Astragaloside IV ameliorates pressure overload-induced heart failure by enhancing angiogenesis through HSF1/VEGF pathway

Astragaloside IV(AS-IV), the main active ingredient of Astragalus, has been used as a treatment for heart failure with favorable effects, but its molecular mechanism has not been fully elucidated. Network pharmacological analysis and molecular docking revealed that Heat shock transcription factor 1 (HSF1) is a potential target of AS-IV. We designed cellular and animal experiments to investigate the role and intrinsic molecular mechanisms of AS-IV in ameliorating pressure overload-induced heart failure. In cellular experiments, Myocardial microvascular endothelial cells (MMVECs) were cultured in isolation and stimulated by adding high and low concentrations of AS-IV, and a cell model with down-regulation of HSF1 expression was constructed by using siRNA technology. Changes in the expression of key molecules of HSF1/VEGF signaling pathway and differences in tube-forming ability were detected in different groups of cells using PCR, WB and tube-forming assay. In animal experiments, TAC technology was applied to establish a pressure overload-induced heart failure model in C57 mice, postoperative mice were ingested AS-IV by gavage, and adenoviral transfection technology was applied to construct a mouse model with down-regulation of HSF1 expression.Small animal ultrasound for cardiac function assessment, MASSON staining, CD31 immunohistochemistry, and Western blotting (WB) were performed on the mice. The results showed that AS-IV could promote the expression of key molecules of HSF1/VEGF signaling pathway, enhance the tube-forming ability of MMVECs, increase the density of myocardial capillaries, reduce myocardial fibrosis, and improve the cardiac function of mice with TAC.AS-IV could modulate the HSF1/VEGF signaling pathway to promote the angiogenesis and improve the pressure overload-induced heart failure.