Mitophagy Induced By Mitochondrial Damage In Chicken Liver Exposed To Cr(?)

As a highly toxic heavy metal,in view of the threat to public health and livestock breeding caused by chromium pollution in recent years.Therefore,it is necessary to conduct a biosafety evaluation of chromium.It is of great scientific and social significance to study the toxicological mechanism of chromium in depth.Based on replicating the mitochondrial autophagy model of chicken liver tissue induced by Cr???,this experiment further clarifies the effect of Cr???on mitochondrial autophagy of chicken liver tissue by damaging mitochondria.In order to study the effect of Cr???on chicken liver tissue,120 healthy 1-day-old Hy-line Brown cockerels were selected for chronic chromium poisoning experiments and randomly divided into control,low,medium and high dose groups.Different doses of Cr???(10%LD₅₀,6%LD₅₀,2%LD₅₀,and 0%LD₅₀)were taken orally every day.The challenge was to feed the chicks with the full price of potassium dichromate.Feeding and drinking amounts were the same in each group.The test period is 45 days,with a sampling point every15 days.Ten chickens were randomly euthanized in each group on the 15th,30th,and 45th days.Immediately after euthanasia,the livers were separated then pieces with a size of 1mm×1 mm×1 mm were immersed in the fixing solution of the electron microscope for transmission electron microscopy.The remaining tissues were stored in an ultra-low temperature refrigerator for subsequent experiments.The levels of ROS,NADPH and ATP were measured by ELISA kits.We used the multi-mode microplate reader indicates the degree of mitochondrial membrane potential decrease.Western blot was used to detect LC3-II,p62/SQSTM1 and TOMM20 expression levels and Parkin displacement.The experimental results showed that with the increase of Cr???dose,the levels of NADPH,ATP,p62/SQSTM1 and TOMM20 in the liver decreased significantly?P<0.05?,and the levels of Parkin protein in ROS,LC3-II and mitochondria increased significantly?P<0.05?.Through transmission electron microscopy,autophagosomes and autolysosomes were observed in chicken liver tissues after 45 days of Cr???treatment.There is also a Cr???concentration dependence in the depolarization of mitochondria.In summary,through the above studies,it can be concluded that Cr???can cause mitochondrial damage and cause autophagic clearance of damaged mitochondria after to enter the chicken liver.And this phenomenon is concentration-dependent on Cr???.