Effect of short hairpin RNA-mediated adiponectin/Acrp30 down-regulation on insulin signaling and glucose uptake in the 3T3-L1 adipocytes
Effect of short hairpin RNA-mediated adiponectin/Acrp30 down-regulation on insulin signaling and glucose uptake in the 3T3-L1 adipocytes
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DOI：
10.3275/6481
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发表时间：
2010-02-01
影响因子：
5.4
通讯作者：
Boden, G.
中科院分区：
文献类型：
--
作者：
Li, K.;Li, L.;Boden, G.
脂联素是一种由脂肪细胞分泌的多肽激素，具有胰岛素增敏和抗炎特性。本研究通过下调脂联素对3 T3-L1脂肪细胞葡萄糖摄取的影响，进一步探讨脂联素对3 T3-L1脂肪细胞葡萄糖摄取的影响及其机制。转染短发夹状RNA（shRNA）载体后，脂联素mRNA表达及蛋白水平均显著降低。脂联素的下调显著降低细胞葡萄糖摄取率，增加细胞内甘油三酯含量。为了研究脂联素的生理作用机制，对胰岛素信号通路中的几个关键调节因子进行了研究。胰岛素受体底物（IRS）-1在基础和胰岛素刺激状态下的mRNA表达在转染细胞中均下调（分别为对照组的72%和52%），胰岛素刺激的IRS-1酪氨酸磷酸化也显著降低。脂联素缺乏的细胞表现出过氧化物酶体增殖物激活受体α，葡萄糖转运蛋白（GLUT）-1，GLUT-4，脂肪敏感脂肪酶（HSL）和脂肪甘油三酯脂肪酶的显著下调。这些结果表明，转染shRNA载体有效地降低了脂联素在3 T3-L1脂肪细胞中的表达，伴随着细胞葡萄糖摄取速率的显著降低和细胞内甘油三酯含量的增加。我们的数据还表明，脂联素缺乏可能通过IRS-1途径在体外损害胰岛素作用，并通过HSL下调部分增加细胞内脂肪积累。(J.年. Invest. 33：96-102，2010）（C）2010，Editrice Kurtis
Adiponectin is a polypeptide hormone that is secreted by adipocytes with insulin-sensitizing and anti-inflammatory properties. The current study was to further investigate the role of adiponetin on glucose uptake and its underlying mechanism by down-regulation of adiponectin in 3T3-L1 adipocytes. Transfection of short hairpin RNA (shRNA)-vector significantly decreased adiponectin mRNA expression and its protein level in the cells. The down-regulation of adiponectin markedly reduced the cellular glucose uptake rate and increased intracellular triglyceride content. To study the mechanism of the physiologic action of adiponectin, several key regulatory factors in insulin signaling pathway were examined. The mRNA expression of insulin receptor substrate (IRS)-1 in both basal and insulin-stimulated states were down-regulated in the transfected cells (72% and 52% of controls, respectively), and the insulin-stimulated IRS-1 tyrosine phosphorylation was also significantly decreased. Adiponectin-deficient cells showed marked down-regulations of peroxisome proliferator-activated receptor alpha, glucose transporter (GLUT)-1, GLUT-4, hormone-sensitive lipase (HSL), and adipose triglyceride lipase. These results thus demonstrated that transfection of shRNA-vector effectively reduced the expression of adiponectin in 3T3-L1 adipocytes accompanied with a significant decrease in cellular glucose uptake rate and an increase in intracellular triglyceride content. Our data also suggested that adiponectin deficiency impair insulin action in vitro probably through the IRS-1 pathway, and increase intracellular fat accumulation partially through HSL down-regulation. (J. Endocrinol. Invest. 33: 96-102, 2010) (C) 2010, Editrice Kurtis