hNIS protein in thyroid: the iodine supply influences its expression and localization.
OBJECTIVE
Nonfunctioning thyroid nodules (NFTNs) display a diminished iodide-concentrating ability, owing to defective expression and cell membrane targeting of the sodium-iodide symporter (NIS). Since NIS expression is primarily modulated by thyroid iodine content in vitro and in animal models, we attempted to determine whether iodine supply influences the expression and localization of human NIS (hNIS) in NFTNs.


METHODS
Using immunohistochemistry, we analyzed cold hyperplastic nodules and nonnodular thyroid samples (controls) from patients living in iodine-sufficient (n = 19) or severely iodine-deficient (n = 15) areas.


RESULTS
Nodules from the iodine-sufficient area exhibited weak or absent hNIS immunostaining whereas almost all nodules from the iodine-deficient area were hNIS positive. Heterogeneous hNIS staining was common among the iodine-deficient samples (p = 0.028). hNIS was localized on membrane in all nodular samples from the iodine-deficient area and in less than 40% in the iodine-sufficient area.


CONCLUSIONS
hNIS is adequately expressed and appropriately localized in NFTNs cell membrane from iodine-deficient areas and its expression in vivo is modulated by iodine supply.
Scipioni
Angela
A
Department of Clinical Sciences and Department of Experimental Medicine and Pathology, University of Rome, La Sapienza, 00161 Rome, Italy.
Ferretti
Elisabetta
E
Soda
Giuseppe
G
Tosi
Emanuele
E
Bruno
Rocco
R
Costante
Giuseppe
G
Meringolo
Domenico
D
Arturi
Franco
F
Durante
Cosimo
C
Amorosi
Andrea
A
Foschini
Maria Pia
MP
Nardi
Francesco
F
Russo
Diego
D
Filetti
Sebastiano
S
D000328:Adult; D000368:Aged; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006042:Goiter / Q000473:pathology / Q000601:surgery; D006801:Humans; D007454:Iodides / Q000378:metabolism; D007455:Iodine / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D027981:Symporters / Q000235:genetics / Q000378:metabolism*; D013961:Thyroid Gland / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D013963:Thyroid Hormones / Q000097:blood; D016606:Thyroid Nodule / Q000378:metabolism; D000099209:Sodium-Iodide Symporters
D007454:Iodides; D007455:Iodine; D027981:Symporters; D013963:Thyroid Hormones; D000099209:Sodium-Iodide Symporters