SIGNAL TRANSDUCT OF INSULINS METABOLIC EFFECT

胰岛素刺激葡萄糖向脂肪和肌肉的转运增加 通过引起胰岛素反应性葡萄糖的移位而引起组织 转运蛋白(GLUT4)从细胞内池到质膜。 胰岛素的靶组织不能以这种方式做出反应 非胰岛素依赖型糖尿病的主要缺陷之一。 然而，导致GLUT4易位的信号事件很少 明白了。这项提案的重点是调查 触发GLUT4的细胞内胰岛素信号通路 易位。胰岛素刺激机制的阐明 葡萄糖转运可能确定新的潜在治疗靶点 对胰岛素抵抗状态的干预。这些实验将是 在3T3-L1脂肪细胞中进行，其中胰岛素刺激的GLUT4 移位可以通过以下方式在单个细胞的基础上进行评估 抗GLUT4抗体免疫荧光染色。微量注射 将被用来将各种试剂输送到 激活或灭活特定的细胞内分子，这些分子可能 参与胰岛素的作用。几乎任何类型的试剂都可以输送 通过这种方式，如抗体、多肽和重组蛋白。那里 是否有许多潜在的信号分子将被研究 通过这个系统，包括胰岛素受体的底物，p21ras， Raf、MEK和ERK Ser/Thr激酶、磷脂酰肌醇3-激酶和 RAB小分子GTP结合蛋白。

Insulin stimulates increased glucose transport into adipose and muscle tissue by causing translocation of the insulin responsive glucose transporter (GLUT4) from an intracellular pool to the plasma membrane. The inability of insulin's target tissues to respond in this manner is one of the primary defects in noninsulin-dependent diabetes mellitus. However, the signaling events that lead to GLUT4 translocation are poorly understood. The focus of this proposal is to investigate the intracellular insulin signaling pathways that trigger GLUT4 translocation. Elucidation of the mechanism whereby insulin stimulates glucose transport may identify new potential targets for therapeutic intervention in insulin resistant states. The experiments will be performed in 3T3-L1 adipocytes, in which insulin-stimulated GLUT4 translocation can be assessed on a single cell basis by immunofluorescence staining with anti GLUT4 antibodies. Microinjection of single living cells will be used to deliver various reagents to activate or inactivate specific intracellular molecules that may be involved in insulin action. Nearly any type of reagent can be delivered in this way, such as antibodies, peptides and recombinant proteins. There are many potentially involved signaling molecules that will be studied with this system, including substrates of the insulin receptor, p21 ras, the Raf, MEK and ERK Ser/Thr kinases, phosphatidylinositol 3-kinase and Rab small GTP-binding proteins.