Polyethylene microparticles may cause the disruption of the rainbow trout’s immune system

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00027162%3A_____%2F21%3AN0000177" target="_blank" >RIV/00027162:_____/21:N0000177 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Polyethylene microparticles may cause the disruption of the rainbow trout’s immune system

Original language description

Despite efforts to reduce the need for plastics, the worldwide production and use of plastic products is enormous. In addition to their ability to mechanically damage the digestive system of aquatic invertebrates and vertebrates, another major risk of plastic particles is their capability to disintegrate into smaller particles, so-called microparticles, which are commonly defined as particles <5 mm in size. Some authors have already described the ability of these microparticles to further disintegrate in the digestive tract and penetrate the tissues of the various organisms. One of the main tasks of our study was whether plastic particles in microsizes can cause inflammatory changes in the body organs and possible disruption of the immune system. One of the most interesting findings of this experiment was the presence of numerous skin lesions on the body surface of exposed groups. Disruption of the skin barrier can have a serious impact on an individual's innate immunity. These findings were also confirmed by histological images in which an increased presence of mucinous cells was observed in response to innate-immunity stimulation. Oral intake of the PE particles also disrupted the intestinal mucosa, on which visible cracks and an increased amount of mucus were detected by electron microscopy in an attempt to prevent mechanical damage to the intestine integrity. However, the most affected organs by PE were gills, liver and kidneys, i.e. organs important for metabolic and detoxification processes. Inflammatory lesions and extensive structure alterations were observed in gills of all PE exposed groups; this could negatively affect oxygen exchange with the external environment. In liver, wide hepatodystrophies were observed histologically for all PE groups and the pro-inflammatory cytokines, tumour necrosis factor alpha (tnfa) and interleukin 8 (il8), had increased mRNA amounts in 2% PE. Same cytokines were also increased in cranial kidneys (5% PE) together with the multiple pigment deposits and hyalinosis of tubules observed histologically in all PE exposed groups. Hyaline droplets are considered to be a marker of degeneration process, tubular necrosis, functional disorders or even neoplasia. Both tnfa and il8 are related to a positive immune response that suggest that the diet supplementation with PE may cause tissue inflammation. Moreover, pathological processes found in gills, liver and kidney together resulted in reactive oxygen species release which was confirmed by the significantly increased antioxidant capacity of plasma in 2% PE indicated by the ferric reducing ability of plasma, i.e. FRAP marker. A leukocyte amount decreased with the increasing PE concentration which could be a result of leukocyte migration to the site of the inflammatory process. This was supported also by increased mRNA amounts of tnfa and il8 in organs which are responsible, among other, for regulation of leukocyte migration and phagocytosis. Given all the results obtained during experiment, authors can state that there was a significant disruption of the immune system caused by PE, especially in higher tested concentrations.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

40301 - Veterinary science

Project

<a href="/en/project/EF16_019%2F0000869" target="_blank" >EF16_019/0000869: Sustainable production of healthy fish in various aquaculture systems - PROFISH</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů