The expression of STATI/SOCS1 on the rat synoviocytes induced by high mobility group box / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effect and possible mechanisms of high mobility group box (HMGB) 1 on the proliferation of RSC-364 synoviocytes. Methods ① RSC-364 cells stimulated by 10 μg/L TNF-α and cells of the normal control groups were collected at 6, 12, 24 h respectively in vitro. HMGB1mRNA and protein was detected by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry (ICC); ②RSC-364 cells induced by 10 μg/L HMGB1 were collected in 6, 12, 24 h respectively, so did normal control group cells in vitro. The expression of signal transducer and activator of transcription (STAT) mRNA 1 was detected by RT-PCR. The expression of STATland SOCSI proteins were detected by ICC and flow cytometry analysis (FCM). The expression of PCNA was detected by ICC. Results ① Compared with the control group, TNF-α markedly up-regulated HMGBI mRNA at 6, 12, 24 h respectively [0.86, 0.92, 1.06 vs 0.70, P<0.01 ], as well as protein expression level. Positive signal of HMGB1 proteins was not only expressed in nuclear but also in cytoplasm after stimulation. ② Compared with normal group, HMGBI increased the expression of P-STAT1 mRNA and protein at 6, 12, 24 h respectively [0.30, 0.69, 1.05 vs 0.24, P<0.01 ] and [1.34±0.09，1.55±0.16，1.74±0.13 vs 1.00±0.15，P<0.01]. The expression of SOCSI protein increased significantly in HMGB1 group at 6 and 12 hours ( 1.43±0.10 vs 1.58±0.05), but it decreased at 24 hours (1.24±0.15). ③The expression of p-STATI protein was negatively correlated with that of SOCS1 protein. Conclusion HMGB1 appears to be an important mediator in the proliferation of RSC-364 cells, partly by up-regulating the expression and aetivity of p-STAT1.