Abstract
Aerobic exercise reduces asthma phenotype by inhibiting purinergic signaling and lymphatic organs hyperactivation
Asthma is a chronic inflammatory airway disease, in which purinergic signaling has a central role, controlling activation of structural and hematopoietic cells. Aerobic exercise (AE) present anti-inflammatory effects to the airways, but no cellular and molecular mechanisms are known. Thus, this project evaluated the effects of AE on purinergic signaling response in a model of asthma induced by house dust mite (HDM). AE was performed in a treadmill at moderate intensity, 5x/week, during 4 weeks, after 3 weeks of prior HDM administration. HDM (dermatophagoides pteronyssinus; 100mg/mouse) was administered 3x/week, during 7 weeks. The results demonstrated that AE reduced ATP accumulation (p<0.001), IL-1beta, IL-4, IL-5, CXCL1/KC, IL-13, IL-17, IL-23, IL-33 and TNF-alpha (p<0.001), while increased IL-1ra, IL-2 and IL-10 in bronchoalveolar lavage (BAL). Total number of leukocytes, eosinophils, lymphocytes and neutrophils in BAL and the number of eosinophils, neutrophils and lymphocytes in the airway wall (p<0.01) were reduced by AE. Airway collagen, elastin, smooth muscle and mucus were reduced by AE (p<0.01). TGF-beta, IGF-1 and VEGF levels was reduced by AE (p<0.001). Lung mechanics (Resistance, Elastance, GTIS, HTIS, RAW) and airway hyperresponsiveness (AHR) to methacholine was ameliorated by AE (p<0.01). IL-4, IL-5 and IL-13 production by lymph nodes, splenocytes and bone marrow cells was also reduced by AE. The expression of P2X7, P2Y2 and P2Y6 by peribronchial leukocytes (p<0.01) and by airway epithelial cells (p<0.01) were reduced by AE. AE reduces asthma phenotype by inhibiting purinergic signaling exacerbation in a model of HDM-induce asthma.