Study Of TAA Effect On PPAR/RXR Conduction Pathway To Induced Liver Fibrosis In Zebrafish

As an organosulfur compound,thioacetamide(TAA)can hinder the synthesis of some key proteins in the liver through a series of oxidation reactions after entering the liver,and can also affect the metabolism of enzymes in liver cells,and eventually induce liver damage.The liver is one of the important metabolic organs of the body,and TAA is activated by liver microsomal metabolism,resulting in oxidative stress and liver parenchymal cell necrosis.Peroxisome proliferator-activated receptors(PPARs)are key nuclear receptors and transcriptional regulators in the liver.The activated PPAR ligand binds to retinoic acid X receptors(RXR)to form heterodimers,which can affect the expression of related genes during lipid metabolism,glucose metabolism,and inflammatory response.Bexarotene(Bexarotene,Bex)is an RXR nuclear receptor agonist that promotes the formation of heterodimers between RXR and its receptor chaperone,regulating the expression of genes that control cell differentiation and proliferation.Our study aims to explore the molecular mechanism of TAA-induced liver fibrosis in zebrafish and provide a theoretical basis for establishing a drug evaluation model for liver fibrosis in clinical practice.In this study,zebrafish embryos were selected 4 hours after fertilization(HPF)in liver and pancreatic double-transgenic zebrafish.A liver fibrosis model was constructed by soaking in 48 hpf with 0.06%TAA culture water for 6 days.The experiment was divided into control group,0.06%TAA group,6.25 ng/mL Bex group,TAA+Bex group.After 6 days of TAA treatment,HE staining of whole fish slices showed liver tissue structure disorder and decreased number of liver cells.Sirius red staining and Masson staining show pronounced collagen fiber deposition.Transcriptome analysis showed that a total of 1696 differentially expressed genes were enriched between the TAA group and the control group.GO enrichment analysis of differentially expressed genes showed that these differentially expressed genes were involved in various bioactive functions such as lipid transport and peroxidase activity.The results of KEGG enrichment analysis showed that PPAR signaling pathway and retinol metabolism were closely related to TAA-induced liver fibrosis of juvenile zebrafish.The number of hepatocytes increased after Bex treatment compared to the TAA group(p<0.01).Sirius red staining and Masson staining showed that collagen fiber deposition was significantly lower than that in the TAA group(p<0.01).Overall oil red O staining showed that fat accumulation in zebrafish liver in the Bex group was reduced.A-SMA antibody staining showed that the level of a-SMA was significantly increased after TAA treatment(p<0.01).Further qPCR detection showed that the expression levels of aldh3,collal,acta,mmp and ppar genes showed an upward regulation trend with the transcriptome.The results showed that PPAR/RXR was involved in regulating TAA-induced zebrafish liver fibrosis by controlling lipid metabolism and retinol metabolism homeostasis.