ABSTRACT
To investigate the effects of fluoride on the expression of thyroglobulin (TG),thyroid peroxidase(TPO),odium iodide symporter (NIS) genes in FRTL cells,FRTL cells cultured in vitro were treated in logarithmic phase with sodium fluoride at different concentration of 20.0,10.0,5.0,2.5,1.25 mg/L,respectively.After 72 h,the cells were collected and semi-quantitative RT-PCR for TG mRNA,TPO mRNA and NIS mRNA and β-actin was performed.The results showed that compared with the control cells,the expression levels of TG gene in FRTL cells treated with lower concentration of sodium fluoride increased compensatively,but decreased significantly (P<0.05) with higher concentration(>5.0 mg/L);the RT-PCR products of TPO and NIS in FRTL cells treated with all concentration of sodium fluoride reduced,some of them were significant (P<0.05).It is concluded that fluoride can reduce the expression of TG,TPO,NIS genes in thyroid cells,conseguently cause dysfunction" of thyroid in uptaking and unilizing of iodine,and synthesizing,storing,secreting of thyroid hormones.
ABSTRACT
FRTL cells were incubated in the culture medium containing 10 -6 -10-3 mol/L KI for 24, 48 and 72 h, and the levels of sodium iodide symporter (NIS) mRNA and protein were measured using RT-PCR and Western blot. The levels of NIS mRNA in FRTL cells incubated with different concentrations of iodide for 24 and 48 h showed no significant difference as compared with the control group, however, NIS protein was reduced gradually in FRTL cells incubated with different concentrations of iodide for 48 and 72 h as compared with that in control group. The higher the iodide concentration, the lower the levels of NIS protein. The results show that acute iodine excess does not affect the expression of NIS mRNA, but down-regulates NIS protein expression. Iodine excess may regulate the expression of NIS through post-transcription.