Effects Of Glucose,fructose And Sucrose On Hepatic Lipid Deposition

Sugar is the essential nutrient for both cells and animals,but excessive intake of sugar will lead to lipid deposition in the liver.Glucose,fructose and sucrose are normally used as the inducers to build disease models related to abnormal sugar and lipid metabolism,but the mechanisms by which they inducelipid deposition are not very clear.Because goose liver has the specificity of liver lipid deposition,goose filling can be used to produce fatty liver in short term.The cultivation of goose primary hepatocytes with different sugars can provide a theoretical basis for the production of goose fat liver,and also to a certain extent reflect the performance of fatty liver of Tianfu goose maternal family.In this study,goose primary hepatocytes were cultured and treated with different concentrations of glucose,fructose and sucrose.The endoplasmic reticulum stress inhibitor 4-PBA was also added in combination with above sugar treatments.The phase of fatty acid synthesis,oxidation and transport were detected by fluorescence quantitative PCR,ELISA kit and oil red O staining.Analysis of the effects of different sugars on lipid metabolism.The effects of different sugars on endoplasmic reticulum stress,fatty acid synthesis,fatty acid oxidation and fatty acid transport were analyzed in order to provide a basis for the study of how different carbohydrates regulate the molecular mechanism of lipid deposition in goose liver.The main results are as follows:(1)Glucose,fructose and sucrose were used to treat goose primary hepatocytes for24 h,the cell viability of each treatment group increased.Oil red staining showed significant lipid droplets increase.(2)Compared with fructose,sucrose had a strong lipid deposition promoting effect,and can raise regulate the expression of lipid synthesis related genes such as FAS and ACC alpha.The higher the concentration leads to the more obvious up-regulation,and the promoting effect of fructose on lipid synthesis was weaker than that of glucose.Three kinds of carbohydrates had no significant effect on SREBP-1 gene expression.The expression of sucrose on FAS and ACC alpha was not significant.It indicates that fructose and glucose increase lipid deposition by increasing fatty acid synthesis.Sucrose had no significant effect on fatty acid synthesis.(3)Glucose,fructose and sucrose treatment did not promote the expression of fatty acid beta oxidation related genes such as ACOX1 and PPAR gamma(P > 0.05).Fructose could promote the gene expression of PPAR alpha(P<0.05),and 50mmol/L fructose,50mmol/ glucose and 30mmol/L sucrose could significantly reduce the gene expression of CPT-1(P<0.05).It was shown that the three sugars increase TG content by inhibiting fatty acid oxidation.Although sucrose did not promote fatty acid synthesis,it can increase the concentration of TG in the cells by inhibiting the oxidation of fatty acids.(4)The effect of sugar treatment on apolipoprotein B(ApoB)was not obvious,and there was no significant difference in gene expression and enzyme activity between the two groups.30mmol/L glucose significantly decreased DGAT1 gene expression(P<0.05),but there was no significant difference was found between the other groups(P > 0.05).50mmol/L sucrose can significantly reduce MTP gene expression(P<0.05),and 50mmol/L fructose treatment can significantly reduce the MTTP enzyme concentration(P<0.05).30mmol/L glucose,50mmol/L glucose,30mmol/L fructose and 50mmol/L fructose could significantly increase the gene expression of DGAT2(P<0.05),while 30mmol/L sucrose and 50mmol/L sucrose was not significantly different from those of the control group.Three kinds of carbohydrates had the effect of increasing lipid deposition by reducing lipid transport.(5)After adding endoplasmic reticulum stress inhibitor 4-PBA on the basis of sugar treatment,the expression of FAS and ACC related genes related to fatty acid synthesis induced by sugar +4-PBA treatment significantly decreased,and the expression of CPT-1and MTP increased.It is suggested that the three carbohydrates may increase lipid deposition and reduce lipid transport and oxidation by inducing endoplasmic reticulum stress.To summarize,glucose,fructose and sucrose promoted lipid deposition by increasing fatty acid synthesis,reducing fatty acid oxidation and transport,and they all increased lipid deposition through the endoplasmic reticulum stress pathway.