The role of CXCR7 on the adhesion, proliferation and angiogenesis of endothelial progenitor cells.
Bottom Line: CXC chemokine receptor 4 (CXCR4) has been considered as the unique receptor of SDF-1 and as the only mediator of SDF-1-induced biological effects for many years.However, recent studies found that SDF-1 could bind to not only CXCR4 but also CXC chemokine receptor 7 (CXCR7).These results suggested that both CXCR7 and CXCR4 are important for EPCs in response to SDF-1, indicating that CXCR7 may be another potential target molecule for angiogenesis-dependent diseases.
Affiliation: Key laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China.Show MeSH
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Mentions: To examine the role of CXCR4 and CXCR7 in EPC survival, we determined serum deprivation-induced EPCs apoptosis by flow cytometry with FITC-conjugated annexin V and PI staining. As shown in Figure 7, serum deprivation induced about 19% of apoptotic cell death, but this apoptotic cell death can be significantly prevented with treatment of SDF-1 for 48 hrs (7.47 ± 0.71%versus 18.93 ± 2.58%, P < 0.01). The anti-apoptotic effect of SDF-1 was almost completely attenuated by CXCR7 antibody or antagonist CCX733 (16.05 ± 1.69% or 18.02 ± 1.95%versus 7.47 ± 0.71%, P < 0.01). However, blocking CXCR4 with anti-CXCR4 antibody or CXCR4 antagonist AMD3100 could not significantly diminish the anti-apoptotic effect of SDF-1 on the EPCs with serum deprivation. In addition, blocking both CXCR4 and CXCR7 has a similar effect to blocking CXCR7 alone in the protection of EPCs from apoptosis. Collectively, the results suggest that SDF-1 mediates EPC survival predominantly via CXCR7.
Affiliation: Key laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China.