Effect And Mechanism Of Taxifolin On Pulmonary Vascular Remodeling In Monocrotaline Induced Pulmonary Arterial Hypertension In Rats

【Background】Pulmonary arterial hypertension(PAH)is a serious pulmonary vascular disease with major pathological changes due to abnormal proliferation and migration of pulmonary arterial smooth muscle cells(PASMCs).Abnormal proliferation and migration of PASMCs lead to pulmonary vascular remodeling(PVR).Currently,there is no ideal drug to treat PAH,a severe pulmonary vascular disease with a high fatality rate and no cure.Studies have shown that abnormal proliferation of PASMCs is related to the activation of PI3K/Akt/mTOR pathway.Abnormal migration of PASMCs is associated with activation of the Wnt/β-catenin pathway.Abnormal migration of PASMCs is associated with activation of the Wnt/β-catenin pathway.Taxifolin(Tax)is a flavonoid compound that has not been reported in the field of PAH.Previous studies have found that Taxifolin can inhibit the proliferation of multitype glioblastoma by inhibiting PI3K/Akt/mTOR pathway.Tax can promote the apoptosis of human colorectal cancer cell lines HCT116 by inhibiting the Wnt/β-catenin pathway.Therefore,we hypothesize that Tax inhibits PASMCs proliferation and migration by targeting PI3K/Akt/mTOR and Wnt/β-catenin pathways,thereby improving PVR and protecting monocrotaline(MCT)induced PAH in rats.【Objectives】MCT induced PAH in rats and Platelet Derived Growth Factor-BB(PDGF-BB)induced PASMCs were studied.It was confirmed that Tax can improve PVR and protect MCT induced PAH in rats by inhibiting PASMCs proliferation and migration.Molecular docking and Western Blot assay were used to investigate the inhibitory effect of Tax on PASMCs proliferation and migration by targeting PI3K/Akt/mTOR and Wnt/β-catenin pathways.【Methods】1、A rat model of MCT induced PAH was constructed,and right ventricular systolic pressure(RVSP),right ventricular hypertrophy index(RVHI),the percentage of pulmonary arterial media area(MA)in total artery area(TAA),the percentage of pulmonary arterial medial thickness(MT)in pulmonary arterial external diameter(ED)were measured in each group.The expression of PCNA protein in each group was observed by immunofluorescence technique in lung tissue.2、The effect of Tax on PASMCs proliferation induced by PDGF-BB in rats was studied by CCK8 and Edu proliferation detection techniques.The effect of Tax on PASMCs migration induced by PDGF-BB in rats was studied by cell scratch assay.3、Molecular docking techniques were used to evaluate the binding ability of Tax to proteins associated with PI3K/Akt/mTOR and Wnt/β-catenin pathways.Western Blot assay was used to study the effect of Tax on P-Akt protein in rat PASMCs induced by PDGF-BB.【Results】1、High dose of Tax can protect MCT induced PAH in rats by decreasing RVSP and RVHI in MCT-induced PAH rats.2、Tax can improve PVR by reducing MA% and MT% of MCT induced PAH rats.3、High dose of Tax can decrease the expression of PCNA protein in PAH rats induced by MCT.Tax can inhibit the proliferation and migration of PASMCs induced by PDGF-BB.4、Through hydrogen bonding and hydrophobic action,Tax forms stable structures with PI3 K,Akt1,mTOR and TNKS1,and targets PI3K/Akt/mTOR and Wnt/β-catenin signaling pathways to inhibit PASMCs proliferation and migration.Tax can inhibit the phosphorylation of Akt protein in rat PASMCs induced by PDGF-BB.【Conclusion】Tax can effectively reduce the RVSP,RVHI,MA% and MT% of MCT induced PAH in rats,inhibit the proliferation and migration of PASMCs induced by PDGF-BB,and thus play a role in improving PVR and protecting MCT induced PAH in rats.Through hydrogen bonding and hydrophobic interaction,it forms stable configuration with PI3 K,Akt1,mTOR and TNKS1,and targets PI3K/Akt/mTOR and Wnt/β-catenin signaling pathways to inhibit PASMCs proliferation and migration.