Effect of acute iodine administration on the regulation of sodium-iodide symporter (NIS) gene expression in vivo and in vitro studies.

Author(s)

Caroline Serrano do Nascimento

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2008-11-19

Examining board members

Maria Tereza Nunes; Janete Maria Cerutti; Edna Teruko Kimura

• Advisor: Maria Tereza Nunes

Abstract

Iodide in excess exerts the Wolff-Chaikoff effect. It is described that some minerals can regulate the expression of proteins. This study aimed to investigate if the iodide could modify the expression of NIS mRNA, in short periods of time. Rats and cells, divided in time-groups of 30 min up to 24h, were used in studies of expression, poly-A tale length and polysomal profile of NIS mRNA. Both in vivo and in vitro studies showed that the iodide treatment promoted a reduction in the expression and the poly-A length of NIS mRNA, in all time-groups, and decreased its recruitment to the polysomes. It is possible that the reduction of NIS mRNA poly-A tale length has increased the instability/degradation of this transcript, and impaired the translation efficiency of it. Concluding: a) the iodine exerts a post-transcriptional regulation of NIS mRNA expression, being essencial in the processes that guide the Wollf-Chaikoff effect; b) the oligoelements have an extremely important role in the expression regulation of proteins related to their transport. (AU)