Excess iodide downregulates Na+/I- symporter gene transcription through activation of PI3K/Akt pathway

Autor(es)

Serrano-Nascimento, Caroline ^[1] ; Pablo Nicola, Juan ^[2] ; Teixeira, Silvania da Silva ^[1] ; Poyares, Leonice Lourenco ^[1] ; Lellis-Santos, Camilo ^[3] ; Bordin, Silvana ^[1] ; Maria Masini-Repiso, Ana ^[2] ; Nunes, Maria Tereza ^[1]

Afiliação do(s) autor(es)

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

^[2] Univ Nacl Cordoba, Fac Ciencias Quim, Dept Bioquim Clin, Ctr Invest Bioquim Clin & Inmunol, RA-5000 Cordoba - Argentina

^[3] Univ Fed Sao Paulo, Inst Environm Chem & Pharmaceut Sci, Dept Biol Sci, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecular and Cellular Endocrinology; v. 426, n. C, p. 73-90, MAY 5 2016.
• Citações Web of Science: 10

Resumo

Transcriptional mechanisms associated with iodide-induced downregulation of NIS expression remain uncertain. Here, we further analyzed the transcriptional regulation of NIS gene expression by excess iodide using PCCl3 cells. NIS promoter activity was reduced in cells treated for 12-24 h with 10(-5) to 10(-3) M NaI. Site-directed mutagenesis of Pax8 and NF-kappa B cis-acting elements abrogated the iodide induced NIS transcription repression. Indeed, excess iodide (10(-3) M) excluded Pax8 from the nucleus, decreased p65 total expression and reduced their transcriptional activity. Importantly, p65-Pax8 physical interaction and binding to NIS upstream enhancer were reduced upon iodide treatment. PI3K/Akt pathway activation by iodide-induced ROS production is involved in the transcriptional repression of NIS expression. In conclusion, the results indicated that excess iodide transcriptionally represses NIS gene expression through the impairment of Pax8 and p65 transcriptional activity. Furthermore, the data presented herein described novel roles for PI3K/Akt signaling pathway and oxidative status in the thyroid autoregulatory phenomenon. 2016 Elsevier Ireland Ltd. All rights reserved. (AU)

• Processo FAPESP: 09/17834-6 - Estudo das bases moleculares envolvidas na regulação a curto prazo da expressão gênica do co-transportador Na+/I- e pendrina pelo iodo em tireóide de ratos e células PCCl3: possível contribuição para a compreensão do efeito Wolff-Chaikoff e seu escape
• Beneficiário: Maria Tereza Nunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 09/50175-6 - Bases moleculares envolvidas na regulacao da expressao do gene do co-transportador de sodio-iodeto (nis) pelo iodeto.
• Beneficiário: Caroline Serrano Do Nascimento
• Modalidade de apoio: Bolsas no Brasil - Doutorado