Vascular Progenitor Cells Isolated From Human Embryonic Stem Cells Give Rise to Endothelial and Smooth Muscle–Like Cells and Form Vascular Networks In Vivo

Abstract

Abstract-We report that human embryonic stem cells contain a population of vascular progenitor cells that have the ability to differentiate into endothelial-like and smooth muscle (SM)-like cells. Vascular progenitor cells were isolated from EBs grown in suspension for 10 days and were characterized by expression of the endothelial/hematopoietic marker CD34 (CD34 ϩ cells). When these cells are subsequently cultured in EGM-2 (endothelial growth medium) supplemented with vascular endothelial growth factor-165 (50 ng/mL), they give rise to endothelial-like cells characterized by a cobblestone cell morphology, expression of endothelial markers (platelet endothelial cell-adhesion molecule-1, CD34, KDR/Flk-1, vascular endothelial cadherin, von Willebrand factor), incorporation of acetylated low-density lipoprotein, and formation of capillary-like structures when placed in Matrigel. In contrast, when CD34 ϩ cells are cultured in EGM-2 supplemented with platelet-derived growth factor-BB (50 ng/mL), they give rise to SM-like cells characterized by spindle-shape morphology, expression of SM cell markers (␣-SM actin, SM myosin heavy chain, calponin, caldesmon, SM ␣-22), and the ability to contract and relax in response to common pharmacological agents such as carbachol and atropine but rarely form capillary-like structures when placed in Matrigel. Implantation studies in nude mice show that both cell types contribute to the formation of human microvasculature. Some microvessels contained mouse blood cells, which indicates functional integration with host vasculature. Therefore, the vascular progenitors isolated from human embryonic stem cells using methods established in the present study could provide a means to examine the mechanisms of endothelial and SM cell development, and they could also provide a potential source of cells for vascular tissue engineering. [3][4][5] Isolating a population of human progenitor cells with potential for cell number expansion and differentiation into both ECs and SMCs with high efficiency could benefit the area of tissue engineering. 2,5,6 Embryonic stem cells (ESCs) are a potential cell source for induction of tissue vascularization. 7 Prior studies have derived ECs and SMCs cells from a common progenitor (Flk-1 ϩ cells) from mouse 6 and monkey ESCs, 8 but not from human ESCs (hESCs). We previously reported that hESCs can spontaneously generate ECs with definitive properties. 9 These cells were isolated based on the expression of platelet EC-adhesion molecule-1 (PECAM1) from embryoid bodies (EBs) grown in suspension for 13 to 15 days. Using the same endothelial 10 or other (eg, CD34 11,12 ) markers, others have isolated endothelial progenitor cells with the ability to differentiate into mature endothelium. In addition, it has been reported that hESCs can differentiate into mesodermal cells that can give rise to ECs and SMCs 13 ; however, it is not clear that these cells were derived from the same progenitor.Here we report that cells isolated from EBs at day 10 and expressing the hematop...

Cell therapies for therapeutic angiogenesis: back to the bench

“…21,113 Additional studies of ESCs differentiated to form endothelial cells and smooth muscle cells have shown the ability of these cells to integrate into the host circulation. 57,114 Indeed, ESC-derived endothelial cells have been shown to enhance revascularization in models of hindlimb ischemia and MI. 115,116 In a recent study tracking the fate of ESC-derived endothelial cells, survival of transplanted cells into infarcted murine myocardium was detected at 8 weeks post-infarct with functional improvement and increased vascular density.…”

The role of mechanical stimuli in the vascular differentiation of mesenchymal stem cells

“…those isolated from native blood vessels) is inherently limited because acquiring them demands an invasive procedure, they are typically available in insufficient quantities and they exhibit a low rate of proliferation (Shin'oka et al, 2001;Koike et al, 2004;L'Heureux et al, 2006). Thus, in order to advance vascular tissue engineering, stem cells have been intensively explored as alternative sources for both mature endothelial cells and SMCs (Ferreira et al, 2007). Among the various stem cell types that are suitable for application in vascular grafts, mesenchymal stem cells (MSCs) have been most extensively studied to date (Seifu et al, 2013).…”

Rapid Anastomosis of Endothelial Progenitor Cell–Derived Vessels with Host Vasculature Is Promoted by a High Density of Cotransplanted Fibroblasts

“…The use of hESC-derived ECs in regenerative medicine has also been reported. 14,15 However, hESCs face the potential problem of sourcing and host immune rejection. 16 Alternatively, there is significant evidence demonstrating the angiogenic potential of endothelial progenitor cells (EPCs), including those of adult origin.…”