New insights about the posttranscriptional mechanisms triggered by iodide excess on sodium/iodide symporter (NIS) expression in PCCl3 cells

Author(s)

Serrano-Nascimento, Caroline ^[1] ; Calil-Silveira, Jamile ^[1] ; Goulart-Silva, Francemilson ^[1] ; Nunes, Maria Tereza ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, BR-05508000 Sao Paulo - Brazil

• Document type: Journal article
• Source: Molecular and Cellular Endocrinology; v. 349, n. 2, p. 154-161, FEB 26 2012.
• Web of Science Citations: 9

Abstract

Iodide excess acutely downregulates NIS mRNA expression, as already demonstrated. PCCl3 cells treated or not with Nal, Nal + NaClO4 or Nal + Methimazole, for 30 min to 24 h, were used to further explore how iodide reduces NIS gene expression. NIS mRNA expression was evaluated by Real-Time PCR; its poly(A) tail length, by RACE-PAT; its translation rate, by polysome profile; total NIS content, by Western blotting. NIS mRNA decay rate was evaluated in actinomycin-D-treated cells, incubated with or without Nal for 0-6 h. Iodide treatment caused a reduction in NIS mRNA expression, half-life, poly(A) tail length, recruitment to ribosomes, as well as NIS protein expression. Perchlorate, but not methimazole, prevented these effects. Therefore, reduced poly(A) tail length of NIS mRNA seems to be related to its decreased half-life, in addition to its translation impairment. These data provide new insights about the molecular mechanisms involved in the rapid and posttranscriptional inhibitory effect of iodide on NIS expression. (C) 2011 Elsevier Ireland Ltd. All rights reserved. (AU)

• FAPESP's process: 10/05503-2 - EFFECT OF ACUTE ADMINISTRATION OF IODINE IN THE PENDRIN GENE EXPRESSION AND PROMOTER ACTIVITY: STUDY IN VIVO AND IN VITRO
• Grantee: Jamile Calil Silveira
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/17834-6 - Study of the molecular basis of the short-term regulation of the Na+/I- symporter (NIS) and pendrin gene expression in rats thyroid and PCCl3 cells: possible contribution to the comprehension of the Wolff-Chaikoff effect and the escape phenomenon
• Grantee: Maria Tereza Nunes
• Support Opportunities: Regular Research Grants