It has been shown that TSH upregulates rat NIS gene expression in vitro, an
d this induction can be modulated by cytokines. Analysis of the distributio
n of rat NIS mRNA ex vivo demonstrated variable levels of NIS transcription
in different tissue samples. - IL-1 beta and IL-6 have been found to decre
ase NIS mRNA expression in TSH-stimulated FRTL-5-cells. IL-6 has no effect
on NIS functional activity, whereas IL-1 beta suppresses iodide accumulatio
n. The NIS is expressed in thyroid tissue of patients with autoimmune thyro
id diseases, and its expression is increased in Graves' disease. With respe
ct to other thyroidal autoantigens such as TPO and Tg, NIS obviously shows
a very similar pattern to the well-described antigenic targets and may part
icipate as an autoantigen in these diseases. - Up to now only data of in vi
tro studies are available which started to evaluate the effects of differen
t cytokines on NIS expression. The mechanisms of NIS regulation with respec
t to cytokine modulation in thyroid autoimmune disease remain still unprove
n and data of experimental in vivo studies and clinical trials in patients
with thyroid autoimmune disease have to further elucidate these open questi
ons in the future.