Buyang huanwu decoction attenuates arterial in-stent restenosis via transforming growth factor beta receptor 1-mediated suppression of neointimal hyperplasia.

ETHNOPHARMACOLOGICAL RELEVANCE

The mortality rate of cardiovascular diseases (CVD) has been increasing year by year. Percutaneous coronary intervention (PCI) is a major treatment for CVDs; however, the occurrence of in-stent restenosis (ISR) has severely impacted the efficacy of PCI. Currently, there are still no effective treatments for ISR. Neointimal hyperplasia (NIH) is the primary pathological change associated with ISR. The proliferation and migration of vascular smooth muscle cells are crucial for the occurrence of NIH. Therefore, finding effective methods to inhibit vascular smooth muscle cell proliferation, migration, and NIH is the key to ISR treatment. While Buyang Huanwu decoction (BYHWD), a blend of traditional Chinese medicinal herbs, has shown therapeutic potential against arterial stenosis diseases. However, its effectiveness on ISR remains unknown. Therefore, exploring how BYHWD influences these processes is crucial for a deeper understanding of its therapeutic effects.

AIM OF THE STUDY

The aim of this study is to investigate the impact of BYHWD on arterial in-stent restenosis and explore the potential involvement of transforming growth factor beta receptor 1 (TGFBR1) in this process.

MATERIALS AND METHODS

The influence of BYHWD on the migration and proliferation of mouse vascular smooth muscle cells (MOVAS) and human aortic smooth muscle cells (HASMCs) was assessed through methylthiazolyldiphenyl-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, wound healing, and Western blotting (WB) assays. In addition, the role of BYHWD was further validated using the TGFBR1-encoding adenovirus vector. In vivo, the impact of BYHWD on intimal formation and TGFBR1 activation was determined based on the adeno-associated virus-mediated TGFBR1 overexpression models and a left common carotid artery (LCCA) ligation mouse model.

RESULTS

BYHWD dose-dependently suppressed vascular smooth muscle cell (VSMC) migration and proliferation, which included inhibiting cyclin A2, cyclin dependent kinase 4 (CDK4), matrix metalloproteinase-9 (MMP9) expression, and increasing tissue inhibitor of metallopeptidase-1 (TIMP1) expression. Additionally, phosphorylated TGFBR1 (p-TGFBR1), phosphorylated mothers against decapentaplegic homolog 2 (p-Smad2), and phosphorylated mothers against decapentaplegic homolog 3 (p-Smad3) expression decreased after BYHWD administration, while their phosphorylation levels were partially reversed by the overexpression of TGFBR1. Similarly, the inhibition of BYHWD against VSMC migration and proliferation was partially mitigated by the overexpression of TGFBR1. Furthermore, BYHWD significantly attenuated NIH and decreased the p-TGFBR1, p-Smad2, and p-Smad3 levels in the LCCA model; however, such inhibitory effect could be partially reversed through the overexpression of TGFBR1.

CONCLUSION

This study provides the initial evidence supporting that BYHWD blocks VSMC migration, proliferation, and NIH by suppressing the TGFBR1 pathway. BYHWD is promising to become a candidate treatment strategy for ISR.