Sphingosine-1-phosphate stimulates the functional capacity of progenitor cells by activation of the CXCR4-dependent signaling pathway via the S1P3 receptor.
OBJECTIVE
Sphingosine-1-phosphate (S1P) is a bioactive lipid, which influences migration and proliferation of endothelial cells through activation of S1P receptors and has been shown to support SDF-1 induced migration and bone marrow homing of CD34+ progenitors.


RESULTS
Here, we show that incubation of patient-derived endothelial progenitor cells (EPCs) with S1P or its synthetic analog FTY720 improved blood flow recovery in ischemic hind limbs. Likewise, recovery of blood flow was dramatically reduced after induction of hindlimb ischemia in mice deficient for the S1P receptor 3 (S1P3). S1P3-/- bone marrow-derived mononuclear cells (BMCs) failed to augment neovascularization after hind limb ischemia. Of note, treatment of BMCs derived from S1P3-/- mice with S1P did not rescue blood flow recovery. Mechanistically, S1P and FTY720 induced phosphorylation of CXCR4, activated the Src kinase, and stimulated phosphorylation of JAK2. The contribution of CXCR4 for S1P-mediated effects was further supported by the findings that S1P preincubation failed to stimulate invasion capacity and in vivo blood flow recovery of BMCs from CXCR4+/- mice. The activation of CXCR4 was dependent on the Src kinase family as demonstrated by preincubation with the Src inhibitor PP2. The activation of the CXCR4 signaling by S1P is mediated via the S1P3 receptor, since S1P-induced Src phosphorylation was abrogated in EPC from S1P3-/- mice.


CONCLUSIONS
S1P agonists might serve as sensitizers of CXCR4-mediated signaling and may be applied in clinical progenitor cell therapy to improve EPC or BMC function in patients with coronary artery disease.
Walter
Dirk H
DH
Molecular Cardiology, Department of Internal Medicine III, University of Frankfurt, Theodor Stern-Kai 7, 60590 Frankfurt, Germany.
Rochwalsky
Ulrich
U
Reinhold
Johannes
J
Seeger
Florian
F
Aicher
Alexandra
A
Urbich
Carmen
C
Spyridopoulos
Ioakim
I
Chun
Jerold
J
Brinkmann
Volker
V
Keul
Petra
P
Levkau
Bodo
B
Zeiher
Andreas M
AM
Dimmeler
Stefanie
S
Haendeler
Judith
J
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects; D000068876:Fingolimod Hydrochloride; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008246:Lysophospholipids / Q000235:genetics / Q000494:pharmacology*; D051379:Mice; D008822:Mice, Transgenic; D011409:Propylene Glycols / Q000494:pharmacology; D019718:Receptors, CXCR4 / Q000235:genetics / Q000502:physiology*; D049349:Receptors, Lysosphingolipid / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000235:genetics / Q000494:pharmacology; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology*; D019061:src-Family Kinases / Q000235:genetics / Q000502:physiology
C514936:CXCR4 protein, mouse; D008246:Lysophospholipids; D011409:Propylene Glycols; D019718:Receptors, CXCR4; D049349:Receptors, Lysosphingolipid; C060506:sphingosine 1-phosphate; D019061:src-Family Kinases; D000068876:Fingolimod Hydrochloride; D013110:Sphingosine