Aging impairs the ability of vascular endothelial stem cells to generate endothelial cells in mice.

Tissue-resident vascular endothelial stem cells (VESCs), marked by expression of CD157, possess long-term repopulating potential and contribute to vascular regeneration and homeostasis in mice. Stem cell exhaustion is regarded as one of the hallmarks of aging and is being extensively studied in several types of tissue-resident stem cells; however, how aging affects VESCs has not been clarified yet. In the present study, we isolated VESCs from young and aged mice to compare their potential to differentiate into endothelial cells in vitro and in vivo.

Isolation of tissue-resident vascular endothelial stem cells from mouse liver.

Endothelial cells (ECs) are fundamental components of the blood vessels that comprise the vascular system; facilitate blood flow; and regulate permeability, angiogenesis, inflammatory responses and homeostatic tissue maintenance. Accumulating evidence suggests there is EC heterogeneity in vivo. However, isolation of fresh ECs from adult mice to investigate this further is challenging.

Isolation of tissue-resident endothelial stem cells and their use in regenerative medicine.

Background: During sprouting angiogenesis, stalk cells, localized behind tip cells, generate endothelial cells (ECs) for the elongation of new vessels. We hypothesized that stalk cells may have endothelial progenitor cell properties because of their highly proliferative ability. We conducted Hoechst dye DNA staining in ECs of preexisting blood vessels from hind limb muscle and found that endothelial-side population (E-SP) cells, which efflux Hoechst rapidly with abundant ABC transporters, show highly producing ability of ECs.