摘要
目的探讨支气管哮喘(简称哮喘)转录因子T-bet/GATA-3表达量比值的变化及其与气道炎症的关系。方法24只雄性SD大鼠按随机数字表法分为对照组、哮喘组,每组12只。用动物肺功能仪测定大鼠气道反应性;用苏木精-伊红染色观察气道病理改变;用酶联免疫吸附测定(ELISA)法检测大鼠支气管肺泡灌洗液(BALF)中白细胞介素4(IL-4)、IL-5、γ干扰素(IFN-γ)含量;用逆转录-聚合酶链反应(RT-PCR)测定法检测肺组织中IL-4、IL-5、IFNγ-、T-bet和GATA-3 mRNA的表达水平;用免疫印迹(W estern b lot)法检测肺组织T-bet和GATA-3蛋白的表达水平。结果用同等剂量氯化乙酰胆碱(20、40、80、160μg/m l)激发时平均呼气阻力哮喘组分别为(6.26±0.85)、(11.55±3.09)、(28.74±5.94)、(3 710.83±197.49)cm H2O.m l-1.s-1,对照组分别为(1.51±0.18)、(2.15±0.36)、(6.08±1.06)、(37.17±6.12)cm H2O.m l-1.s-1,两组不同激素剂量比较差异有统计学意义(P均<0.01);肺组织中嗜酸粒细胞(EOS)、淋巴细胞数,管壁面积/支气管管腔内周长(WA/P i)和支气管平滑肌面积/支气管管腔内周长(ASM/P i)哮喘组分别为(26.0±1.6)个/mm2、(45.2±3.2)个/mm2、12.0±1.4、6.7±0.6,对照组分别为(2.9±1.2)个/mm2、(8.8±1.8)个/mm2、6.4±0.8、2.7±0.5,两组比较差异有统计学意义(P均<0.01);BALF中IL-4、IL-5和IFN-γ含量哮喘组为(23.4±0.7)pg/m l、(24.8±0.5)pg/m l和(21.7±1.1)pg/m l,对照组为(9.3±0.3)pg/m l、(12.5±0.3)pg/m l、(65.8±2.1)pg/m l,两组比较差异有统计学意义(P均<0.01);肺组织中IL-4、IL-5和IFN-γmRNA表达水平哮喘组分别为2.260±0.210、0.510±0.100、0.100±0.020,对照组分别为0.060±0.020、0.160±0.020、0.850±0.260,两组比较差异有统计学意义(P均<0.01)。肺组织中T-bet/GATA-3 mRNA表达量比值对照组为0.73±0.32,哮喘组为0.06±0.09,两组比较差异有统计学意义(P<0.01);肺组织中T-bet/GATA-3蛋白表达量比值哮喘组为0.09±0.04,对照组为0.75±0.25,两组比较差异有统计学意义(P<0.01)。两组大鼠T-bet/GATA-3蛋白表达量比值与20、40、80μg/m l氯化乙酰胆碱激发时的呼气阻力呈负相关(r分别=-0.959、-0.919、-0.943,P均<0.01);与EOS数、淋巴细胞数呈负相关(r=-0.832、-0.831,P均<0.01);与WA/P i、ASM/P i呈负相关(r=-0.837、-0.863,P均<0.01);与BALF中IL-4和IL-5含量呈负相关(r=-0.921、-0.920,P均<0.01);与IFN-γ含量呈正相关(r=0.934,P<0.01);与肺组织中IL-4、IL-5mRNA表达水平呈负相关(r=-0.964、-0.931,P均<0.01);与IFN-γmRNA表达呈正相关(r=0.983,P<0.01)。结论转录因子T-bet/GATA-3失衡表达与气道炎症密切相关,能客观反应哮喘免疫失衡,很可能是哮喘气道炎症形成的重要原因之一。
Objective To identify the change of the mRNA and protein expression of T-bet and GATA-3 in lung tissues, and to investigate the association between the imbalanced T cell-specific transcription factors Tobet/GATA-3 and the airway inflammation in asthmatic rats. Methods Twenty-four male SD rats were randomly divided into a control group and an asthmatic group. Airway responsiveness was measured and the change of airway histology was observed. The concentrations of interleukin-4 （IL-4）, IL-5 ,and interferon-γ （IFN-γ） in bronchoalveolar lavage fluid （BALF） were measured by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expressions of IL-4, IL-5, IFN-γ, T-bet and GATA-3 in the lungs were detected by reverse transcription-polymerase chain reaction （RT-PCR） and Western blot respectively. Results The expiration resistance after injection of acetylcholine chloride （20, 40, 80, 160 μg/ml） in the asthmatic group was （6.26 ±0.85）, （11.55 ±3.09）, （28.74 ±5.94）, （3 710. 83 ± 197.49）cm H2O·ml^-1· s^-1 respectively; and that in the control group was （ 1.51 ±0. 18）, （2. 15 ±0. 36）, （6.08 ± 1.06）, （37. 17 ±6. 12）cm H2O·ml^-1 · s^-1 respectively; the difference being significant between the two groups （all P 〈0.01 ）. In the asthmatic group, the numbers of eosinophils and lymphocytes, the thicknesses of WA/Pi and ASM/Pi were （ 26.0 ± 1.6 ）/mm^2, （ 45.2 ± 3. 2 ）/mm^2, 12.0±1.4, 6.7 ±0.6, respectively; and those of the control group were （2.9 ± 1.2）/mm^2, （8.8 ± 1.8）/mm^2 ,6.4 ±0. 8,2. 7 ±0. 5, respectively; all were significantly different between the two groups （ all P 〈0. 01）. In the asthmatic group, the concentrations of IL-4, IL-5, and IFN-γ in BALF were （23.4 ±0. 7） pg/ml, （24. 8 ± 0. 5 ） pg/ml, （21.7 ± 1.1 ） pg/ml, respectively, and those of the control group were （9. 3 ± 0. 3） pg/ml, （ 12. 5 ± 0. 3 ） pg/ml, （65. 8 ± 2. 1 ） pg/ml, respectively; all were significantly different between the two groups （ all P 〈0.01 ）. In the control group, the mRNA ratio of T-bet to GATA-3 （0. 73 ± 0. 32） was significantly increased compared with the asthmatic group（0. 06 ±0. 09, P 〈0. 01 ）. There was also a significant difference in the ratio of protein expression of T-bet to GATA-3 between the control group （0. 75 ±0. 25） and the asthmatic group （0.09 ±0.04, P 〈0. 01 ）. The ratio of protein expression of T-bet and GATA-3 was correlated negatively with expiration resistance （ r = - 0. 959, - 0. 919, - 0. 949, all P 〈0.01 ）, the numbers of eosinophils and lymphocytes in lung tissues （r = -0. 832, -0. 831, all P 〈 0.01）, the thicknesses of WA/Pi and ASM/Pi （r = -0. 837, -0. 863, all P 〈0.01） and the concentrations of IL-4,IL-5 in BALF （ r = 0.921, 0. 920, all P 〈 0.01 ） , the mRNA of IL-4, IL-5 in lung tissues （r = -0. 964, -0.931, all P 〈0. 01 ）, but positively with the concentrations of IFN-γ in BALF and the mRNA of IFN-γ in lung tissues （ r = - 0. 934, 0. 983, all P 〈 0.01 ）. Condusion Imbalance of transcription factors T-bet and GATA-3, a reflection of the immune imbalance in asthma, may play a key role in the formation of airway inflammation in the disease.
出处
《中华结核和呼吸杂志》
CAS
CSCD
北大核心
2006年第3期176-180,共5页
Chinese Journal of Tuberculosis and Respiratory Diseases
