Oral Exposure to Microplastics Affects the Neurochemical Plasticity of Reactive Neurons in the Porcine Jejunum.

Plastics are present in almost every aspect of our lives. Polyethylene terephthalate (PET) is commonly used in the food industry. Microparticles can contaminate food and drinks, posing a threat to consumers. The presented study aims to determine the effect of microparticles of PET on the population of neurons positive for selected neurotransmitters in the enteric nervous system of the jejunum and histological structure. An amount of 15 pigs were divided into three groups (control, receiving 0.1 g, and 1 g/day/animal orally). After 28 days, fragments of the jejunum were collected for immunofluorescence and histological examination. The obtained results show that histological changes (injury of the apical parts of the villi, accumulations of cellular debris and mucus, eosinophil infiltration, and hyperaemia) were more pronounced in pigs receiving a higher dose of microparticles. The effect on neuronal nitric oxide synthase-, and substance P-positive neurons, depends on the examined plexus and the dose of microparticles. An increase in the percentage of galanin-positive neurons and a decrease in cocaine and amphetamine-regulated transcript-, vesicular acetylcholine transporter-, and vasoactive intestinal peptide-positive neurons do not show such relationships. The present study shows that microparticles can potentially have neurotoxic and pro-inflammatory effects, but there is a need for further research to determine the mechanism of this process and possible further effects.

Influence of polyethylene terephthalate (PET) microplastic on selected active substances in the intramural neurons of the porcine duodenum.

BACKGROUND: Currently, society and industry generate huge amounts of plastics worldwide. The ubiquity of microplastics is obvious, but its impact on the animal and human organism remains not fully understood. The digestive tract is one of the first barriers between pathogens and xenobiotics and a living organism. Its proper functioning is extremely important in order to maintain homeostasis. The aim of this study was to determine the effect of microplastic on enteric nervous system and histological structure of swine duodenum. The experiment was carried out on 15 sexually immature gilts, approximately 8 weeks old. The animals were randomly divided into 3 study groups (n = 5/group). The control group received empty gelatin capsules once a day for 28 days, the first research group received daily gelatin capsules with polyethylene terephthalate (PET) particles as a mixture of particles of various sizes (maximum particle size 300 µm) at a dose of 0.1 g/animal/day. The second study group received a dose ten times higher-1 g/animal/day. RESULTS: A dose of 1 g/day/animal causes more changes in the enteric nervous system and in the histological structure of duodenum. Statistically significant differences in the expression of cocaine and amphetamine regulated transcript, galanin, neuronal nitric oxide synthase, substance P, vesicular acetylcholine transporter and vasoactive intestinal peptide between control and high dose group was noted. The histopathological changes were more frequently observed in the pigs receiving higher dose of PET. CONCLUSION: Based on this study it may be assumed, that oral intake of microplastic might have potential negative influence on digestive tract, but it is dose-dependent.

New insights into the potential effects of PET microplastics on organisms via extracellular vesicle-mediated communication.

Plastics have become an integral part of our daily lives. In the environment, plastics break down into small pieces (<5 mm) that are referred to as microplastics. Microplastics are ubiquitous and widespread in the environment, and all living organisms are exposed to their effects. The present study provides new insights into the potential effects of polyethylene terephthalate (PET) microplastics on organisms via extracellular vesicle (EV)-mediated communication. The study demonstrated that serum-derived EVs are able to transport plastic particles. In addition, PET microplastics alter the content of miRNA in EVs. The identified differentially regulated miRNAs may target genes associated with lifestyle diseases, such as cardiovascular or metabolic diseases, and carcinogenesis. This work expands our understanding of PET microplastics' effects on organisms via EV-mediated communication and identifies directions for further research and strategies.