CD157 marks tissue resident vasculoreparative endothelial stem cells. Mus musculus strain:C57Bl6N

To maintain tissue oxygen demands, new blood vessels are derived from existing vessels through angiogenesis. A role for adult stem cells in this process remains obscure. Here we identify CD157 (bst1, bone-marrow stromal antigen-1) as a marker of tissue resident vascular endothelial stem cells (VESC) in large arteries and veins in organs. Tissue resident CD157+ VESC display properties of endothelial colony-forming cells in vitro and transplantation of a single VESC in the liver generates donor-derived portal vein, sinusoids, and central vein endothelial cells. We monitored gene expression of the individual cells.