Human endothelial-colony forming cells enhance cardiac repair by increasing neovascularization and the pool of Sca1+ cardiac resident stem cells after myocardial infarction in SCID/beige mice

Objective: The potential therapeutic role of endothelial progenitor cells (EPCs) in ischemic heart disease for myocardial repair and regeneration is subject to intense investigation. The aim of the study was to investigate the proregenerative potential of human endothelial colony-forming cells (huECFCs), a very homogenous and highly proliferative endothelial progenitor cell subpopulation, in a myocardial infarction (MI) model of severe combined immunodeficiency (SCID) mice. Methods: CD34+ peripheral blood mononuclear cells were isolated from patient blood samples using immunomagnetic beads. For generating ECFCs, CD34+ cells were plated on fibronectin-coated dishes and were expanded by culture in endothelial-specific cell medium. Either huECFCs (5 × 105) or control medium were injected into the peri-infarct region after surgical MI induction in SCID/beige mice. Hemodynamic function was assessed invasively by conductance micromanometry 30 days post-MI. Hearts of sacrificed animals were analyzed by immunohistochemistry to assess cell fate, infarct size, and neovascularization (huECFCs n = 15 vs. control n = 10). Flow-cytometric analysis of enzymatically digested whole heart tissue was used to analyze different subsets of migrated CD34+/CD45+ peripheral mononuclear cells as well as CD34−/CD45− cardiac-resident stem cells two days post-MI (huECFCs n = 10 vs. control n = 6). Results: Transplantation of human ECFCs after MI improved left ventricular (LV) function at day 30 post-MI (LVEF: 30.43 ± 1.20% vs. 22.61 ± 1.73%, p < 0.001; ΔP/ΔTmax 5202.28 ± 316.68 mmHg/s vs. 3896.24 ± 534.95 mmHg/s, p < 0.05) when compared to controls. In addition, a significantly reduced infarct size (50.3 ± 4.5% vs. 66.1 ± 4.3%, p < 0.05) was seen in huECFC treated animals compared to controls. Immunohistochemistry failed to show integration and survival of transplanted cells. However, anti-CD31 immunohistochemistry demonstrated an increased vascular density within the infarct border zone (8.6 ± 0.4 CD31+ capillaries per HPF vs. 6.2 ± 0.5 CD31+ capillaries per HPF, p < 0.001). Flow cytometry at day two post-MI showed a trend towards increased myocardial homing of CD45+/CD34+ mononuclear cells (1.1 ± 0.3% vs. 0.7 ± 0.1%, p = 0.2). Interestingly, we detected a significant increase in the population of CD34−/CD45−/Sca1+ cardiac resident stem cells (11.7 ± 1.7% vs. 4.7 ± 1.7%, p < 0.01). In a subgroup analysis no significant differences were seen in the cardioprotective effects of huECFCs derived from diabetic or nondiabetic patients. Conclusions: In a murine model of myocardial infarction in SCID mice, transplantation of huECFCs ameliorated myocardial function by attenuation of adverse post-MI remodeling, presumably through paracrine effects. Cardiac repair is enhanced by increasing myocardial neovascularization and the pool of Sca1+ cardiac resident stem cells. The use of huECFCs for treating ischemic heart disease warrants further investigation.

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Local activation of cardiac stem cells for post-myocardial infarction cardiac repair

Journal of Cellular and Molecular Medicine ◽

10.1111/j.1582-4934.2012.01589.x ◽

2012 ◽

Vol 16 (11) ◽

pp. 2549-2563 ◽

Cited By ~ 15

Author(s):

Zhuzhi Wen ◽

Zun Mai ◽

Haifeng Zhang ◽

Yangxin Chen ◽

Dengfeng Geng ◽

...

Keyword(s):

Myocardial Infarction ◽

Stem Cells ◽

Cardiac Repair ◽

Post Myocardial Infarction ◽

Cardiac Stem Cells ◽

Local Activation

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Generation of Cardiomyocytes From Vascular Adventitia-Resident Stem Cells

Circulation Research ◽

10.1161/circresaha.117.312526 ◽

2018 ◽

Vol 123 (6) ◽

pp. 686-699 ◽

Cited By ~ 9

Author(s):

Subba Rao Mekala ◽

Philipp Wörsdörfer ◽

Jochen Bauer ◽

Olga Stoll ◽

Nicole Wagner ◽

...

