title: Interleukin-4-dependent production of PPAR-gamma ligands in macrophages by 12/15-lipoxygenase.
abstract: The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a ligand-dependent nuclear receptor that has been implicated in the modulation of critical aspects of development and homeostasis, including adipocyte differentiation, glucose metabolism and macrophage development and function. PPAR-gamma is activated by a range of synthetic and naturally occurring substances, including antidiabetic thiazolidinediones, polyunsaturated fatty acids, 15-deoxy-delta prostaglandin J2 and components of oxidized low-density lipoprotein, such as 13-hydroxyoctadecadienoic acid (13-HODE) and 15-hydroxyeicosatetraenoic acid (15-HETE). However, the identities of endogenous ligands for PPAR-gamma and their means of production in vivo have not been established. In monocytes and macrophages, 13-HODE and 15-HETE can be generated from linoleic and arachidonic acids, respectively, by a 12/15-lipoxygenase that is upregulated by the TH2-derived cytokine interleukin-4. Here we show that interleukin-4 also induces the expression of PPAR-gamma and provide evidence that the coordinate induction of PPAR-gamma and 12/15-lipoxygenase mediates interleukin-4-dependent transcription of the CD36 gene in macrophages. These findings reveal a physiological role of 12/15-lipoxygenase in the generation of endogenous ligands for PPAR-gamma, and suggest a paradigm for the regulation of nuclear receptor function by cytokines.
authors.affiliation: Department and School of Medicine, University of California, San Diego, La Jolla 92093-0651, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Huang
authors.forename: J S
authors.initials: JS
authors.lastname: Welch
authors.forename: M
authors.initials: M
authors.lastname: Ricote
authors.forename: C J
authors.initials: CJ
authors.lastname: Binder
authors.forename: T M
authors.initials: TM
authors.lastname: Willson
authors.forename: C
authors.initials: C
authors.lastname: Kelly
authors.forename: J L
authors.initials: JL
authors.lastname: Witztum
authors.forename: C D
authors.initials: CD
authors.lastname: Funk
authors.forename: D
authors.initials: D
authors.lastname: Conrad
authors.forename: C K
authors.initials: CK
authors.lastname: Glass
mesh_terms: D000818:Animals; D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism*; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism*; D018955:CD36 Antigens / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D015847:Interleukin-4 / Q000502:physiology*; D008024:Ligands; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
chemical_list: D018955:CD36 Antigens; D008024:Ligands; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D015847:Interleukin-4; D001092:Arachidonate 12-Lipoxygenase; D001093:Arachidonate 15-Lipoxygenase