Abstract:

Objective To investigate the expression characteristics of CXCL13 and CXCR5 in osteogenic microenvironment of bone defect model, and provide evidence for their regulation effects on behavior of mesenchymal stem cells. Methods Twenty New Zealand rabbits were used for establishment of bone defect model, and restoration was conducted with deproteinized bone implantation. Samples were obtained 1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks after operation, and immunohistochemical SP method, Western blotting and Real-Time PCR were employed to determine the expression of CXCL13 and CXCR5 protein and mRNA. Results Immunohistochemical staining revealed that there was high expression of CXCL13 in the interface between scaffold and host bone, whereas there was high expression of CXCR5 in the interface, bone marrow and core of scaffold. Real-Time PCR indicated that the expression of CXCL13 and CXCR5 mRNA 4 weeks after operation was significantly different from that of the other time points （P＜0.05）. Western blotting demonstrated that the expression of CXCL13 and CXCR5 protein reached the peak 4 weeks after operation. Conclusion CXCL13 and CXCR5 are related to the level of osteogenic behavior, with typical characteristics of expression timing and location.

Key words: bone defect, microenvironment, chemokine, CXCL13, CXCR5