信号转导及转录激活子1和3抑制剂对高迁移率族蛋白B1诱导鼠巨噬细胞合成肿瘤坏死因子α的影响

Effect of inhibitors of signal transducer and activator of transcription-1/3 on expression of tumor necrosis factor-α induced by high mobility group box-1 protein inflammatory response in rat peritoneal macrophages

目的探讨信号转导及转录激活子1(STAT1)和3抑制剂对高迁移率族蛋白B1(HMGB1)诱导巨噬细胞合成肿瘤坏死因子α(TNFα)的影响。方法取正常Wistar大鼠腹腔巨噬细胞置24孔培养板中(1×106细胞/孔),培养3d后以HMGB1刺激,采用氟达拉滨(Fludarabine,STAT1特异性抑制剂)及雷帕霉素(Rapamycin,STAT3特异性抑制剂)进行干预。观察HMGB1刺激与肿瘤坏死因子αmRNA表达和蛋白释放的时效、量效关系,Fludarabine和Rapamycin处理对TNFαmRNA表达和蛋白释放的影响。结果(1)HMGB1可导致大鼠腹腔巨噬细胞TNFα基因表达明显升高,于攻击后24h达峰值,至36h减弱。HMGB1的用量为10μg/ml时,TNFα基因表达明显增强;(2)HMGB1可诱导大鼠腹腔巨噬细胞TNFα蛋白早期释放,4h即可达到高峰,8h后减弱。随着HMGB1刺激剂量从5μg/ml增大到25μg/ml,TNFα蛋白释放持续增强;(3)Fludarabine和Rapamycin可抑制大鼠腹腔巨噬细胞TNFα基因表达,但不能影响TNFα蛋白的释放。结论STAT1和STAT3抑制剂可显著下调巨噬细胞由HMGB1诱导的TNFα基因表达,但不能影响其早期(<24h)蛋白释放。

Objective To investigate the inflammatory signal transduction of high mobility group box-1 protein （HMGB1） induced inflammatory response in rat peritoneal macrophages. Methods Peritoneal macrophages obtained from male Wistar rats were seeded in 24-well （ 1 × 10^6 cells/well ） tissue culture plates. The cells were incubated for 3 days before they were stimulated with HMGB1, and treated with Fludarabine[ the specific inhibitor of signal transducer and activator of transcription 1 （ STAT1 ） ] or Rapamycin（ the specific inhibitor of STAT3 ）. The time-dependent and dose-dependent responses between HMGB1 stimulation and tumor necrosis factor-α （TNF-α） gene expression as well as release were analyzed respectively. Moreover, the effect of Fludarabine and Rapamycin on TNF-α mRNA expression and protein release were also observed. Results （ 1 ） After HMGB1 challenge, TNF-α mRNA expressions were up- regulated markedly, peaked at 24 hours, and decreased at 36 hours. When HMGB1 was used at a concentration of 10 μg/ml, TNF-α mRNA expression increased most markedly. （2）HMGB1 could induce TNF-α release in rat peritoneal macrophages, with peaking at 4 hours and decreasing at 8 hours later. When the concentration of HMGB1 stimulation increased from 5 μg/ml to 25 μg/ml, TNF-α release was persistently enhanced. （3） It was also showed that TNF-α mRNA expression was significantly inhibited by treatment of either Fludarabine（ 100 μmol/L） or Rapamycin （25 ng/ml） , while TNF-α release was not markedly suppressed. Conclusions STAT1 and STAT3 might be involved in the regulation of TNF-α gene expression, but not in TNF-α early release （ 〈24 hours） induced by HMGB1 stimulation in rat peritoneal macrophages.