Effect Of Losartan And Tripterygium Glycosides On Bevacizumab-induced Proteinuria In Mice And Related Mechanisms

Objective:Bevacizumab(BEV)is a targeted anti-tumor drug.It specifically binds to vascular endothelial growth factor(VEGF),thereby preventing VEGF from binding to its receptor on the surface of endothelial cells and inhibiting angiogenesis to achieve anti-tumor effect.It is widely used to treat various malignancies.However,hypertension,proteinuria,hemorrhage and thrombophlebitis are common side effects of BEV.At present,there is no effective prevention or treatment for bev-related proteinuria,and patients with severe proteinuria with BEV should generally stop using BEV.Several studies have confirmed that angiotensin ? receptor antagonist and tripterygium glycosides more improve glomerular podocyte slit membrane protein,maintain the glomerular filtration barrier,reduce the leakage of urine protein.Therefore,we transplanted it into the study of bev-related proteinuria.To explore the effect of losartan(LOS)and tripterygium glycosides tablets(TGT)on the intervention of bevacizumab(BEV)induced proteinuria in mice and its related mechanism.To provide beneficial exploration and help for the treatment of bev-induced proteinuria.Methods : ICR mice were randomly divided into 7 groups(6 mice in each group).Control group [saline of the same volume i.v];BEV group [BEV60mg/(kg.w),i.v];LOS1group,LOS2 group,LOS3 group and TGT group were all given [BEV60mg/(kg.w),i.v]and on the basis of this,losartan was given 5mg/(kg.d)in the LOS1 group,losartan was given 10mg/(kg.d)in the LOS2 group,losartan was given 20mg/(kg.d)in the LOS3 group,and tripterygium glycosides were given 10mg/(kg.d)in the TGT group.Combined group: BEV tail vein injection of 60mg/(kg.w),losartan and tripterygium glycosides tablets were given 10mg/(kg.d)each.The specimens were collected on the 28 th day,and the 24h-proteinuria and biochemical index were measured.The kidney tissues of mice were collected and detected by HE staining,Western blotting and immunohistochemistry staining.Results:(1)24h-proteinuria in BEV group was significantly higher than that in the control group,the difference was statistically significant(P ? 0.01).24h-proteinuria in the remaining 5 groups was significantly lower than that in the BEV group,and that in the combined group was significantly lower than that in the LOS2 group and the TGT group, with statistically significant differences.(2)there was no statistically significant difference in blood biochemical results in each group.(3).The results of HE staining: compared with the control group,the endothelial cells in the BEV group showed atrophy and vacuolation.The glomerular structure of LOS1 group was slightly altered compared with that of the control group,while LOS2,LOS3,TGT and the combined group were not significantly altered.(4)Immunohistochemical results: the expressions of VEGF,podocin and nephrin in the BEV group were significantly decreased compared with the control group,the difference was statistically significant(P? 0.01).The expressions in LOS1,LOS2,LOS3,TGT and the combined group were significantly up-regulated compared with those in the BEV group,and the expressions in the combined group were higher than those in the LOS2 group and the TGT group,with statistically significant differences.(5)Results of Western blotting: the expressions of VEGF,podocin and nephrin in the BEV group were significantly decreased compared with the control group,the difference was statistically significant(P?0.01).The expressions in LOS1,LOS2,LOS3,TGT and the combined group were significantly up-regulated compared with those in the BEV group,and the expressions in the combined group were higher than those in the LOS2 group and the TGT group,with statistically significant differences,which were consistent with the results of 24 h urine protein.Conclusion:The proteinuria induced by BEV may be related to the decrease of VEGF,nephrin and podocin protein expressions in renal tissues and the destruction of glomerular filtration membrane.LOS and TGT may reduce the bev-induced proteinuria by up-regulation of the expressions of glomerular VEGF,Nephrin and Podocin,and the improvement degree is positively correlated with the LOS dose.The efficacy of the combination of the two drugs in reducing bev-induced proteinuria was significantly better than that of either single drug,and the two drugs had a synergistic effect.