Identification of molecules implicated in insulin response of glucose transport in skeletal muscle and adinose tissue

我们利用3T3-L1细胞和3T3-C2细胞建立了诱导胰岛素敏感性的条件，如GLUT4的定位、细胞内囊泡的诱导和GLUT4在脂肪细胞分化中的易位增强。我们使用Affmetrix公司的DNA芯片检测了脂肪细胞分化每个步骤中基因表达的变化。使用这种技术，我们确定了在诱导高胰岛素敏感性时表达发生变化的基因。我们确定了大约100-150个已知基因的表达增加或减少。我们发现大约有200-300个ESTs的表达增加。此外，在这些基因表达谱的基础上，我们发现了与细胞内信号转导或转录调控有关的基因。我们用Western blot和Northern blot检测了这些基因在大鼠骨骼肌中的表达。我们在3T3-L1细胞和3T3-C2细胞中发现了一个转录因子，其表达在诱导胰岛素敏感性时增加。该转录因子在骨骼肌中也有表达。该因子在脂质代谢中起重要作用，并参与调节GLUT4囊泡中的一种分子。该分子可能连接脂肪细胞的脂质代谢和碳水化合物代谢。我们正致力于阐明该分子的生理作用。我们证实了与炎症、gtp结合蛋白、信号转导、细胞外基质相关的其他基因表达的变化。我们现在研究这些基因的表达是否受到已知的脂肪细胞分化转录调控。我们还研究了控制脂肪细胞分化的转录调控机制，这可能与GLUT4易位有关。

We established conditions for the induction of insulin sensitivity such as localization of GLUT4, induction of intracellular vesicle and enhancement of GLUT4 translocation in adipocyte differentiation using 3T3-L1 cells and 3T3-C2 cells. We examined changes of gene expression in each steps of adipocyte differentiation using DNA chips from Affmetrix company Using this technique, we identified genes the expression of which was changed on induction of high insulin sensitivity. We identified approximately 100-150 known genes the expression of which were increased or decreased. We found approximately 200-300 ESTs the expression of which were increased Furthermore, on the basis of these gene expression profiles, we picked up the genes implicated in intracellular signal transduction or transcriptional regulation. We checked the expression of the genes using Western blot or Northern blot in rat skeletal muscle. We identified one transcriptional factor the expression of which was increased on induction of insulin sensitivity in 3T3-L1 cells and in 3T3-C2 cells. This transcriptional factor was expressed also in skeletal muscle. This factor plays an important role in lipid metabolism, and is implicated in regulation of a molecule in GLUT4 vesicle. This molecule may connect lipid metabolism and carbohydrate metabolism in adipocyte. We are engaged in elucidation of physiological role of the molecule. We confirmed the change of expression of other genes which are implicated in inflammation, in GTP-binding protein, in signal transduction, extracellular matrix. We now examine whether these the expression of these genes are regulated by known transcriptional regulation in adipocyte differentiation. We also investigate mechanism of transcriptional regulation controlling adipocyte differentiation which may implicated GLUT4 translocation.