胰岛素可逆性抑制牛脂肪细胞脂联素mRNA的表达  

Inverse Inhibition of Adiponectin mRNA Expression by Insulin in Bovine Adipocytes

作　　者：孙永刚[1] 昝林森[2,3] 王洪宝[2,3] 郭红芳[1] 赵宪林[3] 杨大鹏[3] 

机构地区：[1]西北农林科技大学动物医学院,杨凌712100 [2]西北农林科技大学动物科技学院,杨凌712100 [3]国家肉牛改良中心,杨凌712100

出　　处：《农业生物技术学报》2010年第1期45-51,共7页Journal of Agricultural Biotechnology

基　　金：国家十一五科技支撑计划奶业专项(No.2006BAD04A11);农业部公益性行业科技专项(No.nyhyzx07-035);西北农林科技大学拔尖人才支撑计划共同资助

摘　　要：本研究从中国荷斯坦新生公犊的脂肪组织中分离培养前脂肪细胞,体外诱导分化9d后,细胞变圆出现大量脂滴成为脂肪细胞,伴随着前脂肪细胞标志基因前脂肪细胞因子-1(preadipocyte factor-1,Pref-1)的表达消失和脂肪细胞标志基因过氧化物酶体增殖物激活受体-γ(peroxisome proliferator-activated receptor-γ,PPAR-γ)mRNA高丰度表达。利用半定量RT-PCR技术研究胰岛素对脂联素mRNA表达水平的影响,发现1nmol/L胰岛素对脂联素mRNA的表达水平没有影响(P>0.05),10nmol/L、100nmol/L和1000nmol/L胰岛素分别能显著抑制脂联素mRNA48.7%、61.4%和61.9%的表达(P<0.05)。进一步研究发现,100nmol/L胰岛素处理脂肪细胞24h内呈时间依赖性抑制脂联素mRNA的表达,这种抑制效应随胰岛素的除去脂联素的转录水平24h后恢复到对照水平,用LY294002抑制磷脂酰肌醇-3激酶(phosphatidylinositol-3kinase,PI3K/Akt)信号通路后,胰岛素对脂联素的转录没有影响。结果提示,体外胰岛素在脂肪细胞中能通过PI3K/Akt信号通路可逆性抑制脂联素mRNA的表达。In this research,preadipocytes were obtained from newborn Chinese Holstein calves and induced differentiation for 9 days.The cells became larger and circular accompanied by the small lipid droplets confluenting into large ones and increased mRNA expression of peroxisome proliferator-activated receptor-γ（PPAR-γ）.At same time,the expression of preadipocyte factor-1（Pref-1） was decreased and cells differentiated ultimately into typical adipocytes.Using semi-quantitative RT-PCR method,1 nmol/L insulin did not affect the expression adiponectin mRNA,but 10 nmol/L,100 nmol/L and 1 000 nmol/L insulin decreased expression adiponectin mRNA 48.7%,61.4% and 61.9%,respectively（P0.05）.Meanwhile,100 nmol/L insulin in time-dependent fashion inhibited expression adiponectin mRNA within 24 h.Further study found that removal of 100 nmol/L insulin from the medium for 24 h restored adiponectin mRNA to control levels.Furthermore,inhibition of phosphatidylinositol-3 kinase（PI3K/Akt） with LY294002 reverses the inhibitory effected of insulin on adiponectin mRNA expression.These results suggest that insulin at least partially suppressed the expression of adiponectin mRNA via the PI3K/Akt pathway.

关 键 词：牛脂肪细胞 胰岛素 脂联素 PI3K 

分 类 号：S823[农业科学—畜牧学]