Effects Of Sub-Chronic Avermectin Poisoning On Autophagy In The Brain Of Pigeon

Avermectin (AVM) was used in agriculture and veterinary medicine for the prevention of parasitic diseases, which had good insecticide resistance and safety. With intensive use of AVM, it could accumulate in the environment, which had an adverse effect on ecosystem. Due to the pigeons were sensitive to the change of exogenous substances in the environment, they were regarded as the preferred experimental animal for monitoring of ecological environment pollution. In this study, the brain tissues of pigeon in vivo were the research targets which fed with AVM at final concentrations of0mg/(kg-diet),20mg/(kg-diet),40mg/(kg-diet) and60mg/(kg-diet) respectively in30d,60d and90d. And the subchronic AVM poisoning model was constructed. In the study, we investigated the changes of the mRNA levels of autophagy related genes (LC3, Beclin1, Dynein, ATG5, ATG4B, and TOR) and the protein levels of (LC3, Beclin1, and Dynein)and ultrastructure on pigeon brain tissues after sub-chronic exposure to AVM for30d,60d and90d to research the effects of avermectin on autophagy in the brain of pigeon. It would provide the scientific evidence for toxicological information of AVM. The results showed as followed:1.In this study, we expressed fusion proteins of LC3in prokaryotic system. The polyclonal antibodies were prepared and antibody titer was about1:12800in New Zealand white rabbit, which was used to investigated the protein level of LC3in the brain tissues of pigeon.2. We found mitochondrial swelling, autophagosome, autolysosome and autophagic vacuole in the cerebrum, cerebellum and optic lobe different exposed to AVM by transmission electron microscopy. It proved that AVM could induce autophagy in the brain of pigeon from the perspective of morphology. And the number of autophagy in the cell was positively correlated with the exposure time and dose.3. Autophagy related genes in brain were detected by fluorescent quantitation RT-PCR and western blot. The decrease in mRNA level of TORC1and TORC2and increase in mRMA levels of LC3, Beclin1, Dynein, ATG5and ATG4B and the increase in the protein levels of LC3, Beclin1and Dynein in a dose-time-dependent manner in the brain of pigeon were observed. AVM induced pigeon brain autophagy by the way of influencing the content of autophagy-related genes.In summary, AVM could cause the change of the microstructure of brain tissues and the change of the mRNA levels of LC3, Beclin1, Dynein, ATG5, ATG4B and TOR and the change of protein levels of LC3, Beclin1, Dynein, which promoted the autophagy and caused the damage of brain. This study also provide rich theoretical basis and experimental basis for abamectin toxicology data.