Tracking micro- and nanoplastics in Aedes albopictus: From ingestion to metabolic disruption

Abstract

Urban aquatic environments are increasingly contaminated with micro- and nanoplastics (MNLPs), posing risks to biodiversity and human health. These environments are ideal breeding sites for larvae of the Asian tiger mosquito Aedes albopictus, a key arbovirus vector. While plastic pollution is a global concern, physiological and metabolic consequences of MNPL-exposure in mosquitoes remain poorly understood. Combining epifluorescence and confocal imaging, mosquito life-history parameter assessment, and high-throughput metabolomic profiling, we investigated the effects of polystyrene MNPLs on Ae. albopictus. We demonstrated that ingested MNPLs cross the larval gut barrier, persist in various tissues, and are retained through development. Exposure did not significantly affect pre-imaginal survival or development time, but reduced larval body weight and caused profound metabolic alterations. Metabolomic analyses revealed downregulation of central carbon metabolism, particularly glycolysis and pentose phosphate pathway, alongside amino acid alterations linked to stress responses. Notably, MNPL-exposure also affected juvenile hormone biosynthesis, suggesting endocrine disruption. This trend was observed in both NP- and MP-exposed larvae, with a greater number of differentially regulated metabolites following MP-treatment. Interestingly, TCA cycle dysregulation was more pronounced in NP-exposed larvae, whereas perturbations in glutathione metabolism, amino sugar metabolism and nitrogen excretion were associated with MP-exposure. These findings highlight the metabolic and physiological consequences of MNPL-exposure, with potential implications for mosquito ecology, vector capacity, and environmental dissemination of plastic contaminants. Given the role of Ae. albopictus in disease transmission and its adaptation to urban habitats, further research is needed to explore the long-term ecological and epidemiological consequences of plastic pollution on mosquito populations.