CXCL13和CXCR5在骨缺损成骨微环境中的表达特征

Expression characteristics of CXCL13 and CXCR5 in osteogenic microenvironment of bone defect model

目的研究CXCL13和CXCR5在骨缺损成骨微环境中的表达特征,为探索趋化因子调控成骨微环境与间充质干细胞行为提供依据。方法以20只新西兰白兔建立骨缺损模型,以脱蛋白骨移植修复。在术后1、2、4、8和12周分别取材,采用免疫组织化学SP法、Western blotting技术和Real-Time PCR分别检测CXCL13和CXCR5蛋白及mRNA的表达。结果免疫组织化学染色结果显示:CXCL13集中表达于载体支架与宿主骨床的修复界面;CXCR5在修复界面、髓腔及支架核心表达较强。Real-TimePCR检测结果显示:术后4周时,CXCL13和CXCR5 mRNA的表达与其他各时间点比较,差异有统计学意义(P<0.05)。Westernblotting检测结果显示:术后4周时,CXCL13和CXCR5蛋白表达水平最高。结论 CXCL13和CXCR5与成骨活跃程度相关,并表现为明显的时间与位点特征。

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.