摘要
Background Mitophagy is an essential cellular autophagic process which maintains mitochondrial homeostasis,but its role in high fat diet(HFD)-induced lipid accumulation is unclear in the yellow catfish.Thus,this study aimed to elucidate mechanism of mitochondria mediating HFD-induced hepatic fat accumulation.Results In the present study,yellow catfish were fed three diets with dietary fat at 6.31%(low fat;LFD,control),12.03%(middle fat;MFD)and 15.32%(high fat;HFD),respectively,for 8 weeks.High dietary fat addition raised hepatic lipid accumulation,and declined mRNA and protein levels of Parkin-dependent mitophagy,down-regulated the Parkin protein expression and the estrogen-related receptor alpha(Errα)ubiquitination,and induced Errαprotein levels;fatty acid(FA)incubation reduced Parkin-dependent mitophagy,inhibited Errαubiquitination and increased Errαprotein expression,and raised TG accumulation.Furthermore,yellow catfish hepatocytes were isolated and cultured.Nicotinamide mononucleotide,N-acetyl-L-cysteine,Parkin and errαsiRNA knockdown were used under FA incubation,respectively.Parkin downregulation mediated FA incubation-induced TG accumulation and mitoautophagic inhibition;Parkin ubiquitinated Errα,and K63 was an important ubiquitination site for deubiquitinating Parkin activity;Errαtargets fas,acca and pparγgenes,whose activation contributed to FA-induced lipogenesis and lipid accumulation.Thus,high fat diet(HFD)and FA incubation inhibited Parkin activity,suppressed mitophagy and activated Errαpathway,and induced hepatic lipogenic metabolism and lipotoxicity.Conclusions Overall,our study provided new targets against HFD-induced hepatic lipid accumulation and nonalcoholic fatty liver disease in the vertebrates.
基金
funded by National Key R&D Program of China(2024YFD2402000)。
