PU.1和IL-9在肺纤维化大鼠周围免疫器官内的表达及其作用研究

Expression and function of PU.1 and IL-9 in peripheral immune organs of rats with pulmonary fibrosis

目的探讨肺纤维化大鼠周围淋巴器官内PU.1和IL-9的表达以及1,25-(OH)_2D_3对其表达的影响。方法 150只雄性SD大鼠随机分为2个大组:预防组(对照组Ⅰ、模型组Ⅰ、给药组Ⅰ,n=30)和治疗组(对照组Ⅱ、模型组Ⅱ、给药组Ⅱ,n=20)。大鼠气管内注射博来霉素建立肺纤维化模型,给药组腹腔注射1,25-(OH)_2D_3进行预防和治疗。用Real-time PCR和免疫组化方法研究了肺纤维化大鼠淋巴结节和脾脏内PU.1和IL-9的表达状况。结果在建模14、21、28 d 3个时间点,模型组Ⅰ/Ⅱ的淋巴结和脾脏内IL-9蛋白质表达都明显高于对照组Ⅰ/Ⅱ中的表达(P<0.05)。建模21 d时,模型组Ⅰ的脾内PU.1蛋白质表达明显高于对照组Ⅰ(P<0.05);建模28 d时,模型组Ⅰ/Ⅱ的淋巴结和脾脏内PU.1 mRNA和蛋白质表达都明显高于对照组Ⅰ/Ⅱ(P<0.05)。而给药组Ⅰ/Ⅱ的淋巴结和脾脏内IL-9和PU.1的表达与模型组Ⅰ/Ⅱ相比,在各时间点都没有统计学差异(P>0.05)。结论在肺纤维化大鼠的外周淋巴器官中,IL-9较早出现高表达(14 d),并一直维持,而PU.1在较晚时期出现高表达(21 d),提示这2种细胞因子在大鼠肺纤维化发生发展中可能都具有一定的作用。1,25-(OH)_2D_3对肺纤维化大鼠外周淋巴器官中的IL-9和PU.1表达没有明显的影响,说明其治疗作用可能与IL-9和PU.1无关。

[Abstract] This study was performed to explore the expression of PU.1 and IL-9 in peripheral immune organs of pulmonary fibrotic rats, and explore the effect of 1,25-（OH）2D3 on these expression. Total of 150 male SD rats were randomly divided into prevention group （model group Ⅰ, medication group Ⅰ, control groupⅠ, n=30） and treatment group （model group IT, medication group Ⅱ, control group Ⅱ, n=20）. Bleomycin （BLM） （5 mg/kg） was injected into the trachea of rats to establish the model of pulmonary fibrosis. Then 1,25-（OH）2D3 （2 μg/kg） was used to prevent and remedy pulmonary fibrosis via intraperitoneal injection. The mRNA levels of PU.1 in lymphonodi and spleens of SD rats with pulmonary fibrosis were tested by real-time PCR. The protein expression of PU.1 and IL-9 were detected by immunohistochemical technology, and the results were quantified by image analysis. Data showed that the expression level of IL-9 protein in model groups Ⅰ/Ⅱ were increased significantly compared with control groups Ⅰ/Ⅱ at days 14, 21, and 28 post model establishment （P〈0.05）. The PU.1 protein expression in spleen of model group Ⅰ was obviously higher than that of control group Ⅰ at day 21 （P〈0.05）. What is more, the expression levels of PU.1 mRNA and protein in lymphonodi and spleen of model groups Ⅰ/Ⅱ were significantly higher than those of control groups Ⅰ/Ⅱ at day 28 （P〈0.05）. However, there were no apparent difference about expression levels of PU.1 and IL-9 between model groups I/II and treatment group Ⅰ/Ⅱ at all three time points （P〉 0.05）. The overexpression of IL-9 appeared earlier （day 14） and kept up all the way during pulmonary fibrosis in the peripheral immune organs of pulmonary fibrotic rats, while the PU.1 overexpression emerged later （day 21 and/ or day 28）, suggesting that the two cytokines play a certain role in the pathogenesis and development of pulmonary fibrosis. No obvious effects of 1,25-（OH）2D3 were observed on the expression of PU.1 and IL-9 in the peripheral immune organs of rats with pulmonary fibrosis, implying that the therapic function of 1,25-（OH）2D3 has no association with PU. 1 and IL-9 in pulmonary fibrosis probably.