Smooth Muscleα-Actin Expression in Endothelial Cells Derived from CD34⁺Human Cord Blood Cells

Abstract

Human fetal cord blood contains subsets of mononuclear cells with the potential to form both hematological and endothelial cells. Vascular progenitor cells, which can produce all three elements of mature blood vessels, including smooth muscle, have been identified in animals. We hypothesized that similar multipotential progenitor cells exist in humans and used the expression of alpha-smooth muscle actin (alpha-SMA) to identify such cells in fetal cord blood. Mononuclear cell preparations were isolated from human umbilical cord blood and CD34(+) and CD133(+) cells obtained by magnetic bead separation. Isolated cells were cultured on fibronectin-coated dishes with medium containing vascular endothelial growth factor, basic fibroblast growth factor, and insulin-like growth factor. mRNA was extracted, and the expression of alpha-SMA and a number of endothelial cell markers (VEGFR-2, vWF, eNOS, VE-Cadhein, PECAM-1 and Tie-2) was determined by reverse transcriptase-PCR techniques. Human umbilical vein endothelial cells (HUVECs) were used as positive controls. Freshly isolated CD34(+) and CD133(+) cells expressed all endothelial cell markers, but did not express alpha-SMA. HUVECs expressed alpha-SMA. Following 4 weeks of culture, CD34(+) isolates produced morphologically endothelial-like cells that expressed both endothelial cell markers and alpha-SMA. CD133(+) cells failed to produce morphological endothelial-like cells but expressed a range of endothelial markers. However, they did not express alpha-SMA. Following culture in an endothelial cell-promoting environment, CD34(+), but not CD133(+), isolates produced endothelial-like cells that expressed alpha-SMA. Human fetal cord blood contains a population of cells that may differentiate toward both an endothelial and a smooth muscle phenotype in culture.

Application of a partial-thickness human ex vivo skin culture model in cutaneous wound healing study

“…The a-SMA is a cell marker for myofibroblast, 43 or endothelial cells derived from CD34-positive cord blood cells. 44 The CD31 is primarily expressed in endothelial cells 45 whereas CD34 is a marker for dendritic cells 46 or some cells located in hair follicles. 47 Although we do not have enough evidence to identify the cell type with a single cell marker, it is at least indicative of a diversity of the cell types in HESC model.…”

Peripheral Blood CD34 + KDR + Endothelial Progenitor Cells Are Determinants of Subclinical Atherosclerosis in a Middle-Aged General Population

“…Those populations may undergo further differentiation toward the endothelial lineage as well as other phenotypes, such as smooth muscle cells and fibrocytes. 31,32 In the present study, we used flow cytometry to analyze the expression of the 3 most commonly used surface markers to obtain 6 subsets of progenitor cells and measured the levels of EPCs. As a control, we also enumerated total KDR ϩ cells, which cannot be considered EPCs because they lack the immature antigens.…”

Deep Coverage Mouse Red Blood Cell Proteome

“…Initially excluded as low level contaminants, it may be that RBC eNOS diverges from eNOS as annotated in the databases and shows partial similarity to inducible NOS and that this 135-kDa protein is the heavy subunit of the insulinactivated NOS reported by Bhattacharya et al (91). By analogy with protein-tyrosine phosphatase receptor type C-associated protein (PTPRC) shown to have a role in the insulin-mediated activation of NOS in monocytes (92) and endothelial cells (93), the low abundance RBC membranebased receptor-type tyrosine-protein phosphatase ␣ we identified in both proteomes would be the insulin-reactive 95-kDa light chain.…”