title: Inhaled corticosteroid prevents the thickening of airway smooth muscle in murine model of chronic asthma.
abstract: Airway smooth muscle growth contributes to the mechanism of airway hyperresponsiveness (AHR) in asthma. Although current steroid use demonstrates anti-inflammatory activity, there is little reported on the action of corticosteroid on smooth muscle of the asthmatic airway. The present study investigated the effect of inhaled corticosteroid on the thickening of airway smooth muscle in bronchial asthma. We developed a mouse model of airway remodeling including smooth muscle thickening in which ovalbumin (OVA)-sensitized female BALB/c-mice were repeatedly exposed to intranasal OVA administration twice a week for 3 months. Mice were treated intranasally with fluticasone during the OVA challenge. Mice chronically exposed to OVA developed sustained eosinophilic airway inflammation compared with control mice. In addition, the mice chronically exposed to OVA developed features of airway remodeling, including thickening of the peribronchial smooth muscle layer. Intranasal administration of fluticasone inhibited the development of eosinophilic inflammation, and importantly, thickening of the smooth muscle layer. Moreover, intranasal fluticasone treatment reduced the transforming growth factor (TGF)-beta 1 level in bronchoalveolar lavage fluid and regulated active TGF-beta 1 signaling with a reduction in the expression of phospho-Smad2/3 and the concomitant up-regulation of Smad7 in lung tissue sections. These results suggest that intranasal administration of fluticasone can modulate the remodeling of airway smooth muscle via regulation of TGF-beta 1 production and active TGF-beta 1 signaling.
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic, University of Korea, 137-701 Seoul, Korea.
authors.forename: Sook Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Kim
authors.forename: Jung Mi
authors.initials: JM
authors.lastname: Lee
authors.forename: Soon Seok
authors.initials: SS
authors.lastname: Kwon
authors.forename: Kwan Hyung
authors.initials: KH
authors.lastname: Kim
authors.forename: Hwa Sik
authors.initials: HS
authors.lastname: Moon
authors.forename: Jung Sub
authors.initials: JS
authors.lastname: Song
authors.forename: Sung Hark
authors.initials: SH
authors.lastname: Park
authors.forename: Young Kyoon
authors.initials: YK
authors.lastname: Kim
mesh_terms: D000281:Administration, Intranasal; D000730:Androstadienes / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001249:Asthma / Q000276:immunology / Q000473:pathology*; D001980:Bronchi / Q000187:drug effects / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002908:Chronic Disease; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D000068298:Fluticasone; D008168:Lung / Q000187:drug effects / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009130:Muscle, Smooth / Q000187:drug effects* / Q000473:pathology; D010047:Ovalbumin / Q000276:immunology; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis
chemical_list: D000730:Androstadienes; D000893:Anti-Inflammatory Agents; D053773:Transforming Growth Factor beta1; D010047:Ovalbumin; D000068298:Fluticasone