Interferon-induced protein 35 inhibits endothelial cell proliferation, migration and re-endothelialization of injured arteries by inhibiting the nuclear factor-kappa B pathway.

AIM: Endothelial recovery, or re-endothelialization, plays an important role in intimal hyperplasia and atherosclerosis after endothelial injury. Studying the mechanisms of re-endothelialization and strategies to promote efficient endothelial recovery are still needed. Interferon-induced protein 35 (IFI35) is an IFN-γ-induced protein that plays important roles in the antivirus-related immune-inflammatory response. In this study, we tested whether overexpression IFI35 affects the proliferation and migration of endothelial cells (ECs) and re-endothelialization.

METHODS: Wire injury of the carotid artery was induced in C57BL/6 mice, which was followed by IFI35 or null adenovirus transduction. Evans blue staining and HE staining were performed to evaluate the re-endothelialization rate and neointima formation. In vitro studies, primary human umbilical vein endothelial cells (HUVECs) were transfected with Ad-IFI35 or siRNA-IFI35 to evaluate its potential roles in cell proliferation and migration. Furthermore, the potential mechanism relating inhibition of NF-κB/p65 pathway was elaborated by luciferase assay and IFI35 domain deletion assay.

RESULTS: In IFI35 adenovirus-transduced mice, the re-endothelialization rates at days 3, 7 were significantly reduced compared to those in null adenovirus-transduced mice (5% and 35%, vs 20% and 50%, respectively). Meanwhile, subsequent neointimal hyperplasia was obviously increased in IFI35 adenovirus-transduced mice. In vitro studies further indicated that IFI35 inhibits both EC proliferation and migration by inhibiting the NF-κB/p65 pathway. Subsequent studies demonstrated that IFI35 functionally interacted with Nmi through its NID1 domain and that knock-down of Nmi significantly mitigated the inhibitory effect of IFI35 on EC proliferation and migration.

CONCLUSION: Our study revealed a novel mechanism through which IFI35 affects the proliferation and migration of ECs as well as neointima formation, specifically through inhibition of the NF-κB/p65 pathway. Thus, IFI35 is a promising target for the prevention and treatment of post-injury vascular intimal hyperplasia.