Keyword(s):

Myocardial Infarction ◽

Heart Failure ◽

Stem Cells ◽

Endothelial Cells ◽

Aortic Wall ◽

Fluorescent Protein ◽

Therapeutic Option ◽

Cardiac Regeneration ◽

Cardiac Progenitors ◽

Resident Stem Cells

Rationale: Regeneration of lost cardiomyocytes is a fundamental unresolved problem leading to heart failure. Despite several strategies developed from intensive studies performed in the past decades, endogenous regeneration of heart tissue is still limited and presents a big challenge that needs to be overcome to serve as a successful therapeutic option for myocardial infarction. Objective: One of the essential prerequisites for cardiac regeneration is the identification of endogenous cardiomyocyte progenitors and their niche that can be targeted by new therapeutic approaches. In this context, we hypothesized that the vascular wall, which was shown to harbor different types of stem and progenitor cells, might serve as a source for cardiac progenitors. Methods and Results: We describe generation of spontaneously beating mouse aortic wall-derived cardiomyocytes without any genetic manipulation. Using aortic wall-derived cells (AoCs) of WT (wild type), αMHC (α-myosin heavy chain), and Flk1 (fetal liver kinase 1)-reporter mice and magnetic bead-associated cell sorting sorting of Flk1 + AoCs from GFP (green fluorescent protein) mice, we identified Flk1 + CD (cluster of differentiation) 34 + Sca-1 (stem cell antigen-1)-CD44 − AoCs as the population that gives rise to aortic wall-derived cardiomyocytes. This AoC subpopulation delivered also endothelial cells and macrophages with a particular accumulation within the aortic wall-derived cardiomyocyte containing colonies. In vivo, cardiomyocyte differentiation capacity was studied by implantation of fluorescently labeled AoCs into chick embryonic heart. These cells acquired cardiomyocyte-like phenotype as shown by αSRA (α-sarcomeric actinin) expression. Furthermore, coronary adventitial Flk1 + and CD34 + cells proliferated, migrated into the myocardium after mouse myocardial infarction, and expressed Isl-1 + (insulin gene enhancer protein-1) indicative of cardiovascular progenitor potential. Conclusions: Our data suggest Flk1 + CD34 + vascular adventitia-resident stem cells, including those of coronary adventitia, as a novel endogenous source for generating cardiomyocytes. This process is essentially supported by endothelial cells and macrophages. In summary, the therapeutic manipulation of coronary adventitia-resident cardiac stem and their supportive cells may open new avenues for promoting cardiac regeneration and repair after myocardial infarction and for preventing heart failure.

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Abstract 13: Plasminogen Is Required for Hematopoietic Stem Cell-Mediated Cardiac Repair After Myocardial Infarction

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.32.suppl_1.a13 ◽

2012 ◽

Vol 32 (suppl_1) ◽

Author(s):

Yanqing Gong ◽

Jane Hoover-Plow ◽

Ying Li

Keyword(s):

Myocardial Infarction ◽

Stem Cells ◽

Bone Marrow ◽

Stem Cell ◽

Tissue Repair ◽

Critical Role ◽

Cardiac Repair ◽

Internal Diameter ◽

Hematopoietic Stem

Ischemic heart disease, including myocardial infarction (MI), is the primary cause of death throughout the US. Granulocyte colony-stimulating factor (G-CSF) is used to mobilize hematopoietic progenitor and stem cells (HPSC) to improve cardiac recovery after MI. However, poor-mobilization to G-CSF is observed in 25% of patients and 10-20% of healthy donors. Therefore, a better understanding of the underlying mechanisms regulating G-CSF-induced cardiac repair may offer novel approaches for strengthening stem cell-mediated therapeutics. Our previous studies have identified an essential role of Plg in HPSC mobilization from bone marrow (BM) in response to G-CSF. Here, we investigate the role of Plg in G-CSF-stimulated cardiac repair after MI. Our data show that G-CSF significantly improves cardiac tissue repair including increasing neovascularization in the infarct area, and improving ejection fraction and LV internal diameter by echocardiogram in wild-type mice. No improvement in tissue repair and heart function by G-CSF is observed in Plg -/- mice, indicating that Plg is required for G-CSF-regulated cardiac repair after MI. To investigate whether Plg regulates HPSC recruitment to ischemia area, bone marrow transplantion (BMT) with EGFP-expressing BM cells was performed to visualize BM-derived stem cells in infarcted tissue. Our data show that G-CSF dramatically increases recruitment of GFP+ cells (by 16 fold) in WT mice but not in Plg -/- mice, suggesting that Plg is essential for HPSC recruitment from BM to the lesion sites after MI. In further studies, we investigated the role of Plg in the regulation of SDF-1/CXCR-4 axis, a major regulator for HPSC recruitment. Our results show that G-CSF significantly increases CXCR-4 expression in infarcted area in WT mice. While G-CSF-induced CXCR-4 expression is markedly decreased (80%) in Plg -/- mice, suggesting Plg may regulate CXCR-4 expression during HSPC recruitment to injured heart. Interestingly, Plg does not affect SDF-1 expression in response to G-CSF treatment. Taken together, our findings have identified a critical role of Plg in HSPC recruitment to the lesion site and subsequent tissue repair after MI. Thus, targeting Plg may offer a new therapeutic strategy to improve G-CSF-mediated cardiac repair after MI.

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