Sodium/iodide symporter (NIS) and pendrin are expressed differently in hot and cold nodules of thyroid toxic multinodular goiter.
OBJECTIVE
The expression of two iodide transporters, the sodium/iodide symporter (NIS) and pendrin, was analyzed in thyroid tissues of patients with toxic multinodular goiter (TMNG) and non-toxic multinodular goiter (MNG).


METHODS
The levels of NIS and pendrin proteins were analyzed in total protein extracts from nodular and non-nodular tissues by Western blot.


RESULTS
In tissue samples from TMNG, we found an increased expression of NIS (2.5-fold) in the hot nodules, and similar levels between cold nodules and non-nodular tissues. In contrast, the levels of pendrin were slightly increased in both hot and cold nodules from TMNG, and decreased (about twofold) in cold nodules from MNG. We also noticed that there was no relationship between NIS and pendrin expression.


CONCLUSIONS
Our data demonstrate that hot nodules from TMNG express a higher number of iodide transporters (mainly NIS), whereas cold nodules from TMNG, but not from MNG, show levels of the two proteins comparable with normal tissue, suggesting a role in vivo of TSH in maintaining the expression of NIS and pendrin protein in normal thyroid tissue. Finally, different mechanisms are involved in the regulation of NIS and pendrin expression.
Russo
D
D
Dipartimento di Scienze Farmacobiologiche, Universita di Catanzaro, Via T. Campanella, 115, 88100 Catanzaro, Italy.
Bulotta
S
S
Bruno
R
R
Arturi
F
F
Giannasio
P
P
Derwahl
M
M
Bidart
J M
JM
Schlumberger
M
M
Filetti
S
S
D000199:Actins / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015153:Blotting, Western; D002352:Carrier Proteins / Q000096:biosynthesis*; D005260:Female; D006044:Goiter, Nodular / Q000378:metabolism*; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins; D008875:Middle Aged; D000076988:Sulfate Transporters; D027981:Symporters / Q000096:biosynthesis*; D013972:Thyrotropin / Q000097:blood; D000099209:Sodium-Iodide Symporters
D000199:Actins; D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D000076988:Sulfate Transporters; D027981:Symporters; D013972:Thyrotropin; D000099209:Sodium-Iodide Symporters; C085609:SLC26A4 protein, human