Objective      To study the role of CXCR7 in angiogenesis involving SDF-1-mediated endothelial cells.        Methods      Expression of CXCR7 and CXCR4 in human umbilical vein endothelial cells (HUVEC) was detected by Western blotting and flow cytometry

respectively. CXCR4 or CXCR7 was blocked with small molecule antagonists. Effect of CXCR4 and CXCR7 on proliferation

migration

and tube-like structure formation of SDF-1-mediated HUVEC was tested by MTT

Transwell chamber

3D-gel tube formation assay

respectively.        Results      CXCR4 and CXCR7 were expressed in HUVEC. The proliferation of HUVEC induced by SDF-1 was significantly inhibited by CXCR7 antagonist(P0.01); The migration of HUVEC induced by SDF-1 was inhibited by CXCR4 antagonist(P0.01); While the tube-like structure formation of HUVEC was inhibited by either blocking of CXCR4 or CXCR7(P0.01).       Conclusion      CXCR7 and CXCR4 play an important but a different role in angiogenesis involving SDF-1-mediated HUVEC. SDF-1-mediated HUVEC proliferate via CXCR7 while CXCR4 is mainly involved in the migration of SDF-1-mediated HUVEC. Both CXCR7 and CXCR4 participate in the tube-like structure formation of SDF-1-mediated HUVEC.