In Vitro Fish Models for the Analysis of Ecotoxins and Temperature Increase in the Context of Global Warming

Abstract

Rising temperatures can affect fish survival, especially from shallower waters, as temperatures increase faster and more intensively in these areas; thus, species-specific temperature tolerance can be exceeded. Additionally, the amounts of anthropogenic pollutants are higher in coastal waters. Although increasing metabolic activity at higher temperatures could lead to stronger effects of toxins, there are hardly any studies on this topic. Subsequently, the aim was to investigate the response of fish cells upon exposure to industrial solvents (ethanol, isopropanol, dimethyl sulfoxide (DMSO)) in relation to a temperature increase (20 °C and 25 °C). Concerning the 3Rs (the replacement, reduction and refinement of animal experiments), in vitro tests were used for two threatened, vulnerable fish species: maraena whitefish (Coregonus maraena) and Atlantic sturgeon (Acipenser oxyrinchus). Both cell lines exhibited higher proliferation at 25 °C. However, ecotoxicological results indicated significant differences regarding the cell line, toxin, temperature and exposure time. The evolutionarily older fish lineage, Atlantic sturgeon, demonstrated lower mortality rates in the presence of isopropanol and recovered better during long-term ethanol exposure than the maraena whitefish. Atlantic sturgeon cells have higher adaptation potential for these alcohols. In summary, fish species respond very specifically to toxins and changes in temperature, and new ecotoxicological questions arise with increasing water temperatures.

Establishment of an in vitro model from the vulnerable fish species Coregonus maraena (maraena whitefish): Optimization of growth conditions and characterization of the cell line

“…Since the cells of this cell line have a very high proliferation rate, it can also be used as a high‐throughput test system and therefore, find application in applied research. We have already been able to demonstrate this application within a toxicological study, in which we studied the effects of different toxins and concentrations on cell reactions at different temperatures (Grunow, Franz et al, 2021). This study shows that the cell physiology of C. maraena has very complex responses and much research needs to be done in future studies.…”

“…Furthermore, the cell line was characterized via immunocytochemistry and gene expression analysis. The detailed description of this cell line is therefore also significant, as we have already demonstrated the application for ecotoxicological studies to investigate cell response in relation to solvent, exposure time and temperature (Grunow, Franz et al, 2021). The results of this study indicate that cell physiological processes differ between fish species and in vitro models are urgently needed to study and understand them.…”

“…), in vitro cell culture systems can serve as an invaluable tool. The high potential of fish cell cultures could be already shown in other fields of research, like ecotoxicological studies (Drieschner et al, 2019;Grunow, Franz et al, 2021;Scott & Minghetti, 2020), in fish virology (Kumar et al, 2019;Noguera et al, 2017;Ruiz-Palacios et al, 2020), and for hazard assessments (Bermejo-Nogales et al, 2017;Castaño et al, 2003). In the past few years, fish cell lines could serve as an alternative to animal experiments, depending on the research topic (Schirmer, 2006;Tanneberger et al, 2013).…”

Embracing prospects for reducing the numbers of animals used in aquaculture research

“…In vitro studies are often carried out using 3–15 fish, depending on the type of experimental setup. In aquaculture research, it is possible to design lab‐based trials where we can test how fish (i.e., cells, tissues, organs) respond to different stimuli relevant to production, such as new dietary ingredients, pathogens, toxins, and chemotherapeutics, among a few others (Chang et al, 2021; Goswami et al, 2022; Grunow et al, 2021; Løkka et al, 2023; Pasquariello et al, 2023). However, these strategies are sometimes met with skepticism because of the argument that the multiwell plates cannot reflect the complex aquatic environment, which to some extent is true.…”

Effects of Temperature Adaptation on the Metabolism and Physiological Properties of Sturgeon Fish Larvae Cell Line

“…In 2011, Grunow et al succeeded in establishing a cell line derived from Atlantic sturgeon larvae known as AOXlar7y (Acipenser oxyrinchus larvae number 7) through trypsin digestion [18]. This cell line has already been used in studies on temperature adaptation and ecotoxicology [19,20].…”