Abstract: Objective To construct rat mesenchymal stem cells (rMSCs) coexpressing CXCR4 and EGFP and observe the effect of CXCR4 on rMSCs migration. Methods The total RNA was isolated from SD rat's liver with Trizol, the CXCR4 gene was amplified by RT-PCR. The CXCR4 was inserted into the transfer vector of lentivirus after the vector was digested with restriction endonuclease. The lentiviral particles were produced in 293T cells by transient cotransfection involving a three-plasmid expression system, then were harvested and concentrated. The rMSCs were transfected by obtained lentiviral particles or null lentiviral particles. The expressing of CXCR4 gene in CXCR4-rMSCs or null-rMSCs was evaluated with RT-PCR, Western blotting, cellular immunofluorescence and flow cytometry. The migration ability of transfected cells induced by SDF-1 was assessed in the transwell system. Results The results showed that the full-length fragment of CXCR4 gene was successfully cloned into the transfer vector of lentivirus. The result of sequencing showed that the cloned CXCR4 gene was consistent with that reported in GenBank. The CXCR4 gene-modified rMSCs could express both the CXCR4 and EGFP. The expression of CXCR4 gene in the CXCR4-rMSCs group (experimental group) was significantly higher than that in the null-rMSCs group (control group) at both mRNA and protein levels. The migration ratios of the CXCR4-rMSCs group was significantly higher than that of the null-rMSCs group. Conclusion The rMSCs coexpressing CXCR4 and EGFP was successfully constructed, this will greatly facilitate further research, such as the evaluation of the effect of SDF-1/CXCR4 on rMSCs' recruitment to damaged tissue.

Key words: CXCR4, EGFP, lentiviral vector, mesenchymal stem cells, migration