title: Insulin induces fatty acid desaturase expression in human monocytes.
abstract: Increasing evidence suggests that fatty acid desaturases, rate-limiting enzymes in unsaturated fatty acid biosynthesis, are important factors in the pathogenesis of lipid-induced insulin resistance. The conversion of dihomogamma linolenic acid (DGLA) into arachidonic acid (AA) in human plasma phospholipids has been shown to be regulated by insulin, suggesting a role for insulin in fatty acid desaturase 1 regulation. However insulin's role in monocyte inflammation associated with obesity and lifestyle disease development is uncertain. We therefore investigated if insulin is able to induce expression of stearoyl-CoA desaturase (SCD, Δ9 desaturase), fatty acid desaturase 1 (FADS1, Δ5 desaturase), and fatty acid desaturase 2 (FADS2, Δ6 desaturase), as well as the sterol regulatory element binding transcription factor 1-c (SREBP-1c) in monocytes. Here, for the first time, we demonstrate that THP-1 monocytes are insulin-responsive in inducing expression of SCD, FADS1, and FADS2 in a time- and dose-dependent manner. Understanding secondary consequences of postprandial hyperinsulinemia may open up new strategies for prevention and/or treatment of obesity-related metabolic complications.
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Ingerid
authors.initials: I
authors.lastname: Arbo
authors.forename: Cathinka
authors.initials: C
authors.lastname: Halle
authors.forename: Darshan
authors.initials: D
authors.lastname: Malik
authors.forename: Hans-Richard
authors.initials: HR
authors.lastname: Brattbakk
authors.forename: Berit
authors.initials: B
authors.lastname: Johansen
mesh_terms: D002460:Cell Line; D003470:Culture Media; D000090943:Delta-5 Fatty Acid Desaturase; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000378:metabolism; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D003470:Culture Media; D000090943:Delta-5 Fatty Acid Desaturase; D007328:Insulin; D051780:Sterol Regulatory Element Binding Protein 1; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase; C000716847:FADS1 protein, human; C533241:FADS2 protein, human