鼻息肉组织中固生蛋白C的表达与转化生长因子β1的关系

目的探讨细胞外基质(extracellularmatrix,ECM)成分固生蛋白C(tenascinC,TNC)在鼻息肉组织中异常表达的原因。方法采用免疫组化方法检测TNC和转化生长因子β1(transforminggrowthfactor-β1,TGF-β1)在鼻息肉组织中的表达和关系。进一步采用细胞培养、实时定量RTPCR和原位ELISA技术研究TGFβ1及嗜酸粒细胞对人呼吸道上皮细胞系BEAS2B细胞TNC表达的调控作用。结果①TNC和TGF-β1蛋白在鼻息肉组织中的表达显著上调,TNC表达强度与TGFβ1阳性细胞总数(r=-0.58,P<0.01)和TGFβ1阳性的嗜酸粒细胞数显著相关(r=-0.61,P<0.01);②浓度为1ng/ml和10ng/ml的TGFβ1刺激4h后BEAS2B细胞TNCmRNA的表达分别为未刺激状态下的(7.20±3.43,x±s,下同)倍和(22.48±5.35)倍,与未刺激状态下的表达水平相比差异有统计学意义(P值<0.01);与刺激24h后TNC蛋白表达的荧光强度相比差异亦有统计学意义(P<0.05);③BEAS2B细胞和嗜酸粒细胞以2∶1、1∶1和1∶2的数量比例进行共培养,4h后BEAS2B细胞TNCmRNA的表达与未刺激状态下的表达水平相比,差异均有统计学意义(P值均<0.01);24h后TNC蛋白表达的荧光强度与未刺激状态下的荧光强度相比差异亦均有统计学意义(P值均<0.05);嗜酸粒细胞的这种诱导作用可以被抗TGFβ1的中和抗体显著抑制(P<0.05)。结论TGF-β1和嗜酸粒细胞可以诱导呼吸道上皮细胞对TNC的表达,嗜酸粒细胞的作用部分通过TGFβ1介导,鼻息肉组织中TNC表达的增高同嗜酸粒细胞来源的TGF-β1有关。

Relationship between the expression of tenascin C and TGF-β1 in human nasal polyp tissues

OBJECTIVE: To explore the mechanism underlying the increased expression of tenascin C (TNC) in human nasal polyp tissues. METHODS: The method of immunohistochemistry was used to detect the protein expression of TNC and transforming growth factor-beta1 (TGF-beta1) and their relationship in nasal polyp tissues. The cell culture, real-time RT-PCR and in situ ELISA techniques were employed to investigate the effect of TGF-beta1 and eosinophils on the TNC mRNA and protein expression in BEAS-2B immortalized human bronchial epithelial cells. RESULTS: (1) TNC and TGF-beta1 protein expression were up-regulated in nasal polyp tissues. TNC expression level was associated with the number of TGF-beta1 positive cells (r = -0.58, P < 0.01) and TGF-beta1 positive eosinophils (r = -0.61, P < 0.01); (2) 1 ng/ml and 10 ng/ml TGF-beta1 induced TNC mRNA expression by 7.20 +/- 3.43-fold and 22.48 +/- 5.35-fold (P < 0.01) in BEAS-2B cells after 4 h stimulation respectively. The fluorescence intensity of TNC protein expression was 129. 50 +/- 47.42 and 151.20 +/- 48.36 after 24 h stimulation respectively. The protein expression was significantly increased compared with that without stimulation (60.60 +/- 38.53, P < 0.05); (3) Coculture BEAS-2B cells and eosinophils at 2:1, 1:1 and 1:2 ratio, TNC mRNA expression was induced by 4.90 +/- 1.40-fold, 5.48 +/- 1.60-fold and 4.78 +/- 1.32-fold (P < 0.01) in BEAS-2B cells after 4 h coculture respectively. The fluorescence intensity of TNC protein expression was 128.75 +/- 44.15, 142.33 +/- 29.06 and 131.33 +/- 20.87 after 24 h coculture respectively. The protein expression was significantly increased compared with that without eosinophils coculture (59.40 +/- 10.14, P < 0.05). Treatment with neutralizing antibody to TGF-beta1 significantly inhibited eosinophil-induced BEAS-2B cells TNC expression in a dose-dependent manner (P < 0.05). CONCLUSION: TGF-beta1 and eosinophlis can induce TNC expression in airway epithelial cells. The effect of eosinophils is partially mediated through TGF-beta1. Up-regulated expression of TNC in nasal polyp tissues is related to eosinophil-derived TGF-beta1.