title: Treatment with a sphingosine-1-phosphate analog inhibits airway remodeling following repeated allergen exposure.
abstract: Sphingosine-1-phosphate (S1P) is an immunomodulatory lipid mediator that plays an important role in lymphocyte trafficking. Elevated levels of S1P are found in bronchoalveolar lavage (BAL) fluid of patients with asthma; however, its role in disease is not known. FTY720, a synthetic analog of S1P, has been shown to abrogate allergic inflammation and airway hyperresponsiveness following acute allergen challenge. However, its effects on asthmatic airway remodeling induced by repeated allergen exposure are unknown. Ovalbumin (OVA)-sensitized rats were challenged on days 14, 19, and 24 after sensitization. FTY720 or vehicle (PBS) therapy was administered 1 h prior to each challenge. BAL fluid and quantitative histological analysis were performed 48 h after the last challenge. FTY720 inhibited OVA-induced features of airway remodeling including increased airway smooth muscle mass and bronchial neovascularization, without affecting lymphocyte numbers in secondary lymphoid organs. Furthermore, CD3+ cells adjacent to airway smooth muscle bundles were increased in OVA-challenged rats but the increase was inhibited by FTY720. There was an expansion of bronchus-associated lymphoid tissue following FTY720 treatment of OVA-challenged animals. Real-time quantitative PCR revealed that Th2-associated transcription factors were inhibited following FTY720 therapy. Airway remodeling is a cardinal feature of severe asthma. These results demonstrate that allergen-driven airway remodeling can be inhibited by FTY720, offering potential new therapies for the treatment of severe asthma.
authors.affiliation: Meakins-Christie Laboratories, McGill University, Montreal, Canada. hkarquin@gmail.com
authors.forename: Harry
authors.initials: H
authors.lastname: Karmouty-Quintana
authors.forename: Sana
authors.initials: S
authors.lastname: Siddiqui
authors.forename: Muhannad
authors.initials: M
authors.lastname: Hassan
authors.forename: Kimitake
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Paul-Andre
authors.initials: PA
authors.lastname: Risse
authors.forename: Laura
authors.initials: L
authors.lastname: Xicota-Vila
authors.forename: Maria
authors.initials: M
authors.lastname: Marti-Solano
authors.forename: James G
authors.initials: JG
authors.lastname: Martin
mesh_terms: D056151:Airway Remodeling / Q000187:drug effects*; D000485:Allergens / Q000009:adverse effects*; D000818:Animals; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy; D001980:Bronchi / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid; D017252:CD3 Complex / Q000032:analysis; D000068876:Fingolimod Hydrochloride; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D008246:Lysophospholipids / Q000819:agonists* / Q000627:therapeutic use*; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects; D011409:Propylene Glycols / Q000627:therapeutic use*; D051381:Rats; D012720:Severity of Illness Index; D013110:Sphingosine / Q000819:agonists / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000485:Allergens; D018927:Anti-Asthmatic Agents; D017252:CD3 Complex; D007166:Immunosuppressive Agents; D008246:Lysophospholipids; D011409:Propylene Glycols; C060506:sphingosine 1-phosphate; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine