ObjectiveTo investigate the role and potential mechanisms of neuropilin-1 (NRP1) in the pathogenesis of vein graft failure.MethodsThe rat vascular smooth muscle cells (VSMCs) were transfected with NRP1-shRNA adenovirus and negative control adenovirus respectively. Cell counting kit-8, flow cytometry, Transwell and Western blot were used to investigate the effects of inhibition of NRP1 on VSMCs proliferation viability, apoptosis, migration capacity and its downstream signaling pathway protein expression.ResultsThe proliferation and migration of rat VSMCs could be inhibited after down-regulation of NRP1, and the increase of apoptosis was also observed. Moreover, inhibition of NRP1 significantly reduced Akt and NF-κB phosphorylation in rat VSMCs, but had little effect on activation of ERK1/2.ConclusionNRP1 may promote vein graft hyperplastic remodeling by regulating the proliferation and migration of VSMCs through PI3K/Akt and NF-κB pathways, but further animal study is required.