Iodinated TG in Thyroid Follicles Regulate TSH/TSHR Signaling for NIS Expression.

Iodinated TG in Thyroid Follicles Regulate TSH/TSHR Signaling for NIS Expression.
Biol Trace Elem Res. 2017 Apr 10;:
Authors: Huang H, Shi Y, Liang B, Cai H, Cai Q
Abstract
Our previous research has suggested that high degree of iodinated thyroglobulin (TG) may inhibit the expression and function of sodium iodide symporter (NIS), but the underlying mechanism remains unclear. In present study, we discuss a newly constructed follicle model in vitro, which was used to simulate the follicular structure of the thyroid and explore the regulatory roles of iodinated TG in the follicular lumen on NIS expression. The results showed that both NIS expression and PKA activity were increased in lowly iodinated TG group, while decreased NIS expression with increased PKC activity was found in highly iodinated TG group. Also, NIS expression was increased in PKA agonist-treated group, while decreased NIS was found in PKC agonist-treated group. Moreover, when the PLC-PKC pathway was blocked by PKC-specific inhibitor, highly iodinated TG significantly promoted the expression of NIS. However, when the cAMP-PKA pathway was blocked by a PKA-specific blocker, highly iodinated TG slightly suppressed NIS expression. TG with a low degree of iodination had the reverse effect on NIS. When the PLC-PKC pathway was blocked, TG with a low degree of iodination slightly promoted NIS expression. However, when the cAMP-PKA pathway was blocked, TG with a low degree of io...

Source: Biological Trace Element Research - April 10, 2017 Category: Biology Authors: Huang H, Shi Y, Liang B, Cai H, Cai Q Tags: Biol Trace Elem Res Source Type: research