Effects Of Pbde-47 On The Apoptosis And Function Of Cultured Human Thyrocytes

Objectives:(1) To investigate the effects of PBDE-47 on the proliferation and apoptosis of human thyrocytes in vitro.(2) To observe the effects of PBDE-47 on the function of human thyrocytes in vitro.(3) To investigate the probable mechanism by which PBDE-47 exerts its effects on thyrocytes.Methods:(1) Thyroid follicular epithelium cells (TEC) were cultured in the absence or presence of different concentrations of PBDE-47 for 24h. The proliferation of TEC was measured with methyl thiazolyl tetrazolium (MTT) method.(2) The cell apoptosis was detected by flowcytometry (FCM).(3) The secretory function of TEC was detected via the measurement of concentration of Thyroglobulin (Tg) levels by electrochemiluminescence immunoassay (ECLIA).(4) Semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) were performed to detect the gene expression of Bax/Bcl-2, Tg, and Paired box gene 8 (Pax-8) in thyrocytes.Results:(1) The survival rate was significantly decreased in a dose dependent manner, when the concentrations of PBDE-47≥10-10mol/L(P<0.05).(2) The apoptosis rate was significantly increased in a dose dependent manner, when the concentrations of PBDE-47≥10-10mol/L(P<0.05).(3) The Tg-secretory function was significantly decreased, when the concentration of PBDE-47 were 10-12 and 10-10mol/L(P<0.05). However, the significant difference wasn't found at the concentration of 10-8mol/L.(4) The expression of Bax gene was remarkably enhanced in a dose dependent manner as the concentration of PBDE-47≥10-10mol/L (P<0.05). The expression of Bcl-2 gene was efficiently reduced in a dose dependent manner by all concentrations of PBDE-47 (P<0.05).(5) The expression of Tg and Pax-8 genes were significantly reduced by all concentrations of PBDE-47 in a dose dependent manner (P<0.05).Conclusions:(1) PBDE-47 is cytotoxic to TEC.(2) PBDE-47 could efficiently inhibit the function of TEC.(3) The mechanism by which PBDE-47 exerts its cytotoxic effects is probably related to upregulation of Bax gene and downregulation of Bcl-2 gene .(4) The mechanism by which PBDE-47 efficiently inhibits the function of TEC is probably related to downregulation of Tg and Pax-8 genes...