Association of the expressions of glomerular nephrin, vascular endothelial growth factor and its receptor with proteinuria in preeclampsia rats / 中华肾脏病杂志

ABSTRACT

Objective To investigate the association of the expressions of glomerular nephrin, vascular endothelial growth factor (VEGF) and its receptor (VEGFR) with proteinuria in preeclampsia rats. Methods A rat model of preeclampsia was developed by inhibitor of nitric oxide synthase (L-NAME). The systolic blood pressure (SBP) and 24 h urine protein were compared among the normal female group (n=6), the normal pregnant group (n=8), nonpregnant control group (n=6) and preeclampsia group(n=8). The kidney biopsies of each group were observed by light and electron microscopy. The glomerular nephrin was detected by Western blotting and real-time PCR. Immunofluorescence was used to detect the expression of WT1. The level of glomerular VEGF and VEGFR (Flt-1 and Flk-1) were evaluated by Western blotting. Results The level of glomerular nephrin protein in the rats with preeclampsia (0.0726±0.0074) was significantly lower compared with normal female group (0.3795±0.0509), normal pregnant group (0.2361±0.0437) and nonpregnant control group (0.7265±0.0503) (P＜0.01, respectively), while the levels of nephrin mRNA were not significantly different among 4 groups. The expression of WT1 was not significantly different among 4 groups as well. The level of glomerular VEGF in preeclampsia group (1.5429±0.0898) was significantly higher compared with normal female group (1.1870±0.1160), normal pregnant group (1.3741 ±0.1165) and nonpregnant control group (1.0155±0.0742)(P＜0.01,respectively). VEGFR (Flt-1 and Flk-1) was also significantly higher in preeclampsia rats compared with other control groups (P＜0.05, respectively). Conclusions In preeclampsia rats, nephrin is decreased significantly and the glomerular VEGF-VEGFR is increased significantly compared with the other control groups. The abnormal expression of nephrin and VEGF-VEGFR may be involved in the preeclampsia proteinuria. The underlying mechanism of this phenomenon needs further research.