Endothelial Progenitor Cell Vascular Endothelial Growth Factor Gene Transfer for Vascular Regeneration

TLDR

Previous studies have established that bone marrow‑derived endothelial progenitor cells (EPCs) circulate systemically. The study investigates whether VEGF gene transfer can phenotypically modulate EPCs to enhance proliferation, adhesion, and incorporation into endothelial monolayers. The authors transduced EPCs with an adenoviral VEGF vector and injected them into athymic nude mice with hindlimb ischemia to assess neovascularization and blood flow recovery. VEGF‑transduced EPCs improved neovascularization and blood flow, reduced limb necrosis/autoamputation by 63.7 %, required 30 times fewer cells than prior trials, and demonstrated enhanced in vivo incorporation, confirming the strategy’s potential for ischemic limb salvage.

Abstract

Previous studies have established that bone marrow-derived endothelial progenitor cells (EPCs) are present in the systemic circulation. In the current study, we investigated the hypothesis that gene transfer can be used to achieve phenotypic modulation of EPCs.In vitro, ex vivo murine vascular endothelial growth factor (VEGF) 164 gene transfer augmented EPC proliferative activity and enhanced adhesion and incorporation of EPCs into quiescent as well as activated endothelial cell monolayers. To determine if such phenotypic modulation may facilitate therapeutic neovascularization, heterologous EPCs transduced with adenovirus encoding VEGF were administered to athymic nude mice with hindlimb ischemia; neovascularization and blood flow recovery were both improved, and limb necrosis/autoamputation were reduced by 63.7% in comparison with control animals. The dose of EPCs used for the in vivo experiments was 30 times less than that required in previous trials of EPC transplantation to improve ischemic limb salvage. Necropsy analysis of animals that received DiI-labeled VEGF-transduced EPCs confirmed that enhanced EPC incorporation demonstrated in vitro contributed to in vivo neovascularization as well.In vitro, VEGF EPC gene transfer enhances EPC proliferation, adhesion, and incorporation into endothelial cell monolayers. In vivo, gene-modified EPCs facilitate the strategy of cell transplantation to augment naturally impaired neovascularization in an animal model of experimentally induced limb ischemia.