[Effect of inhibitors of signal transducer and activator of transcription-1/3 on expression of tumor necrosis factor-alpha induced by high mobility group box-1 protein inflammatory response in rat peritoneal macrophages].
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 x 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-alpha (TNF-alpha) gene expression as well as release were analyzed respectively. Moreover, the effect of Fludarabine and Rapamycin on TNF-alpha mRNA expression and protein release were also observed.


RESULTS
(1) After HMGB1 challenge, TNF-alpha mRNA expressions were up-regulated markedly, peaked at 24 hours, and decreased at 36 hours. When HMGB1 was used at a concentration of 10 microg/ml, TNF-alpha mRNA expression increased most markedly. (2) HMGB1 could induce TNF-alpha 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 microg/ml to 25 microg/ml, TNF-alpha release was persistently enhanced. (3) It was also showed that TNF-alpha mRNA expression was significantly inhibited by treatment of either Fludarabine (100 micromol/L) or Rapamycin (25 ng/ml), while TNF-alpha release was not markedly suppressed.


CONCLUSIONS
STAT1 and STAT3 might be involved in the regulation of TNF-alpha gene expression, but not in TNF-alpha early release (< 24 hours) induced by HMGB1 stimulation in rat peritoneal macrophages.
Liu
Hui
H
Burns Institute, 304th Hospital Affiliated to People's Liberation Army General Hospital, Beijing 100037, China.
Yao
Yong-ming
YM
Yu
Yan
Y
Sheng
Zhi-yong
ZY
D000818:Animals; D002478:Cells, Cultured; D004347:Drug Interactions; D024243:HMGB1 Protein / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D050794:STAT1 Transcription Factor / Q000037:antagonists & inhibitors*; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors*; D015398:Signal Transduction; D020123:Sirolimus / Q000494:pharmacology*; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics; D014740:Vidarabine / Q000031:analogs & derivatives* / Q000494:pharmacology
D024243:HMGB1 Protein; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D014409:Tumor Necrosis Factor-alpha; D014740:Vidarabine; C024352:fludarabine; D020123:Sirolimus