Stromal cell-derived factor 1 (CXCL12) binds to endothelial cells and signals through a receptor different from CXCR4.
Stromal cell-derived factor 1 (CXCL12) is an angiogenic chemokine that is believed to act solely via its cognate receptor CXCR4. Evidence is now provided for the existence of a different CXCL12 binding and signaling receptor on endothelial cells. Bovine aortic endothelial cells (BAECs) strongly expressed CXCR4 and exhibited high binding capacity for fluorescently labeled CXCL12. However, CXCL12 binding was not correlated with the CXCR4 expression level and was virtually unaffected by the specific CXCR4 antagonists AMD3100 or T22. Similar observations were made in endothelial cells of mouse and human origin. Also, AMD3100 failed to block CXCL12 internalization and CXCL12-induced intracellular signal transduction via extracellular signal-regulated kinases 1/2 in BAECs. In contrast, CXCL12 binding and signaling were almost completely inhibited by the CXCR4 antagonist in T-lymphoid SupT1 cells. Together, our data point to the existence of an additional receptor through which CXCL12 exerts its biological effects in endothelial cells.
Hatse
Sigrid
S
Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium. sigrid.hatse@rega.kuleuven.be
Balzarini
Jan
J
Liekens
Sandra
S
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism; D001596:Benzylamines; D002417:Cattle; D002478:Cells, Cultured; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000378:metabolism*; D000080027:Cyclams; D004730:Endothelium, Vascular / Q000378:metabolism*; D006571:Heterocyclic Compounds / Q000494:pharmacology; D006801:Humans; D020935:MAP Kinase Signaling System; D051379:Mice; D019718:Receptors, CXCR4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction
D001596:Benzylamines; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D000080027:Cyclams; D006571:Heterocyclic Compounds; D019718:Receptors, CXCR4; C088327:plerixafor