title: 25-Hydroxycholesterol-3-sulfate attenuates inflammatory response via PPARγ signaling in human THP-1 macrophages.
abstract: The nuclear receptor peroxisome proliferator-activated receptors (PPARs) are important in regulating lipid metabolism and inflammatory responses in macrophages. Activation of PPARγ represses key inflammatory response gene expressions. Recently, we identified a new cholesterol metabolite, 25-hydroxycholesterol-3-sulfate (25HC3S), as a potent regulatory molecule of lipid metabolism. In this paper, we report the effect of 25HC3S and its precursor 25-hydroxycholesterol (25HC) on PPARγ activity and on inflammatory responses. Addition of 25HC3S to human macrophages markedly increased nuclear PPARγ and cytosol IκB and decreased nuclear NF-κB protein levels. PPARγ response element reporter gene assays showed that 25HC3S significantly increased luciferase activities. PPARγ competitor assay showed that the K(i) for 25HC3S was ∼1 μM, similar to those of other known natural ligands. NF-κB-dependent promoter reporter gene assays showed that 25HC3S suppressed TNFα-induced luciferase activities only when cotransfected with pcDNAI-PPARγ plasmid. In addition, 25HC3S decreased LPS-induced expression and release of IL-1β. In the PPARγ-specific siRNA transfected macrophages or in the presence of PPARγ-specific antagonist, 25HC3S failed to increase IκB and to suppress TNFα and IL-1β expression. In contrast to 25HC3S, its precursor 25HC, a known liver X receptor ligand, decreased nuclear PPARγ and cytosol IκB and increased nuclear NF-κB protein levels. We conclude that 25HC3S acts in macrophages as a PPARγ ligand and suppresses inflammatory responses via the PPARγ/IκB/NF-κB signaling pathway.
authors.affiliation: Department of Medicine, Virginia Commonwealth University, Richmond, VA 23249, USA.
authors.forename: Leyuan
authors.initials: L
authors.lastname: Xu
authors.forename: Shanwei
authors.initials: S
authors.lastname: Shen
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Ma
authors.forename: Jin Koung
authors.initials: JK
authors.lastname: Kim
authors.forename: Daniel
authors.initials: D
authors.lastname: Rodriguez-Agudo
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Heuman
authors.forename: Phillip B
authors.initials: PB
authors.lastname: Hylemon
authors.forename: William M
authors.initials: WM
authors.lastname: Pandak
authors.forename: Shunlin
authors.initials: S
authors.lastname: Ren
mesh_terms: D000893:Anti-Inflammatory Agents; D015153:Blotting, Western; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002788:Cholesterol Esters / Q000494:pharmacology*; D016207:Cytokines / Q000032:analysis / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D006888:Hydroxycholesterols / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D020672:I-kappa B Proteins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D016328:NF-kappa B / Q000378:metabolism; D047495:PPAR gamma / Q000037:antagonists & inhibitors / Q000502:physiology*; D021381:Protein Transport / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D000077154:Rosiglitazone; D015398:Signal Transduction / Q000187:drug effects; D045162:Thiazolidinediones / Q000494:pharmacology
chemical_list: C534977:25-hydroxycholesterol 3-sulfate; D000893:Anti-Inflammatory Agents; D002788:Cholesterol Esters; D016207:Cytokines; D006888:Hydroxycholesterols; D007004:Hypoglycemic Agents; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D047495:PPAR gamma; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D045162:Thiazolidinediones; D000077154:Rosiglitazone