Suppression of Glutamine: Fructose-6-Phosphate Amidotransferase-1 Inhibits Adipogenesis in 3T3-L1 Adipocytes
Suppression of Glutamine: Fructose-6-Phosphate Amidotransferase-1 Inhibits Adipogenesis in 3T3-L1 Adipocytes
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DOI：
10.1002/jcp.22707
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发表时间：
2012-01-01
影响因子：
5.6
通讯作者：
Shin, Shyi-Jang
中科院分区：
文献类型：
--
作者：
Hsieh, Tusty-Jiuan;Lin, Tzu;Shin, Shyi-Jang
O-连接N-乙酰氨基葡萄糖(O-GlcNAc)蛋白修饰参与信号通路、细胞功能和基因表达的调节。谷氨酰胺：果糖-6-磷酸氨基转移酶-1(GFAT-1)是己糖胺生物合成途径(HBP)中的限速酶，产生糖核苷酸UDP-GlcNAc，该核苷酸作为O-GlcNAc修饰的供体。在这项研究中，我们确定了GFAT-1是否调节脂肪细胞的脂肪生成。3T3-L1前脂肪细胞在含高糖、胰岛素、地塞米松和异丁基甲基黄嘌呤的培养液中诱导分化。于分化开始后4、8、12h和1、2、3、4、6、8d取材。O-GlcNAc修饰的整体水平在诱导后4h升高，并持续观察8d。GFAT-1mRNA和蛋白在诱导后4h开始表达上调。药物抑制GFAT-1或GFAT-1 siRNA处理可阻断脂肪细胞O-GlcN酰化的增加和脂滴的形成。在脂肪形成过程中，GFAT-1可能调节C/EBPβ、PPAR-γ、SREBP-1、脂肪酸合成酶、S3-12、Perilipin或ADI的表达。我们的结果表明，GFAT-1通过调节脂肪细胞中蛋白质O-GlcN酰化，在调节脂肪细胞的脂肪生成中起着关键作用。J.细胞。物理。227：108-115,2012。(C)2011年威利期刊公司。
O-linked N-acetylglucosamine (O-GlcNAc) protein modification has been implicated in the regulation of signaling pathways, cell function, and gene expression. Glutamine: fructose-6-phosphate amidotransferase-1 (GFAT-1) is the rate-limiting enzyme in the hexosamine biosynthetic pathway (HBP), which generates the sugar nucleotide UDP-GlcNAc, where this nucleotide acts as the donor for O-GlcNAc modification. In this study, we determined whether GFAT-1 regulates adipogenesis in adipocytes. 3T3-L1 preadipocytes were differentiated using medium containing high glucose, insulin, dexamethasone, and isobutylmethylxanthine. Cells were harvested 4, 8, and 12 h and 1, 2, 3, 4, 6, and 8 days after the initiation of differentiation. Global level of O-GlcNAc modification increased 4 h after induction and persisted for 8 days of observation. GFAT-1 mRNA and protein expression was also upregulated beginning 4 h after induction. Pharmacological inhibition of GFAT-1 or GFAT-1 siRNA treatment blocked the increase in O-GlcNAcylation and the formation of lipid droplets in adipocytes. GFAT-1 may regulate the expression of C/EBP beta, PPAR gamma, SREBP-1, fatty acid synthase, S3-12, perilipin, or adipophilin during adipogenesis. Our results suggest that GFAT-1 plays a critical role in modulating adipogenesis via the regulation of protein O-GlcNAcylation in adipocytes. J. Cell. Physiol. 227: 108-115, 2012. (C) 2011 Wiley Periodicals, Inc.