Transcriptome analysis reveals benzotriazole ultraviolet stabilisers regulate networks related to inflammation in juvenile zebrafish (Danio rerio) brain

Benzotriazole ultraviolet stabilisers (BUVSs) are widely applied ultraviolet absorbing compounds in industrial materials and personal care products. Due to their ubiquitous use and reports of bio-accumulation in aquatic organisms, these compounds are significant environmental pollutants; however, data are limited for BUVSs toxicity. In this study, juvenile zebrafish (Danio rerio) were exposed to 4 commonly used BUVSs (UV-234, UV-326, UV-329, and UV-P) at one dose of 10 or 100 ?g/L for 28 days. To characterise the underlying mechanisms of different BUVSs-induced toxicities, the authors performed global transcriptome sequencing (RNA-Seq) in the brain (100 ?g/L). There were 390, 575, 483, and 470 differentially expressed genes (DEGs) detected following UV-234, UV-326, UV-329, and UV-P exposure at 100 ?g/L, respectively. Only 59 genes were identified as DEGs following exposure to each of the BUVSs, suggesting that these chemicals can induce unique responses in fish. Noteworthy was that there were 81 common gene networks (~10%) identified following exposure to BUVSs, many of which were related to inflammation and immune function. Uniquely regulated pathways affected by different BUVSs included those related to mitochondrial respiration, interleukin 1/brain-damaging signalling, dopaminergic signalling, and adrenergic receptor cascades. Furthermore, quantitative PCR (qPCR) results revealed that mgst1 levels were increased in fish from the 100 ?g/L UV-329 treatment, while the expression of pck2 was significantly down-regulated in fish from both the 10 and 100 ?g/L UV-P treatment. Transcriptomic data suggest that BUVSs can alter mitochondrial bioenergetics, alter expression of a broad range of genes in the oxidative stress response, and can induce pathways related to the immune system in zebrafish brain.

Authors: Li Z, Li W, Zha J, Chen H, Martyniuk CJ, Liang X. ; Full Source: Environmental Toxicology. 2018 Oct 13. doi: 10.1002/tox.22663. [Epub ahead of print]