Mice lacking 12/15-lipoxygenase have attenuated airway allergic inflammation and remodeling.
Arachidonate 15-lipoxygenase (LO)-1 has been implicated in allergic inflammation and asthma. The overall effect of 15-LO in allergic inflammation in vivo is, however, unclear. This study investigates systemic allergen sensitization and local allergic airway inflammation and remodeling in mice lacking the murine 12/15-LO, the ortholog to human 15-LO-1. Upon systemic sensitization with intraperitoneal ovalbumin, 12/15-LO-/- mice produced elevated levels of allergen-specific immunoglobulin E compared with wild-type (Wt) controls. However, when challenged with repeated aerosolized allergen, sensitized 12/15-LO-/- mice had an impaired development of airway allergic inflammation compared with Wt controls, as indicated by reduced bronchoalveolar lavage fluid leukocytes (eosinophils, lymphocytes, macrophages) and Th2 cytokines (IL-4, IL-5, IL-13), as well as tissue eosinophils. Allergen-induced airway epithelial proliferation was also significantly attenuated in 12/15-LO-/- mice, whereas goblet cell hyperplasia was unaffected. However, 12/15-LO-/- mice had significantly reduced luminal mucus secretions compared with Wt controls. The repeated allergen challenges resulted in a dramatic increase of alpha-smooth muscle actin-positive alveolar cells in the peripheral airways, a phenomenon that was significantly less developed in 12/15-LO-/- mice. In conclusion, our data suggest that 12/15-LO-/- mice, although having a fully developed systemic sensitization, did not establish a fully developed allergic airway inflammation and associated manifestations of central and peripheral airway remodeling. These data suggest that 12/15-LO-derived metabolites play an important pathophysiologic role in allergen-induced inflammation and remodeling. Hence, pharmacologic targeting of the human 15-LO-1 may represent an attractive therapeutic strategy to control inflammation and remodeling in asthma.
Department of Lung Medicine, Lund University Hospital, Lund, Sweden.
Cecilia K
CK
Andersson
Hans-Erik
HE
Claesson
Kristina
K
Rydell-Törmänen
Stellan
S
Swedmark
Anneli
A
Hällgren
Jonas S
JS
Erjefält
D000485:Allergens / Q000276:immunology; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D017209:Apoptosis; D001092:Arachidonate 12-Lipoxygenase / Q000172:deficiency* / Q000378:metabolism; D001093:Arachidonate 15-Lipoxygenase / Q000172:deficiency* / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D002452:Cell Count; D016207:Cytokines / Q000378:metabolism; D004802:Eosinophilia / Q000201:enzymology / Q000276:immunology; D020397:Goblet Cells / Q000201:enzymology / Q000473:pathology; D006965:Hyperplasia; D006967:Hypersensitivity / Q000201:enzymology* / Q000276:immunology / Q000473:pathology*; D007114:Immunization; D007249:Inflammation; D007962:Leukocytes / Q000473:pathology; D008168:Lung / Q000201:enzymology* / Q000276:immunology / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology
C475064:12-15-lipoxygenase; D000485:Allergens; D000906:Antibodies; D016207:Cytokines; D010047:Ovalbumin; D001092:Arachidonate 12-Lipoxygenase; D001093:Arachidonate 15-Lipoxygenase; D053148:Caspase 3