【作者】 卓梅琴； 罗智； 吴坤； 朱庆玲； 郑家浪； 张丽晗； 陈启亮；

【Author】 Mei-Qin Zhuo;Zhi Luo;Kun Wu;Qing-Ling Zhu;Jia-Lang Zheng;Li-Han Zhang;Qi-Liang Chen;Fishery College,Huazhong Agricultural University;

【机构】 华中农业大学水产学院；

【摘要】 通过建立体外分离黄颡鱼肝细胞模型,探讨不同胰岛素浓度(0,10,100,1000 n M)不同孵育时间下(0,24,48 h),肝细胞内甘油三酯(TG)的含量,以及脂肪酸合成酶(FAS)、葡萄糖6磷酸脱氢酶(G6PD)、6-磷酸葡萄糖酸脱氢酶(6PGD)、肉碱脂酰转移酶I(CPT I)等脂代谢相关酶活性的变化和基因的表达,以及脂代谢相关转录因子胆固醇调节元件结合蛋白I(SREBP-1)、过氧化物酶体增殖物激活受体α(PPARα)的表达变化。结果显示:胰岛素能够提高离体肝细胞TG的含量,同时促进FAS,G6PD,6PGD的酶活性和基因的表达,并且降低CPT I基因的表达,但不影响CPT I酶活性,此外胰岛素还能促进转录因子SREBP-1的表达,但是降低PPARα的表达,并且这些变化在48-h尤为显著。本实验结合了脂肪合成和分解相关基因的共同探讨,从酶活性水平与m RNA水平相互验证,以及转录因子与相关基因表达的相关性分析,比较系统的探讨了胰岛素对黄颡鱼肝细胞脂代谢的调控作用,有望为胰岛素在黄颡鱼体内的深入研究奠定基础。更多还原

【Abstract】 Freshly hepatocytes were isolated from yellow catfish, cultured and subjected to different insulin levels(0, 10, 100 and 1000 n M) for 0 h, 24 h and 48 h. Triglyceride(TG) content, activity and expression of several key enzymes involved in lipid metabolism, as well as m RNA levels of key transcription factors related to lipid metabolism were assessed. Insulin incubation tended to increase the activities and expression of several lipogenic enzymes(such as FAS, G6 PD, 6PGD). However, reduced CPT I gene expression was observed in hepatocytes following incubation treatment. Insulin administration also tended to up-regulate SREBP-1 expression but down-regulate PPARα m RNA levels. Insulin incubation enhanced lipogenesis and reduced lipolysis of freshly isolated hepatocytes of yellow catfish, in coincidence with increased TG content. Pearson correlations between expression of SREBP-1 and PPARα, and expression and activity of several enzymes were also observed, especially at 48-h insulin incubation. To our best knowledge, this is the first to study the effects of insulin on lipogenesis and lipolysis at both transcriptional and enzymatic levels using primary hepatocytes culture model in fish, which will help to understand the regulation of lipid metabolism by insulin in vivo.更多还原