Converging roads: evidence for an adult hemangioblast.

摘要: Classical studies of the developing embryo first suggested existence hemangioblast, a precursor cell with potential to differentiate into both blood and vessels. Several lines investigation demonstrated that many genes activated during early hematopoietic development are also expressed in vascular endothelium. Gene-targeting using embryonic stem cells have identified Flk-1, SCL, Runx-1 as important regulatory molecules specify outcomes. Although it was anticipated hemangioblast would be present only earliest stages yolk sac, accumulating evidence now indicates activity persist adulthood. In adult, bone marrow-derived, circulating endothelial progenitors contribute postnatal neovascularization enhance repair following ischemic injury. Highly purified populations from humans mice can tissue at single level. These recent findings suggest marrow-derived or their progeny may maintenance systems adult life.