Jun-Hao Huang, Hui-Wen Gao, Dong-Dong Gao, Wei-Yue Yang, Meng-Ke Zhao, Bing Shen, Min Hu
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引用次数: 1
Abstract
Purpose: Increased evidence has shown that aerobic exercise reduces airway hyperresponsiveness in asthmatic individuals. However, the underlying mechanisms of action remain elusive. This study aimed to investigate the effect of exercise on airway smooth muscle (ASM) contractile function in asthmatic rats, and uncover the possible involvement of interleukin 4 (IL-4) and the store-operated Ca2+ entry (SOCE) pathway.
Methods: In this study, chicken ovalbumin was used to induce asthma in male Sprague-Dawley rats. The exercise group received moderate-intensity aerobic exercise training for 4 weeks. IL-4 concentrations in bronchoalveolar lavage fluid (BALF) samples were evaluated by enzyme linked immunosorbent assay. The contractile function of the ASM was investigated using tracheal ring tension experiments and intracellular Ca2+ imaging techniques. Western blot analysis was used to evaluate expression levels of calcium-release activated calcium (CRAC) channel protein (Orai) and stromal interaction molecule 1 (STIM1) in ASM.
Results: Our data showed that the carbachol-stimulated, SOCE-mediated contraction of rat ASM was significantly increased in asthmatic rats, which could be abolished by exercise. Pharmacological studies revealed that GSK5498A and BTP-2, selective blockers of CRAC channels significantly inhibited SOCE-induced ASM contraction. In addition, exercise inhibited the up-regulation of IL-4 in BALF as well as STIM1 and Orai expression in the ASM of asthmatic rats. In line with these observations, we demonstrated that pretreatment of the ASM with IL-4 up-regulated the expression level of STIM1, Orai1 and Orai2, thereby promoting SOCE-mediated ASM contraction.
Conclusions: The data in this study reveal that aerobic exercise may improve the ASM contractile function in asthmatic rats by inhibiting IL-4 secretion and by down-regulating the expression of STIM1, Orai1 and Orai2, thus decreasing excessive SOCE-mediated ASM contraction in asthmatic rats.
期刊介绍:
The journal features cutting-edge original research, brief communications, and state-of-the-art reviews in the specialties of allergy, asthma, and immunology, including clinical and experimental studies and instructive case reports. Contemporary reviews summarize information on topics for researchers and physicians in the fields of allergy and immunology. As of January 2017, AAIR do not accept case reports. However, if it is a clinically important case, authors can submit it in the form of letter to the Editor. Editorials and letters to the Editor explore controversial issues and encourage further discussion among physicians dealing with allergy, immunology, pediatric respirology, and related medical fields. AAIR also features topics in practice and management and recent advances in equipment and techniques for clinicians concerned with clinical manifestations of allergies and pediatric respiratory diseases.