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Characterization and Molecular Regulation of Embryonic Hemogenic Endothelium
Author(s) -
Sills Tiffany M,
Hirschi Karen K
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb74-b
Subject(s) - haematopoiesis , embryonic stem cell , biology , hemangioblast , yolk sac , microbiology and biotechnology , stem cell , endothelium , population , immunology , dorsal aorta , pathology , embryo , medicine , genetics , gene , environmental health
Blood and blood vessels develop in parallel in mammalian embryos. At sites of definitive hematopoiesis, blood cells are thought to be derived from the endothelium. Previous work in our lab defined a population of Hoechst dye‐effluxing (SP), Flk+, cKit + , CD45 − hemogenic endothelial cells (HEC) residing in the developing yolk sac. The goal of this research is to determine whether such cells reside in the aorta‐gonad‐mesonephros (AGM) region, the first intra‐embryonic site of definitive hematopoiesis, and function as HEC capable of giving rise to all blood lineages and have repopulation capabilities when transplanted into irradiated animal recipients. We are using both immunohistochemical (IHC) techniques and in vivo imaging to track cells throughout development and demonstrate their differentiation from cells residing in the endothelium to blood cells in circulation. Toward this goal, we have isolated SP cells from the AGM region at various stages of development that demonstrate acquired hematopoietic potential in vitro. Also, we have observed endothelial cells expressing stem markers and hematopoietic markers in close approximation to clusters of blood cells within developing vasculature. A greater understanding of the interdependent regulation of blood and blood vessel formation aids in the development of therapeutic strategies to treat human vascular and hematopoietic diseases. NIH #5 R01 EB005173 ‐02