佐剂性关节炎大鼠肺功能变化与Foxp3、TGF-β1/Smads信号传导通路的相关性研究

Studies on the relationship between pulmonary function changes with Foxp3,TGF-β1/Smads signal transduction pathway in adjuvant arthritis rats

目的:观察佐剂性关节炎(Adjuvant arthritis,AA)大鼠肺系数、肺功能变化、调节性T细胞及Foxp3、TGF-β1、Smad3、Smad7蛋白表达,探讨Foxp3与TGF-β/Smads信号传导通路在佐剂性关节炎大鼠肺功能降低中的可能作用机制。方法:将24只Wistar大鼠随机分为正常对照组和模型组,每组12只,向模型组大鼠右后足跖皮内注射弗氏完全佐剂0.1 ml致炎,复制成佐剂性关节炎模型。致炎48天后,观察两组大鼠足跖肿胀度及关节炎指数(AI),计算两组大鼠肺系数,检测大鼠肺功能,测定调节性T细胞百分率,HE染色观察肺病理学改变,免疫组化染色观察Foxp3、TGF-β1、Smad3、Smad7蛋白表达情况。结果:①与正常对照组相比,AA模型组大鼠足跖肿胀度、AI、肺系数、1秒内平均呼气流量(FEV1/FVC)、肺泡炎积分、TGF-β1及Smad3蛋白表达明显升高(P<0.01);用力肺活量(FVC)、25%肺活量的最大呼气流量(FEF25)、50%肺活量的最大呼气流量(FEF50)、75%肺活量的最大呼气流量(FEF75)、最大呼气中期流量(MMF)、用力最大呼气流量(PEF)、肺动态顺应性(Cldyn)、CD4+T细胞、CD25+T细胞、CD4+CD25+T细胞百分率、Foxp3蛋白及Smad7蛋白表达显著降低(P<0.01)。②Spearman相关分析可知,AA大鼠肺功能参数中FEF50、MMF与足跖肿胀度呈负相关,MMF与肺系数呈负相关,Cldyn与TGF-β1蛋白积分光密度值呈负相关;FEF50、MMF与关节炎指数呈正相关,FEF75与肺系数呈正相关,FEV1/FVC与Foxp3蛋白表达染色指数、Foxp3蛋白积分光密度值呈正相关(P<0.05或P<0.01)。结论:AA大鼠在足跖肿胀度、关节炎指数升高的同时出现肺功能的下降,提示可能是致炎后炎症的持续、发展而出现慢性炎症反应导致肺的损伤(肺间质纤维化),而肺功能的下降与Foxp3、Smad3、Smad7、TGF-β1蛋白表达呈相关性,说明转录因子Foxp3和TGF-β1/Smads信号传导通路共同参与其作用机制。

Objective： To observe the changes of lung index, hmg function, regulatory T cells and Foxp3, TGF-β1, Smad3, Smad7 protein expression in adjuvant arthritis（AA） rats, and to investigate the possible mechanism of Foxp3 and TGF-β/Smacls signal transduction pathway in reducing hmg function. Methods： 24 Wistar rats were randomly divided into normal control group and model group, 12 rats in each group.The rats were injected with 0. 1 ml Freunds＇ complete adjuvant to induce inflammation at the part of their rightback foot in model group. On the 48th day post-inflammatory, the swelling degree of toe and arthritis index（M） were observed. Lung index of the rats was calculated, and pulmonary function of the rats was detected. The percentage of regulatory T cells was determined, and pathological changes of the lungs was observed by HE staining. Foxp3 ,TGF-β1, Smad3, Smad7 protein expression in the lungs of the two groups of rats was examined by immunohistochemistry. Results： ①Compared with those of the normal, the swelling degree of toes, AI, and the lung index were increased. The average peak expiratory flow in 1 second （FEV1/FVC）, alveolitis points, TGF-β1 and Smad3 protein expression was significantly higher in the A_A model group rats（ P 〈 0.01 ）. Forced vital capacity （FVC）,25% of vital capacity of the peak expiratory flow （FEF25）, 50% of vital capacity of the peak expiratory flow （FEF50）, 75 % of vital capacity of the peak expiratory flow （FEF75）, maximum mid-expiratory flow （MMF）, forced maximal expiratory flow （PEF）, pulmonary dynamic comphance （Cldyn）, the percentage of CD4^＋ T cell, CD25^＋ T cell, CD4^＋ CD25^＋ T cell, Foxp3 and Smad7 protein expression was obviously lower in the AA model group rats（ P 〈 0. 01）. ②FEF50, Cldyn and MMF were negative cor-related with the swelling degree of toes, pulmonary coefficient and TGF-β1. FEF50, FEF75, MMF and FEV1/FVC were positiyely correlated with the arthritis index, pulmonary coefficient and Foxp3（ P 〈 0. 05 or P 〈 0. 01 ）. Conclusion： The decline in lung function in AA rats. Tip-induced may be sustained after the inflammation, and the development of cause inflammation, to chronic inflammatory response leading to lung injury. Simultaneously, the decline in lung function and Foxp3. Smad3, Smad7, TGF-β1 protein expression was associated. Description transcription factor Foxp3 and TGF-β1/Smads signal transducation pathway may participate in the mechanism.