牛磺酸对染矽尘大鼠肺泡巨噬细胞TNF-α表达的影响及其凋亡抑制作用

Effect of taurine on TNF-αexpression in alveolar macrophages of silicosis rats and its inhibitory effect on apoptosis

目的:探讨牛磺酸对染矽尘大鼠肺泡巨噬细胞(AM)肿瘤坏死因子α(TNF-α)的表达和对细胞凋亡的影响及其作用机制,为尘肺的临床治疗提供依据。方法:24只大鼠随机分为对照组、模型组和牛磺酸组,每组8只。收集各组大鼠肺泡灌洗液(BALF),分离AM。应用ELISA检测灌洗液中TNF-α水平;采用TUNEL法检测各组大鼠AM凋亡情况;采用琼脂糖凝胶电泳检测DNA断裂情况。结果:对照组、模型组和牛磺酸组大鼠肺泡灌洗液中TNF-α水平分别为(215.8±11.7)、(528.2±23.3)和(364.3±21.4)ng·L-1,与模型组比较,牛磺酸组矽尘大鼠肺BALF中TNF-α水平明显降低(P<0.05)。牛磺酸组AM凋亡指数为(9.38±1.64)%,显著高于对照组[(5.01±1.17)%](P<0.01);牛磺酸组与模型组AM凋亡指数[(14.03±0.74)%]比较显著降低(P<0.05)。模型组大鼠AM呈现细胞凋亡的特征性DNA梯状带,对照组和牛磺酸组AM未见特征性DNA梯状带。结论:牛磺酸通过下调TNF-α的表达,抑制二氧化硅引起的大鼠AM的凋亡。

Objective To explore the effects of taurine on the expression of tumor necrosis factor-α （TNF-α） and apoptosis of alveolar macrophages （AM） in silieosis rats and its aetion mechanism, and to provide basis for treatment of silicosis. Methods 24 rats were randomly divided into control group, model group and taurine group, and there were 8 rats in each group. The AM of the rats were collected from bronehoalveolar lavage fluid （BALF）. The levels of TNF-α in BALF in different groups were measured by ELISA method, the apotosis of the AM of the rats was measured by TUNEL method, and agarose gel eleetrophoresis was used to evaluate the alteration of DNA fragment. Results The levels of TNF-α of rats in control group, model group and taurine group were （215.8± 11.7）, （528.2±23.3）, and （364.3±21.4） ng·L-1, respectively. Compared with model group, the TNF-α expression level in BALF of silicosis rats in taurine group was decreased （P〈0. 05）. The apoptotic index in taurine group （9.38%±1.64%） was significantly higher than that in control group （5.01%± 1.17%） （P〈0.01） and lower than that in model group （14.03%±0.74 %） （P〈0.05）. The characteristic DNA ladder appeared in model group, which was not found in control group and taurine group. Conclusion Taurine can effectively inhibit AM apoptosis induced by SiO2 through down-regulating the expression of TNF-α.