Expression of Caspase1,8,9 in liver tissue of high-fat diet mice

Objective The effects of high fat diet (HFD) on liver injury and Caspases expression were observed in mouse models,and the possible mechanisms were discussed. Methods C57BL/6J male mice were randomly divided into two groups after one week of environmental adaptation,and were given high-fat diet (high-fat group) or ordinary diet (normal group),respectively.The mice were fed for 4,8 and 12 weeks,and the levels of aspartate aminotransferase (AST),alanine aminotransferase (ALT),triglyceride (TG) and cholesterol (TC) were determined using biochemical methods.The expression levels of IL-1,IL-6 and TNF-α in serum and liver tissues were detected by ELISA.Another portion of liver tissue was embedded in paraffin,and the morphology of liver cells in each group was detected by hematoxylin-eosin staining (HE).The expressions of caspase-1,caspase-8 and caspase-9 proteins in liver of each group were observed using immunohistochemical staining and Western blotting. Results As the feeding weeks increased,the liver histopathological and pathological changes in the high-fat group were more severe compared with the normal group.The levels of AST,ALT,TG,TC,IL-1,IL-6,and TNF-α were increased.In the HE staining experiment,the morphology and structure of liver cells in the normal group were normal,while bulbous lipid droplets were seen in the liver tissue of mice in the high-fat group.In the immunohistochemical experiments,the cytoplasm of hepatocytes served as the anchor point for the expression of Caspase-1,Caspase-8 and Caspase-9,with positive expression appearing brownish yellow or brown.The staining was more pronounced in the high-fat group than in the normal group.In Western blot assay,the protein levels of caspase-1,caspase-8 and caspase-9 in the high-fat group were significantly higher than those in the normal group (P< 0.01). Conclusions Liver injury induced by high-fat diet may be related to the up-regulation of Caspase-1,Caspase-8 and Caspase-9 expression.