Chemokine receptor 7 overexpression promotes mesenchymal stem cell migration and proliferation via secreting Chemokine ligand 12

Great interest has been shown in mesenchymal stem cell (MSC) therapy in a wide variety of clinical domains. However, the therapeutic efficiency depends on the proliferation and migration of MSCs. Chemokine receptors are involved in regulating the proliferation and migration to the specific organs of MSCs in different microenvironments. CXC receptor seven (CXCR7), a newly discovered Chemokine ligand 12 (CXCL12) receptor, has organ specificity for tumour migration. We hypothesized that CXCR7 expression affects proliferation and migration of MSCs. In present study, we constructed long-term and stable mMSCs lines overexpressing and suppressing CXCR7 modifications with lentiviral vectors. The transduction efficiencies, mRNA and protein expression of CXCR7 were significantly regulated. CXCR7 gene overexpression promoted mMSCs proliferation and migration, whereas suppressing CXCR7 had the opposite effect. Additional CXCL12 improved the vertical migration of mMSCs. The overexpression of CXCR7 increased the MSC-secreted CXCL12, VCAM-1, CD44 and MMP2 levels, which contributed to the improvement of mMSC proliferation and migration. Therefore, overexpressing CXCR7 improved the proliferation and migration of mMSCs, which may be attributable to the CXCL12 secreted by MSCs, leading to a positive feedback loop for CXCL12/CXCR7 axis. Our results may provide a potential method for improving the treatment effectiveness of mMSCs by overexpressing CXCR7.