The repressor element 1-silencing transcription factor is a novel molecular target for the neurotoxic effect of the polychlorinated biphenyl mixture aroclor 1254 in neuroblastoma SH-SY5Y cells.
J Pharmacol Exp Ther
; 338(3): 997-1003, 2011 Sep.
Article
em En
| MEDLINE
| ID: mdl-21693630
ABSTRACT
Chronic exposure to polychlorinated biphenyls (PCBs), a class of ubiquitous environmental toxicants, causes neurocognitive anomalies. The transcription factor repressor element 1-silencing transcription factor (REST) plays a critical role in neuronal phenotype elaboration in both neural progenitor cells and non-neuronal cells. Here, we investigated the possible relationship between PCBs and REST in neuroblastoma SH-SY5Y cells. In these cells, chronic exposure to the PCB mixture Aroclor 1254 (A-1254; 5-30 µg/ml) caused dose-dependent cell death via the induction of calpain but not caspase-3. Intriguingly, this effect was prevented by the calpain inhibitor calpeptin. Furthermore, A-1254 enhanced REST mRNA and protein expression levels after both 24 and 48 h. REST down-regulation by small interfering RNA prevented A-1254-induced cell death. In addition, A-1254 enhanced the binding of REST to the synapsin 1 gene promoter, and synapsin 1 knockdown potentiated A-1254-induced cell death. A-1254 (10 µg/ml) also increased the expression of the two REST cofactors, the REST corepressor and the mammalian SIN3 homolog A transcription regulator. Moreover, the PCB mixture decreased acetylation of the histone proteins H3 and H4. It is noteworthy that the histone deacetylase inhibitor trichostatin A prevented such decreases and reduced the A-1254-induced neurotoxic effect. Collectively, these results suggest that A-1254 exerts its toxic effect via REST by down-regulating synapsin 1 and decreasing H3 and H4 acetylation.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas Repressoras
/
Antitireóideos
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Síndromes Neurotóxicas
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article