Ca(2+)-binding protein expression in primary human thyrocytes.
Biochim Biophys Acta
; 1833(12): 2703-2713, 2013 Dec.
Article
em En
| MEDLINE
| ID: mdl-23886630
ABSTRACT
We recently identified several Ca(2+)-binding proteins (CaBP) from the S100 and annexin family to be regulated by TSH in FRTL-5 cells. Here, we study the regulation of S100A4, S100A6 and ANXA2 in primary human thyrocytes (PHT) derived from surrounding tissues (ST), cold benign thyroid nodules (CTN) and autonomously functioning thyroid nodules (AFTN). We investigated the expression and regulation of CaBP and the effect of their expression on Ca(2+) and TSHR signaling. We used an approach that accounts for the potential of an individual PHT culture to proliferate or to express thyroid differentiation features by assessing the expression of FOS and TPO. We found a strong correlation between the regulation of CaBP and the proliferation-associated transcription factor gene FOS. PKA and MEK1/2 were regulators of ANXA2 expression, while PI3-K and triiodothyronine were additionally involved in S100 regulation. The modulated expression of CaBP was reflected by changes in ATP-elicited Ca(2+) signaling in PHT. S100A4 increased the ratio of subsequent Ca(2+) responses and showed a Ca(2+) buffering effect, while ANXA2 affected the first Ca(2+) response to ATP. Overexpression of S100A4 led to a reduced activation of NFAT by TSH. Using S100A4 E33Q, D63N, F72Q and Y75K mutants we found that the effects of S100A4 expression on Ca(2+) signaling are mediated by protein interaction. We present evidence that TSH has the ability to fine-tune Ca(2+) signals through the regulation of CaBP expression. This represents a novel putative cross-regulating mechanism in thyrocytes that could affect thyrocyte signaling and physiology.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glândula Tireoide
/
Proteínas S100
/
Cálcio
/
Anexina A2
/
Proteínas de Ciclo Celular
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Alemanha