Paeoniflorin binds to VEGFR2 to restore autophagy and inhibit apoptosis for podocyte protection in diabetic kidney disease through PI3K-AKT signaling pathway

• Published in: Phytomedicine (Stuttgart) 2022-11, Vol.106, p.154400-154400, Article 154400
• Main Authors: Wang, Xian, Jiang, Ling, Liu, Xue-qi, Huang, Yue-bo, Wang, An-li, Zeng, Han-xu, Gao, Li, Zhu, Qi-Jin, Xia, Ling-ling, Wu, Yong-gui
• Format: Article
• Language: English
• Subjects: Apoptosis; Autophagy; Diabetic kidney disease; Paeoniflorin; Podocyte; VEGFR2
• ISSN: 0944-7113; 1618-095X
• DOI: 10.1016/j.phymed.2022.154400

Paeoniflorin (PF) was found to exhibit renal protection from diabetic kidney disease (DKD) in previous trials, but its specific mechanism remains to be elucidated. This study furtherly explored the specific mechanism of PF in protect podocyte injury in DKD. We observed the effects of PF on renal tissue and podocytes in DKD by constructing the vitro and vivo models after measuring the pharmacokinetic characteristics of PF. Target proteins of PF were found through target prediction, and verified by molecular docking, CESTA, and SPR, and then furtherly explored the downstream regulation mechanism related to podocyte autophagy and apoptosis by network prediction and co-immunoprecipitation. Finally, by using the target protein inhibitor in vivo and knocking down the target protein gene in vitro, it was verified that PF played a role in regulating autophagy and apoptosis through the target protein in diabetic nephropathy. This study found that in STZ-induced mice model, PF could improve the renal biochemical and pathological damage and podocyte injure (p < 0.05), upregulate autophagy activity (p < 0.05), but inhibit apoptosis (p < 0.01). Vascular endothelial growth factor receptor 2 (VEGFR2), predicted as the target of PF, directly bind with PF reflected by molecular docking and surface plasmon resonance detection. Animal studies demonstrated that VEGFR2 inhibitors have a protective effect similar to that of PF on DKD. Network prediction and co-immunoprecipitation further confirmed that VEGFR2 was able to bind PIK3CA to regulate PI3K-AKT signaling pathway. Furthermore, PF downregulated the phosphorylation of PI3K and AKT (p < 0.05). In vitro, similarly to autophagy inhibitors, PF was also found to improve podocyte markers (p < 0.05) and autophagy activity (p < 0.05), decrease caspase 3 protein (p < 0.05) and further inhibited VEGFR2-PI3K-AKT activity (p < 0.05). Finally, the results of VEGFR2 knockdown were similar to the effect of PF in HG-stimulated podocytes. In conclusion, PF restores autophagy and inhibits apoptosis by targeting the VEGFR2-mediated PI3K-AKT pathway to improve renal injury in DKD, that provided a theoretical basis for PF treatment in DKD. [Display omitted] Schematic illustration of PF binds directly to VEGFR2 for modulating PI3K-AKT signaling pathway to regulate autophagy and apoptosis of podocyte. In DKD, autophagy is inhibited and apoptosis is increased in podocytes, which lead to podocyte injury and aggravates kidney injury. PF directly b