Identification of microRNA-mRNA regulatory network associated with microplastic exposure in Mytilus galloprovincialis

Abstract

The ever-growing plastics production and their natural fragmentation in micro- and nanoparticles have made plastic debris ubiquitous, with aquatic environments as the final collection basin. Plastic pollution is responsible for physical damage and biological pathways disruption in marine animals at almost all trophic levels, interfering with primary processes as development, growth, and reproduction. Micro- and nanoplastics accumulate in the food chain and represent a concrete risk for human health. Mussels have a worldwide spread and, as a starring seafood product, may constitute an important vehicle for microplastic uptake in humans.

Micro- and nanoplastics affect biological processes at the nuclear level, altering DNA methylation and gene regulators, including long non-coding (lncRNAs) and microRNAs (miRNAs). MicroRNAs, interacting with several mRNA targets, can prompt several processes, including antioxidant responses, inflammation, immune system cell recruitment, up to apoptosis.

The present study investigates the impact of microplastic particles on the modulation of microRNAs in adult mussels Mytilus galloprovincialis and the identification of microRNA-mRNA regulatory network. In this work, we exposed adult mussels to different concentrations and several temporal window to polystyrene monodispersed microparticles and analysed the expression of selected microRNAs and related target genes. Our results revealed that microplastic exposure induces miRNAs modulation and target genes associated with the activation of specific regulatory networks, including immune response, cellular stimuli response, protein interactions, apoptosis, and cell death.

This study provides new insights into the microplastic capability to affect gene expression and regulatory pathways mRNA miRNA-regulated, contributing to wider knowledge about the adverse effects of plastic pollution and providing useful data for further trials, not just in nature, but also in human health.