ABSTRACT: VSELs are a population of rare Oct-4+CXCR4+ CD133+lin-CD45- cells that are deposited during early embryogenesis in developing organs/tissues as a reserve population of pluripotent stem cells for regeneration. We reported recently that they are mobilized into peripheral blood during acute myocardial infarction (AMI) in mice and humans. However, although freshly isolated VSELs in experimental AMI mouse models improve cardiac function, the number of these cells is limited and an ex vivo expansion strategy is needed to employ these cells more efficiently for cardiac regeneration. The aim of this study was to establish an efficient method to expand ex vivo BM-derived very small embryonic-like stem cells (VSELs) into cardiomyocytes. VSELs, highly purified by FACS from the bone marrow of GFP transgenic mice, were expanded over C2C12 cell line myoblasts and exposed to cardiac differentiating media. The changes in gene expression during cardiac differentiation of VSELs were evaluated by RTQ-PCR, immunostaining and gene array analysis. We developed an efficient, two-step, ex vivo expansion/differentiation model of BM-derived VSELs into cardiomyocytes. First, purified GFP+ VSELs are plated over C2C12 murine cell line myoblasts, where they expand and differentiate into characteristic spheres. Subsequently, cells from these spheres are expanded on cardiac differentiating media into cardiomyocytes. This study demonstrates that murine BM-derived VSELs can be efficiently expanded in vitro and differentiated into cardiomyocytes.
International Journal of Oncology 08/2010; 37(2):237-47. · 2.40 Impact Factor
ABSTRACT: This study sought to assess of the mobilization of nonhematopoietic very small embryonic-like stem cells (VSELs) in acute myocardial infarction (MI).
Acute MI induces mobilization of bone marrow stem cells. Recently, a rare population of VSELs, expressing markers of embryonic pluripotent stem cells (PSCs), was identified in adult murine bone marrow and human umbilical cord blood.
Thirty-one patients with acute MI and 30 healthy subjects were enrolled. Blood was sampled on admission, after 24 h, and 5 days later. Erythrocytes were lysed and lin(-)CD45(-) VSELs were isolated using a live cell sorting system (FACSAria, Beckton Dickinson, San Jose, California).
In healthy subjects the median number of circulating VSELs was very low (median 0.8 [range 0 to 1.3]) cells/microl. In acute MI, VSELs were mobilized early (median 2.7 [range 0.2 to 3.9] cells/microl; p < 0.001) and remained elevated after 24 h and 5 days (median 4.7 [range 0.2 to 6.4] cells/microl; p < 0.003, and median 2.6 [range 0.3 to 3.6] cells/microl; p < 0.03, respectively). The mobilization of VSEL was significantly reduced in patients older than 50 years and with diabetes in comparison with younger and nondiabetic patients. Circulating VSELs were small (7 to 8 microm) and enriched in the messenger ribonucleic acid of PSC markers (Oct-4, Nanog), cardiac lineage (GATA-4, Nkx2.5/Csx, MEF2C), and endothelial (VE-cadherin) markers. The presence of PSC markers (Oct-4, SSEA-4) and the chemokine receptor CXCR4 in circulating VSELs was confirmed at the protein level by immunofluorescent staining and ImageStream system (Amnis Corporation, Seattle, Washington) analysis.
Acute MI induced mobilization of VSELs expressing pluripotent markers, early cardiac and endothelial markers, and chemokine receptor CXCR4.
Journal of the American College of Cardiology 02/2009; 53(1):1-9. · 14.16 Impact Factor
European Heart Journal 09/2007; 28(15):1785-6. · 10.48 Impact Factor