| Objective: To investigate the effects of TNF-αinduced insulin resistance (IR)on lipid metabolism related gene expression in mice.Methods: Male C57BL/6J mice were randomly divided into 2 groups. The mice were given an intraperitoneal injection of TNF-α(TNF group , 6μg/kg/d ;n =10) and saline (NC group, n=10) twice daily for 7 days. The role of TNF-αwas being analyzed in vivo on related genes of lipid metabolism in the development of insulin resistance.Results: 1) After TNF-αtreatment, fasting blood glucose ( FBG ), plasma insulin and free fatty acids (FFA) were significantly elevated in TNF group compared with NC group (p< 0 .01 and p < 0.05, respectively). 2)Adipic INSIG2 mRNA expression and protein levels of TNF group were significantly higher than that of NC group (p <0 .01 and p <0 .05 , respectively),but no correlation was found between the two groups in liver tissues (p> 0.05). In TNF-αtreatment mice, SCAP mRNA levels in adipose and liver tissues were significantly up-regulated than the controls(P<0.05). The mRNA expressions of INSIG1,S REBP1 in two groups were not significantly changed(p>0.05).Conclusion: INSIG2 and SCAP might have been involved in the pathways of lipid metabolism in inducing insulin resistance mediated by TNF-a.PART 2 THE EFFECTS OF HIGH-FAT INDUCED INSULIN RESISTANCE ON LIPID METABOLISM IN APOE-/- MICEObjective: To establish an insulin resistance (IR) model and investigate the lipid metabolism in high-fat fed ApoE-/- mice.Methods: Healthy male ApoE-/- mice, eight-week-old, were randomly divided into normal-chow diet fed group (NF group, n=10) and high-fat diet fed group (HF group, n=10) and fed with corresponding food for 16 weeks. The mRNA expression and protein levels of some lipid metabolism related genes in adipose and liver tissues were measured by RT-PCR and western blot. Results: 1)Fasting blood glucose (FBG),Plasma insulin (PIns), free fatty acids (FFA), total cholesterol (TC), triglyeride (TG), low density lipoprotein (LDL-C) and high density lipoprotein(HDL-C) were significantly elevated in high-fat diet fed ApoE-/- mice (HF group) compared with normal-chow diet fed ApoE-/- mice (NF group, all P<0.01). 2)The mRNA expressions of INSIG1,INSIG2,SCAP,SREBP1 in adipose tissues and INSIG1,FAS,GK,PEPCK in liver tissues were not significantly changed(p > 0.05).In liver tissues, the INSIG2 mRNA expression and protein level in HF group were significantly higher than that of NF group (p<0.05).Compared with NF group,the mRNA expression of SCAP was also increased(p<0.01),but SREBP1 was decreased(p<0.05).Conclusion: INSIG2,SCAP and SREBP1 might have been involved in the pathways of lipid metabolism in induing insulin resistance mediated by high-fat fed ApoE-/- mice... |
PDF Full Text Request