Study Of The Mechanism Of Glut4 In The Insulin Signaling Pathway

Type 2 Diabetes mellitus is a matabolic disease caused by defective tissue sensitivity to insulin and subsequent impairment in insulin secretion. The disease is defined as a state in which carbohydyate and lipid metabolism are improperly regulated by insulin , resulting in elevated fasting and postprandial serum glucose that leads to many complications. Type 2 diabetes accounts for more than 90% of all cases, and is becoming increasing common worldwide.Insulin resistance has been identified as a major causative factor in the pathogenesis of type 2 diabetes. Abnormity in the insulin signaling pathway is thought to result in insulin resistance directly. A defect in insulin action leading to the plasma membrane incorporation of GLUT4 may result in impaired glucose transport. GLUT4 is the major glucose transporter of muscle and adipose tissue . Insulin promotes glucose uptake into muscle and adipose tissues through GLUT4.In order to understand the precise mechanisms of insulin-stimulated GLUT4 translocation , we designed this experiment to observe the process of GLUT4 trafficking in adipose cells. First, methods of rat adipocyte isolation and incubation were established. Second, in isolated rat adipose cells, glucose transporter 4 trafficking can be visualized by transfection of HA-GLUT4-GFP. The results showed that without insulin most of the glucose transporter 4 was intracellular;insulin stimulation induced the translocation of the glucose transporter 4 from intracellular vesicular compartments to the plasma membrane.