地塞米松及N-乙酰半胱氨酸抑制A549细胞IL-8及ICAM-1表达的机制研究

发布时间：2018-12-12 10:33

【摘要】：目的:研究地塞米松(DXM)及N-乙酰半胱氨酸(NAC)抑制人肺泡上皮细胞(A549)炎症因子白介素-8(IL-8)、细胞间黏附分子-1(ICAM-1)表达的机制。方法:肿瘤坏死因子-α(TNF-α)、脂多糖(LPS)、曲古霉素A(TSA)、DXM及NAC分别作用于A549细胞,用ELISA及流式细胞术方法分别检测炎症因子IL-8、ICAM-1的表达;蛋白印迹法检测糖皮质激素受体(GR)、组蛋白去乙酰化酶1及组蛋白去乙酰化酶2(HDAC1、2)、转录因子活化蛋白-1(AP-1)、核因子-κB(NF-κB)的蛋白表达,分光光度法检测HDAC的活性。结果:A549细胞在TNF-α作用前后IL-8蛋白浓度明显增高,两组相比差异有统计学意义(P0.05)。与TNF-α单独作用组相比,DXM、NAC预作用细胞后可明显降低TNF-α诱导下IL-8的表达,差异有统计学意义(P0.05)。A549细胞在TNF-α作用前后细胞ICAM-1蛋白浓度(荧光强度)明显增高,两组相比差异有统计学意义(P0.05)。与TNF-α单独作用组相比,DXM、NAC预作用细胞可明显降低TNF-α诱导的ICAM-1的表达,差异有统计学意义(P0.05)。TNF-α、LPS诱导A549细胞AP-1、NF-κB转录活化;DXM明显抑制转录因子AP-1、NF-κB转录活化。NAC明显抑制转录因子NF-κB转录活化,对AP-1无影响。TNF-α、LPS降低A549细胞HDAC1、HDAC2的蛋白表达,DXM明显增加A549细胞HDAC1、HDAC2蛋白表达;NAC对A549细胞HDAC1、HDAC2蛋白表达无影响。与未处理组相比TNF-α、LPS作用明显降低细胞HDAC活性,差异有统计学意义(P0.05)。DXM明显增加细胞HDAC活性,差异有统计学意义(P0.05),NAC对细胞HDAC活性无影响(P0.05)。结论:DXM、NAC能明显拮抗TNF-α诱导下的IL-8、ICAM-1蛋白表达,具有较强的抗炎作用。DXM主要通过增加HDAC蛋白表达和HDAC活性,抑制转录因子AP-1、NF-κB转录活化发挥抗炎作用,而NAC对HDAC蛋白表达及活性无影响,提示NAC不是通过乙酰化信号机制发挥抗炎作用。
[Abstract]:Aim: to investigate the mechanism of dexamethasone (DXM) and N-acetylcysteine (NAC) inhibiting the expression of interleukin-8 (IL-8) and intercellular adhesion molecule-1 (ICAM-1) in human alveolar epithelial cells (A549). Methods: tumor necrosis factor- 伪 (TNF- 伪), lipopolysaccharide (LPS),) A (TSA), DXM and NAC were applied to A549 cells respectively. The expression of IL-8,ICAM-1 was detected by ELISA and flow cytometry. Protein expression of glucocorticoid receptor (GR), histone deacetylase 1 (HDAC1,2), transcription factor activator protein-1 (AP-1), nuclear factor- 魏 B (NF- 魏 B) was detected by Western blot. The activity of HDAC was determined by spectrophotometry. Results: the concentration of IL-8 protein in A549 cells increased significantly before and after treatment with TNF- 伪, and the difference between the two groups was statistically significant (P0.05). Compared with TNF- 伪 alone, DXM,NAC pretreated cells significantly decreased the expression of IL-8 induced by TNF- 伪. The concentration of ICAM-1 protein (fluorescence intensity) of A549 cells increased significantly before and after the treatment of TNF- 伪 (P0.05), and the difference between the two groups was statistically significant (P0.05). Compared with TNF- 伪 alone, DXM,NAC pretreated cells significantly decreased ICAM-1 expression induced by TNF- 伪 (P0.05). TNF- 伪, LPS induced AP-1,NF- 魏 B transcriptional activation in A549 cells. DXM inhibited transcription activation of AP-1,NF- 魏 B. NAC inhibited transcription activation of NF- 魏 B. TNF- 伪, LPS decreased HDAC1,HDAC2 protein expression in A549 cells, and DXM increased HDAC1,HDAC2 expression in A549 cells. HDAC2 protein expression; NAC had no effect on the expression of HDAC1,HDAC2 protein in A549 cells. Compared with the untreated group, the effect of TNF- 伪 and LPS significantly decreased the HDAC activity of the cells, the difference was statistically significant (P0.05). DXM significantly increased the cell HDAC activity, the difference was statistically significant (P0.05). NAC had no effect on HDAC activity (P0.05). Conclusion: DXM,NAC can antagonize the expression of IL-8,ICAM-1 protein induced by TNF- 伪 and has a strong anti-inflammatory effect. DXM inhibits the transcription factor AP-1, mainly by increasing the expression of HDAC protein and the activity of HDAC. NF- 魏 B transcriptional activation played an anti-inflammatory effect, but NAC had no effect on the expression and activity of HDAC protein, suggesting that NAC did not play an anti-inflammatory effect through acetylation signaling mechanism.
【学位授予单位】：宁夏医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R563

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