Supplementary Material for: TCN1 expression is increased in asthma

Introduction: Asthma is a chronic disease that affects populations worldwide. The purpose of this study was to investigate the expression of TCN1 in sputum and its correlation with inflammation and lung function in asthma. Methods: We recruited 141 subjects, detected TCN1 mRNA level by qRT-PCR, detected TCN1 protein expression by western-blot, detected TCN1 protein level by ELISA, and analyzed the correlation between TCN1 and FeNO, IgE, EOS%, lung functions and some Th2 cytokines. The diagnostic value of TCN1 was evaluated by ROC curve. The expression of TCN1 was further confirmed by human bronchial epithelial cell in vitro. Results: Compared with the health group, the expression of TCN1 in induced sputum cells increased in asthma group and was correlated with FeNO, IgE and EOS%. TCN1 level was also elevated in the induced sputum supernatant of asthma patients. The protein level of TCN1 in induced sputum supernatant was correlated with FeNO, IgE and PC-20, FEV1%pred, FEV1/FVC and some cytokines (IL-4, IL-5, IL-10, IL-13, MUC5AC). TCN1 was also differentially expressed in patients with different severity of asthma. Four weeks after ICS treatment, the expression of TCN1 in induced sputum supernatant increased. In vitro, the protein level of TCN1 in human bronchial epithelial cells’ supernatant increased after stimulated with IL-4 and IL-13. Conclusion: The expression of TCN1 was increased in asthma patients' sputum, and was positively correlated with some inflammatory markers, negatively correlated with lung function. TCN1 may be used as a potential biomarker for the diagnosis and treatment of asthma.

引言：哮喘是一种影响全球人群的慢性疾病。本研究旨在探究转钴胺素1（TCN1）在痰液中的表达水平，及其与哮喘患者炎症反应和肺功能的相关性。方法：本研究共纳入141名受试者，采用实时荧光定量逆转录聚合酶链反应（qRT-PCR）检测TCN1的mRNA表达水平，采用蛋白质印迹法（western-blot）检测TCN1的蛋白表达水平，采用酶联免疫吸附试验（ELISA）检测TCN1的蛋白含量，并分析TCN1与呼出气一氧化氮（FeNO）、免疫球蛋白E（IgE）、嗜酸性粒细胞百分比（EOS%）、肺功能指标及部分Th2型细胞因子的相关性。通过受试者工作特征曲线（ROC曲线）评估TCN1的诊断价值。此外，通过体外人支气管上皮细胞模型进一步验证TCN1的表达情况。结果：与健康对照组相比，哮喘患者诱导痰细胞中TCN1的表达水平显著升高，且与FeNO、IgE及EOS%呈显著相关性。哮喘患者诱导痰上清液中TCN1的蛋白水平同样升高。诱导痰上清液中的TCN1蛋白水平与FeNO、IgE、PC-20、第一秒用力呼气容积占预计值百分比（FEV1%pred）、FEV1/FVC及部分细胞因子（IL-4、IL-5、IL-10、IL-13、黏蛋白5AC（MUC5AC））均存在显著相关性。不同哮喘严重程度的患者中，TCN1的表达存在显著差异。经吸入性糖皮质激素（ICS）治疗4周后，哮喘患者诱导痰上清液中TCN1的表达水平进一步升高。体外实验结果显示，经IL-4与IL-13刺激后，人支气管上皮细胞上清液中的TCN1蛋白水平显著升高。结论：哮喘患者痰液中TCN1的表达水平升高，且与部分炎症标志物呈正相关，与肺功能指标呈负相关。TCN1有望成为哮喘诊断与治疗的潜在生物标志物。