高糖、胰岛素对肾小球系膜细胞GLUT4、P21表达

Objective The aim of this study was to investigate the effects of high glucose, insulin on expression of Glut4、P21 and cytoskeleton protein F-actin of glomerular mesangial cell and study their important action in diabetic nephropathy(DN) further. Methods Cultured1097 rat GMC were divided into 8 groups: High Glucose—treated group; Mannitol—treated group; Insulin—treated groups along with different concentration; High Glucose and Insulin—treated groups along with different concentration and control. Semi—quantity RT—PCR method and Flow cytometer technique were used to detect GLUT4mRNA and P21mRNA levels and GMC volumes. GMC were by Rhodamine-phalloidin staining , observed morph of F-actin with con-focusing microscope of laser and measured fluorescence intensity. Results 1 Control group GMC has the expression of GLUT4mRNA and P21mRNA. 2 High Glucose decreased Glut4mRNA level and increased P21mRNA levels. But Insulin increased GLUT4mRNA expression in dose—dependent way. The more P21mRNA expressed, the stronger Forward scatter(FSC) had. 3 High Glucose decreased fluorescence intensity of F-actin and Insulin increased fluorescence intensity of F-actin in dose—dependent way. 4 The correlation between the expression of GLUT4mRNA and fluorescence intensity of F-actin is direct and correlation coefficient is 0.786（p<0.05）. Conclusion 1 High Glucose can cause hypertrophy of GMC. Up-regulation of P21 and down-regulation of GLUT4 seem to involve in hypertrophy of GMC and glomerular hypertrophy in the early diabetic nephropathy. 2 High glucose can decreased Glut4mRNA level and increased depolymerization of F-actin. Insulin can reverse the action of high glucose partly in dose—dependent way. 3 GLUT4, P21and F-actin are important factors of DN.