Endothelial progenitor cells in neovascularization of infarcted myocardium

Abstract

Historically, revascularization of ischemic tissue was believed to occur through the migration and proliferation of endothelial cells in nearby tissues; however, evidence accumulated in recent years indicates that a subpopulation of adult, peripheral-blood cells, collectively referred to as endothelial progenitor cells (EPCs1), can differentiate into mature endothelial cells. After ischemic insult, EPCs are believed to home to sites of neovascularization, where they contribute to vascular regeneration by forming a structural component of capillaries and by secreting angiogenic factors; new evidence indicates that EPCs can also differentiate into cardiomyocytes and smooth-muscle cells. These insights into the molecular and cellular processes of tissue formation suggest that cardiac function may be preserved after myocardial infarction by transplanting EPCs into ischemic heart tissue, thereby enhancing vascular and myocardial recovery. This therapeutic strategy has been effective in animal models of ischemic disorders, and results from randomized clinical trials suggest that cellbased strategies may be safe and feasible for treatment of myocardial infarction in humans and have provided early evidence of efficacy. However, the scarcity of EPCs in the peripheral blood and evidence that several disease states reduce EPC number and/or function have prompted the development of several strategies to overcome these limitations, such as the administration of genetically modified EPCs that overexpress angiogenic growth factors. To optimize therapeutic outcomes, researchers must continue to refine methods of EPC purification, expansion, and administration, and to develop techniques that overcome the intrinsic scarcity and phenotypic deficiencies of EPCs.

Angiogenesis and hypertension: an update

“…[75][76][77] Clinical investigations of endothelial progenitor cells for regenerative medicine are now under way. 78 Theoretically, therapeutic angiogenesis might also be administered as an anti-hypertensive therapy. In animal models, a direct link between blood pressure reduction and microvessel formation has been demonstrated.…”

Impact of anti-apoptotic and anti-oxidative effects of bone marrow mesenchymal stem cells with transient overexpression of heme oxygenase-1 on myocardial ischemia

“…These results demonstrate that MSCHO-1 exhibit markedly enhanced antiapoptotic and anti-oxidative capabilities compared with MSCs, thus contributing to improved repair of ischemic myocardial injury through cell survival and VEGF production associated with the PI 3-kinase/ Akt pathway. apoptosis; cell transplantation; heme oxygenase-1; mesenchymal stem cells; myocardial ischemia THE TRANSPLANTATION OF BONE marrow cells, embryonic stem cells, and cardiac stem cells has been reported to contribute to myocardial regeneration or neovascularization after ischemic myocardial injury (6,23,29,45). Of these cells, mesenchymal stem cells (MSCs) may differentiate not only into osteoblasts, chondrocytes, neurons, and skeletal muscle cells but also into vascular endothelial cells (2,35).…”

Induction of Cardiac Angiogenesis Requires Killer Cell Lectin-Like Receptor 1 and α4β7 Integrin Expression by NK Cells

“…As monocytes/macrophages have been shown to play a crucial role in myocardial angiogenesis and remodeling postinfarction (53), their reduced infiltration might also explain the phenotype of NOD SCID mice. Several studies reported EPCs to be subpopulation of these cells with a critical role in angiogenesis (54)(55)(56).…”