Endothelial reconstitution by CD34+ progenitors derived from baboon embryonic stem cells

Abstract

In this study we used a large nonhuman primate model, the baboon, to establish a stepwise protocol to generate CD34+ endothelial progenitor cells (EPCs) from embryonic stem cells (ESCs) and to demonstrate their reparative effects. Baboon ESCs were sequentially differentiated from embryoid body cultures for 9 days and then were specified into EPCs by culturing them in monolayer for 12 days. The resulting EPCs expressed CD34, CXCR4, and UEA-1, but neither CD31 nor CD117. The EPCs were able to form intact lumen structures when seeded on Matrigel, took up Dil-LDL, and responded to TNF-α. Angioblasts specified in EGM-2 medium and ECGS medium had 6.41±1.16% (n=3) and 9.32±3.73% CD34+ cells (n=3). The efficiency of generating CD34+ EPCs did not differ significantly from ECGS to EGM-2 culture media, however, angioblasts specified in ECGS medium expressed a higher percentage of CD34+/CXCR4+ cells (3.49 ±1.32%, n=3) than those specified in EGM-2 medium (0.49±0.52%, n=3). To observe their reparative capacity, we purified CD34+ progenitors after specification by EGM-2 medium; inoculated fluorescently labeled CD34+ EPCs into an arterial segment denuded of endothelium in an ex vivo system. After 14 days of ex vivo culture, the grafted cells had attached and integrated to the denuded surface; in addition, they had matured further and expressed terminally differentiated endothelial markers including CD31 and CD146. In conclusion, we have proved that specified CD34+ EPCs are promising therapeutic agents for repairing damaged vasculature.

Nonhuman Primates and Translational Research—Cardiovascular Disease

“…It follows, then, that stem cell therapies might be used in treating disorders in which the endothelium has been damaged or is deteriorating (see Chong et al 2016). Toward that end, Shi et al (Shi et al 2012(Shi et al , 2013 induced baboon ESCs to differentiate into CD34+, CD31−, and CD146− endothelial progenitor cells (multi-potential hematopoietic stem cells), labelled them with a fluorescent tag, and inoculated them into an arterial segment that had been denuded of endothelial cells in an ex vivo system. By 14 days postinoculation, the cells had attached and integrated into the denuded surface and had undergone maturation events that led to the expression of CD31 and CD146 (antigens expressed on mature endothelial cells).…”

Nonhuman Primate Models in Translational Regenerative Medicine

“…Baboon embryonic stem cells (bESCs) are used for deriving endothelial progenitors to reconstruct experimentally damaged arterial vessels [29]. The investigators are developing technologies to engineer vascular tissue by driving vascular progenitors into…”

Inhibition of nitric oxide synthase activity and chemokine (CXCL12) supplementation can improve hematopoietic reconstitution in mice lethally irradiated by 60Co gamma radiation

“…These studies tested some important parameters, as repopulating potential of hematopoietic stem cells using CFU (colony-forming unit) assays, and cell-surface phenotyping by flow cytometry techniques to determinewhich cell populations can potentially rescue from IR-induced effects, and which can keep their proliferation and differentiation capabilities. Its expression was observed in hematopoietic precursors [7] and in endothelial cells [8]. In a simplistic manner, counts of cells bearing a CD34 + phenotype frequency in hematopoietic organs cell suspensions can be a start point to determine whether a therapy may be effective in recovering the cellularity of hematopoietic tissues Many protocols relying in CD34+ counts were described for this purpose, including clinical uses [9,10].…”