The Role Of Lipophagy In DEHP-induced Renal Ferroptosis In Quail

Di-2-ethylhexyl phthalate(DEHP)is considered to be one of the most widespread environmental pollutants worldwide as a plasticiser that can easily escape from its carrier into the environment and cause pollution to the atmosphere,water and soil.Studies have shown that DEHP is developmental,reproductive,endocrine and immunotoxic.These toxic effects may have adverse effects on the growth and development,reproductive capacity,endocrine and immune system of animals,posing a potential threat to human health and the environment.As a commonly used laboratory animal,quails are small,inexpensive to keep and high sensitivity to poisons,making them suitable for studies on physiology,pathology and drug metabolism.The kidney is the main organ for metabolising environmental toxins in most species,including quail.However,current research on the mechanisms of kidney damage by DEHP is relatively scarce.In this context,to investigate the specific mechanisms of kidney damage caused by DEHP in quail,150 female quail were divided into blank control,lysate control and DEHP-infected groups(250,500 and 750 mg/kg BW/d)and after 45 days of gavage treatment.Observe the morphological structure of the kidney.Detection of biochemical parameters of renal function,oxidative stress markers and glutathione level.And the expression level of genes and proteins related to lipophagy and ferroptosis signalling pathways were determined.The test results show that:(1)DEHP exposure caused atrophy of the glomerular volume,enlargement of the Bowman’s capsule lumen,loss of tubular lumen,abnormal renal cell ultrastructure,reduction or absence of mitochondrial cristae,and other pathological damage.Increased levels of biochemical indicators related to renal function such as Cys C,Scr,BUN and UA.These results indicated that DEHP can cause pathological damage and impaired function of the kidney.(2)DEHP exposure decreased TG level,affected the normal expression level of lipophagy-related factors(ATG5,ATG7,ATG9,RAB7A and LC3B)and AMPK/ULK1-PLIN2 signalling pathway-related factors(PPAR-α,AMPK,ULK1 and PLIN2).These results indicated that DEHP activated of the AMPK/ULK1-PLIN2 signalling pathway and induced the development of renal lipophagy.(3)DEHP exposure induced renal oxidative stress and impaired glutathione metabolism,induced iron accumulation,affected factors related to the iron metabolic pathway(FPN,FTH1 and TFRC),System Xc~-/GPX4 pathway-related factors(SLC7A11,SLC3A2 and GPX4)and lipid metabolic pathway-related factors(ACSL4,PTGS2 and LPCAT3).These results indicated that DEHP induced iron-dependent lipid peroxidation in the kidney and promoted the development of ferroptosis.In summary,DEHP induced renal iron accumulation and oxidative stress by affecting the iron metabolism,System Xc~-/GPX4 and lipid metabolism pathway.At the same time,the activation of the AMPK/ULK1-PLIN2 signalling pathway induced renal lipophagy and released large amounts of free fatty acids,which further promoted the process of renal ferroptosis.This study revealed the mechanism of renal lipophagy induced by DEHP exposure,elucidated the potential link between lipophagy and renal ferroptosis.This study provides new evidence for the prevention and treatment of DEHP-related diseases.