Autologous tissue patches acquire vascular identity depending on the environment

Vascular identity is genetically determined, but can be altered during surgical procedures. We hypothesized that the environment of the procedure critically alters the identity of autologous tissue patches implanted into the arterial or venous environment. Autologous jugular vein or carotid artery was used as a patch to repair a rat aorta or inferior vena cava. In the aortic environment patches contained neointimal cells that were CD34/Ephrin-B2-dual positive but not CD34/Eph-B4-dual positive; patches expressed Ephrin-B2, notch-4 and dll-4 but not Eph-B4 and COUP-TFII. In the venous environment patches contained neointimal cells that were CD34/Eph-B4-dual positive but not CD34/Ephrin-B2-dual positive; patches expressed Eph-B4 and COUP-TFII but not Ephrin-B2, notch-4 and dll-4. These data show that autologous tissue patches heal by acquisition of the vascular identity determined by the environment into which they are implanted, suggesting some plasticity of adult vascular identity.