Nestin and WT1 expression in small-sized vasa vasorum from human normal arteries

Introduction. Vasa vasorum (VV) neovasculogenic potential is now widely accepted, and possibly related to the presence of progenitor cells. We studied the morphology of VV in healthy arteries and their immunohistochemical (IHC) expression of Nestin and WT1, two markers of endothelial progenitor cells. Materials and Methods. Twenty arteries from 16 multiorgan donors were analyzed; IHC was performed manually (CD34, CD31, Nestin) or automatically (WT1). Microvessel positivity “density” for each antibody was calculated dividing vascular adventitia in 1-mm2 fields with an ocular micrometer. Double immunofluorescence was used to investigate Nestin and WT1 co-localization in VV. Results. The mean positivity “densities” for CD31, CD34, Nestin and WT1 were 13.63, 12.20, 8.90 and 7.98/mm2 respectively. Mean Nestin/CD31 and WT1/CD31 ratios were 0.69 and 0.63 respectively. VV