| Food safety is an important issue affecting people all over the world,food can be contaminated in the process of production and distribution.Bisphenol A(BPA)is a typical endocrine disruptor.2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline(MeIQx)andacrylamide(ACR)are main carcinogens from food thermal processing.In recent years,epidemiological studies have shown that BP A,MelQx and ACR are all associated with many adverse health effects,which can impair the function of multi-organ system,metabolic function,and have potential carcinogenicity.However,whether the above substances will affect autophagy and the exact effect on autophagy remains to be studied.This paper systematically studies the effects of the above three harmful substances in food on autophagy and related molecular mechanisms,and in combination with metabonomics and lipidomics methods to explore the effects of these harmful substances on the body’s metabolism.The main research contents and results are as follows:1 Effect of Bisphenol A(BPA)on autophagy and its molecular mechanismIn this section,the expression of autophagy proteins and changes in autophagy flux were detected by western blot and immunofluorescence techniques,to determine the effect of BPA on autophagy.These results showed that BPA significantly up-regulated the protein expression levels of LC3-II and p62,and increased the amount of positive LC3 and p62 puncta.These results of autophagy flux detection showed that BPA inhibited autophagy flux,significantly reduced the colocalization between LC3 and LAMP2,indicating that BPA inhibits the fusion process of autophagosomes and lysosomes.Subsequently,we investigated the mechanism of BPA interfering with the fusion of autophagosomes and lysosomes,these results suggested that BPA inhibited the classic autophagy pathway dependent on Atg5.In addition,BPA weakened the interaction between Stx 17-Snap29-Vamp8 proteins,and inhibited the formation of SNARE complexes.Meanwhile,BPA increased ROS levels and lipid droplet content.In summary,BPA inhibits the Atg5-dependent classic autophagy pathway by disrupting the interaction of Stx17-Snap29-Vamp8 proteins.The impaired autophagy flux can cause increased ROS levels and lipid droplet accumulation.2 Effect of 2-Amino-3,8-dimethyIimidazo[4,5-f]quiinoxaIine(MeIQx)on autophagy and lipidomicsIn this chapter,we explored the effects of MelQx on autophagy and its molecular mechanism.Our results showed that MeIQx significantly increased the colocalization of LC3 and LAMP2;however;,we found that the red fluorescence intensity of LysoTracker Red was significantly decreased when exposed to MeIQxs indicating that MeIQx effectively disturbed the acidic environment of lysosomes and inhibited autophagy.In addition,we explored the effects of MeIQx exposure on lipidomic profiles,the result showed that a clear separation between the control and MeIQx-treated groups,no overlap.Based on VIP>1,P<0.05 in the PLS-DA model,a total of 76 lipid metabolites with significant differences were identified.Three kinds of phospholipid species,including PE,PC,and CL,were significantly upregulated upon exposure to MelQx when compared with control group,SM,HexlCer and ChE were also increased.In contrast,the levels of DG and AcCa were significantly reduced.In summary,MeIQx effectively prevents autophagosome maturation by inhibiting lysosomal acidification,can alter lipid rnetabolism of cells,especially increased phospholipids and sphingolipids.3 Effect of Acrylamide(ACR)on autophagy and metabonomicsIn this work,we detected the expression of autophagy protein to investigate the effect of ACR on autophagy.There results showed that ACR blocked autophagy flux.In addition,we compared the metabolic difference between ACR-treated and control group by untargeted metabonomics analysis method,and determined key differential metabolites in combination with multivariate analysis.We found that exposure to ACR exhibited a distinct difference in metabolic profiles from principal component analysis(PCA),partial least squares-discriminant analysis(PLS-DA)and hierarehial clustering analysis in comparison with controls,indicating that ACR can significantly change the body’s metabolite levels.Based on VIP>1,P<0.05 in the PLS-DA model,a total of 73 key differential metabolites were identified,ACR significantly up-regulated amino acids(L-Threonine,L-Tryptophan and L-Phenylalanine,etc.),fatty acids and lipids levels(Lauric acid(12:0),LPA and LPC,etc.),down-regulated glycolytic intermediates(Fructose-1,6 bisphosphate,Dihydroxyacetone phosphate and Gluconate-3 phosphate,etc.)and TCA cycle intermediates(Isocitric acid,Malic acid and Methylmalonic acid).In summary,ACR inhibits autophagy flow and interferes with cell metabolic homeostasis... |
PDF Full Text Request