Development of cultures of the marine sponge Hymeniacidon perleve for genotoxicity assessment using the alkaline comet assay

Abstract

Sponges are a potential alternative model species to bivalves in pollution biomonitoring and environmental risk assessment in the aquatic ecosystem. In the present study, a novel in vivo exposure sponge culture model was developed from field-collected and cryopreserved sponge (Hymeniacidon perleve) cells to investigate the genotoxic effects of environmentally relevant metals in the laboratory. Sponge cell aggregates were cultured and exposed to noncytotoxic concentrations (0-0.4 mg/L) of cadmium chloride, nickel chloride, and sodium dichromate as quantified by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and DNA-strand breaks assessed by the comet assay. Reactive oxygen species (ROS) formation was quantified by oxidation of 2',7'-dichlorofluorescin diacetate in sponge cell aggregates exposed to the same concentrations of Cd, Cr, and Ni. There was a statistically significant (p < 0.05) concentration-dependent increase in the level of DNA-strand breaks and ROS formation in all of the metals investigated. To the best of our knowledge, we have utilized for the first time the alkaline comet assay to detect DNA-strand breaks in marine sponge cells and demonstrated that exposure to noncytotoxic concentrations of Cd, Cr, and Ni for 12 h results in a concentration-dependent increase in DNA damage and levels of ROS production. In conclusion, we have developed a novel in vivo model based on culture of cryopreserved sponge cells that is compatible with the alkaline comet assay. Genotoxicity in marine sponges measured by the comet assay technique may be a useful tool for biomonitoring research and risk assessment in aquatic ecosystems. Environ Toxicol Chem 2017;36:3314-3323. © 2017 SETAC.

A broad‐taxa approach as an important concept in ecotoxicological studies and pollution monitoring

“…Other physiological changes that may be observed following exposure to sublethal concentrations of pollutants include changes in sponge cell behaviour (Cebrian et al ., 2003, 2006), metabolism (Saby et al ., 2009; Selvin et al ., 2009), production of ROS, expression of stress genes (Müller et al ., 1994, 1995, 1996) and increased apoptosis (Batel et al ., 1993). For example, in the case of induction of genotoxicity by exposure to heavy metals (Akpiri, Konya & Hodges, 2017), changes in the expression of metallothionein (Berthet et al ., 2005), post‐translational modification of tubulin (Ledda et al ., 2013), and expression of apoptosis‐associated prosurvival factor (Luthringer et al ., 2011) have been reported. Other biomarkers currently used in sponges include the altered expression or activity of heat shock proteins (HSPs) (e.g.…”