Gene expression profiles in brain of male juvenile zebrafish (Danio rerio) treated with triclosan

Abstract

Triclosan (TCS) is a broad-spectrum antibacterial agent and has been widely used in a diversity of personal care products. However, recent studies suggest that TCS has some adverse effects, and some evidences suggest in vitro neurotoxicity and developmental neurotoxicity of embryos. There are currently few studies concerning the mechanisms of TCS induced late developmental neurotoxic effect. Therefore, we investigated effects of juvenile zebrafish (Danio rerio) exposure to TCS. Male juvenile zebrafish were exposed to 68.0 μg/L TCS for 42 days. After the exposure experiment, eight Agilent Zebrafish V3 Gene Expression Microarrays were used to identify gene expression changes on brains from the control and TCS treated zebrafish. Microarray analysis yielded 364 differentially expressed genes (FDR adjusted P-value <.05; fold change >2) predominately represented by visual perception, immune system process, multicellular organismal development, antigen processing and presentation, macrophage differentiation functional categories. Pathway analysis showed that TCS mainly influenced Phototransduction and Cytokine-cytokine receptor interaction. In addition, visual perception functional genes involved in Phototransduction were upregulated, while immune system process functional genes involved in Cytokine-cytokine receptor interaction were downregulated. Quantitative real-time PCR (qRT-PCR) analysis confirmed the microarray data. These data suggest that TCS could affect visual centers, immune system, and development in the brain of juvenile fish to cause central neurotoxicity. Our study reveals new molecular targets for TCS and provides further insights into the molecular mechanisms of TCS toxicity during late development.