Department of Respiratory Medicine, Affiliated Hospital of Nantong University, Nantong 226001, China.
J Thorac Dis. 2013 Dec;5(6):797-805. doi: 10.3978/j.issn.2072-1439.2013.12.42.
Asthma is a chronic inflammatory disease characterized by airway inflammation with mucus hypersecretion and hyperresponsiveness to various nonspecific stimuli. Corticosteroids are usually used to prevent β2 adrenoceptor (β2AR) desensitization in clinical and experimental practice. But the exact mechanism of corticosteroid effectiveness on β2AR desensitization is unclear.
To find the potential mechanisms related to the protective effects of corticosteroid on salbutamol induced β2AR desensitization by a proteomics approach.
Thirty-two BALB/c (6-8 weeks old) mice were divided into four groups: group A, control group, phosphate buffered saline (PBS)-treated group; group B, asthmatic group, treated by ovalbumin (OVA); group C, β2AR desensitized asthmatic group, treated by OVA and salbutamol (SBT) and group D, corticosteroid-treated β2AR desensitized asthmatic group, treated with OVA, SBT and Dexamethasone (DEX). After administrated with those drugs, their serum total IgE, bronchoalveolar lavage fluid (BALF) cytokine concentration, airway resistance and membrane receptor number of β2AR were evaluated. After then, the mice of group C and D were sacrificed, their protein from lung tissue were extracted and then seperated by two-dimensional gel electrophoresis (2DE). Then, the isolated protein spots were analyzed by ImageMaster software and mass spectrometry. Bioinformatic tools were used to search these protein spots and find interesting protein spots associated with corticosteroid protective effect on β2AR desensitization. Finally, these protein spots were confirmed by Western blotting.
With inflammatory cell count, cytokine concentration of BALF, pathological sections, total serum IgE, airway resistance, membrane receptor number and β2AR total amount changes, asthmatic mouse model and β2AR desensitization asthmatic mouse model were successfully established. Seventeen protein spots were found different expression between group C and group D, 4 protein spots were down-regulated and 13 protein spots were up-regulated compared to group C. Proteasome subunit beta type 3 was down-regulated.
Increased proteasome subunit beta type 3 expression may be responsible for salbutamol-induced β2AR desensitization in asthmatic disease, and DEX possibly render the β2AR resensitization partially by decreasing the content of proteasome.
哮喘是一种慢性炎症性疾病，其特征是气道炎症伴有黏液过度分泌和对各种非特异性刺激的高反应性。在临床和实验实践中，通常使用皮质类固醇来预防β2 肾上腺素能受体（β2AR）脱敏。但是，皮质类固醇对β2AR 脱敏的有效性的确切机制尚不清楚。
通过蛋白质组学方法寻找与皮质类固醇对沙丁胺醇诱导的β2AR 脱敏的保护作用相关的潜在机制。
将 32 只 BALB/c（6-8 周龄）小鼠分为四组：A 组，对照组，磷酸盐缓冲盐水（PBS）处理组；B 组，哮喘组，卵清蛋白（OVA）处理组；C 组，β2AR 脱敏哮喘组，OVA 和沙丁胺醇（SBT）处理组；D 组，皮质类固醇治疗的β2AR 脱敏哮喘组，用 OVA、SBT 和地塞米松（DEX）处理。给予这些药物后，评估其血清总 IgE、支气管肺泡灌洗液（BALF）细胞因子浓度、气道阻力和β2AR 膜受体数量。然后，处死 C 组和 D 组的小鼠，提取其肺组织蛋白，然后通过二维凝胶电泳（2DE）分离。然后，使用 ImageMaster 软件和质谱分析分离的蛋白斑点。生物信息学工具用于搜索这些蛋白斑点，并找到与皮质类固醇对β2AR 脱敏的保护作用相关的有趣蛋白斑点。最后，通过 Western blot 验证这些蛋白斑点。
通过炎症细胞计数、BALF 细胞因子浓度、病理切片、血清总 IgE、气道阻力、β2AR 总数量的变化，成功建立了哮喘小鼠模型和β2AR 脱敏哮喘小鼠模型。与 C 组相比，C 组和 D 组之间发现了 17 个表达不同的蛋白斑点，其中 4 个蛋白斑点下调，13 个蛋白斑点上调。蛋白酶体亚基β型 3 下调。
蛋白酶体亚基β型 3 表达增加可能是导致哮喘疾病中沙丁胺醇诱导的β2AR 脱敏的原因，而 DEX 可能通过降低蛋白酶体的含量使β2AR 部分重新敏感。
