A population of multipotent CD34-positive adipose stromal cells share pericyte and mesenchymal surface markers, reside in a periendothelial location, and stabilize endothelial networks. Circ Res 2008; 102: 77–85

Abstract—It has been shown that stromal–vascular fraction isolated from adipose tissues contains an abundance of CD34 cells. Histological analysis of adipose tissue revealed that CD34 cells are widely distributed among adipocytes and are predominantly associated with vascular structures. The majority of CD34 cells from freshly isolated stromal–vascular fraction were CD31/CD144 and could be separated from a distinct population of CD34/CD31/CD144 (endothelial) cells by differential attachment on uncoated plastic. The localization of CD34 cells within adipose tissue suggested that the nonendothelial population of these cells occupied a pericytic position. Analysis of surface and intracellular markers of the freshly isolated CD34/CD31/CD144 adipose-derived stromal cells (ASCs) showed that 90 % coexpress mesenchymal (CD10, CD13, and CD90), pericytic (chondroitin sulfate proteoglycan, CD140a, and CD140b), and smooth muscle (-actin, caldesmon, and calponin) markers. ASCs demonstrated polygonal self-assembly on Matrigel, as did human microvascular endothelial cells. Coculture of ASCs with human microvascular endothelial cells on Matrigel led to cooperative network assembly, with enhanced stability of endothelial networks and preferential localization of ASCs on the abluminal side of cords. Bidirectional paracrine interaction between these cells was supported by identification of angiogenic factors (vascular endothelial growth factor, hepatocyte growth factor, basic fibroblast growth factor), inflammatory factors (interleukin-6 and-8 and monocyte chemoattractant protein-1 and-2), and mobilization factors (macrophage colony-stimulating factor and granulocyte/macrophage colony-stimulating factor) in media conditioned b