Effect of Al2O3NPs on gene expression in Daphnia magna: Implications for environmental risk assessment
Nina Doskocz, Katarzyna Anna Affek, Magdalena Matczuk, Monika Załęska-Radziwiłł
This study investigates the expression of molecular biomarkers related to cellular functions such as oxidative stress, detoxification, and mitochondrial electron transport in Daphnia magna when exposed to aluminum oxide nanoparticles (Al₂O₃NPs) present in wastewater, both before and after biological treatment, and in their pristine form. The problem of increasing nanoparticle pollution in aquatic environments, particularly their presence in treated wastewater, poses significant environmental and ecological risks. Despite extensive research on nanoparticle toxicity, there is a lack of understanding of how different forms of Al₂O₃NPs (pristine and wastewater-borne) affect gene expression, especially over varying exposure durations. The novelty of this study lies in assessing the molecular impacts of Al₂O₃NPs under environmentally realistic conditions, including treated and untreated wastewater, using D. magna as a model organism. Results from qRT-PCR after 48 h and 21 days of exposure revealed increased expression of oxidative stress-related genes (cat, gst) and mitochondrial dysfunction-related genes (nadh). These findings highlight the persistent bioactivity and potential toxicity of NPs even post-treatment, emphasizing the need for effective monitoring and regulation. This study contributes to bridging the gap in understanding the genetic-level impacts of nanoparticle pollution in freshwater ecosystems.