The Role Of VEGFR1 In High Glucose-induced Podocyte Insulin Resistant And Podocyte Injury

Objective: Explore the role and mechanism of Vascular endothelial growth factor receptor1( VEGFR1) in podocytes with high sugar induced insulin resistance.Methods: 1.The expression level of VEGFR1 in diabetic nephropathy patients was oberserved by immunohistochemical compare with normal group; 2.The expression level of VEGFR1 in STZ-induced diabetic mice kidney cortex and high sugar cultured human podocytes was oberserved by Western blot; 3.In vitro cultured human podocytes, GNQWFI pretreated podocytes to detect podocytes glucose uptake with 2-NBDG, GLUT-4transposition detected with immunofluorescence and Western blot, insulin signaling pathway detected with Western blot; 4.Transfection si RNA-VEGFR1 to knockdown VEGFR1 protein expression in human podocytes, Western blot method detected transfection efficiency; 5.GNQWFI or si RNA-VEGFR1 pretreated human podocytes to detect ERK1/2 signaling pathway detect with Western blot, desmin expression was detected by Western blot; 6.Feeding 8 weeks wild-type 30 male C57 BL / 6J mice, randomly divided into 3 groups: control group(Ctrl group), diabetic nephropathy(DN group) model group,diabetic nephropathy VEGFR1 inhibitor intervention group(DN+GNQWFI group);One-time intraperitoneal injection of STZ(135 mg/kg) to establish a mouse model of diabetic nephropathy, DN + GNQWFI mice subcutaneously every day GNQWFI 200 mu(g/L) for 15 consecutive days at a time; after 12 weeks collect 24 hours urine of mice,detection of urinary albumin;Take venous blood in mice serum creatinine, blood urea nitrogen;Take part of the renal cortex with Western blot method to detect Erk1/2, p38 phosphorylated proteins and desmin protein expression level.Results: 1. VEGFR1 expression level was increased in glomerular of Diabetic nephropathypatients; 2. VEGFR1 expression was level increased in kidney cortex of Diabetic nephropathy model mice and in human podocytes with the stimulation of high sugar; 3.The inhibition of VEGFR1 can reduce podocyte glucose uptake and cell membrane surface GLUT-4 protein expression, reduce podocyte IRS-1 active protein expression;4. si RNA-VEGFR1 transfection can effectively knockdown podocyte VEGFR1 protein expression;5. High sugar stimulates cells cause insulin signaling pathway phosphorylated ERK1/2 and p38 activity protein expression level, knockdown VEGFR1 or inhibit the activity of protein expression can alleviate this protein expression changes.6.Phosphorylation protein of ERK1/2 and p38 increased expression significantly in the group of diabetic mice kidney cortex, VEGFR1 inhibitor intervention group p-ERK1/2, p-p38 and desmin protein expression significantly lower compared with the diabetic nephropathy group.Conclusion: VEGFR1 high expression in high sugar treated podocytes may be one of the important mechanisms of insulin resistance by high sugar, and inhibit VEGFR1 can partially relieve the podocyte injury. VEGFR1 may be leading to cell damage by participating in activation of ERK1/2 signaling pathways, and participating in mediating insulin induced glucose uptake, mediated GLUT-4 transposition and mediating insulin signaling pathways.