scholarly journals Conserved charged amino acid residues in the extracellular region of sodium/iodide symporter are critical for iodide transport activity

2010 ◽  
Vol 17 (1) ◽  
pp. 89 ◽  
Author(s):  
Chia-Cheng Li ◽  
Tin-Yun Ho ◽  
Chia-Hung Kao ◽  
Shih-Lu Wu ◽  
Ji-An Liang ◽  
...  
2007 ◽  
Vol 51 (5) ◽  
pp. 672-682 ◽  
Author(s):  
Denise P. Carvalho ◽  
Andrea C.F. Ferreira

The thyroid gland has the ability to uptake and concentrate iodide, which is a fundamental step in thyroid hormone biosynthesis. Radioiodine has been used as a diagnostic and therapeutic tool for several years. However, the studies related to the mechanisms of iodide transport were only possible after the cloning of the gene that encodes the sodium/iodide symporter (NIS). The studies about the regulation of NIS expression and the possibility of gene therapy with the aim of transferring NIS gene to cells that normally do not express the symporter have also become possible. In the majority of hypofunctioning thyroid nodules, both benign and malignant, NIS gene expression is maintained, but NIS protein is retained in the intracellular compartment. The expression of NIS in non-thyroid tumoral cells in vivo has been possible through the transfer of NIS gene under the control of tissue-specific promoters. Apart from its therapeutic use, NIS has also been used for the localization of metastases by scintigraphy or PET-scan with 124I. In conclusion, NIS gene cloning led to an important development in the field of thyroid pathophysiology, and has also been fundamental to extend the use of radioiodine for the management of non-thyroid tumors.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Anna Popławska-Kita ◽  
Beata Telejko ◽  
Katarzyna Siewko ◽  
Maria Kościuszko-Zdrodowska ◽  
Natalia Wawrusewicz-Kurylonek ◽  
...  

Aim. The aim of the study was to compare the expression of sodium iodide symporter (NIS), thyroglobulin (Tg), tumor necrosis factor-α(TNFα), and interleukin-1βgenes in patients with Hashimoto’s thyroiditis (HT) and healthy individuals.Subjects and Methods.Thyroid cells were obtained from 39 patients with HT and 15 controls by an ultrasound guided fine needle aspiration biopsy.Results. The patients with HT had lower Tg and NIS mRNA (P=0.002andP=0.001, resp.), as well as higher TNFαmRNA expression (P=0.049) than the controls. In the HT group Tg mRNA expression correlated positively with NIS mRNA expression (R=0.739,P=0.0001) and thyroid volume (R=0.465,P=0.0005), as well as negatively with TNFαmRNA expression (R=-0.490,P=0.001) and anti-peroxidase antibodies (TPOAb) level (R=-0.482,P=0.0002), whereas NIS mRNA expression correlated positively with thyroid volume (R=0.319,P=0.02), as well as negatively with TNFαmRNA expression (R=-0.529,P=0.0006) and TPOAb level (R=-0.422,P=0.001).Conclusions.Our results suggest that decreased Tg and NIS expression in thyroid cells may result in reduced active iodide transport and reduced thyroid volume in patients with HT.


2001 ◽  
pp. 139-144 ◽  
Author(s):  
PH Eng ◽  
GR Cardona ◽  
MC Previti ◽  
WW Chin ◽  
LE Braverman

OBJECTIVE: The acute decrease in iodide organification in the thyroid in response to excess iodide is termed the acute Wolff-Chaikoff effect and normal organification resumes in spite of continued high plasma iodide concentrations (escape from the acute Wolff-Chaikoff effect). We have recently reported that large doses of iodide given to rats chronically decrease the sodium/iodide symporter (NIS) mRNA and protein, suggesting that escape is due to a decrease in NIS and subsequent iodide transport. We have now studied the effect of excess iodide on NIS in FRTL-5 cells to further explore the mechanisms whereby excess iodide decreases NIS. DESIGN: FRTL-5 cells were employed and were incubated in the presence or absence of various concentrations of iodide. NIS mRNA and protein and the turnover of NIS were assessed. METHODS: NIS mRNA was measured by Northern analysis, NIS protein by Western analysis and NIS turnover by pulse-chase labeling experiments. RESULTS: Iodide (10(-) mol/l) had no effect on NIS mRNA in FRTL-5 cells at 24 and 48 h compared with cells cultured in the absence of iodide. However, excess iodide decreased NIS protein by 50% of control values at 24 h and by 70% at 48 h. This effect of iodide was dose dependent. Pulse-chase experiments demonstrated that there was no effect of iodide on new NIS protein synthesis and that the turnover of NIS protein in the presence of iodide was 27% faster than in the absence of added iodide. CONCLUSIONS: Excess iodide does not decrease NIS mRNA in FRTL-5 cells but does decrease NIS protein, suggesting that in this in vitro thyroid cell model iodide modulates NIS, at least in part, at a post-transcriptional level. This iodide-induced decrease in NIS protein appears to be due, at least partially, to an increase in NIS protein turnover.


2001 ◽  
Vol 170 (1) ◽  
pp. 185-196 ◽  
Author(s):  
B Perron ◽  
AM Rodriguez ◽  
G Leblanc ◽  
T Pourcher

Iodide concentration in milk by mammals is a necessary step for thyroid hormone synthesis by the newborn. With the purpose of using the mouse as an animal model to analyse the role of the sodium iodide symporter (NIS) in iodide transport and its regulation in the mammary gland, mouse NIS (mNIS) cDNA was isolated from lactating mice. The cloned sequence shows an open reading frame of 1854 nucleotides encoding a protein of 618 amino acids highly homologous to the rat and human NIS (95% and 81% identity respectively). Expression of mNIS in cultured mammalian cells induced cellular iodide accumulation. This iodide uptake process is sodium dependent and inhibited by thiocyanate and perchlorate. Tissue distribution analysis revealed that mNIS mRNAs are predominantly expressed in thyroid, stomach and in the lactating mammary gland and are present to a lower extent in several other tissues. Our data show for the first time that the level of mNIS mRNA is upregulated in the mammary gland during lactation.


2010 ◽  
Vol 2010 ◽  
pp. 1-3 ◽  
Author(s):  
Wakako Jo ◽  
Katsura Ishizu ◽  
Kenji Fujieda ◽  
Toshihiro Tajima

Loss-of-function mutations of the PAX8 gene are considered to mainly cause congenital hypothyroidism (CH) due to thyroid hypoplasia. However, some patients with PAX8 mutation have demonstrated a normal-sized thyroid gland. Here we report a CH patient caused by a PAX8 mutation, which manifested as iodide transport defect (ITD). Hypothyroidism was detected by neonatal screening and L-thyroxine replacement was started immediately. Although I scintigraphy at 5 years of age showed that the thyroid gland was in the normal position and of small size, his iodide trapping was low. The ratio of the saliva/plasma radioactive iodide was low. He did not have goiter; however laboratory findings suggested that he had partial ITD. Gene analyses showed that the sodium/iodide symporter (NIS) gene was normal; instead, a mutation in the PAX8 gene causing R31H substitution was identified. The present report demonstrates that individuals with defective PAX8 can have partial ITD, and thus genetic analysis is useful for differential diagnosis.


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