title: Effects of corticosteroid on the expression of thymus and activation-regulated chemokine in a murine model of allergic asthma.
abstract: BACKGROUND
  Thymus and activation-regulated chemokine (TARC; CCL17) is a lymphocyte-directed CC chemokine that specifically attracts T-helper (Th) 2 cells positive for the CC chemokine receptor 4 (CCR4(+)). Corticosteroids reduce airway inflammation, as reflected by reduced numbers of eosinophils and T cells and reduced expression of cytokines. We investigated TARC production and the inhibitory effects of corticosteroids on TARC expression in a murine model of allergic asthma.
  
  
  METHODS
  BALB/c mice were sensitized by intraperitoneal injection of ovalbumin (OVA) with alum. Once daily for 1 week, mice received injections of dexamethasone or 0.2 ml saline (control), then 1 h later inhaled aerosolized 1% OVA for 30 min. Mice were killed 24 h after OVA challenge for bronchoalveolar lavage and lung tissue examination.
  
  
  RESULTS
  TARC was expressed mainly in the bronchial epithelial cells. Dexamethasone attenuated OVA-induced airway eosinophilia, lymphocyte infiltration, and airway hyperresponsiveness. Dexamethasone also decreased TARC production in the bronchoalveolar lavage fluid and decreased expression of TARC mRNA and TARC protein in lung tissue.
  
  
  CONCLUSIONS
  The corticosteroid dexamethasone inhibits TARC production in a murine model of allergic asthma in vivo. The beneficial effect of corticosteroids in bronchial asthma is due in part to their direct inhibitory effects on TARC production.
authors.affiliation: First Department of Internal Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Kurokawa
authors.forename: Fumio
authors.initials: F
authors.lastname: Kokubu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsukura
authors.forename: Mio
authors.initials: M
authors.lastname: Kawaguchi
authors.forename: Koushi
authors.initials: K
authors.lastname: Ieki
authors.forename: Shintarou
authors.initials: S
authors.lastname: Suzuki
authors.forename: Miho
authors.initials: M
authors.lastname: Odaka
authors.forename: Shin
authors.initials: S
authors.lastname: Watanabe
authors.forename: Hiroko
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Akabane
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Asano
authors.forename: Michiko
authors.initials: M
authors.lastname: Iwase
authors.forename: Ikuo
authors.initials: I
authors.lastname: Honma
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Adachi
mesh_terms: D000305:Adrenal Cortex Hormones / Q000494:pharmacology*; D000818:Animals; D001249:Asthma / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology / Q000276:immunology; D002452:Cell Count; D054414:Chemokine CCL17; D019742:Chemokines, CC / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D003907:Dexamethasone / Q000494:pharmacology*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D007150:Immunohistochemistry; D008168:Lung / Q000276:immunology / Q000473:pathology; D008297:Male; D016210:Methacholine Chloride / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D012313:RNA / Q000737:chemistry / Q000235:genetics; D054398:Receptors, CCR4; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000305:Adrenal Cortex Hormones; C499538:Ccl17 protein, mouse; C515355:Ccr4 protein, mouse; D054414:Chemokine CCL17; D019742:Chemokines, CC; C515188:Cxcr3 protein, mouse; D054398:Receptors, CCR4; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine; D016210:Methacholine Chloride; D012313:RNA; D003907:Dexamethasone; D010047:Ovalbumin