Study On Oxidative Damage And Hepatic Injury Mechanism Of Furan In BALB/c Mice Model Based On High-throughput Sequencing Technology

This research was funded by the National Natural Science Foundation of China(31471666).Furan is a contaminant commonly found in hot processed foods.It has carcinogenic effects on the rodent model and is potentially carcinogenic to human.The purpose of this study is to investigate the mechanism of oxidative damage and liver injury at the molecular level by studying the systemic inflammation,various organ damages and the transcriptome changes induced by different doses of furan.Firstly,the oxidative damage of furan on different organs of mice was investigated.80 male BALB/c mice were orally administered with 0,8,24 and 40 mg/kg b.w./day furan and the general state(morphology,body weight),oxidative stress level(reactive oxygen species,DNA damage index),and systemic inflammatory response were analysed after 15 days,30 days,45 days,and 60 days of administration.IL-1?,IL-6,IL-10,TNF-? levels,tissue oxidative damage indexes(superoxide dismutase and malondialdehyde),and histopathological changes(liver,kidney,cerebral cortex,and hippocampus)were detected.The results showed that furan exerts obvious oxidative damage on mice.Furan could induce a significant increase in ROS in the serum of mice.Accumulated ROS will attack DNA,trigger the increase of 8-OHd G,a DNA oxidative damage index.The injury can also up-regulate serum pro-inflammatory factors IL-1?,IL-6,TNF-?,and down-regulate the content of anti-inflammatory factor IL-10;furan can reduce the activity of antioxidant enzyme SOD in liver,kidney,spleen and testis,increase the content of MDA,and increase the content of AST,ALT,ALP,TBA,BUN,Cr and LDH in serum,and affect liver and kidney function.Pathological sections show low-dose furan can induce inflammatory cell infiltration in the hepatic lobular,and high-dose will induce fibrosis around the lobules.The kidney developed symptoms of inflammatory cell infiltration,and occasionally the epithelial cells were hyaline degenerated with prolonged administration time.There were no obvious lesions in the cerebral cortex and hippocampus in any section.Among the four tissues examined,the liver was the most sensitive organ to furan,so it is exactly the target organ of oxidative damage of furan.In addition,furan-induced changes in liver transcriptome were studied based on high-throughput sequencing technology.Combined with former research,the liver tissues after 60 days of high-dose administration were selected as the gene sequencing samples.The regulation of liver m RNA was detected by Illumina high-throughput sequencer,2750 genes were significantly regulated.The GO function analysis and KEGG signal pathway analysis were performed based on the differentially expressed genes.The expression of ten genes in the Wnt signaling pathway was verified by q PCR.The results showed that furan(40 mg/kg b.w./day)significantly up-regulated the genes related to oxidative stress,inflammation and cancer,and down-regulated the expression of antioxidant enzymes,xenobiotic metabolism,and solute carrier organic anion transporter family genes.Furan caused a series of disorders of function and signaling pathways related to furan toxicity,such as oxidative stress,bile secretion and Wnt signaling pathway.Collectively,it was proved that furan has a strong influence on the gene expression of the mice liver.58 differentially expressed genes were enriched in the oxidative stress item.There were multiple genes encoding key proteins in the bile secretion and the Wnt signaling pathway were regulated as well.The expression differences of these genes may trigger and develop toxic reactions of furan.In summary,furan induced significant oxidative damage in the mouse model,and liver was its target organ.Furan also affected the kidney,spleen and testis to some degree.The high expression of oxidative stress-related genes induced by furan and the disorder of bile secretion pathway may be involved in the occurrence and development of the inflammation,and the disorder of Wnt signaling pathway may be a turning point between the hepatocyte regenerative response and the carcinogenesis induced by furan.This thesis can provide a theoretical basis for the establishment of the furan injury model,the mechanism of liver injury and the mitigation of toxic injury.