Bolus endovascular PDGFR-(beta) antisense treatment suppressed intimal hyperplasia in a rat carotid injury model

BACKGROUND: Intimal thickening in accelerated arteriopathies relies on the migration of medial vascular smooth muscle cells (VSMCs) and their proliferation within the neointima. Activation of platelet-derived growth factor receptor-beta (PDGFR-beta) expressed in injured VSMCs is responsible for the migration of medial VSMCs to the intima. In the present study, we wanted to assess whether a single local endovascular delivery of antisense PDGFR-beta in injured rat carotid arteries would be sufficient to prevent intimal hyperplasia and how it might contribute to the vascular healing process. METHODS AND RESULTS: A bolus of antisense PDGFR-beta delivered into injured rat carotid arteries reduced PDGFR-beta protein overexpression by >90% from day 3 to 28 after injury. At day 28 after injury, compared with injured untreated carotids, treatment with antisense PDGFR-beta reduced intimal hyperplasia by 58% and medial VSMC migration by 49% and improved vascular reendothelialization by 100% and vascular reactivity (EC(50)) to acetylcholine by 5-fold. CONCLUSIONS: A single-bolus luminal delivery of antisense PDGFR-beta to injured rat carotids reduced intimal hyperplasia, improved the reendothelialization process, and led to the recovery of endothelium-dependent regulation of vascular tone.