Analysis of tissue repair and regeneration in a variety of organisms has demonstrated that stem and progenitor cells play a critical role in the healing and regenerative response. In particular, during cutaneous wound healing bone marrow-derived cells are recruited to the site of injury in large numbers, often comprising over 50% of the cells within the wound milieu. These bone marrow-derived cells are comprised mostly of a heterogeneous mix of myeloid cells. In the early stages of wound healing, the most prominent subtypes are Gr-1+ CD11b+ cells that consist of progenitor cells and more differentiated granulocytes. Under certain conditions, these cells have the potential to strongly promote angiogenesis, and thus tissue repair and regeneration. This chapter provides methods by which one can isolate these cells from wound tissue and assess their pro-angiogenic capacity via gene expression analyses and functional in vivo angiogenesis assays.
