穗花杉双黄酮通过靶向NF-κB-MMP2/9轴抑制血管平滑肌细胞表型转换减缓腹主动脉瘤进展OA

Objective To investigate the role and mechanism of amentoflavone(AMF)in abdominal aortic aneurysm(AAA)pathogenesis,providing novel therapeutic candidates and theoretical foundations.Methods ①Animal studies:AAA models were induced by angiotensin Ⅱ(Ang Ⅱ)in 6 to 8-week-old male ApoE⁻/⁻ mice randomized(n=10/group)into saline+DMSO,saline+AMF,Ang Ⅱ+DMSO(1 000 ng·kg⁻¹·min⁻¹),and Ang Ⅱ+AMF(10,20,50 mg/kg)groups.AMF or DMSO(100 μL)was intraperitoneally administered every 48 h from day 2 for 28 d;20 mg/kg AMF(optimal dose by AAA incidence)was selected for subsequent experiments.Alternatively,AAA was induced by periaortic elastase incubation in C57BL/6J mice randomized(n=6)into sham+DMSO,sham+AMF(heat-inactivated elastase),elastase+DMSO,and elastase+AMF groups for 14 d with identical AMF/DMSO protocols.Survival was monitored;AAA dilation was assessed by ultrasonography;elastic fiber degradation was evaluated via HE and VVG staining;MMP2/MMP9 expression was quantified by RT-qPCR/Western blotting.②Network pharmacology:AAA-related targets(top 2 000 genes from Genecards)and AMF targets(predicted via Galaxy WEB/SuperPred/SwissTargetPrediction)were intersected;protein-protein interaction(PPI)networks were constructed using STRING and visualized in Cytoscape.③Cellular experiments:Primary rat aortic vascular smooth muscle cells(RAVSMCs)were treated with:DMSO+CTL,DMSO+PDGFBB(25 ng/mL),AMF+CTL(20 μmol/L),or AMF+PDGFBB.Calponin,α SMA,MMP2,MMP9,IκBα,and phospho-IκBα levels were assessed;NF-κB activation was evaluated via p65 nuclear translocation;proliferation(CCK-8)and migration(scratch/Transwell)were measured.Pathway rescue:TNF-α(20 ng/mL)was co-administered with AMF+PDGFBB to assess target reversibility.Results ① AMF significantly improved the survival rate of Ang Ⅱ-induced AAA model mice(P<0.05),decreased the incidence of AAA,reduced the degree of abdominal aortic dilation(P<0.01),attenuated elastic fiber fragmentation and degradation in the aortic media(P<0.001),and inhibited the expression of MMP2(P<0.01)and MMP9(P<0.05)in AAA tissues.AMF also markedly reduced the extent of abdominal aortic dilation(P<0.001),mitigated medial elastic fiber disruption(P<0.001),and suppressed MMP2(P<0.001)and MMP9(P<0.05)expression in the elastase-induced AAA model.② PPI network analysis revealed that MMP2 and MMP9 occupied a core position within the therapeutic target network.③ RT-qPCR analysis showed that AMF treatment(20 μmol/L)significantly reversed the PDGF BB(25 ng/mL)-induced increases in MMP2(P<0.05)and MMP9(P<0.01)mRNA levels and the decreases in Calponin(P<0.001)and αSMA(P<0.05)mRNA levels in RAVSMCs.Western blotting demonstrated that AMF attenuated the PDGF BB-induced upregulation of MMP2(P<0.001)and MMP9(P<0.001)proteins and the downregulation of Calponin(P<0.01)and αSMA(P<0.001)proteins.The CCK-8 assay indicated that AMF markedly suppressed PDGFBB-induced excessive proliferation(P<0.001),and wound healing and Transwell assays showed that AMF significantly inhibited PDGFBB-induced cell migration(P<0.001).TRRUST transcription factor network analysis identified RELA(p65)as the top-ranked transcription factor.Western blotting revealed that AMF substantially decreased the phosphorylation level of IκBα(P<0.001),and immunofluorescence staining demonstrated that AMF effectively reduced the nuclear translocation of p65,thereby inhibiting the NF-κB signaling pathway.In the pathway rescue experiment,RT-qPCR showed that TNF-α(20 ng/mL)treatment counteracted the AMF-induced decreases in MMP2(P=0.087)and MMP9(P<0.05)mRNA levels and the increases in calponin(P<0.05)and αSMA(P<0.05)mRNA levels.Western blotting confirmed that TNF-α reversed the AMF-mediated reduction in MMP2(P<0.001)and MMP9(P<0.001)protein expression and the elevation of Calponin(P<0.05)and α SMA(P=0.063)protein levels.Conclusion AMF attenuates AAA progression by targeting the NF-κB-MMP2/9 axis,demonstrating its potential as a novel AAA therapeutic agent.