Phenotypic and Functional Mapping of Mesenchymal Stem Cells Harvested from Different Portions of the Human Arterial Tree

The human arterial wall contains progenitors and mesenchymal stem cells (MSCs) acting as a postnatal reservoir of stem cells during lifetime. They are nestled in distinct arterial zones close to blood support, that is, the intima and the media-adventitia vasa vasorum plexus, representing vascular stem cell niches. In previous studies, MSCs were successfully isolated from fresh and cadaveric human large- and middle-sized arteries; these cells have a mesenchymal phenotype, self-renewal ability, and tri-lineage plasticity with high endothelial and smooth muscle cell differentiation potential. Here we present an overview of human MSCs derived from the vascular wall (hVW-MSCs) of different anatomical sites focusing on their phenotypic expression, multilineage potency, and stemness properties based on the localization in the arterial tree. We describe the isolation protocols as well as immunophenotyping, functional, and ultrastructure methods used to investigate these cell properties. hVW-MSCs from distinct portions of the vascular tree exhibit distinct phenotypic expression, multilineage potency, and stemness properties. This observation may contribute to explain the regional differences seen in vascular disease; moreover the different attitudes that hVW-MSCs exhibit in vascular differentiation should be taken in consideration whenever cell therapy, regenerative medicine, and tissue engineering strategies are attempted to replace tissues and organs.