Time does matter! Acute copper exposure abolishes rhythmicity of clock gene in Danio rerio.
Ecotoxicol Environ Saf
; 155: 26-36, 2018 Jul 15.
Article
em En
| MEDLINE
| ID: mdl-29499429
ABSTRACT
The circadian clock is a key cellular timing system that coordinates physiology and behavior. Light is a key regulator of the clock mechanism via its activation of Per and Cry clock gene expression. Evidence points to a key role of reactive oxygen species (ROS) in resetting this process. In this context, the aim of the present study was to explore copper as a ROS generator, using an innovative approach investigating its effects on circadian timing. Liver and brain from Danio rerio specimens exposed to 0, 5, 25 and 45⯵g/L copper concentrations were obtained. Daily oscillations of superoxide dismutase (SOD) and catalase (CAT) enzymatic activity and their correlations both with clock genes (per1, per2, and cry1a) and with organism energy cost were determined. CAT expression correlates with per2 and cry1a and, thus, provides data to support the hypothesis of hydrogen peroxide production by a phototransducing flavin-containing oxidase. Higher SOD activity is correlated with higher intracellular ATP levels. Copper disturbed the daily oscillation of antioxidant enzymes and clock genes, with disturbed per1 rhythmicity in both the brain and liver, while cry1a rhythmicity was abolished in the liver at 25⯵g/L copper. Coordination between the SOD and the CAT enzymes was lost when copper concentrations exceeded the limits established by international laws. These results indicate that organism synchronization with the environment may be impaired due to acute copper exposure.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cobre
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Proteínas de Peixe-Zebra
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Proteínas Circadianas Period
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Relógios Circadianos
Limite:
Animals
Idioma:
En
Revista:
Ecotoxicol Environ Saf
Ano de publicação:
2018
Tipo de documento:
Article