维生素D_3上调蛋白1在哮喘嗜酸粒细胞中的表达及其与细胞活化的关系

Expression of VDUP1 in peripheral eosinophil of asthmatic patients and its relation with eosinophil activation

目的:探讨维生素D3上调蛋白1(VDUP1)在哮喘患者外周血嗜酸粒细胞(EOS)中的表达及与EOS活化的关系。方法:实验分为对照组、哮喘发作组和缓解组。抽取外周静脉血15mL,计算诱导痰EOS%,测定第1秒最大呼气量占预计值百分比(FEV1.0%)和最大呼气中期流速占预计值百分比(PEF%);ELISA法检测血清嗜酸粒细胞阳离子蛋白(ECP)浓度。RT-PCR及Western blotting方法检测外周血EOSVDUP1表达情况。IL-5与EOS共孵育,检测EOSVDUP1表达情况,ELISA法检测培养上清液ECP浓度。结果:哮喘发作组外周血EOSVDUP1表达均显著低于正常组及缓解组,与诱导痰EOS%及血清ECP浓度呈明显负相关;缓解组基因表达与正常对照组无显著差异,与上述指标也无明显相关。IL-5刺激下,EOSVDUP1表达明显降低,同时伴上清ECP明显升高。结论:哮喘发作时外周血EOSVDUP1表达明显下调,EOSVDUP1表达与血清ECP及诱导痰EOS%呈明显负相关,IL-5促进EOS活化可能与VDUP1通路有关。

AIM： To investigate the expression of vitamin D3 up - regulated protein 1 （ VDUP1 ） in peripheral eosinophils of asthma patients and its relation with eosinophil activation. METHODS： 10 normal volunteers and 31 mild to moderate asthma patients were selected. Symptom severity, pulmonary function index, induced sputum eosinophil counts were recorded. Then, gene and protein expressions of VDUP1 and β - actin were evaluated by RT - PCR and Western blot-ring, respectively. In addition, eosinophils were incubated with IL - 5, both VDUP1 and β - actin were amplified by RT - PCR. The eosinophil cationic protein （ECP） of supernatant and serum were also detected by ELISA assay. RESULTS： There was a significant decrease in expression of VDUP1 in asthma attack patients without treatment compared with normal volunteers and patients in remission. In contrast, no significant difference between the patients in remission and normal volunteers was observed. In patients with asthma attacks, a negative relationship between expression intensity of VDUP1 and EOS% in induced sputum and serum ECP concentration was also observed. The expression of VDUP1 in eosinophils was decreased by IL -5 stimulation, simultaneously, the ECP in supernatant was increased. CONCLUSION： The expression of VDUP1 in eosinophils decreases in asthma patients, and is negatively associated with serum ECP and induced sputum EOS%. EOS activation by IL- 5 may be related to VDUP1 pathway.