title: Double Bond Position Plays an Important Role in Delta-9 Desaturation and Lipogenic Properties of Trans 18:1 Isomers in Mouse Adipocytes.
abstract: The objective of this research was to study the delta-9 desaturation of individual trans (t) fatty acids that can be found in ruminant fat or partially hydrogenated vegetable oils (PHVO) and determine their effects on lipogenic gene expression in adipocytes. It was hypothesized that delta-9 desaturation and lipogenic properties of t-18:1 isomers depend on the position of double bond. Differentiated 3T3-L1 adipocytes were treated with 200 µM of t6-18:1, t9-18:1, t11-18:1, t13-18:1 or t16-18:1, cis (c)-9 18:1 or bovine serum albumin (BSA) vehicle control for 48 h. Cells were then harvested for fatty acid and gene expression analyses using gas chromatography and quantitative PCR respectively. Among t-18:1 isomers, t13-18:1 and t11-8:1 had the greatest percent delta-9 desaturation (44 and 41 % respectively) followed by t16-18:1 and t6-18:1 (32 and 17 % respectively), while c9-18:1 and t9-18:1 did not undergo delta-9 desaturation. Trans9-18:1 up-regulated (P < 0.05) the expression of lipogenic genes including fatty acid synthase and stearoyl-CoA desaturase-1 (P < 0.05), whereas the expression of these genes were not affected with other t-18:1 isomers (P > 0.05). Consistent with gene expression results, t9-18:1 increased the de novo lipogenic index (16:0/18:2n-6) compared with control cells and increased delta-9 desaturation index (c9-16:1/18:0) compared to other t-18:1 isomers (P < 0.05). The current study provides further evidence that the predominant trans fatty acid in PHVO (t9-18:1) has isomer specific lipogenic properties.
authors.affiliation: Lacombe Research Centre, Agriculture and Agri-Food Canada, Lacombe, AB, T4L 1W1, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Vahmani
authors.affiliation: Lacombe Research Centre, Agriculture and Agri-Food Canada, Lacombe, AB, T4L 1W1, Canada.
authors.forename: W J
authors.initials: WJ
authors.lastname: Meadus
authors.affiliation: Lacombe Research Centre, Agriculture and Agri-Food Canada, Lacombe, AB, T4L 1W1, Canada.|Department of Animal Sciences, Faculty of AgriSciences, Stellenbosch University, P. Bag X1, Matieland, 7602, South Africa.
authors.forename: C
authors.initials: C
authors.lastname: Mapiye
authors.affiliation: Lacombe Research Centre, Agriculture and Agri-Food Canada, Lacombe, AB, T4L 1W1, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Duff
authors.affiliation: Lacombe Research Centre, Agriculture and Agri-Food Canada, Lacombe, AB, T4L 1W1, Canada.
authors.forename: D C
authors.initials: DC
authors.lastname: Rolland
authors.affiliation: Lacombe Research Centre, Agriculture and Agri-Food Canada, Lacombe, AB, T4L 1W1, Canada. mike.dugan@agr.gc.ca.
authors.forename: M E R
authors.initials: ME
authors.lastname: Dugan
mesh_terms: D041721:3T3-L1 Cells; D052438:Adipocytes, White / Q000201:enzymology* / Q000378:metabolism; D000818:Animals; D002470:Cell Survival; D004041:Dietary Fats / Q000032:analysis; D004790:Enzyme Induction; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D064429:Fatty Acid Synthases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D057141:Food, Preserved / Q000032:analysis; D006865:Hydrogenation; D050155:Lipogenesis; D051379:Mice; D015394:Molecular Structure; D009829:Oleic Acids / Q000737:chemistry / Q000378:metabolism*; D010938:Plant Oils / Q000737:chemistry; D012333:RNA, Messenger; D013230:Stearoyl-CoA Desaturase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013237:Stereoisomerism; D044242:Trans Fatty Acids / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004041:Dietary Fats; D009829:Oleic Acids; D010938:Plant Oils; D012333:RNA, Messenger; D044242:Trans Fatty Acids; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C029627:delta-9 fatty acid desaturase; D064429:Fatty Acid Synthases
keywords: Adipocytes; Cell culture; Fatty acid metabolism; Lipogenic gene expression; Trans fatty acids