Resident Endothelial Precursors in Muscle, Adipose and Dermis Contribute to Post-Natal Vasculogenesis

¹ Sprott Centre for Stem Cell Research, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, Ontario, K1H 8L6, Canada
² Vanderbilt Center for Stem Cell Biology, 802-LH Vanderbilt University, 2215 Garland Avenue, Nashville, TN, USA 37232-0225

^* To whom correspondence should be addressed. E-mail: mrudnicki{at}ohri.ca.

	Abstract

A novel population of tissue-resident endothelial precursors (TEP) was isolated from small blood vessels in dermal, adipose and skeletal muscle of mouse based on their ability to be grown as spheres. Cellular and molecular analyses of these cells revealed that they were highly related regardless of the tissue of origin and distinct from embryonic neural stem cells. Notably, TEPs did not express hematopoietic markers, but expressed numerous characteristics of angiogenic precursors and their differentiated progeny such as CD34, Flk-1, Tie-1, CD31 and VE-cadherin. TEPs readily differentiated into endothelial cells in newly formed vascular networks following transplantation into regenerating skeletal muscle. Taken together, these experiments suggest that TEPs represent a novel class of endothelial precursors that are closely associated with small blood vessels in muscle, adipose and dermal tissue. This finding is of particular interest since it could bring new insight in cancer angiogenesis and collateral blood vessels developed following ischemia.