Abstract
The transcription of metal-responsive genes in the rainbow trout (Oncorhynchus mykiss) gill tissue can be used to detect effects of bioreactive metals in natural waters. Here we take advantage of an in vitro gill epithelium, which can be directly exposed to test water samples. The in vitro gill epithelial model mimics the molecular response of in vivo gill epithelial cells to waterborne contaminants. The same culture system can detect trace metals and organic waterborne contaminants. Furthermore, combining this epithelial model with transcriptomic profiling yields an extremely discriminatory biomonitoring tool able to detect and differentiate waterborne metal contaminants. The bioreactive fraction of metal in the water sample is detected using the cells naturally occurring metal sensor, metal-responsive transcription factor 1 (MTF1), which acts upon Metal Response Elements (MRE's) in the enhancer region of metal regulated genes. Induction of the MTF1 responsive genes, metallothionein-A (MTA), metallothionein-B (MTB), and zinc transporter 1 (ZnT-1) in the cell culture was strongly dependent of the concentrations of bioreactive zinc and silver in the test water. Importantly, gene expression in cell culture reflected animal toxicity, measured as inhibition of Ca2+ and Na+ influx, in live rainbow trout exposed to the same waters. A cDNA microarray was deployed to determine the differential profiles of transcripts characteristic of exposure to silver, copper or cadmium within this in vitro system. These experiments illustrated the potential power of combining the in vitro gill model epithelium with genetic profiling for accurate characterisation and identification of bioreactive toxicants in waterborne samples. (C) 2008 Elsevier Inc. All rights reserved
Original language | English |
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Pages (from-to) | 67 - 77 |
Number of pages | 11 |
Journal | Toxicology and Applied Pharmacology |
Volume | 230 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Jul 2008 |