Effects Of High Glucose, Insulin On Expression Of Glu T4mRNA And Cytoskeleton Protein F-actin Of Glomerular Mesangial Cell

Objective: The effects of high glucose, insulin on expression of GluT4mRNA and cytoskeleton protein F-actin of glomerular mesangial cell (GMC) were investigated in order to explore the mechanism of diabetic nephropathy (DN).Methods: Cultured 1097 rat GMC were divided into 8 groups: control, 10-9M insulin, 10-8M insulin, 10-6M insulin, high glucose, mannitol, high glucose and 10-6M insulin, high glucose and 10-9M insulin. Expression of GluT4mRNA was measured by RT-PCR method, F-actin was stained by rhodamine-pholloidin and the fluorescent intensity was calculated by image analysis system.Results: 1. GluT4mRNA can be detected in normal GMC. 2. High glucose can decrease the expression of GluT4mRNA to 68.7% (p<0.05), 10-8M insulin, 10-6M insulin can increase to 230.2%, 297.2% (p<0.01) in aconcentration-dependent way, high glucose and 10-6 insulin, high glucose and 10-9M insulin can increase to 170.6%, 140.3% (p<0.05) comparing with simple high glucose group. 3. High glucose can decrease the fluorescent intensity of F-actm to 44.5% (p<0.01); 10-8M insulin, 10-6M insulin can increase to 122.4% (p<0.05), 129.6% (p<0.01) in a concentration-dependent way; high glucose and 10-9M insulin can increase to 183.8% (p<0.05) comparing with simple high glucose group. 4. The spearman correlation coefficient between Glut4mRNA and F-actin is 0.786 (p<0.05). Conclusion: 1.Normal GMC can express GluT4mRNA. 2. High glucose can inhibit the expression of GluT4mRNA and facilitate the depolymerization of F-actin. Insulin can partly reverse the effects caused by high glucose above. 3. The correlation between the expression of GluT4mRNA and the fluorescent intensity of F-actin is positive. 4. GluT4 and F-actin are important factors in the development of DN.