摘要
Abstract Objective Hyperthyroidism and a diffuse goiter are the main symptoms of Graves' disease (GD) associated with autoantibodies to thyroid stimulating hormone (TSH) receptor (TRAb). The present study was conducted to evaluate effects of autoantibodies in patients with GD (TRAb IgG) on induction of the proliferation and c fos mRNA expression in FRTL 5 cells (Fisher rat thyroid cell line). Methods Highly purified IgG fractions were isolated from 11 patients with GD, TRAb IgG and 15 normal individuals (normal controls) with Protein A Sepharose CL 4B affinity column chromatograph. FRTL 5 cells, which had been grown to subconfluency and deprived of TSH for a few days. Then, these cells were used for measuring cAMP content, 3H thymidine incorporation in cells and the expression of c fos mRNA respectively. Results After stimulation of TRAb IgG, the cAMP production and 3 H thymidine incorporation in FRTL 5 cells were much higher than those from normal controls (P<0.05 respectively). Using 32 P labelled v fos probe by the Northern Blot method, the expression of c fos mRNA could be induced by IgGs from patients with GD. Conclusions These data suggest that the stimulation of TRAb IgG followed by cAMP production and 3H thymidine incorporation is related to the induction of c fos mRNA and, thus, to the growth of FRTL 5 cells.
Abstract Objective Hyperthyroidism and a diffuse goiter are the main symptoms of Graves' disease (GD) associated with autoantibodies to thyroid stimulating hormone (TSH) receptor (TRAb). The present study was conducted to evaluate effects of autoantibodies in patients with GD (TRAb IgG) on induction of the proliferation and c fos mRNA expression in FRTL 5 cells (Fisher rat thyroid cell line). Methods Highly purified IgG fractions were isolated from 11 patients with GD, TRAb IgG and 15 normal individuals (normal controls) with Protein A Sepharose CL 4B affinity column chromatograph. FRTL 5 cells, which had been grown to subconfluency and deprived of TSH for a few days. Then, these cells were used for measuring cAMP content, 3H thymidine incorporation in cells and the expression of c fos mRNA respectively. Results After stimulation of TRAb IgG, the cAMP production and 3 H thymidine incorporation in FRTL 5 cells were much higher than those from normal controls (P<0.05 respectively). Using 32 P labelled v fos probe by the Northern Blot method, the expression of c fos mRNA could be induced by IgGs from patients with GD. Conclusions These data suggest that the stimulation of TRAb IgG followed by cAMP production and 3H thymidine incorporation is related to the induction of c fos mRNA and, thus, to the growth of FRTL 5 cells.
