Objective To investigate the effects of vascular endothelial growth factor(VEGF) gene modification of rat amniotic mesenchymal stem cells on blood biochemical parameters in rats with nephrotic syndrome.

Methods Sixty male rats were selected, and randomly divided into four groups(15 cases in each group): the control group(healthy), model group(nephrotic syndrome), treatment group 1(amniotic mesenchymal stem cell suspension), treatment group 2(VEGF gene-modified amniotic mesenchymal stem cell suspension).The renal tissue pathology, and survival and distribution of amniotic mesenchymal stem cells in four groups were observed, and the urine creatinine(SCr), blood urea(BU), total cholesterol(TC), triacylglycerol(TG), low-density lipoprotein(LDL), interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α), 24 h urine protein quantification(24 h UTP), resistance index(RI), peak systolic flow velocity(PSV), end diastolic flow velocity(EDV) and expression of VEGF in renal tissue were compared among four groups.

Results In the control group, the renal tissue showed complete and clear structure, while in the model group, the glomerulus showed swelling, more cells in the glomerulus, the mesangial region widened significantly, and the mesangial cells and stroma were moderate to severe hyperplasia.Compared with the model group, the pathological changes of all treatment groups were lighter, and the degree of pathological changes of all treatment groups were lighter than that of model group, and the pathological changes of treatment group 1 was more obvious than that of the treatment group 2.No fluorescent cells were found in kidney tissue of rats in control group and model group.Red fluorescent positive cells were observed in renal tissue of the treatment group 1 and treatment group 2, and only in renal interstitium and tubule, but not in glomerulus.The positive cells in the treatment group 2 were more than that in treatment group 1.Compared with the control group, the levels of SCr, BU, 24 h UTP, TC, TG, LDL, IL-1β and TNF-α in the model group significantly increased(P < 0.05).The levels of SCr, BU, 24 h UTP, TC, TG, LDL, IL-1β and TNF-α in the treatment group 1 and treatment group 2 were significantly lower than those in model group, and which was the lowest in treatment group 2(P < 0.05).Compared with the control group, the RI significantly increased, the levels of PSV and EDV significantly decreased in the model group(P < 0.05).Compared with the model group, the PSV and EDV in treatment group 1 and treatment group 2 significantly increased, the RI level significantly decreased, and the RI was the lowest and the PSV and EDV were the highest in the treatment group 2(P < 0.05).Compared with the control group, the VEGF protein and mRNA expressions in the kidney tissue of model group significantly decreased(P < 0.05).The VEGF protein and mRNA expressions in kidney tissue of treatment group 1 and treatment group 2 significantly increased compared with the model group, and which was the highest in the treatment group 2(P < 0.05).

Conclusions VEGF gene modified amniotic mesenchymal stem cell transplantation can significantly improve the blood lipid level, microinflammatory state, renal function and renal artery blood flow in rats with nephrotic syndrome, which can provide a strong basis for cell transplantation therapy of nephrotic syndrome.