| Aflatoxin B1((aflatoxin,AFB1),produced by Aspergillus flavus and Aspergillus parasiticus,is widely distributed in many crops and causes pollution to feed,and has strong teratogenic,carcinogenic and mutagenic effects on animals.In order to detect the toxicity of AFB1,zebrafish embryos(AB line and liver transgenic zebrafish)were used as model animals in this study to explore the developmental toxicity and mechanism of AFB1 from the morphological,histological,gene(omics)and protein levels.Zebrafish subjected to fertilization for 4 h(4 HPF)were used for AFB1 exposure(control group,0.05 μg/m L,0.075 μg/m L and 0.1μg/m L),and various indicators were detected at different development times.he results showed that AFB1 could induce hepatic steatosis and liver nucleus concentration.Compared with the control group,0.05 μg/m L,0.075 μg/m L,and 0.1 μg/m L groups showed increased nuclear concentration and concentration dependence.Correspondingly,AFB1 resulted in low liver area(inhibiting growth)of zebrafish.Compared with the control group,the liver fluorescence area of zebrafish in medium concentration group and high concentration group was significantly reduced,showing concentration dependence.Gene testing showed that AFB1 induced down-regulation of the expression levels of liver developmental genes(Hhex and prox1).The results showed that at 24 hpf,the Hhex and prox1 concentration groups showed a downward trend compared with the control group,but there was no significant difference At 48 hpf,the Hhex high-concentration and medium-concentration groups showed a decreasing trend compared with the control group,but there was no significant difference.Compared with the control group,the gene expression level of Prox1 in the high concentration group decreased significantly.At 72 hpf the expression levels of apoptosis-related genes(p53,Bcl-2,Bax)were detected.The expression levels of p53 gene in the high concentration group were significantly higher than those in the control group.Bcl-2 gene expression was significantly decreased in the control group compared with the high concentration group.The expression of Bax gene was significantly increased compared with the control group.Furthermore,AFB1 induced lipid metabolism disorder in zebrafish by regulating the expression levels of genes related to lipid balance(PPAR-α,PPAR-β,PPAR-γ)at 48 hpf and 72 hpf.These results suggest that the low liver area induced by AFB1 may be caused by the activation of apoptosis and the influence of gene expression level on liver development.istology,protein level detection,gene level detection,the results showed that: compared with the control group,high concentration group and medium concentration group liver tissue vacuole rate significantly increased.By Masson and Sirius red histological staining,blue collagen fibers were generated and concentration-dependent(p< 0.001).The high concentration group resulted in increased expression of α-smooth muscle actin protein and darker brown color compared to the control group.The expression levels of liver fibrosis(Hand-2,Acta-2)and inflammatory injury(Tgf-β,SDF)genes in zebrafish were detected.The results showed that the expression levels of Acta-2 genes in high concentration group were significantly increased compared with the control group.Compared with the control group,the gene expression level of Hand-2 was significantly increased in the medium-concentration and high-concentration groups.TGF-β gene expression level: compared with the control group,the gene expression level of medium concentration group and high concentration group was significantly increased.SDF gene discovery: Compared with the control group,the gene expression level of high concentration group and medium concentration group was significantly increased.This study showed that exposure to AFB1 in different periods can inhibit liver development and cause liver fibrosis,find out the related mechanism,build a model,and provide a high-throughput drug screening model for animal husbandry treatment of AFB1 damage. |
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