ABSTRACT
Endothelial progenitor cells (EPC) are believed to be the postnatal equivalent of angioblasts, i.e.
those cells found in embryonic life which form the walls of “blood island that gradually develop into vasculature. Alongside an understanding of potential therapeutic applications, there has also been increasing appreciation of the physiological roles that these precursor cells might play in the homesostasis of the adult vasculature.
Autologous transplantation of culture-expanded EPC successfully promotes therapeutic neovascularization in both ischemic hind limbs as well as acute myocardial infarction models.
Mechanistically, these cells can either induce angiogenesis by incorporation into vascular structures depicting phenotypes of endothelial cells or may induce angiogenesis by production of growth factors acting in a paracrine manner
However, EPC derived from patients are functionally impaired compared with EPC from healthy donors. Recent data indicate that the therapeutic success is determined by functional properties of transplanted cells, providing the basis for improvement of functional activities, eg, by pharmacological stimulation of surface receptors in order to enhance homing of progenitor or stem cells. One important family of surface receptors is the family of the S1P receptors. These receptors bind sphingosine 1-phosphate (S1P), a bioactive sphingolipid, that has been demonstrated to play a crucial role in the cardiovascular system modulating essential cellular processes including cell growth and survival, regulation of cell motility and invasion, angiogenesis and vascular maturation, lymphocyte trafficking and immune regulation.
Therefore, we investigated the expression of S1P receptors on human EPC isolated from mononuclear cells of peripheral blood, to provide experimental evidence that S1P treatment modulates some functional properties of EPC.
Therefore, we investigated the expression of S1P receptors on human EPC isolated from mononuclear cells of peripheral blood, to provide experimental evidence that S1P treatment modulates some functional properties of EPC.