Obesity and airway responsiveness: Role of TNFR2 - 09/06/13
Abstract |
Obese mice exhibit innate airway hyperresponsiveness (AHR), a feature of asthma. Tumor necrosis factor alpha (TNFα) is implicated in the disease progression and chronic inflammatory status of both obesity and asthma. TNF acts via two TNF receptors, TNFR1 and TNFR2. To examine the role of TNFR2 in the AHR observed in obese mice, we generated obese Cpefat mice that were either sufficient or deficient in TNFR2 (Cpefat and Cpefat/TNFR2−/− mice, respectively) and compared them with their lean controls (WT and TNFR2−/− mice). Compared to WT mice, Cpefat mice exhibited AHR to aerosolized methacholine (measured using the forced oscillation technique) which was ablated in Cpefat/TNFR2−/− mice. Bioplex or ELISA assay indicated significant increases in serum leptin, G-CSF, IL-7, IL-17A, TNFα, and KC in obese versus lean mice, as well as significant obesity-related increases in bronchoalveolar lavage fluid (BALF) G-CSF and IP-10, regardless of TNFR2 status. Importantly, BALF IL-17A was significantly increased over lean controls in Cpefat but not Cpefat/TNFR2−/− mice. Functional annotation clustering of significantly affected genes identified from microarray analysis comparing gene expression in lungs of Cpefat and WT mice, identified blood vessel morphogenesis as the gene ontology category most affected by obesity. This category included several genes associated with AHR, including endothelin and trkB. Obesity increased pulmonary mRNA expression of endothelin and trkB in TNFR2 sufficient but not deficient mice. Our results indicate that TNFR2 signaling is required for the innate AHR that develops in obese mice, and suggest that TNFR2 may act by promoting IL-17A, endothelin, and/or trkB expression.
Le texte complet de cet article est disponible en PDF.Keywords : Bronchoalveolar lavage, Airway responsiveness, TNFα, Inflammation, Endothelin, trkB, IL-17A
Plan
Vol 26 - N° 4
P. 444-454 - août 2013 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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