumulation was studied by analysing the transcript abundance of selected genes involved in triacylglycerol synthesis (LRO1, DGA1, ARE1 and ARE2) in the presence of the two bioactive CLA isomers: trans-10,cis-12 and the cis-9,trans-11 CLA. None of the enzymes was reduced in transcription but the expression of ARE2 was induced by trans-10,cis-12 CLA. However, the ARE2 overexpression did not contribute to lipid accumulation. The expression of the Δ9 desaturase gene, OLE1, was reduced by the cis-9,trans-11 but not by the trans-10,cis-12 isomer. In the TGL3/TGL4-knockout strain the triacylglycerol content also remained high in the CLA fed cells.
  
  
  CONCLUSIONS
  Triacylglycerol hydrolysis rather than synthesis was the most probable reason for the reduced lipid content in yeast induced by CLA.
  
  
  CONCLUSIONS
  This study revealed new aspects of the functionality of CLA in eukaryotic lipid metabolism. Yeast was proven to be an applicable model to study further the mechanism of trans-10,cis-12 CLA functionality on lipid metabolism.
authors.affiliation: Department of Bioproducts and Biosystems, Aalto University, Espoo, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Hokkanen
authors.affiliation: Department of Bioproducts and Biosystems, Aalto University, Espoo, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Laakso
authors.affiliation: Laves-Arzneimittel GmbH, Schötz, Switzerland.
authors.forename: C M
authors.initials: CM
authors.lastname: Senn
authors.affiliation: Department of Bioproducts and Biosystems, Aalto University, Espoo, Finland.
authors.forename: A D
authors.initials: AD
authors.lastname: Frey
keywords: antilipogenic; conjugated linoleic acid; desaturase; lipid metabolism; triacylglycerol hydrolysis; yeast